Форум Новости Космонавтики

ЦитироватьПЕКИН, 2 мар — РИА Новости, Иван Булатов. Китай планирует запустить в космос спутник ретрансляции данных для своей программы по зондированию Луны "Чанъэ", заявил ведущий научный сотрудник программы Е Пэйцзянь.

По его словам, спутник-ретранслятор должен помочь поддерживать связь между Землей и спутником, который совершит посадку на обратной стороне Луны, передает агентство Синьхуа. Ученый сообщил, что запуск спутника ретрансляции данных будет осуществлен за полгода до запуска спутника "Чанъэ-4", намеченного на 2018 год.

В середине января Государственное управление оборонной науки, техники и промышленности КНР сообщило, что в 2018 году аппарат "Чанъэ-4" должен совершить посадку на обратную сторону Луны.

ЦитироватьQuооndo пишет:
Вот китайцы молодцы сумели нас опередить даже по новой российской программе исследования Луны. Возможно и высадятся первыми.

ЦитироватьPrimary Design of the Flight Profile of the Relay Satellite
 
The relay satellite is directly launched into the Earth-Moon transfer trajectory with the perigee at 200km and the apogee at 380000km.

The flight takes about 5~6 days and requires 2~3 times of trajectory correction maneuver (TCM). The relay satellite brakes at the perilune and becomes stable in manifold instead of orbiting the moon as it decelerates. After 3~4 days, the relay satellite approaches the L2 point and reaches the plane that is formed by the normal of lunar orbit and the ligature of the Earth and the moon.

After arriving at the L2 point, the relay satellite carries out three times of orbit control at the first orbit revolution to enter the mission orbit. The mission orbit is a halo orbit and the relay satellite will carry out relay communication and scientific test.

ЦитироватьPIN пишет:
Кто-нибудь понимает, почему разные диапазоны (S и X) используются в разных каналах?

Цитировать/.../
"In the first half of 2018, we will first launch a relay satellite to Lagrange L2 Point, where the satellite can keep communications with both the far side of the Moon and the Earth. Therefore, we can control the lunar probe for data transmission using this relay satellite," said Zhao.
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Цитировать(https://img.novosti-kosmonavtiki.ru/29906.jpg)Andrew Jones‏ @AJ_FI (https://twitter.com/AJ_FI) 6 ч. назад (https://twitter.com/AJ_FI/status/988645043043958786)

Chang'e-4: It was announced today that the relay satellite to launch in May to facilitate communications with lander & rover on lunar far side will be called QueQiao (鹊桥), while the 2 microsatellites are named LongJiang-1 & 2 (龙江一号/二号)

5 ч. назад (https://twitter.com/AJ_FI/status/988648810925576193)

The Chang'e-4 relay satellite name Queqiao comes from the love story 'the Cowherd & the Weaver Girl'. Separated by the silver river (Milky Way), every year a flock of magpies form a bridge (QueQiao) to bring the lovers together for a day. https://en.wikipedia.org/wiki/The_Cowherd_and_the_Weaver_Girl ... (https://t.co/L8RYXWVKzj)
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ЦитироватьChang'e-4 lunar far side satellite named 'magpie bridge' from folklore tale of lovers crossing the Milky Way
by Andrew Jones (https://gbtimes.com/authors/658) Apr 24, 2018 09:25 GERMANY (https://gbtimes.com/tag/germany)  MOON (https://gbtimes.com/tag/moon)  CHINA'S SPACE PROGRAM (https://gbtimes.com/tag/china%27s%20space%20program)

(https://img.novosti-kosmonavtiki.ru/191942.jpg)
A rendering of the Chang'e-4 relay satellite, to launch in May 2018, and lander and rover to set down on the lunar far side in late 2018. Chinese Academy of Sciences

China's Chang'e-4 relay satellite, which will launch next month to facilitate communications with a lander and rover on the lunar far side, has been named Queqiao - or magpie bridge - from a Chinese myth.

The name was announced by the China National Space Administration (CNSA) in Harbin, northeast China, on Tuesday April 24 at an event marking the advent of China's third Space Day.

Спойлер

The name comes the Chinese myth and love story of the Weaver Girl and the Cowherd (https://gbtimes.com/qixi-festival-and-story-chinese-valentines-day). Separated by the Silver River, which symbolises the Milky Way, the lovers are reunited for one day each year by a bridge formed by a flock of magpies - Queqiao (鹊桥) - allowing them to cross the heavens.

Two microsatellites (https://gbtimes.com/change-4-lunar-far-side-mission-to-carry-microsatellites-for-pioneering-astronomy), which will accompany the launch in May and be placed in lunar orbit, also received names.

These are Longjiang-1 and Longjiang-2 (龙江一号 and 龙江二号), meaning Dragon River 1 and 2. The developer of the microsatellites is the Harbin Institute of Technology, situated in the capital of Heilongjiang (Black Dragon River) Province. The Heilongjiang river is also known as the Amur.

(https://img.novosti-kosmonavtiki.ru/192040.jpg)
Star-crossed lovers Niulang and Zhinu are permitted to be together one day a year, during the Qixi Festival. The painting is in the Long Corridor of the Summer Palace in Beijing. Public Domain

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Queqiao relay satellite

Chang'e-4 (https://gbtimes.com/channel/features/123) is a mission which will attempt the first-ever soft-landing on the far side of the Moon with a lander and rover in late 2018.

As the lunar far side never faces the Earth, a relay satellite is required to be in place to facilitate communications between terrestrial ground stations and the Chang'e lander and rover.

It is planned to launch from the Xichang Satellite Launch Centre on May 21 via a Long March 4C rocket.

Спойлер

The Queqiao relay satellite is based on a small satellite platform developed by the China Academy of Space Technology (CAST), and equipped with modified and newly developed components in order to meet the extra challenges posed by its mission requirements.

The satellite will operate in a halo orbit around the gravitationally stable second Earth-Moon Lagrange Point, more than 60,000 kilometres away from the lander and rover on the lunar far side.

(https://img.novosti-kosmonavtiki.ru/191941.png)
Launch profile for the Chang'e-4 communications relay satellite. Chinese Academy of Sciences

The distance will be around twice that of satellites in geosynchronous Earth orbit for terrestrial communications, while also being close to half a million kilometres from Earth, meaning greater power demands.

The halo orbit will allow Queqiao to be accessible to both ground stations on Earth and the lander on the lunar far side at times.

(https://img.novosti-kosmonavtiki.ru/191910.jpg)
Image demonstrating a halo orbit around the second Earth-Moon Lagrange point, from which the Chang'e-4 communications relay satellite will operate. NAOC/CAS

It will reach this point some eight or nine days after launch from Xichang via a lunar swing-by. Once in its planned orbit, the satellite will carry out tests for its communications relay role and begin its science experiments.

As well as its main communications role, the relay satellite will carry the Netherlands-China Low-Frequency Explorer (NCLE (https://www.astron.nl/r-d-laboratory/ncle/netherlands-china-low-frequency-explorer-ncle)) for low-frequency radio astronomy experiments.

The Longjiang-1 and 2 microsatellites (https://gbtimes.com/change-4-lunar-far-side-mission-to-carry-microsatellites-for-pioneering-astronomy), meanwhile, will test low frequency radio astronomy and space-based interferometry, as well as amateur radio activities (https://amsat-uk.org/2018/04/03/dslwp-lunar-amateur-radio-satellites/). It will also carry a small optical camera developed by Saudi Arabia (https://spacewatch.global/2018/02/saudi-arabia-contribute-optical-camera-chinas-change-4-lunar-far-side-mission/).

(https://img.novosti-kosmonavtiki.ru/191938.png)
Testing on the Chang'e-4 DSLWP-A1 and DSLWP-A2 microsatellites in early 2018. CCTV/Youtube/Framegrab

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Landing, roving and preparing

Спойлер

The lander and rover for the mission, launching late this year, were originally manufactured at the same time as the Chang'e-3 spacecraft, which landed on the Moon in late 2013, in order to provide a backup mission.

Now repurposed for objectives on the lunar far side, the pair have recently been progressing through space environment tests (https://gbtimes.com/change-4-lander-and-rover-undergoing-thermal-vacuum-tests-ahead-of-lunar-far-side-mission).

Five of the science payloads, including the cameras, radar and imaging spectrometer noted below, are inherited from the 2013 Chang'e-3 (https://www.nbcnews.com/science/china-launches-jade-rabbit-rover-its-first-moon-landing-mission-2D11674372) mission, but new and international payloads will also travel.

(https://img.novosti-kosmonavtiki.ru/192012.jpg)
Chang'e-3, which landed on the Moon in December 2013. Chang'e-4, initially slated as a backup mission, will launch by 2020. CNS

The lander will carry a Landing Camera (LCAM), Terrain Camera (TCAM), Low Frequency Spectrometer (LFS), and Lunar Lander Neutrons and Dosimetry (LND (https://www.hou.usra.edu/meetings/lpsc2017/eposter/1320.pdf)), all of which were developed in Germany.

The rover will be equipped with a Panoramic Camera (PCAM), a Lunar Penetrating Radar (LPR), a Visible and Near-Infrared Imaging Spectrometer (VNIS (https://www.ncbi.nlm.nih.gov/pubmed/25173243)), and an Advanced Small Analyser for Neutrals (ASAN (https://gbtimes.com/sweden-joins-chinas-historic-mission-land-far-side-moon)), all from Sweden.

TCAM and PCAM on Chang'e-3 returned astounding images (http://www.planetary.org/blogs/emily-lakdawalla/2016/01281656-fun-with-a-new-data-set-change.html) from Mare Imbrium.

(https://img.novosti-kosmonavtiki.ru/192026.jpg)
A view of Mare Imbrium taken by China's Chang'e-3 mission. Chinese Academy of Sciences

Also joining the mission is a small, student-developed biosphere experiment (https://gbtimes.com/student-experiment-to-put-plants-silkworms-on-far-side-of-the-moon-with-change-4-mission)that includes potato and arabidopsis seeds and silkworm eggs.

The landing area will be within the scientifically intriguing South Pole-Aitken Basin (https://www.nasa.gov/mission_pages/LRO/multimedia/lro-20100709-basin.html). While some candidates (https://www.airspacemag.com/daily-planet/chinas-journey-lunar-far-side-missed-opportunity-180963703/), including the Von Kármán (http://www.planetary.org/blogs/guest-blogs/2017/20170920-change-5-and-4-landing-sites.html) impact crater, have been noted, the precise landing site has not been publicly released.

For latest news and developments on the mission, see our feature on China's Chang'e-4 mission to the far side of the Moon (https://gbtimes.com/channel/features/123)

(https://img.novosti-kosmonavtiki.ru/192035.jpg)
The far side of the Moon and the distant Earth, imaged by the Chang'e-5T1 mission in 2014. Chinese Academy of Sciences

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Цитировать(https://img.novosti-kosmonavtiki.ru/185997.jpg)ASTRON‏ @ASTRON_NL (https://twitter.com/ASTRON_NL) 7 ч. назад (https://twitter.com/ASTRON_NL/status/988659321629302784)

The Netherlands Chinese Low-Frequency Explorer (#NCLE (https://twitter.com/hashtag/NCLE?src=hash)) successfully passed the last assessment by the Chinese space agency! The instrument will be launched on board the Chinese Chang'e 4 relay satellite to a position behind the Moon in May. @RadRadioLab (https://twitter.com/RadRadioLab) @isis_space (https://twitter.com/isis_space)
(https://img.novosti-kosmonavtiki.ru/162915.jpg)

ЦитироватьChina's Chang'e-4 relay satellite named "Queqiao"
Source: Xinhua | 2018-04-24 17:02:29 | Editor: ZD

HARBIN, April 24 (Xinhua) -- The relay satellite for the Chang'e-4 lunar probe expected to land on the far side of the Moon later this year, has been named "Queqiao" -- magpie bridge.

The name was announced by the China National Space Administration (CNSA)Tuesday, China's Space Day.

In a Chinese folktale, magpies form a bridge with their wings on the seventh night of the seventh month of the lunar calendar to enable Zhi Nu, the seventh daughter of the Goddess of Heaven, to cross and meet her beloved husband, separated fr om her by the Milky Way.

Together with the relay satellite, two microsatellites developed by the Harbin Institute of Technology, "Longjiang-1" and "Longjiang-2," will also be sent into orbit.

Work on Chang'e-4 is progressing well, said Li Guoping, a spokesman for CNSA.

Chang'e-4 will carry payloads for Germany, the Netherlands, Saudi Arabia and Sweden.

Спойлер

The far side of the Moon is of great scientific interest but landing there requires a relay satellite to transmit signals.

One of China's planned 36 launches this year, the relay satellite will be sent into the halo orbit of the Earth-Moon Lagrange Point L2 in late May, and the Chang'e-4 lunar lander and rover will be sent to the Aitken Basin of the south pole region of the Moon about six months later.

"We designed an orbit at the Earth-Moon Lagrange Point L2 about 450,000 kilometers from the Earth, wh ere a gravitational equilibrium can be maintained, and the relay satellite will be able to 'see' both the Earth and the far side of the Moon," said Bao Weimin, director of the Science and Technology Commission of the China Aerospace Science and Technology Corporation.

The Aitken Basin is an ancient lunar region containing lots of primeval information, and as the far side of the Moon is shielded from electromagnetic interference from the Earth, it is an ideal place to study the space environment. The probe can "listen" to the deeper reaches of the cosmos, said Bao.

The relay satellite will be carried by Long March-4 rocket. The relay satellite and rocket are both at the launch center in Xichang, southwest China's Sichuan Province.

"The whole mission is very complex and challenging. We feel great pressure, but we are confident," Bao said.

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Цитировать(https://img.novosti-kosmonavtiki.ru/187306.jpg). (https://vk.com/chinaspaceflight)
Космические полёты Китая - ChinaSpaceFlight (https://vk.com/chinaspaceflight)
35 минут назад (https://vk.com/wall-119361981_2795)

Китайский ретрансляционный спутник "Чанъэ-4" получил новое название

Харбин, 24 апреля /Синьхуа/ — Китайский ретрансляционный спутник для лунного зонда "Чанъэ-4", который, как ожидается, совершит посадку на дальней стороне Луны в конце текущего года, получил название QueQiao (鹊桥) "Цюэцяо" /"Сорочий мост"/. Об этом объявило Государственное космическое управление КНР во вторник, когда в Китае отмечается День космонавтики.

Спойлер

Древнекитайская легенда гласит, что сороки образуют мост, соединив крылья, в седьмую ночь седьмого месяца по лунному календарю, чтобы позволить Чжинюй, седьмой дочери Богини Сиванму — повелительницы Запада в китайском даосизме, пройти по нему и встретиться с любимым мужем, с которым их разделяет Млечный Путь. 

Вместе с ретрансляционным спутником на орбиту также будут выведены два микроспутника, разработанные Харбинским политехническим институтом /пров. Хэйлунцзян, Северо-Восточный Китай/ и названные соответственно LongJiang-1 & 2 (龙江 一号 / 二号) "Лунцзян-1&2".

Работа на лунном зонде "Чанъэ-4" идет хорошо, сообщил Ли Гопин, представитель Государственного космического управления. Лунный зонд "Чанъэ-4" будет перевозить грузы для Германии, Нидерландов, Саудовской Аравии и Швеции. 

Дальняя сторона Луны представляет большой научный интерес, однако для посадки на нее требуется ретрансляционный спутник для передачи сигналов. Спутниковый ретранслятор планируется отправить на гало-орбиту точки Лагранжа L2 между Землей и Луной в конце мая, а лунный зонд "Чанъэ-4" - в Бассейн Южный полюс-Эйткен Луны в конце текущего года.

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ЦитироватьChina's Yuanwang 7 space tracking ship sailing to support Chang'e-4 relay satellite launch
by Andrew Jones (https://gbtimes.com/authors/658) | May 04, 2018 15:19 | MOON (https://gbtimes.com/tag/moon) ▪ CHINA'S SPACE PROGRAM (https://gbtimes.com/tag/china%27s%20space%20program) ▪ XICHANG (https://gbtimes.com/tag/xichang)

(https://img.novosti-kosmonavtiki.ru/191890.jpg)
China's Yuanwang 7 space tracking vessel after completing tasks related to the launch of the Tianzhou-1 cargo spacecraft in April 2017. CNS

China's Yuanwang 7 space tracking vessel is heading for waters in the Pacific Ocean ready to support the launch of the relay satellite which will facilitate the Chang'e-4 lunar far side lander and rover mission.

Yuanwang 7 is China's newest space tracking ship, which launched in July 2016 and was involved in the Shenzhou-11 (https://gbtimes.com/chinas-crewed-shenzhou-11-spacecraft-docks-tiangong-2-space-lab) mission, the debut flight (http://www.planetary.org/blogs/guest-blogs/2016/1103-long-march-5-launch-blasts.html) of the heavy-lift Long March 5 (https://gbtimes.com/why-chinas-long-march-5-crucial-its-space-ambitions), and the Tianzhou-1 (https://gbtimes.com/tianzhou-1-reenters-earths-atmosphere-after-experimental-mission) cargo spacecraft launch.

Having just assisted in the launch of the Apstar-6C satellite (https://gbtimes.com/china-lofts-apstar-6c-satellite-with-13th-launch-of-2018) from Xichang on Friday, Yuanwang 7 is now sailing for an undisclosed location to support the launch of the Queqiao communications relay satellite (https://gbtimes.com/change-4-lunar-far-side-satellite-named-magpie-bridge-from-folklore-tale-of-lovers-crossing-the-milky-way), the Chinese language Science and Technology Daily reports (http://www.stdaily.com/index/kejixinwen/2018-05/04/content_666787.shtml).

The satellite is scheduled to launch from the Xichang Satellite Launch Centre on May 21 via a Long March 4C rocket, heading for an orbit beyond the Moon.

The Yuanwang ships, whose name means 'long view', are equipped with an array of dishes and electronics to support the launching and tracking of space launch vehicles. They observe trajectories and provide survey and control capabilities as rockets fly downrange.

Спойлер

Shortly after launch of the crewed Shenzhou-11 mission, Yuanwang 7 tracked the spacecraft for nearly 400 seconds and issued orders for the unfolding of solar panels and antenna, and perform other movements after entering orbit.

https://www.youtube.com/watch?v=ZuqJdBc2gj8 (https://www.youtube.com/watch?v=ZuqJdBc2gj8)
(video (https://www.youtube.com/watch?v=ZuqJdBc2gj8) 1:23)
Yuanwang 7 Maritime Tracking of Shenzhou-11 Completed

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Lunar far side pioneer

Спойлер

The launch of the Queqiao satellite, scheduled for May 21, is a precursor to the Chang'e-4 (https://gbtimes.com/channel/features/123) lander and rover mission, which will attempt the first-ever soft-landing on the far side of the Moon in late 2018.

The relay satellite is required to be in place to facilitate communications between terrestrial ground stations and the Chang'e-4 lander and rover (https://gbtimes.com/change-4-lander-and-rover-undergoing-thermal-vacuum-tests-ahead-of-lunar-far-side-mission?feature=chinas-change-4-mission-to-the-far-side-of-the-moon). Its intended halo orbit around the second Earth-Moon Lagrange point more than 60,000 kilometres beyond the Moon will make it accessible to both ground stations on Earth and the lander on the lunar far side at all times.

Queqiao means 'magpie bridge' and comes from the Chinese myth and love story of the Weaver Girl and the Cowherd (https://gbtimes.com/qixi-festival-and-story-chinese-valentines-day).

As well as its main communications role, the relay satellite will carry the Netherlands-China Low-Frequency Explorer (NCLE (https://www.astron.nl/r-d-laboratory/ncle/netherlands-china-low-frequency-explorer-ncle)) for low-frequency radio astronomy experiments.

(https://img.novosti-kosmonavtiki.ru/191943.jpg)
A rendering of the Chang'e-4 relay satellite, to launch in May 2018, and lander and rover to set down on the lunar far side in late 2018. Chinese Academy of Sciences

Two microsatellites (https://gbtimes.com/change-4-lunar-far-side-mission-to-carry-microsatellites-for-pioneering-astronomy), named Longjiang-1 and Longjiang-2 (龙江一号 and 龙江二号), meaning Dragon River 1 and 2, will also be aboard for launch and will be placed in lunar orbit.

The pair will test low frequency radio astronomy and space-based interferometry, as well as carry an amateur radio (https://amsat-uk.org/2016/11/18/lunar-amateur-radio-satellites-dslwp-a1a2/) payload developed by students at the Harbin Institute of Technology (HIT), and a microcamera (https://gbtimes.com/spacewatch.global/2018/02/saudi-arabia-contribute-optical-camera-chinas-change-4-lunar-far-side-mission/)developed by the King Abdulaziz City for Science and Technology (KACST) of Saudi Arabia.

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Lander and rover

Спойлер

The lander and rover - repurposed backups to the Chang'e-3 mission - will launch around six months later, in November or December, and attempt the first-ever soft landing on the lunar far side.

The candidate landing sites (http://www.planetary.org/blogs/guest-blogs/2017/20170920-change-5-and-4-landing-sites.html) are within the South Pole–Aitken basin, a huge crater that may include lunar mantle excavated by the impact that formed it and thus offer unique insights into the interior of the Moon, what it is made of and how it formed.

The lander will carry a Landing Camera (LCAM), Terrain Camera (TCAM), a Low Frequency Spectrometer (LFS), and Lunar Lander Neutrons and Dosimetry (LND (https://www.hou.usra.edu/meetings/lpsc2017/eposter/1320.pdf)), with the latter developed in Germany.

The rover will be equipped with a Panoramic Camera (PCAM), a Lunar Penetrating Radar (LPR), a Visible and Near-Infrared Imaging Spectrometer (VNIS (https://www.ncbi.nlm.nih.gov/pubmed/25173243)) and, from Sweden, an Advanced Small Analyser for Neutrals (ASAN (https://gbtimes.com/sweden-joins-chinas-historic-mission-land-far-side-moon)).

(https://img.novosti-kosmonavtiki.ru/192031.jpg)
The Chang'e-3 lander on Mare Imbrium, imaged by the Yutu rover. Chinese Academy of Sciences

TCAM and PCAM on Chang'e-3 returned astounding images (http://www.planetary.org/blogs/emily-lakdawalla/2016/01281656-fun-with-a-new-data-set-change.html) from Mare Imbrium. The Chang'e-4 landing mission will also include a student outreach-inspired mini ecosystem (https://gbtimes.com/forget-stratospheric-chicken-sandwich-china-sending-potato-seeds-and-silkworms-moon), including potatoes, arabidopsis seeds and silkworm eggs.

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Цитировать(https://img.novosti-kosmonavtiki.ru/29906.jpg)Andrew Jones‏ @AJ_FI (https://twitter.com/AJ_FI) 9 ч. назад (https://twitter.com/AJ_FI/status/992753603264811013)

Yuanwang 6 tracking ship is on the way to the Pacific to support launch of the Chang'e-4 relay satellite launch. Yuanwang 7 already on the way https://www.zaobao.com.sg/realtime/china/story20180505-856440 ... (https://t.co/qWaSh3cNKo)

ЦитироватьКитайское судно "Юаньван-6" приступило к выполнению миссии по слежению за спутником-ретранслятором "Цюэцяо" для лунного зонда "Чанъэ-4"  
Нанкин, 6 мая /Синьхуа/ -- Судно мониторинга космических полетов "Юаньван-6" в субботу вышло из порта провинции Цзянсу на востоке Китая и отправилось в заданный район Тихого океана, чтобы следить за полетом "Цюэцяо" - спутника-ретранслятора для лунного зонда "Чанъэ-4".
Лунный зонд "Чанъэ-4" будет запущен в конце нынешнего года, он должен будет совершить первую в истории человечества посадку на обратной стороне Луны. Спутник-ретранслятор "Цюэцяо" будет отвечать за передачу сигнала между Землей и обратной стороной Луны.
Слежение и контроль над "Цюэцяо" с моря будет осуществляться судами "Юаньван-6" и "Юаньван-7". Судно "Юаньван-7" только что завершило миссию по слежению за спутником связи APSTAR-6C и уже отправилось в заданную акваторию для выполнения нового задания.

Цитировать(https://img.novosti-kosmonavtiki.ru/29906.jpg)Andrew Jones‏ @AJ_FI (https://twitter.com/AJ_FI) 5 ч. назад (https://twitter.com/AJ_FI/status/993765057640259584)

Yuanwang 6 & Yuanwang 7 space tracking ships are currently heading for locations to support launch of the Chang'e-4 relay satellite, set for May 21. https://gbtimes.com/change-4-yuanwang-6-tracking-vessel-prepares-for-moon-relay-satellite-launch ... (https://t.co/eM30jKy1dc)
(https://img.novosti-kosmonavtiki.ru/163590.jpg)

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(https://img.novosti-kosmonavtiki.ru/163589.jpg)

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ЦитироватьChang'e-4: Yuanwang 6 tracking vessel prepares for Moon relay satellite launch
by Andrew Jones (https://gbtimes.com/authors/658) | May 07, 2018 15:23 | CHINA (https://gbtimes.com/tag/China) ▪ GERMANY (https://gbtimes.com/tag/germany) ▪ MOON (https://gbtimes.com/tag/moon)

(https://img.novosti-kosmonavtiki.ru/191946.jpg)
Relatives of the crew watch as the Yuanwang 6 space tracking vessel leaves port controlled by the China Satellite Launch and Tracking Control General on May 5, 2018 to support launch of the Chang'e-4 relay satellite later in the month. CNS

The Yuanwang 6 space tracking vessel has left port in preparation to support the launch of the relay satellite required for China's ambitious Chang'e-4 lunar far side landing.

The Queqiao communications relay satellite (https://gbtimes.com/change-4-lunar-far-side-satellite-named-magpie-bridge-from-folklore-tale-of-lovers-crossing-the-milky-way) is scheduled to launch from the Xichang Satellite Launch Centre on May 21 or later via a Long March 4C rocket, heading for an orbit beyond the Moon.

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Yuanwang 6 will track the spacecraft after launch from southwest China as it heads into orbit, observing its trajectory and providing survey and control capabilities.

Yuanwang space tracking ships, whose name means 'long view' play a vital role in China's space tracking and data network, with systems aboard providing accurate information.

A second ship, Yuanwang 7, is already sailing (https://gbtimes.com/chinas-yuanwang-7-space-tracking-ship-sailing-to-support-change-4-relay-satellite-launch) for an undisclosed location to support the launch, after assisting the launch of the Apstar-6C satellite (https://gbtimes.com/china-lofts-apstar-6c-satellite-with-13th-launch-of-2018) from Xichang on Friday.

The relay satellite is a precursor to the Chang'e-4 (https://gbtimes.com/channel/features/123) lander and rover mission, which will attempt the first-ever soft-landing on the far side of the Moon in late 2018.

As the far side of the Moon never faces the Earth, due to tidal locking, the relay satellite is required to be in place beyond the Moon to facilitate communications between terrestrial ground stations and the Chang'e-4 lander and rover (https://gbtimes.com/change-4-lander-and-rover-undergoing-thermal-vacuum-tests-ahead-of-lunar-far-side-mission?feature=chinas-change-4-mission-to-the-far-side-of-the-moon).

Its intended halo orbit around the second Earth-Moon Lagrange point more than 60,000 kilometres beyond the Moon will make it accessible to both ground stations on Earth and the lander on the lunar far side at all times.

(https://img.novosti-kosmonavtiki.ru/191910.jpg)
Image demonstrating a halo orbit around the second Earth-Moon Lagrange point, from which the Chang'e-4 communications relay satellite will operate. NAOC/CAS

As well as its main communications role, the relay satellite will carry the Netherlands-China Low-Frequency Explorer (NCLE (https://www.astron.nl/r-d-laboratory/ncle/netherlands-china-low-frequency-explorer-ncle)) for low-frequency radio astronomy experiments, and two microsatellites (https://gbtimes.com/change-4-lunar-far-side-mission-to-carry-microsatellites-for-pioneering-astronomy), named Longjiang-1 and Longjiang-2, test low frequency radio astronomy and space-based interferometry, as well as carry an amateur radio (https://amsat-uk.org/2016/11/18/lunar-amateur-radio-satellites-dslwp-a1a2/) experiments.

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Цитировать(https://img.novosti-kosmonavtiki.ru/187306.jpg). (https://vk.com/chinaspaceflight)
Космические полёты Китая - ChinaSpaceFlight (https://vk.com/chinaspaceflight)
три часа назад (https://vk.com/wall-119361981_2832)

КИТАЙ ПЛАНИРУЕТ 21 МАЯ ЗАПУСТИТЬ СПУТНИКИ К ЛУНЕ

Пекин, /Синьхуа/. Обратная сторона Луны представляет большой научный интерес, однако для посадки на нее требуется ретрансляционный спутник для передачи сигналов. В КНР 21 мая 2018 года планируют запустить спутник-ретранслятор "Цюэцяо" (鹊桥) для обеспечения связи с межпланетной станцией "Чанъэ-4" при её предстоящей посадке на Луну.

Как сообщил заместитель главы Китайского национального космического управления (CNSA) У Яньхуа, вместе с ретрансляционным спутником на орбиту также будут выведены два микроспутника, разработанные Харбинским политехническим институтом и названные соответственно LongJiang-1 & 2 (龙江 一号 / 二号) "Лунцзян-1 & 2".

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"Лунцзян-1" и "Лунцзян-2" будут использоваться для экспериментов в сфере низкочастотной радиоастрономии. Космические аппараты будут летать вместе и вести наблюдение за небом Луны на длинных волнах, что соответствует крайне низкому частотному диапазону. 

"Запуск "Чанъэ-4" является одной из важных задач КНР. Это яркое событие в мировой космонавтике к которому приковано внимание многих стран", - отметил У Яньхуа. "Планируем осуществить два запуска. Первым из них станет запланированный на май запуск спутника-ретранслятора "Цюэцяо" для "Чанъэ-4", - сообщил он.. 

"Этот космический аппарат будет находиться в точке гравитационного равновесия Земли и Луны L2 (одна из точек Лагранжа) и будет обеспечивать связь для "Чанъэ-4", - рассказал У Яньхуа. "Это произойдет впервые в истории человечества", - подчеркнул специалист. 

Запуск самой автоматической межпланетной станции "Чанъэ-4" с посадочным модулем и луноходом который, как ожидается, совершит посадку на обратной стороне Луны /Бассейн Южный полюс-Эйткен/ запланирован в конце текущего года. 

http://www.chinanews.com/gn/2018/04-24/8498843.shtml (https://vk.com/away.php?to=http%3A%2F%2Fwww.chinanews.com%2Fgn%2F2018%2F04-24%2F8498843.shtml&post=-119361981_2832&cc_key=)

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Цитировать(https://img.novosti-kosmonavtiki.ru/67577.jpg)Cosmic Penguin‏ @Cosmic_Penguin (https://twitter.com/Cosmic_Penguin) 1 ч. назад (https://twitter.com/Cosmic_Penguin/status/996323618463232001)

Just saw unconfirmed rumors of the launch scheduled at around 21:00 UTC on May 20 (around 5 am LT May 21) on Chinese forums.

Цитировать据说21日凌晨5点发射，预祝成功！

ЦитироватьГоворят, что запуск в 5 часов утра 21-го, желаю успеха!

ЦитироватьChina preparing to launch Chang'e-4 relay satellite May 21
by Andrew Jones (http://spacenews.com/author/andrew-jones/) — May 14, 2018

(https://img.novosti-kosmonavtiki.ru/155796.jpg)
The far side of the Moon and distant Earth, imaged by the Chang'e-5 T1 mission service module in 2014 Credit: Chinese Academy of Sciences

HELSINKI, Finland – China is set to launch a relay satellite to the second Earth-moon Lagrange point May 21, in a necessary precursor to the planned Chang'e-4 soft-landing on the lunar far side late in the year.

Chang'e-4 is the backup to the Chang'e-3 mission which put a lander and rover on Mare Imbrium in late 2013. Following that success, the lunar craft have been repurposed for a pioneering landing on the moon's far side.

The lunar far side does not face the Earth as the moon's orbital period matches its rotational period, thus requiring a relay satellite to facilitate communications.

Launch of the satellite will take place at the Xichang Satellite Launch Center in the southwest of the country via a Long March 4C rocket, with the three-day launch window opening on May 21.

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The relay satellite, recently named Queqiao – or Magpie Bridge, taken fr om a Chinese folklore tale that sees two lovers reunited once a year when a flock of magpies form a bridge across the Milky Way — will orbit around the Lagrange point around 65,000 kilometers beyond the moon, so as to be visible to both ground stations on the Earth and the lander and rover on the lunar far side at all times.

Its main function will be to relay telecommands from the ground to the Chang'e-4 lunar spacecraft and transmit data and telemetry back to Earth via S-band, while using x-band to communicate with the lander and rover.

Should launch and commissioning of the relay satellite proceed as planned, the lander and rover will be launched by a Long March 3B from Xichang around six months later, in November or December.

Ian Crawford, professor of planetary science and astrobiology at Birkbeck, University of London, told SpaceNews the mission would be a "tremendous undertaking, as it would be the first time any spacecraft has successfully landed on the far side of the moon."

The landing is currently expected to target the Von Kármán crater within the South Pole-Aitken Basin, though a decision on the final site has not been announced by Chinese scientists.

The South Pole-Aitken Basin is, Crawford notes, a high priority scientific objective for exploration, potentially offering unique insights into the formation of the moon and history of the solar system.

Astronomy goals

The relay satellite, developed by the China Academy of Space Technology, will also carry the Netherlands-China Low-Frequency Explorer (NCLE), a low-frequency, space-based astronomy pathfinder experiment that will attempt to detect radio signals from the cosmic dark ages, before emission of light by the first stars in the universe.

Radioastronomybelow around 30 MHzcan only be carried outeffectively outside of the Earth's ionosphere, and the satellite's position beyond the moon will allow it to take a unique look at this largely unexplored region of the electromagnetic spectrum, with minimal interference from Earth.

Professor Heino Falckeof Radboud Universityin the Netherlands and part of the NCLE team told SpaceNewshe doesn't want to set the bar too high for this attempt at picking up a cosmic dark ages signal. It could put an upper lim it on the signal and is expected to be instructive for future low frequency astronomy space missions.

Along with its main objective, NCLE will also aim to characterize the galactic background and measure emissions from the Sun and Jupiter, as well as measure the wake of the solar wind behind the moon.

Falcke says getting the instrument ready in time and integrated on the spacecraft was a "ride on the edge," with the call for international participation in Chang'e-4 only coming in 2015, and the Dutch team needing to develop their own antenna from scratch, due to ITAR regulations limiting exports to China.

The antenna is only expected to be deployed for use sometime in 2019, after the main Chang'e-4 mission, with the rover having a designed operation time of three months on the lunar surface.

The May launch will also carry two microsatellites, named Longjiang-1 and 2 and meaning 'dragon river', which were developed by the Harbin Institute of Technology (HIT) in north-eastern province of Heilongjiang.

The pair will carry synchronized receivers for low frequency astronomy and very long baseline interferometry experiments and operate in a highly elliptical lunar orbit. They will also be available for amateur radio tests, with one of the two 45-kilogram, 50x50x40-centimeter satellites also set to carry a micro optical camera developed by the King Abdulaziz City for Science and Technology (KACST) of Saudi Arabia.

The launch this month will be China's fifth lunar mission, following two orbiters, Chang'e-1 and Chang'e-2 in 2007 and 2010 respectively, Chang'e-3 in 2013, and the 2014 Chang'e-5 T1 probe which flew a capsule around the moon and back to test re-entry for a planned lunar sample return. The full sample mission, Chang'e-5, is expected to take place in 2019.

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ЦитироватьHere's what you need to know about China's Chang'e-4 relay satellite launch
by Andrew Jones (https://gbtimes.com/authors/658) | May 17, 2018 17:07 | CHINA (https://gbtimes.com/tag/China) ▪ SICHUAN PROVINCE (https://gbtimes.com/tag/Sichuan%20Province) ▪ MOON (https://gbtimes.com/tag/moon)

(https://img.novosti-kosmonavtiki.ru/192034.jpg)
The far side of the Moon and the distant Earth, imaged by the Chang'e-5T1 mission in 2014. Chinese Academy of Sciences

China is preparing to launch its Chang'e-4 relay satellite into an orbit beyond the Moon late on May 20, or later on in the three-day launch window.

The mission is the first of two launches that aim to bring about the first-ever landing on the far side of the Moon. Here's what need to know about its job, astronomy goals, orbit and more.

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Communications for lunar far side landing

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The Chang'e-4 relay satellite, named Queqiao ('magpie bridge'), is a precursor to an unprecedented attempt to soft-land on the lunar far side in late 2018, when a lander and rover will be send to the Moon.

As the far side of the Moon never faces the Earth, the communications relay needs to be in place in order to facilitate the sending of commands from the Earth to the spacecraft on the Moon, and getting data and telemetry back from the lander and rover (https://gbtimes.com/change-4-lander-and-rover-undergoing-thermal-vacuum-tests-ahead-of-lunar-far-side-mission) down to waiting ground stations.

This is the main role of the 425 kg spacecraft, developed by the China Academy of Space Technology (CAST), which is being sent into position around six months before the landing mission in order to test and verify is functions.

(https://img.novosti-kosmonavtiki.ru/191943.jpg)
A rendering of the Chang'e-4 relay satellite, to launch in May 2018, and lander and rover to set down on the lunar far side in late 2018. Chinese Academy of Sciences

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Earth-Moon Lagrange point orbit

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To be able to do this, the relay satellite needs to have a line of sight to both ground stations on Earth and the Chang'e-4 lander and rover simultaneously.

To achieve this, the relay satellite will take advantage of a gravitationally stable point, called a Langrange Point (http://hyperphysics.phy-astr.gsu.edu/hbase/Mechanics/lagpt.html), that will allow it to remain in a stable orbit with respect to the Earth and Moon.

By orbiting in a halo (or sometimes Lissajous) around the second Earth-Moon Langranian point, between 65,000 and 80,000 km beyond the Moon, the relay satellite will by able to stay visible to the ground and far side of the Moon, using S-band and X-band frequencies for communications.

The spacecraft is expected to reach E-M L2 around 8-9 days after launch, following a lunar swing-by.

(https://img.novosti-kosmonavtiki.ru/191941.png)
Launch profile for the Chang'e-4 communications relay satellite. Chinese Academy of Sciences

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Pioneering astronomy and cosmic dark ages

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The satellite will, along with its communications role, also carry a radio antenna to carry out low frequency astronomy which is not possible on Earth, with frequencies below 10 to 30 MHz blocked by the atmosphere.

The Netherlands-China Low-Frequency Explorer (NCLE (https://www.astron.nl/r-d-laboratory/ncle/netherlands-china-low-frequency-explorer-ncle)) was developed by Radboud University in Nijmegen, the Netherlands Institute for Radio Astronomy (ASTRON) and Dutch company Innovative Solutions In Space (ISIS), and integrated with the relay satellite in April.

Marc Klein Wolt (https://twitter.com/MarcWolt) of Radboud University and NCLE project leader says the experiment will begin after lander and rover operations, sometime in 2019. Once the antenna is deployed it will open a new window on the universe with unprecedented observations and set the stage for future missions.

Beginning with observations of solar activity and Jupiter emissions and aurora to establish the solar system baseline - or background radio environment - it will then attempt to detect the faint, redshifted signals from after the Big Bang when the first stars were beginning to form.

As this is a pathfinder mission, Wolt says he hopes to, "get enough time and have our instrument sufficiently calibrated that we can put some constraints on the signal from the cosmic Dark Ages."

Asked if NCLE could also - despite not being a science objective for the team - contribute to the search for extraterrestrial intelligence (SETI), Wolt says that, "In principle it could, as we are opening a new window on the universe, but I'm not expecting to find ET."

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Queqiao - Magpie Bridge

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The name for the relay satellite, Queqiao - or magpie bridge - comes from a Chinese myth and was announced late last month (https://gbtimes.com/change-4-lunar-far-side-satellite-named-magpie-bridge-from-folklore-tale-of-lovers-crossing-the-milky-way) at an event marking China's third Space Day.

The name comes from the Chinese myth and love story of the Weaver Girl and the Cowherd (https://gbtimes.com/qixi-festival-and-story-chinese-valentines-day). Separated by the Silver River, which symbolises the Milky Way, the lovers are reunited for one day each year by a bridge formed by a flock of magpies - Queqiao (鹊桥) - allowing them to cross the heavens.

(https://img.novosti-kosmonavtiki.ru/192040.jpg)
Star-crossed lovers Niulang and Zhinu are permitted to be together one day year by a bridge of magpies, during the Qixi Festival. The painting is in the Long Corridor of the Summer Palace in Beijing. Public Domain

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Piggybacking microsatellites

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Also along for the Long March 4C ride from Xichang to the Moon will be two microsatellites (https://gbtimes.com/change-4-lunar-far-side-mission-to-carry-microsatellites-for-pioneering-astronomy) developed by the Harbin Institute of Technology (HIT).

Named Longjiang-1 and Longjiang-2 (meaning 'river dragon'), the 45-kg, 50x50x40-cm sats will not follow the relay satellite to the Lagrange point, but instead operate in a highly elliptical orbit around the Moon (300 x 9,000 km).

There, the pair, using 1-metre antennas, will test low frequency radio astronomy and space-based interferometry, as well as amateur radio activities (https://amsat-uk.org/2018/04/03/dslwp-lunar-amateur-radio-satellites/). It will also carry a small optical camera developed by Saudi Arabia (https://spacewatch.global/2018/02/saudi-arabia-contribute-optical-camera-chinas-change-4-lunar-far-side-mission/).

The size of the satellites and need for fuel for propulsion means they will operate for only 10 minutes at a time for observation, followed by 20 minutes for data transmission. The aim is technical verification for future missions.

(https://img.novosti-kosmonavtiki.ru/191938.png)
Testing on the Chang'e-4 DSLWP-A1 and DSLWP-A2 microsatellites in early 2018. CCTV/Youtube/Framegrab

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Chang'e-3 backup

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The lander and rover for the Chang'e-4 mission were originally manufactured at the same time as the Chang'e-3 (https://www.nbcnews.com/science/china-launches-jade-rabbit-rover-its-first-moon-landing-mission-2D11674372) spacecraft, which landed on the Moon in late 2013, in order to provide a backup mission in case of launch failure or other issues.

These spacecraft, totalling near 4,000 kg, have now been repurposed for objectives on the lunar far side, and have recently been progressing through space environment tests (https://gbtimes.com/change-4-lander-and-rover-undergoing-thermal-vacuum-tests-ahead-of-lunar-far-side-mission).

Cameras on Chang'e-3 returned astounding images (http://www.planetary.org/blogs/emily-lakdawalla/2016/01281656-fun-with-a-new-data-set-change.html) from Mare Imbrium, and the same is hoped for Chang'e-4. Chang'e-3 made a number of discoveries with its instruments, including multiple distinct layers  (http://www.skyandtelescope.com/astronomy-news/change-3-lunar-layers-031320154/)beneath the surface, suggesting the Moon has a more complex geological history than previously thought.

(https://img.novosti-kosmonavtiki.ru/192026.jpg)
A view of Mare Imbrium taken by China's Chang'e-3 mission. Chinese Academy of Sciences

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The landing - Von Kármán crater?

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China has finalised, but not officially announced, the site for the Chang'e-4 landing. Candidates (https://www.airspacemag.com/daily-planet/chinas-journey-lunar-far-side-missed-opportunity-180963703/) have been stated to be within the Von Kármán (http://www.planetary.org/blogs/guest-blogs/2017/20170920-change-5-and-4-landing-sites.html) impact crater within the South Pole-Aitken Basin (https://www.nasa.gov/mission_pages/LRO/multimedia/lro-20100709-basin.html).

Ian Crawford (http://www.bbk.ac.uk/geology/our-staff/ian-crawford), professor of planetary science and astrobiology at Birkbeck University of London, told gbtimes.com in 2016 that a successful landing would be an, "enormously significant event in the history of space exploration, in the exploration of the Moon, and a tremendous boost for lunar science."

Crawford explains that the 2,500 kilometre diameter and roughly 13-kilometre-deep impact crater is an intriguing site, which could tell us more about the deep interior of the Moon than any other landing site so far.

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Launch - live?

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Latest indications are that the Long March 4C carrying the relay satellite will launch around 21:00 UTC on Sunday, May 20 (17:00 EDT; 05:00 Beijing time May 21).

China has previously provided live footage of its lunar missions, but there is no word yet on possibilities for this launch. Check here for updates.

The European Space Agency provided ground station support for Chang'e-3 and other Chinese lunar missions, but Chang'e-4 will rely solely on Chinese facilities, thanks in part to a new, 35m-diameter parabolic antenna in Argentina (https://thediplomat.com/2016/05/china-builds-space-monitoring-base-in-the-americas/).

Yuanwang space tracking ships are also in position (https://gbtimes.com/change-4-yuanwang-6-tracking-vessel-prepares-for-moon-relay-satellite-launch) ready in the Pacific, ready to observe the rocket's trajectory and providing survey and control capabilities as it heads to orbit.

(https://img.novosti-kosmonavtiki.ru/191905.png)
Preparations for the November 2017 launch of the Beidou-3 M1 and M2 satellites via Long March 3B from Xichang, Sichuan Province. beidou.gov.cn

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Chinese lunar exploration past and future

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Chang'e-4 will be China's fifth mission, following two orbiters (Chang'e-1 and 2), the 2013 Chang'e-3 lander and rover, and a 2014 test mission.

This last mission, the Chang'e-5 T1 mission to test reentry on return from the Moon in preparation for a sample return missions, gave hints that China was considering a lunar far side landing. These clues were picked up on and reported by Emily Lakdawalla (http://www.planetary.org/blogs/emily-lakdawalla/2014/11031013-change-5-test-vehicle-flying.html) of the Planetary Society.

China is also preparing for a (delayed) sample return mission, Chang'e-5 (https://gbtimes.com/channel/features/129), in 2019, and is developing a plan for expanding its lunar exploration programme (https://gbtimes.com/channel/features/122), with the lunar south pole (https://gbtimes.com/chinese-lunar-exploration-enter-new-phase-missions-moons-poles-and-far-side?feature=chinas-lunar-exploration-programme) expected to be the main target.

For latest news and developments on the mission, see our feature on China's Chang'e-4 mission to the far side of the Moon (https://gbtimes.com/channel/features/123)

(https://img.novosti-kosmonavtiki.ru/191928.jpg)
The Moon's south pole as seen by the 1994 NASA Clementine mission. NASA/Goddard Space Flight Center Scientific Visualization Studio

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Цитировать(https://img.novosti-kosmonavtiki.ru/185596.jpg)Marc Klein Wolt‏ @MarcWolt (https://twitter.com/MarcWolt) 22 мин. назад (https://twitter.com/MarcWolt/status/997132211085369344)

Follow the Chang'e 4 launch to the moon with the Dutch NCLE instrument on the http://RU.nl  (https://t.co/ufH762GvJw) website! @RadRadioLab (https://twitter.com/RadRadioLab) @ASTRON_NL (https://twitter.com/ASTRON_NL) @isis_space (https://twitter.com/isis_space) @Radboud_Uni (https://twitter.com/Radboud_Uni)

(https://img.novosti-kosmonavtiki.ru/163871.jpg)

ЦитироватьReady to launch: Dutch radio antenna to depart for the moon on Chinese mission
Date of news: 17 May 2018

On 20 May 2018*, the Chinese space agency will launch the relay satellite Chang'e 4 to an orbit behind the Moon. On board will be a Dutch radio antenna, the Netherlands Chinese Low-Frequency Explorer (NCLE). The radio antenna is the first Dutch-made scientific instrument to be sent on a Chinese space mission (http://www.ru.nl/english/news-agenda/news/vm/imapp/astrophysics/2016/dutch-radio-antenna-depart-moon-chinese-mission/), and it will open up a new chapter in radio astronomy. With the instrument, made by engineers from the Radboud Radio Lab (http://www.ru.nl/astrophysics/research-0/radboud-radio-lab-0/)of Radboud University, ASTRON (https://www.astron.nl/), the Netherlands Institute for Radio Astronomy in Dwingeloo, and the Delft-based company ISIS (https://www.isispace.nl/), astronomers want to measure radio waves originating from the period directly after the Big Bang, when the first stars and galaxies were formed.

*DISCLAIMER: The launch depends on favorable weather conditions, therefore, the launch may be delayed. Follow the launch via Radboud Radio Lab (http://www.ru.nl/astrophysics/research-0/radboud-radio-lab-0/).

Спойлер

The far side of the moon

Why is it so important for the measuring instruments to be placed behind the moon? Professor of Astrophysics from Radboud University and ASTRON Heino Falcke: "Radio astronomers study the universe using radio waves, light coming from stars and planets, for example, which are not visible with the naked eye. We can receive almost all celestial radio wave frequencies here on Earth. We cannot detect radio waves below 30 MHz, however, as these are blocked by our atmosphere. It is these frequencies in particular that contain information about the early universe, which is why we want to measure them."

(https://img.novosti-kosmonavtiki.ru/233955.jpg)
The satellite rotates around a fixed point behind the moon – the second Lagrange, or L2, point in the Earth-moon system. This point is located approximately 65,000 kilometers from the moon.

Special about the radio antenna is that it will receive radio waves with a large frequency range. "In the past this was not possible and therefore a receiver with a narrow frequency band was used, in order to avoid electromagnetic interference of the satellite itself," Albert-Jan Boonstra of ASTRON explains. "We have now succeeded in avoiding the electromagnetic interference and making a broadband receiver. That is, of course, good news for subsequent missions and can, for example, be used for future nano-satellites."

Ready to launch? Final test

The instrument passed an important risk assessment review by the Chinese space agency at the end of April. Marc Klein Wolt, Managing Director of the Radboud Radio Lab (http://www.ru.nl/astrophysics/research-0/radboud-radio-lab-0/), looks back on the endeavour with a sense of accomplishment: "The last few months have been quite challenging for the Dutch team, who have put in a lot of effort to complete the instrument for the launch as the final phase of a two-year bi-lateral project with our Chinese counterparts. The Chinese lunar programme is like a bus we were trying to catch, mostly due to the hard work and enormous dedication from the teams on both sides".

On April 30, the antenna successfully passed final pre-flight test. Heino Falcke reported: "Antennas were successfully deployed and retracted. Next step in this adventure is L2-point behind moon."

(https://img.novosti-kosmonavtiki.ru/233954.jpg)
The radio antenna  Netherlands Chinese Low-Frequency Explorer (NCLE) developed by Radboud Radio Lab of Radboud University, ASTRON, ISIS and the Chinese National Astronomical Observatory of the Chinese Academy of Sciences (NAOC (http://english.nao.cas.cn/)).

Collaboration with China

In 2016 the Netherlands Space Office (https://www.spaceoffice.nl/en/) and its Chinese counterpart CNSA (http://www.cnsa.gov.cn/n6443408/index.html) signed an agreement to cooperate in this project, which was an elaboration of the Memorandum of Understanding the two space agencies signed the year before during a trade mission in presence of the Chinese President Xi Jinping and the Dutch King Willem Alexander. "NCLE does not only pave the way for new exciting science, but also provides new means for the two countries to expand their international collaboration", says Mr. Harry Forster of the NSO.

[свернуть]

Цитировать1、发射时间：2018年5月21日凌晨5时左右。

Цитировать1, время запуска: 21 мая 2018 года около 5 часов утра.

ЦитироватьJ4031/18 - ALTN RTE FOR A582/R595/Y579/Y27/Y533/Y531/Y59/ ARE ESTABLISHED DUE TO SPACEFLIGHT ACTIVITIES. 1.FLT PLANNED RTE IS REQ TO BE FILED AS FLW (1)A582:  (BTN MAMIK AND NIMOX) ALTN RTE: NHC V91 MJC-ALBAX-NIMOX (2)R595:  (BTN MJC AND TUNTO) ALTN RTE: MJC-ALBAX-NIMOX-TUNTO (3)Y579: (BTN AZAMA AND SAKON) ALTN RTE: AZAMA Y74 NHC V91 MJC-ALBAX-NIMOX (4)Y27: (BTN AMMEK AND SAKON) ALTN RTE: YURIX Y62 IKEMA-ALBAX-NIMOX (5)Y533: (BTN ALBAX AND AZAMA) ALTN RTE: ALBAX-IKEMA Y57 AZAMA (6)Y531: (BTN ALBAX AND YURIX) ALTN RTE: ALBAX-IKEMA Y62 YURIX (7)Y59: (BTN KAZIK AND AZAMA) ALTN RTE: AZAMA Y74 NHC V91 MJC B462 KAZIK 2.SEE NOTAM RJAAYNYX J4030/18. SFC - UNL, 2125/2140 2255/2310, 20 MAY 21: 25 2018 UNTIL 20 MAY 23: 10 2018. CREATED:  18 MAY 09: 51 2018
J4030/18 - DUE TO SPACEFLIGHT ACTIVITIES,THE FLIGHT SAFETY OF THE AIRCRAFT IN FOLLOWING AREAS MAY BE AFFECTED ON MAY 20, 2018 DETAILS ARE AS FOLLOWS:  ON MAY 20,2018 FROM 21: 31-21: 40 UTC AND 23: 01-23: 10 UTC AREA:  242432N1271117E 234250N1265819E 240231N1254146E 244420N1255418E,FOUR-POINT CONNECTION RANGE. VERTICAL ALTITUDE: SFC-UNL RMK/ATC WILL NOT CLEAR IFR FLT THRU THIS AREA FOR THE FLIGHT SAFETY. SFC - UNL, 2131/2140 2301/2310, 20 MAY 21: 31 2018 UNTIL 20 MAY 23: 10 2018. CREATED:  18 MAY 09: 49 2018

Цитироватьhttps://img.novosti-kosmonavtiki.ru/220250.jpg
(https://img.novosti-kosmonavtiki.ru/220250.jpg)

ЦитироватьChina to launch relay satellite for Chang'e-4 lunar probe
Source: Xinhua| 2018-05-18 15:22:35 | Editor: Xiang Bo

BEIJING, May 18 (Xinhua) -- China plans to launch a relay satellite into space next Monday, May 21, for the Chang'e-4 lunar probe scheduled later this year.

The Chang'e-4 lunar probe will undertake the first ever soft landing on the far side of the Moon. However, direct communication with the far side of the Moon is not possible, which is one of the many challenges of the Chang'e-4 lunar probe mission.

The relay satellite, named Queqiao, will be responsible for transmitting signals between the Earth station and the Chang'e-4 lander and rover.

Relay satellites are communication satellites that can provide data relay and monitoring services for spacecraft, improving the efficiency and emergency capability of various satellites. They also enable data from earth resource and environmental satellites to be transmitted in real time.

The Chang'e-4 probe will also carry scientific payloads for four countries, including the Netherlands and Germany.

Цитировать

Китай запустит спутник-ретранслятор для лунного зонда "Чанъэ-4" в следующий понедельник
2018-05-18 17:05:10丨Russian.News.Cn

Пекин, 18 мая /Синьхуа/ -- Китай запланировал запустить в следующий понедельник, 21 мая, спутник-ретранслятор для лунного зонда "Чанъэ-4".

"Чанъэ-4" будет запущен в конце нынешнего года и совершит первую в истории человечества посадку на обратной стороне Луны. Прямая связь с обратной стороны Луны невозможна, что является одним из главных вызовов миссий "Чанъэ-4".

Спутник-ретранслятор под названием "Цюэцяо" будет отвечать за передачу сигналов между наземной станцией и луноходом "Чанъэ-4".

Спутник-ретранслятор - это коммуникационный спутник, который может предоставлять услуги передачи данных и мониторинга для космических аппаратов, а также позволяет повысить эффективность и способность реагирования во время аварийных ситуаций различных спутников. Он также способен передавать данные от наземных ресурсов и экологических спутников в режиме реального времени.

Зонд "Чанъэ-4" также доставит на Луну научное оборудование для четырех стран, включая Нидерланды и Германию.

ЦитироватьChina's moon mission will probe cosmic dark ages
By Daniel Clery (http://www.sciencemag.org/author/daniel-clery) | May. 16, 2018, 3:00 PM

On 21 May, China plans to launch a satellite with a vital but unglamorous mission. From a vantage point beyond the moon, Queqiao, as the satellite is called, will relay data from Chang'e 4, a lander and rover that is supposed to touch down on the lunar far side before the end of the year. But a Dutch-made radio receiver aboard Queqiao will attempt something more visionary. In the quiet lunar environment, it will listen to the cosmos at low frequencies that carry clues to the time a few hundred million years after the big bang, when clouds of hydrogen gas were spawning the universe's first stars.

Спойлер

The mission is a proof of principle for other efforts to take radio astronomy above the atmosphere, which blocks key radio frequencies, and far from earthly interference. "Putting the whole show into space is extremely appealing," says Michael Hecht of the Massachusetts Institute of Technology's Haystack Observatory in Westford, whose team is also developing small radio satellites that could be used to probe the cosmos. For Europe's astronomers, it is also a test of cooperation with China, something their U.S. counterparts at NASA are barred from doing.

The Netherlands-China Low-Frequency Explorer (NCLE) project stems from a 2015 Dutch trade mission to China (http://science.sciencemag.org/content/346/6210/688), during which the two countries agreed to collaborate on space missions. The Netherlands is strong in radio astronomy: Its Low-Frequency Array (LOFAR) stretches across much of northern Europe. NCLE Principal Investigator Heino Falcke, of Radboud University in the Netherlands, has long advocated a "LOFAR on the moon." China has an ambitious program of moon missions, so he jumped at the chance to take a first step. "We put together a proposal in 2 weeks," he says. Once funded, the team had just 1.5 years to build the instrument. "Half of the experiment is how you work together" Falcke says. Jinsong Ping of the National Astronomical Observatories of China in Beijing, who leads the Chinese team working on the NCLE, agrees: "It is really challenging both sides. ... Different culture, habit, language, working manner."

To see back into the dark age before the first stars, astronomers look for a signal emitted when electrons in the primordial neutral hydrogen gas spontaneously flipped their orientation. These photons started out with short radio wavelengths, but over their more than 13-billion-year journey to Earth, the universe's expansion stretched them out to long wavelengths, or low megahertz frequencies. After the gas clumped together to form the first stars, their radiation ionized the neutral gas and eventually snuffed out the faint signal.

Telescopes such as the LOFAR aim to detect the ancient signal and use it to map the distribution of primordial matter. But the signal is hard to discern in the maelstrom of radio noise from terrestrial sources and other objects across the universe. Only one detector, the Experiment to Detect the Global Epoch of Reionization Signature, a set of ground-based antennas in Australia, has so far claimed a detection (http://science.sciencemag.org/content/359/6379/969).

Queqiao, orbiting a gravitational balance point beyond the moon called L2, will offer a quieter vantage. In order to relay signals from the moon to Earth, the satellite can't be completely in the moon's shadow, which means that Earth noise could still be a problem, says Jack Burns, an astronomer at the University of Colorado in Boulder who has long campaigned for a lunar radio observatory. Burns adds that the spacecraft itself will also be a source of interference. But by testing hardware in space, the NCLE "will set the stage for other missions."

Once Queqiao arrives at L2, the NCLE will wait its turn until after the Chang'e 4 lander has achieved its main mission: exploring the South Pole-Aitken Basin, a huge far side depression. Then, around March 2019, the instrument will unspool three 5-meter-long carbon-fiber antennas, each at right angles to the others.

Because Earth's atmosphere blocks all radio signals below 30 megahertz, the data will delight a range of astronomers. Falcke says the team will study solar flares, the aurora of Jupiter, and the galaxy's radio emissions. "There's nothing as good as having real data," he says. The dark age signal is a long shot, he admits. Realistically, the mission is about "gaining expertise to build a follow-up."

The Chinese NCLE team has its own plans. It has placed basic receivers on the Chang'e 4 lander and two microsatellites that Queqiao will release into lunar orbit to study solar radio bursts. Ping says his team will also try to combine signals received by the NCLE with those taken by earthbound detectors—a technique known as interferometry, which can improve resolution. "It is a demonstration," he says. It could show that, once detectors are sensitive enough, interferometry could help them map the newborn universe.

Burns and his colleagues are working on a proposal for a small satellite called the Dark Ages Polarimetry Pathfinder, which he says will be more sensitive to the dark age signal. But eventually, he wants to see an observatory on the lunar far side, deep with the moon's radio quiet shadow. He predicts a NASA-funded low-frequency telescope in the next 5 years. "There's great interest in the far side."

*Correction 18 May, 9:55 a.m.: This story has been updated to correct the length of the antennas of the Netherlands-China Low-Frequency Explorer.

[свернуть]

Цитировать(https://img.novosti-kosmonavtiki.ru/29906.jpg)Andrew Jones‏ @AJ_FI (https://twitter.com/AJ_FI) 41 мин. назад (https://twitter.com/AJ_FI/status/997848783059935233)

Not looking good for a live stream of the Chang'e-4 relay satellite/Queqiao launch on Sunday. First time CZ-4C will be launching from Xichang & pushed into a hectic schedule for the launch site. And as @Cosmic_Penguin (https://twitter.com/Cosmic_Penguin) notes, it's been very quiet on this front.

Цитировать...
接县人防办通知，西昌卫星发射中心将于5月21日早晨5点28分择机使用CZ-4C运载火箭执行探月工程嫦娥四号中继发射任务 (http://www.spaceflightfans.cn/event/cz-4c-ce4-zhongjixing)。
...

Цитировать...
Управление гражданской авиации округа сообщило, что Центр запуска спутников Сичан 21 мая в 5:28 утра осуществит пуск ракеты-носителя CZ-4C  с КА-ретранслятором для лунной миссии Chang'E-4.
...

Цитировать(https://img.novosti-kosmonavtiki.ru/29906.jpg)Andrew Jones‏ @AJ_FI (https://twitter.com/AJ_FI) 2 ч. назад (https://twitter.com/AJ_FI/status/998152851305172993)

Here's the launch trajectory, taking the Queqiao Chang'e-4 relay sat to the second Earth-Moon Lagrange point via a lunar swing-by, and reaching it's destination in around 8-9 days.

https://video.twimg.com/tweet_video/DdommXiVQAE9QqS.mp4 (https://video.twimg.com/tweet_video/DdommXiVQAE9QqS.mp4)
(video (https://video.twimg.com/tweet_video/DdommXiVQAE9QqS.mp4) 0:04)

Цитировать(https://img.novosti-kosmonavtiki.ru/29906.jpg)Andrew Jones‏ @AJ_FI (https://twitter.com/AJ_FI) 2 ч. назад (https://twitter.com/AJ_FI/status/998153125558091776)

And an illustration of the lissajous/halo orbit that Queqiao will perform around Earth-Moon L2.

https://video.twimg.com/tweet_video/Ddomx_kUQAAgzgl.mp4 (https://video.twimg.com/tweet_video/Ddomx_kUQAAgzgl.mp4)
(video (https://video.twimg.com/tweet_video/Ddomx_kUQAAgzgl.mp4) 0:05)

Цитировать(https://img.novosti-kosmonavtiki.ru/29906.jpg)Andrew Jones‏ @AJ_FI (https://twitter.com/AJ_FI) 57 мин. назад (https://twitter.com/AJ_FI/status/998220881196474368)

The Netherlands-China Low-frequency Explorer (#NCLE (https://twitter.com/hashtag/NCLE?src=hash)) instrument and 3 x 5m antennas for the Queqiao Chang'e-4 lunar relay satellite, set for launch ~21:00 UTC.

https://video.twimg.com/tweet_video/DdpkPDYVMAAW_Dq.mp4 (https://video.twimg.com/tweet_video/DdpkPDYVMAAW_Dq.mp4)
(video (https://video.twimg.com/tweet_video/DdpkPDYVMAAW_Dq.mp4) 0:10)

Цитировать(https://img.novosti-kosmonavtiki.ru/29906.jpg)Andrew Jones‏ @AJ_FI (https://twitter.com/AJ_FI) 2 ч. назад (https://twitter.com/AJ_FI/status/998212904116776960)

Wait, what's this? A possible hint of live coverage of the #queqiao (https://twitter.com/hashtag/queqiao?src=hash) Chang'e-4 lunar relay satellite launch (~21:00 UTC/17:00 EDT) from Xichang by iFeng/Phoenix TV. https://www.weibo.com/1992613670/Ghza7yFOd?refer_flag=1001030103_&type=comment#_rnd1526826945984 ... (https://t.co/aihGVNhNHp)

https://video.twimg.com/tweet_video/Ddpc0KZU0AAEeU-.mp4 (https://video.twimg.com/tweet_video/Ddpc0KZU0AAEeU-.mp4)
(video (https://video.twimg.com/tweet_video/Ddpc0KZU0AAEeU-.mp4) 0:05)

Цитировать

m.ifeng.com (https://m.ifeng.com/5Of2mHcu/shareNews?guid=01c86ae2-7c29-436f-b63f-f030415aba3a&forward=1&aman=b6a62fi45cZ433521050abz7647787h33bX3d3ud71&gud=97X878Q746)

Цитировать(https://img.novosti-kosmonavtiki.ru/29906.jpg)Andrew Jones‏ @AJ_FI (https://twitter.com/AJ_FI) 3 мин. назад (https://twitter.com/AJ_FI/status/998291614475980801)

Someone driving to Xichang to view the Chang'e-4 relay satellite launch also filmed their journey and linked on Weibo. Just over an hour away from launch now.

(https://img.novosti-kosmonavtiki.ru/164111.jpg)

ЦитироватьСтарый пишет:
А почему мы летим на межпланетную траекторию на CZ-4?

ЦитироватьSchwalbe пишет:

ЦитироватьСтарый пишет:
А почему мы летим на межпланетную траекторию на CZ-4?

Из наличия?

Цитировать(https://img.novosti-kosmonavtiki.ru/186381.jpg)Quan-Zhi Ye‏ @Yeqzids (https://twitter.com/Yeqzids) 33 мин. назад (https://twitter.com/Yeqzids/status/998294396792537088)

Looks like the launch info of #Queqiao (https://twitter.com/hashtag/Queqiao?src=hash) is embargoed, reported by the NCLE team (Netherlands Chinese Low-Frequency Explorer), an intl payload on Queqiao http://www.ru.nl/astrophysics/research-0/radboud-radio-lab-0/launch-netherlands-chinese-low-frequency-explorer/ ... (https://t.co/44pXNL3BqO)
.
Phoenix TV indicates they have crew at Xichang but will only report ~2 hour after launch (23:30 UT).

Цитировать(https://img.novosti-kosmonavtiki.ru/29906.jpg)Andrew Jones‏ @AJ_FI (https://twitter.com/AJ_FI) 4 мин. назад (https://twitter.com/AJ_FI/status/998310123155189760)

Here's a sneaky look at the Long March 4C due to launch the Queqiao Chang'e-4 lunar relay satellite in under 20 minutes from Xichang in China.

(https://img.novosti-kosmonavtiki.ru/164096.jpg)

Цитировать(https://img.novosti-kosmonavtiki.ru/29906.jpg)Andrew Jones‏ @AJ_FI (https://twitter.com/AJ_FI) 2 мин. назад (https://twitter.com/AJ_FI/status/998311630135013377)

(https://img.novosti-kosmonavtiki.ru/164097.jpg)

Цитировать(https://img.novosti-kosmonavtiki.ru/185739.png)Radboud Radio Lab‏ @RadRadioLab (https://twitter.com/RadRadioLab) 46 сек. назад (https://twitter.com/RadRadioLab/status/998314905735491584)

engines on - liftoff

(https://img.novosti-kosmonavtiki.ru/164098.jpg)

Цитировать(https://img.novosti-kosmonavtiki.ru/29906.jpg)Andrew Jones‏ @AJ_FI (https://twitter.com/AJ_FI) 2 мин. назад (https://twitter.com/AJ_FI/status/998314911112589313)

Liftoff of Queqiao Chang'e-4 lunar relay satellite!

(https://img.novosti-kosmonavtiki.ru/164099.jpg)
(https://img.novosti-kosmonavtiki.ru/164100.jpg)

Цитировать(https://img.novosti-kosmonavtiki.ru/185739.png)Radboud Radio Lab‏ @RadRadioLab (https://twitter.com/RadRadioLab) 3m3 minutes ago (https://twitter.com/RadRadioLab/status/998317079915909125)

Stage separation confirmed @isis_space (https://twitter.com/isis_space) @ASTRON_NL (https://twitter.com/ASTRON_NL) #NCLELaunch (https://twitter.com/hashtag/NCLELaunch?src=hash)

ЦитироватьОтвод ферм
(https://forum.novosti-kosmonavtiki.ru/forum/file/83815)

Зажигание
(https://forum.novosti-kosmonavtiki.ru/forum/file/83816)

Пуск
(https://forum.novosti-kosmonavtiki.ru/forum/file/83817)

Полёт
(https://forum.novosti-kosmonavtiki.ru/forum/file/83818)
(https://forum.novosti-kosmonavtiki.ru/forum/file/83819)

Цитировать(https://img.novosti-kosmonavtiki.ru/29906.jpg)Andrew Jones‏ @AJ_FI (https://twitter.com/AJ_FI) 14 мин. назад (https://twitter.com/AJ_FI/status/998319161590808576)

Another look at the launch, in all its wobbly glory.

https://video.twimg.com/tweet_video/Ddq94mRUwAAAeF2.mp4 (https://video.twimg.com/tweet_video/Ddq94mRUwAAAeF2.mp4)
(video (https://video.twimg.com/tweet_video/Ddq94mRUwAAAeF2.mp4) 0:18 )

Цитировать(https://img.novosti-kosmonavtiki.ru/29906.jpg)Andrew Jones‏ @AJ_FI (https://twitter.com/AJ_FI) 6 мин. назад (https://twitter.com/AJ_FI/status/998322802498441216)

Longjiang 1 & 2 microsatellites successfully separated from launch vehicle #queqiao (https://twitter.com/hashtag/queqiao?src=hash)

Цитировать(https://img.novosti-kosmonavtiki.ru/30820.jpg)BG2BHC‏ @bg2bhc (https://twitter.com/bg2bhc) 6 мин. назад (https://twitter.com/bg2bhc/status/998322544972197888)

DSLWP-A/B successfully seprated from vehicle @AMSAT (https://twitter.com/AMSAT) @AmsatUK (https://twitter.com/AmsatUK)

Цитироватьhttp://ugc-vliveochy.tc.qq.com/om.tc.qq.com/ACdEt1WeZ_f5P64VFOUrVCKRTQOaI4VaUA3dNAwcEbQU/h0660vjgtd5.p712.1.mp4?sdtfrom=v1010&guid=e05fa3c640baf89b9c90f7ea619eb8f0&vkey=0B6C729A932562866058C8332870B7C7399F5335A5B8874755F0684D9F60E6B944A39CA24D283991AA4EA6651911F37DAACC26FAA4C199338A19E3E7FD31B4388E92E27744607731B4C7D925D559DE05325AE4E3C1E54B5914C58FDB3425D2FF272E3C6292C84CB6C59ED6A750C4CE264C2D17158C077948&ocid=1320424876 (http://ugc-vliveochy.tc.qq.com/om.tc.qq.com/ACdEt1WeZ_f5P64VFOUrVCKRTQOaI4VaUA3dNAwcEbQU/h0660vjgtd5.p712.1.mp4?sdtfrom=v1010&guid=e05fa3c640baf89b9c90f7ea619eb8f0&vkey=0B6C729A932562866058C8332870B7C7399F5335A5B8874755F0684D9F60E6B944A39CA24D283991AA4EA6651911F37DAACC26FAA4C199338A19E3E7FD31B4388E92E27744607731B4C7D925D559DE05325AE4E3C1E54B5914C58FDB3425D2FF272E3C6292C84CB6C59ED6A750C4CE264C2D17158C077948&ocid=1320424876)
(video (http://ugc-vliveochy.tc.qq.com/om.tc.qq.com/ACdEt1WeZ_f5P64VFOUrVCKRTQOaI4VaUA3dNAwcEbQU/h0660vjgtd5.p712.1.mp4?sdtfrom=v1010&guid=e05fa3c640baf89b9c90f7ea619eb8f0&vkey=0B6C729A932562866058C8332870B7C7399F5335A5B8874755F0684D9F60E6B944A39CA24D283991AA4EA6651911F37DAACC26FAA4C199338A19E3E7FD31B4388E92E27744607731B4C7D925D559DE05325AE4E3C1E54B5914C58FDB3425D2FF272E3C6292C84CB6C59ED6A750C4CE264C2D17158C077948&ocid=1320424876) 2:36)

Цитировать(https://img.novosti-kosmonavtiki.ru/185739.png)Radboud Radio Lab‏ @RadRadioLab (https://twitter.com/RadRadioLab) 2 мин. назад (https://twitter.com/RadRadioLab/status/998329827840155649)

Some close-up shots of the rocket before launch. more to come .. stay tuned. @ASTRON_NL (https://twitter.com/ASTRON_NL) @isis_space (https://twitter.com/isis_space) @Radboud_Uni (https://twitter.com/Radboud_Uni) @RUastro (https://twitter.com/RUastro)

(https://pbs.twimg.com/media/DdrHcJFVAAAu3pK.jpg)
(https://pbs.twimg.com/media/DdrHel6V4AAsz15.jpg)

ЦитироватьChina launches relay satellite to explore Moon's far side
Source: Xinhua | 2018-05-21 06:30:08 | Editor: yan

XICHANG, May 21 (Xinhua) -- China launched a relay satellite early Monday to set up a communication link between Earth and the planned Chang'e-4 lunar probe that will explore the mysterious far side of Moon.

The satellite, named Queqiao (Magpie Bridge), was carried by a Long March-4C rocket that blasted off at 5:28 a.m. from southwest China's Xichang Satellite Launch Center, according to the China National Space Administration (CNSA).

Цитировать(https://img.novosti-kosmonavtiki.ru/29906.jpg)Andrew Jones‏ @AJ_FI (https://twitter.com/AJ_FI) 4 мин. назад (https://twitter.com/AJ_FI/status/998330680810573825)

Chang'e-4: Main space programme contractor CASC confirms successful launch and insertion in lunar transfer orbit for the #Queqiao (https://twitter.com/hashtag/Queqiao?src=hash) relay satellite

(https://img.novosti-kosmonavtiki.ru/164126.jpg)

Цитироватьhttps://img.novosti-kosmonavtiki.ru/240321.jpg
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Цитировать(https://img.novosti-kosmonavtiki.ru/30820.jpg)BG2BHC‏ @bg2bhc (https://twitter.com/bg2bhc) 17 мин. назад (https://twitter.com/bg2bhc/status/998331123846402048)

DSLWP-A/B downlink conformed by PY2SDR then CD3NDC

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Цитировать5月21日5点28分，在我国西昌卫星发射中心，由中国航天科技集团有限公司抓总研制的嫦娥四号中继星"鹊桥"搭乘长征四号丙运载火箭升空。卫星由火箭送入近地点约200公里、远地点约40万公里的地月转移轨道。

ЦитироватьВ 5:28 21 мая из Центра запуска космических аппаратов Сичан в Китае ракетой-носителем "Великий поход-4C" осуществлён запуск космического аппарата-ретранслятора «Цюэцяо» для лунной миссии Chang'E-4, разработанный Китайской аэрокосмической научно-технической корпорацией (КАСК). Спутник выведен на переходную орбиту «Земля-Луна» с перигеем около 200 км и апогеем около 400 000 км.

Цитировать(https://img.novosti-kosmonavtiki.ru/29906.jpg)Andrew Jones‏ @AJ_FI (https://twitter.com/AJ_FI) 3 мин. назад (https://twitter.com/AJ_FI/status/998339540715823104)

And the 448 kg Queqiao Chang'e-4 relay sat before launch

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ЦитироватьВ Китае осуществлен запуск спутника-ретранслятора для лунного зонда "Чанъэ-4"
2018-05-21 07:05:10丨Russian.News.Cn

Сичан, 21 мая /Синьхуа/ -- Китай запустил в понедельник утром спутник-ретранслятор, предназначенный для установки связи между Землей и лунным зондом "Чанъэ-4".

"Чанъэ-4" будет запущен в конце нынешнего года и совершит первую в истории человечества посадку на обратной стороне Луны. Прямая связь с обратной стороны Луны невозможна, что является одним из главных вызовов миссий "Чанъэ-4".

Спутник-ретранслятор под названием "Цюэцяо" будет отвечать за передачу сигналов между наземной станцией и луноходом "Чанъэ-4".

Спутник-ретранслятор был запущен с помощью ракеты-носителя "Чанчжэн-4C" в 5:28 с космодрома Сичан на северо-западе Китая, сообщило Китайское космическое агентство. -0-

ЦитироватьChina launches Queqiao relay satellite to support Chang'e-4 lunar far side landing mission
by Andrew Jones (https://gbtimes.com/authors/658) | May 21, 2018 01:44 | CHINA (https://gbtimes.com/tag/China) ▪ MOON (https://gbtimes.com/tag/moon) ▪ XICHANG (https://gbtimes.com/tag/xichang)

China has successfully launched a lunar communications relay satellite designed to support an unprecedented mission to put a lander and rover on the far side of the Moon in late 2018, as well as carry out pioneering astronomy.

The Chang'e-4 (https://gbtimes.com/channel/features/123) relay satellite, accompanied by two microsatellites (https://gbtimes.com/change-4-lunar-far-side-mission-to-carry-microsatellites-for-pioneering-astronomy), lifted off atop a Long March 4C rocket from the Xichang Satellite Launch Centre at 21:28 UTC on Sunday (05:28 Beijing time, May 21).

Спойлер

The spacecraft was successfully ins erted in to a lunar transfer orbit and separated from the rocket's upper stage, the China Aerospace Science and Technology Corporation (CASC) – the main contractor for the space programme – confirmed just under an hour after launch.

Named 'Queqiao' – referencing a 'Magpie Bridge (https://gbtimes.com/change-4-lunar-far-side-satellite-named-magpie-bridge-from-folklore-tale-of-lovers-crossing-the-milky-way)' from a Chinese folklore of lovers crossing the Milky Way – the relay satellite is now on an 8-to-9 day journey to the second Earth-Moon Lagrange point (http://hyperphysics.phy-astr.gsu.edu/hbase/Mechanics/lagpt.html) (E-M L2) some 60-80,000 kilometres beyond the Moon and nearly half a million kilometres from Earth.

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An animated demonstration of the role of the Queqiao Chang'e-4 lunar relay satellite. CAS

The main aim of the mission is to provide a means of communications for setting down and operating a lunar lander and rover on the far side of the Moon (https://gbtimes.com/change-4-lander-and-rover-undergoing-thermal-vacuum-tests-ahead-of-lunar-far-side-mission), a feat that has never been attempted.

As the Moon is 'tidally locked', taking the same time to go around the Earth as it does to rotate once, the lunar far side never faces the Earth. The landing mission thus requires a communications relay satellite with simultaneous line-of-sight to both the lander and rover on the Moon and terrestrial ground stations.

The gravitationally stable E-M L2 will allow for a stable orbit from which the satellite can perform this task.

Queqiao will make a lunar swing-by to send it towards its intended destination beyond the Moon and use its own propulsion to enter a halo orbit around the Lagrange point.

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Image demonstrating a halo orbit around the second Earth-Moon Lagrange point, from which the Chang'e-4 communications relay satellite will operate. NAOC/CAS

Once in place the 448 kg CAST100 satellite, developed by the China Academy of Space Technology (CAST), a spacecraft maker under CASC, will undergo testing of its 4.2m parabolic antenna and functions ahead of the landing mission which will take place in around six months.

The relay satellite marks China's fifth lunar mission, following two orbiters, Chang'e-1 in 2007 and Chang'e-2 in 2010), the 2013 Chang'e-3 lander and rover, and a 2014 test lunar return mission.

In 2019 China will launch the Chang'e-5 mission to collect 2 kg of samples from the Moon and bring them to Earth.

Today's launch was China's 15th of the year, with the country aiming for a national record of around 40 in 2018 (https://gbtimes.com/china-to-attempt-more-than-40-space-launches-in-2018-including-long-march-5-and-lunar-far-side-missions).

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The Long March 4C rocket at the Xichang Satellite Launch Centre on May 20, 2018. Courtesy of Marc Klein Wolt
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ЦитироватьChina launches relay satellite to explore Moon's far side
Source: Xinhua | 2018-05-21 06:50:11 | Editor: yan

XICHANG, May 21 (Xinhua) -- China launched a relay satellite early Monday to se t up a communication link between Earth and the planned Chang'e-4 lunar probe that will explore the mysterious far side of Moon, which can not be seen fr om Earth.

The satellite, named Queqiao (Magpie Bridge), was carried by a Long March-4C rocket that blasted off at 5:28 a.m. from southwest China's Xichang Satellite Launch Center, according to the China National Space Administration (CNSA).

"The launch is a key step for China to realize its goal of being the first country to send a probe to soft-land on and rove the far side of the Moon," said Zhang Lihua, manager of the relay satellite project.

About 25 minutes after liftoff, the satellite separated from the rocket and entered an Earth-Moon transfer orbit with the perigee at 200 km and the apogee at about 400,000 km. The solar panels and the communication antennas were unfolded.

Queqiao is expected to enter a halo orbit around the second Lagrangian (L2) point of the Earth-Moon system, about 455,000 km from the Earth. It will be the world's first communication satellite operating in that orbit.

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But the mission must overcome many challenges, including multiple adjustments to its orbit and braking near the Moon and taking advantage of the lunar gravity, Zhang said.

In a Chinese folktale, magpies form a bridge with their wings on the seventh night of the seventh month of the lunar calendar to enable Zhi Nu, the seventh daughter of the Goddess of Heaven, to cross and meet her beloved husband, separated from her by the Milky Way.

Chinese scientists and engineers hope the Queqiao satellite will form a communication bridge between controllers on Earth and the far side of the Moon wh ere the Chang'e-4 lunar probe is expected to touch down later this year.

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Monday's launch was the 275th mission of the Long March rocket series.

ЦитироватьChina launches relay satellite for Chang'e-4 lunar probe

CGTN (https://www.youtube.com/channel/UCgrNz-aDmcr2uuto8_DL2jg)

Опубликовано: 20 мая 2018 г.

ЦитироватьA step closer to Human's first experience of the far side of the Moon

CGTN (https://www.youtube.com/channel/UCgrNz-aDmcr2uuto8_DL2jg)

Опубликовано: 20 мая 2018 г.

ЦитироватьChina Launches Relay Satellite to Explore Moon's Far Side

CCTV+ (https://www.youtube.com/channel/UCmv5DbNpxH8X2eQxJBqEjKQ)

Опубликовано: 20 мая 2018 г.

ЦитироватьChina launches relay satellite to explore mysterious far side of Moon

New China TV (https://www.youtube.com/channel/UCHBDXQDmqnaqIEPdEapEFVQ)

Опубликовано: 20 мая 2018 г.

Цитировать(https://img.novosti-kosmonavtiki.ru/29906.jpg)Andrew Jones‏ @AJ_FI (https://twitter.com/AJ_FI) 37 мин. назад (https://twitter.com/AJ_FI/status/998489166135644161)

What goes up...China has successfully launched the exciting #Queqiao (https://twitter.com/hashtag/Queqiao?src=hash) Chang'e-4 lunar relay satellite, but here's the downside: a spent yet toxic Long March 4C stage falling downrange in Jiangkou County, Guzizhou province. No casualties, no property damage.

https://video.twimg.com/tweet_video/DdtYNFJU8AE4xl2.mp4 (https://video.twimg.com/tweet_video/DdtYNFJU8AE4xl2.mp4)
(video (https://video.twimg.com/tweet_video/DdtYNFJU8AE4xl2.mp4) 0:08 )

ЦитироватьВасилий Ратников пишет:
tnt22 , спасибо огромный труд )) очень удобно в одном месте все новости мира по космосу.

ЦитироватьКитай первым в мире отправил в точку Лагранжа L2 спутник связи
Сичан, 21 мая /Синьхуа/ -- Спутник-ретранслятор "Цюэцяо", который запустил Китай рано утром в понедельник, стал первым в мире спутником связи, размещенным в точке Лагранжа L2, сообщили организаторы проекта.
Запуск спутника "Цюэцяо" был произведен в 5:28 утра с космодрома Сичан с помощью ракеты-носителя "Чанчжэн-4C". Этот "сорочий мост" /мост через Млечный Путь, который, по китайскому преданию, образовали сороки, чтобы Ткачиха и Пастух могли встретиться/ - так переводится название спутника - будет обеспечивать связь между Землей и лунным зондом "Чанъэ-4", который планируется запустить в конце нынешнего года на обратную сторону Луны.
Через 25 минут после старта спутник-ретранслятор отделился от ракеты-носителя и вышел на заданную орбиту со следующими параметрами: 200 км - в перигее, 400 тыс. км в апогее. Выход в точку Лагранжа L2 ожидается позже.
Как рассказал главный инженер Китайской лунной программы академик У Вэйжэнь, лунный зонд "Чанъэ-4" совершит первую в истории человечества посадку на обратной стороне Луны, но прямая связь с обратной стороны Луны невозможна, и решить эту проблему поможет спутник-ретранслятор, который будет отвечать за передачу сигналов между "Чанъэ-4" и наземной станцией.
Директор проекта "Цюэцяо", специалист из Китайской корпорации космической науки и техники Чжан Лихуа в свою очередь отметил, что спутник-ретранслятор несет в себе также низкочастотный передатчик нидерландской разработки, позволяющий в перспективе организовать на орбите соответствующие эксперименты.
Это 275-й запуск ракеты-носителя семейства "Чанчжэн", но первый для "Чанчжэн-4" с космодрома Сичан.

Цитировать(https://img.novosti-kosmonavtiki.ru/30998.jpg)CGWIC‏ @CGWIC (https://twitter.com/CGWIC) 4 ч. назад (https://twitter.com/CGWIC/status/998529659494109184)

LM-4C Conduct CE-4 Lunar Exploration Mission Launch with KLCP Payload in the Mission

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ЦитироватьFull Video: China launches relay satellite to explore far side of the Moon

CGTN (https://www.youtube.com/channel/UCgrNz-aDmcr2uuto8_DL2jg)

Опубликовано: 20 мая 2018 г.

ЦитироватьChina's Queqiao satellite carries "large umbrella" into deep space
Source: Xinhua | 2018-05-21 14:31:41 | Editor: Yurou

XICHANG, Sichuan Province, May 21 (Xinhua) -- The relay satellite, launched Monday for China's Chang'e-4 lunar probe, is carrying the largest communication antenna ever used in deep space exploration, according to Chinese experts.

Спойлер

The launch of the satellite Queqiao, or Magpie Bridge, is a key step for China to realize its goal of sending the Chang'e-4 lunar probe to soft-land on the far side of the Moon.

Queqiao, developed by China Spacesat Co., Ltd. under the China Academy of Space Technology (CAST), will be the world's first communication satellite operating in an orbit around the L2 point of the Earth-Moon system to establish a communication link between controllers on Earth and the probe.

Chinese experts designed several antennas for the relay satellite, including one shaped like an umbrella with a diameter of 5 meters, which opened in space after the satellite separated from the carrier rocket.

It must endure temperatures as cold as 230 degrees centigrade below zero. Chinese experts conducted countless experiments during the development of the antenna, said Chen Lan, deputy chief engineer of the Xi'an Branch of CAST.

The satellite is of great scientific and engineering importance in the exploration of the universe, said Zhang Lihua, manager of the relay satellite project.

A reliable long-distance data transmission link is a key technological goal for space experts around the world.

A relay satellite is a type of communication satellite that provides data transmission, observation and control services for other spacecraft.

China has already sent a series of relay satellites into geosynchronous orbit at an altitude of 36,000 km for manned spacecraft.

Queqiao is similar to those relay satellites, but its orbit is more than 10 times farther, which is the main technological difficulty.

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ЦитироватьС помощью спутника "Цюэцяо" Китай проведет эксперимент по лазерному измерению дальности на рекордной дистанции
2018-05-21 20:25:11丨Russian.News.Cn

Сичан /пров. Сычуань/, 21 мая /Синьхуа/ -- Китайские ученые готовы провести эксперимент с лазерным дальномером на максимальной дистанции 460 тыс. км между спутником-ретранслятором для лунного зонда "Чанъэ-4" и наземной обсерваторией. Данный эксперимент призван заложить основу для обнаружения гравитационных волн в космосе.

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Китай в понедельник осуществил успешный запуск спутника-ретранслятора "Цюэцяо", который должен будет выйти в точку гравитационного равновесия Земли и Луны L2 /одна из точек Лагранжа/. Он предназначен для установки связи между Землей и лунным зондом "Чанъэ-4", который будет запущен в конце нынешнего года и совершит первую в истории человечества посадку на обратной стороне Луны.

Ученые также готовы использовать спутник-ретранслятор для проведения эксперимента с лазерным дальномером на максимальном расстоянии в 460 тыс. км -- рекордной дистанции для подобного рода экспериментов в истории человечества, заявил глава проекта спутника-ретранслятора Чжан Лихуа.

Как сообщается, Китай успешно осуществил лазерное измерение расстояния между Луной и Землей 22 января этого года с использованием 1,2-метрового телескопа, установленного в обсерватории в юго-западной провинции Юньнань. Измерение удалось совершить благодаря сигналам лазерных импульсов, отраженных от ретро-рефлектора, установленного американским космическим кораблем "Аполлон-11" на поверхности Луны более чем 40 лет назад.

Чтобы измерить дистанцию, ученые подсчитали время, в течение которого лазерный импульс, посланный с наземной станции, достиг ретро-рефлектора на Луне и вернулся обратно.

На данный момент лишь США, Франция и Китай освоили технологии лазерного измерения расстояния до Луны.

Ожидается, что спутник "Цюэцяо"с разработанным китайским университетом имени Сунь Ятсена рефлектором расширит диапазон лазерного измерения расстояния до нового рекордного уровня.

Между тем задача не обещает быть легкой. Поскольку спутник будет летать с постоянной высокой скоростью, лазерный луч с Земли будет чрезвычайно трудно направить на рефлектор на спутнике, находящийся на расстоянии в 460 тыс. км.

Китайская научная программа по обнаружению гравитационных волн в космосе инициирована академиком Академии наук Китая, ректором университета имени Сунь Ятсена Ло Цзюнем. Для осуществления этой программы необходимы технологии лазерного измерения дальности.

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Цитировать(https://img.novosti-kosmonavtiki.ru/29906.jpg)Andrew Jones‏ @AJ_FI (https://twitter.com/AJ_FI) 4 ч. назад (https://twitter.com/AJ_FI/status/998903337172029440)

A few more images of debris from the Long March 4C rocket used to send the #queqiao (https://twitter.com/hashtag/queqiao?src=hash) Chang'e-4 relay satellite to the Moon.

(https://img.novosti-kosmonavtiki.ru/164304.jpg)

Спойлер

(https://img.novosti-kosmonavtiki.ru/164306.jpg)(https://img.novosti-kosmonavtiki.ru/164307.jpg)(https://img.novosti-kosmonavtiki.ru/164305.jpg)

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Цитировать(https://img.novosti-kosmonavtiki.ru/31400.jpg)UHF Satcom‏ @uhf_satcom (https://twitter.com/uhf_satcom) 26 мин. назад (https://twitter.com/uhf_satcom/status/998989304369221632)

Chinese DSLWP-B on S-Band, a great signal on 2275.211MHz.

(https://img.novosti-kosmonavtiki.ru/163723.jpg)

Цитировать(https://img.novosti-kosmonavtiki.ru/186381.jpg)Quan-Zhi Ye‏ @Yeqzids (https://twitter.com/Yeqzids) 12 мин. назад (https://twitter.com/Yeqzids/status/998994161033334784)

#Queqiao (https://twitter.com/hashtag/Queqiao?src=hash) imaged by Xingming Observatory in China about an hour ago. Also detected by @fallingstarIfA (https://twitter.com/fallingstarIfA) at about the same time... caused a small fuss in the NEO mailing group as being a potential impactor.

https://video.twimg.com/tweet_video/Dd0iO7BUwAAg5iy.mp4 (https://video.twimg.com/tweet_video/Dd0iO7BUwAAg5iy.mp4)
(Video (https://video.twimg.com/tweet_video/Dd0iO7BUwAAg5iy.mp4) 0:03)

Цитировать(https://img.novosti-kosmonavtiki.ru/185571.jpg)supertrack‏ @supertrack_it (https://twitter.com/supertrack_it) 24 ч. назад (https://twitter.com/supertrack_it/status/998970614366064640)

#QUEQIAO (https://twitter.com/hashtag/QUEQIAO?src=hash) signal on 2234.576 MHz (downconverter L.O. 916 MHZ)

(https://img.novosti-kosmonavtiki.ru/163726.jpg)

Цитировать(https://img.novosti-kosmonavtiki.ru/185571.jpg)supertrack‏ @supertrack_it (https://twitter.com/supertrack_it) 2 мин. назад (https://twitter.com/supertrack_it/status/999331911246983169)

#QUEQIAO (https://twitter.com/hashtag/QUEQIAO?src=hash) moon relay satellite signal on 2234.582 MHz, low doppler

(https://img.novosti-kosmonavtiki.ru/163798.jpg)

ЦитироватьQueqiao update: Tracking the Chang'e-4 relay satellite on its way to the Moon
by Andrew Jones (https://gbtimes.com/authors/658) | May 23, 2018 18:46 | CHINA (https://gbtimes.com/tag/China) ▪ GBTIMES (https://gbtimes.com/tag/gbtimes) ▪ MOON (https://gbtimes.com/tag/moon)

(https://img.novosti-kosmonavtiki.ru/191954.png)
A rendering of the Queqiao Chang'e-4 lunar relay satellite. CASC

China launched its Queqiao Chang'e-4 relay satellite towards the Moon early on Monday Beijing time, but there have been no official updates since trans-lunar injection. So, you might want to ask where is Queqiao now and is it operating?

According to a Chinese social media post (https://www.weibo.com/6528178851/GhO7qhdQR?from=page_1005056528178851_profile&wvr=6&mod=weibotime) the lunar relay satellite, which launched  (https://gbtimes.com/china-launches-queqiao-relay-satellite-to-support-change-4-lunar-far-side-landing-mission)late on May 20, made its first trajectory correction manoeuvre on May 22, which is a standard part of a journey to the Moon, but no further details were offered.

But both Queqiao (https://gbtimes.com/heres-what-you-need-to-know-about-chinas-change-4-relay-satellite-launch) and its Longjiang-1 and -2 microsatellite companions have been actively and inadvertently tracked on their way through cis-lunar space to the Moon by amateurs and professionals alike, providing insights into the spacecraft's journey and functions.

Спойлер

Ye Quanzhi, a postdoctoral astronomer at Caltech/IPAC who searches for small bodies such as asteroids and comets, tweeted yesterday that Queqiao had been spotted by Xingming Observatory in China, noting that its appearance also created a stir.

Both Queqiao and Longjiang-1 and -2 microsatellites (https://gbtimes.com/change-4-lunar-far-side-mission-to-carry-microsatellites-for-pioneering-astronomy), also known as DSLWP-A and -B, have also been tracked by amateur radio and satellite tracking enthusiasts.

(https://img.novosti-kosmonavtiki.ru/163723.jpg)

The UHF Satcom account is run by Paul Marsh, an amateur satellite tracker who in early 2014 picked up a downlink  (https://twitter.com/uhf_satcom/status/433699648096595969)from Yutu ('Jade Rabbit') from theChang'e-3 mission (https://gbtimes.com/chinas-telescope-moon-still-working-and-could-do-30-years), proving that the rover was still operational despite press reports that it had 'died'.

Marsh has also seen S-band downlinks from Queqiao. S-band refers to a frequency range within the microwave band of the electromagnetic spectrum, and will be used for communications between Earth and the relay satellite. X-band will be used for communications between Queqiao and the lander and rover  (https://gbtimes.com/change-4-lander-and-rover-undergoing-thermal-vacuum-tests-ahead-of-lunar-far-side-mission)on the lunar far side, following the planned landing in late 2018, but such signals have not yet been detected.

DSLWP-B was set to make a trajectory correction manoeuvre at 22:55 UTC (https://twitter.com/bg2bhc/status/999011216340090880)on Tuesday, though this was not confirmed (https://twitter.com/supertrack_it/status/999212610674417664), while others have also picked up signals from Queqiao.

(https://img.novosti-kosmonavtiki.ru/163726.jpg)

Where is Queqiao now?

According to data computed (https://www.projectpluto.com/pluto/mpecs/18045a.htm) by Bill Gray, an independent orbit analyst, Queqiao was close to 333,000 kilometres away from Earth at time of publishing on May 23 (with the average Earth-Moon distance being 384,400 km).

Queqiao is expected to reach and swing-by the Moon on May 25, before heading to its destination, the second Earth-Moon Lagrange point.

Gray told gbtimes that Queqiao will need to perform a manoeuvre to slow its speed as it comes close to the Moon in order to send it towards its intended destination. If not, Queqiao will leave the Moon with as much energy as when it arrived, and go back into orbit around the Earth.

"We now have Queqiao going past the moon at 110 +/- 54 km at 13:41 UT on 25 May. That's based just on tracking it optically, though, with no knowledge of when it might manoeuvre," Gray said.

The expected manoeuvre is the next key moment in the Chang'e-4 mission, which ultimately aims to help operate a lander and rover on the lunar far side.

(https://img.novosti-kosmonavtiki.ru/191955.gif)
Animation demonstrating the trajectory of the Queqiao Chang'e-4 lunar relay satellite, followed by the lander and rover six months later. CASC

[свернуть]

Цитировать(https://img.novosti-kosmonavtiki.ru/67516.jpg)Jonathan McDowell‏Подлинная учетная запись @planet4589 (https://twitter.com/planet4589) 2 ч. назад (https://twitter.com/planet4589/status/999506665581023233)

The Queqiao communications relay spacecraft, the two Longqiao science satellites, and the CZ-4C third stage rocket are now about 120,000 km from the Moon and will enter the lunar sphere of influence about 2000 UTC.

2 ч. назад (https://twitter.com/planet4589/status/999506791464652800)

Queqiao will make a 100 km flyby above the lunar surface at 1340 UTC May 25 before heading out to EML2.

2 ч. назад (https://twitter.com/planet4589/status/999507075288981504)

The CZ-4C third stage will make a 9900 km flyby of the Moon at 1403 UTC May 25 and end up in a 17000 x 444000 km x 14.5 deg orbit in the Earth-Moon system

2 ч. назад (https://twitter.com/planet4589/status/999507470199476225)

The Longjiang 1 and 2 science satellites are expected to be in a 200 km lunar flyby trajectory and will perform braking burns to enter 200 x 9000 km lunar orbits, inclination unknown

Цитировать(https://img.novosti-kosmonavtiki.ru/67516.jpg)Jonathan McDowell‏Подлинная учетная запись @planet4589 (https://twitter.com/planet4589) 8 мин.8 минут назад (https://twitter.com/planet4589/status/999867313691283458)


Queqiao is now 37000 km from the Moon, under 10 hours to flyby closest approach. It should reach EML2 around 0645 UTC May 26.

ЦитироватьAstro Cat пишет:
Бгг. Судя по траектории ретранслятора по последнему ролику точка Лагранжа L2 обладает притяжением? Вокруг нее и будет вращаться ретранслятор? )))

Цитировать(https://img.novosti-kosmonavtiki.ru/29906.jpg)Andrew Jones‏ @AJ_FI (https://twitter.com/AJ_FI) 52 мин. назад (https://twitter.com/AJ_FI/status/1000035959780642816)

Queqiao Chang'e-4 satellite performs Moon flyby, makes successful braking manoeuvre

Цитировать(https://img.novosti-kosmonavtiki.ru/29906.jpg)Andrew Jones‏ @AJ_FI (https://twitter.com/AJ_FI) 32 мин. назад (https://twitter.com/AJ_FI/status/1000041910294196227)

While #queqiao (https://twitter.com/hashtag/queqiao?src=hash) is on its way to the 2nd Earth-Moon Lagrange point, the Longjiang-1 & -2 microsatellites (aka DSLWP-A & B) have successfully entered lunar orbit.

Цитировать(https://img.novosti-kosmonavtiki.ru/30820.jpg)BG2BHC‏ @bg2bhc (https://twitter.com/bg2bhc) 33 мин. назад (https://twitter.com/bg2bhc/status/1000041106279550976)

DSLWP-B now orbiting moon @AMSAT (https://twitter.com/AMSAT) @AmsatUK (https://twitter.com/AmsatUK) @cgbassa (https://twitter.com/cgbassa) @n6rfm (https://twitter.com/n6rfm) @scott23192 (https://twitter.com/scott23192) @ea4gpz (https://twitter.com/ea4gpz) @HAMSATNL (https://twitter.com/HAMSATNL) @HarryKeizer (https://twitter.com/HarryKeizer)

Цитировать(https://img.novosti-kosmonavtiki.ru/67577.jpg)Cosmic Penguin‏ @Cosmic_Penguin (https://twitter.com/Cosmic_Penguin) 2 ч. назад (https://twitter.com/Cosmic_Penguin/status/1000027570014797825)

The perilune burn has been successfully performed at 13:32 UTC and has sent the S/C to a transfer orbit towards EM-L2.

2 ч. назад (https://twitter.com/Cosmic_Penguin/status/1000027838341251078)

Source: https://weibo.com/6528178851/GikE78yqy ... (https://t.co/BR8tDz3QiD)?

ЦитироватьQueqiao Chang'e-4 satellite performs Moon flyby, makes successful braking manoeuvre
by Andrew Jones (https://gbtimes.com/authors/658) | May 25, 2018 18:27 | CHINA (https://gbtimes.com/tag/China) ▪ BEIJING (https://gbtimes.com/tag/beijing) ▪ MOON (https://gbtimes.com/tag/moon)

(https://img.novosti-kosmonavtiki.ru/191953.jpg)
A rendering of the Queqiao Chang'e-4 lunar satellite performing its communications relay functions beyond the Moon. Chinese Academy of Sciences

The Queqiao Chang'e-4 relay satellite has passed the Moon and successfully performed a propulsive manoeuvre to slow itself and send it towards its intended destination beyond the Moon.

The Beijing Aerospace Control Centre (BACC) issued the command at 21:32 Beijing time (13:32 UTC), and by 21:46 confirmed through telemetry that Queqiao had performed the burn and entered a transfer orbit towards the second Earth-Moon Lagrange point, People's Liberation Army Daily reported.

The spacecraft passed the Moon at 100 km above the surface at closest approach. Failure to perform the braking manoeuvre would have seen the spacecraft head back towards the Earth.

Спойлер

The Queqiao satellite was launched on late on Sunday (https://gbtimes.com/china-launches-queqiao-relay-satellite-to-support-change-4-lunar-far-side-landing-mission), and its main role is to act as a communications relay between the Earth and a lander and rover than China aims to launch to the far side of the Moon late this year.

It also carries a pioneering low-frequency astronomy instrument that will attempt to detect a signal from the cosmic dark ages.

For latest news and developments on the mission, see our feature on China's Chang'e-4 mission to the far side of the Moon (https://gbtimes.com/channel/features/123)

(https://img.novosti-kosmonavtiki.ru/191951.gif)
An animated demonstration of the role of the Queqiao Chang'e-4 lunar relay satellite. CAS

[свернуть]

ЦитироватьChinese relay satellite brakes near moon for entry into desired orbit
Source: Xinhua | 2018-05-26 01:28:23 | Editor: yan

BEIJING, May 25 (Xinhua) -- A Chinese relay satellite Friday braked near the Moon, completing a vital step before entering a desired orbit, according to the China National Space Administration.

The satellite, Queqiao, braked 100 km above the surface of the Moon in line with instructions from a ground control center in Beijing, and then entered a transfer orbit from the moon to the second Lagrangian (L2) point of the Earth-Moon system.

"There was only a short window for the braking," said Zhang Lihua, project manager of the mission. "And Queqiao had only one chance due to limited fuel."

Спойлер

The relay satellite was launched Monday to set up a communication link between Earth and the planned Chang'e-4 lunar probe that will explore the Moon's mysterious far side.

The satellite is expected to adjust orbit several times before it reaches a halo orbit around the L2 point, about 455,000 km from the Earth.

It will be the world's first communication satellite operating in that orbit.

[свернуть]

Цитировать(https://img.novosti-kosmonavtiki.ru/67516.jpg)Jonathan McDowell‏Подлинная учетная запись @planet4589 (https://twitter.com/planet4589) 11 мин. назад (https://twitter.com/planet4589/status/1000831214603898880)

So it looks like Longjiang-2 (DSLWP-B) is in a 350 x 13800 km x 21 deg lunar orbit. Longjiang-1 seems to have failed on May 21 and presumably remains in distant Earth orbit following its lunar flyby

ЦитироватьQueqiao update: Chang'e-4 lunar relay satellite establishing halo orbit after approaching Lagrange point
by Andrew Jones (https://gbtimes.com/authors/658) | Jun 01, 2018 09:58 | CHINA (https://gbtimes.com/tag/China) ▪ MOON (https://gbtimes.com/tag/moon) ▪ CHINA'S SPACE PROGRAM (https://gbtimes.com/tag/china%27s%20space%20program)

(https://static.gbtimes.com/uploads/old/2017/05/05/chang-e-5t1-moon-far-side-2014-cas-crop.jpg)
A view of the far side of the Moon and the distant Earth, captured by the service module for the 2014 Chang'e 5-T1 mission. Chinese Academy of Sciences

It has been a week since the Queqiao Chang'e-4 lunar relay satellite made its lunar swing-by, sending it on a transfer trajectory towards the second Earth-Moon Lagrange Point (EML2). There have been no official updates fr om China, so wh ere is the spacecraft now?

Спойлер

Having launched (https://gbtimes.com/china-launches-queqiao-relay-satellite-to-support-change-4-lunar-far-side-landing-mission) late on May 20 UTC, Queqiao made its lunar swing-by on May 25, performing a braking burn (https://gbtimes.com/queqiao-change-4-satellite-performs-moon-flyby-makes-successful-braking-manoeuvre) at 13:32 UTC to send the communications satellite towards EML2, some 60-80,000 km beyond the Moon.

EML2 is one of five libration points in the Earth-Moon system that allow a much smaller third body to orbit while maintaining its position relative to the larger two, making it a perfect place for Queqiao to perform its main objective.

Queqiao should have approached the EML2 point by May 29 after two orbital corrections, but no updates have come from China. This has brought confusion, but making the distinction between reaching EML2 and establishing the desired orbit around it helps bring clarity.

On approaching EML2, assuming all is well, Queqiao will have begun manoeuvres required to obtain a halo orbit (or more accurately a Lissajous orbit (https://en.wikipedia.org/wiki/Lissajous_orbit) shown below) around EML2 with a radius sufficient to allow it constant line of sight with both tracking stations on the Earth and the lunar far side, on which a lander and rover are planned to set down in late 2018.

(https://img.novosti-kosmonavtiki.ru/191961.gif)
A demonstration of the Lissajous/halo orbit to be used by the Queqiao Chang'e-4 relay satellite mission. CASC

According to the illustration below - showing the planned trajectory, manoeuvres and orbit for Queqiao - the spacecraft will have made a gravitational capture manoeuvre around May 29 to begin a 15-day segment of its journey to obtain a halo orbit around EML2, which is its mission orbit.

This fits with the preliminary flight profile design outlined in an article published in Science China - Technological Sciences in 2017 titled An Overview of the Mission and Technical Characteristics of Change'4 Lunar Probe (http://engine.scichina.com/publisher/scp/journal/SCTS/60/5/10.1007/s11431-016-9034-6?slug=full%20text)authored by senior figures from the China Academy of Space Technology (CAST) and the Institute of Spacecraft System Engineering in Beijing.

(https://img.novosti-kosmonavtiki.ru/191959.jpg)
A chart laying out the trajectories for the Queqiao Chang'e-4 lunar relay satellite to obtain a halo orbit around the second Earth-Moon Lagrange point.

The paper outlined three transfer options for arriving at EML2, with the lunar swing-by chosen over direct and low-energy transfers. The flight profile outlines that the spacecraft will make three orbital corrections after the EML2 capture phase to establish the halo orbit.

According to the outlined schedule, the halo orbit may not be obtained until mid-June, which may also be the next time we get an official Queqiao mission update. Hopefully this will include images from the onboard cameras (https://gbtimes.com/the-queqiao-change-4-lunar-relay-satellite-could-return-more-cool-images-like-this).

We are also awaiting an update on the status of the one of two microsatellites (Longjiang-1/-2 or DSLWP-A/B) launched along with Queqiao. While Longjiang-2 successfully entered an elliptical lunar orbit, there has been silence from Longjiang-1 (https://gbtimes.com/change-4-lunar-microsatellite-may-be-lost-queqiao-continues-toward-lagrange-point-beyond-moon).

(https://img.novosti-kosmonavtiki.ru/191960.png)
The Longjiang-1 and -2 (aka DSLWP-A/B) microsatellites launched to the Moon with the Queqiao Chang'e-4 lunar relay satellite on May 20 UTC, 2018. Harbin Institute of Technology

Landing, astronomy and...sample return?

Queqiao (https://gbtimes.com/heres-what-you-need-to-know-about-chinas-change-4-relay-satellite-launch) is expected to be able to operate in this orbit for at least three years, with the fuel requirement for station keeping at EML2 being relatively low. It will use a 4.2 m diameter parabolic antenna and s- and x-band frequencies to facilitate data relay between the Earth and far side of the Moon.

The lander and rover for the mission, to be launched on a Long March 3B from Xichang in November or December, in March underwent thermal vacuum testing (https://gbtimes.com/change-4-lander-and-rover-undergoing-thermal-vacuum-tests-ahead-of-lunar-far-side-mission), which are the last of a range of space environment tests which began in January (https://gbtimes.com/testing-on-chinas-change-4-lunar-far-side-lander-and-rover-steps-up-in-preparation-for-launch?feature=chinas-change-4-mission-to-the-far-side-of-the-moon) before the Chang'e-4 spacecraft can leave the Assembly, Integration and Testing (AIT) Centre.

After the initial landing and roving section of the mission, with the rover designed to operate for at least three months, a low-frequency radio astronomy antenna, NCLE (https://www.astron.nl/r-d-laboratory/ncle/netherlands-china-low-frequency-explorer-ncle), will be deployed to determine the activity in the solar system at frequencies between 1-30 MHz, and eventually attempt to detect a signal from the cosmic 'Dark Ages' (http://www.sciencemag.org/news/2018/05/china-s-moon-mission-will-probe-cosmic-dark-ages).

The relay satellite could facilitate future international missions, or a lunar far side sample return with Chang'e-6 (https://gbtimes.com/ten-years-ago-china-began-its-long-march-to-the-moon-and-its-plans-are-evolving), should the 2019 near side Chang'e-5 sample return mission (https://gbtimes.com/chinas-change-5-lunar-sample-return-mission-to-launch-in-2019) be successful.

(https://img.novosti-kosmonavtiki.ru/192020.jpg)
China's Chang'e-3 lander and Yutu (Jade Rabbit) rover operating on the Moon after landing in late 2013.

[свернуть]

Цитировать(https://img.novosti-kosmonavtiki.ru/67516.jpg)Jonathan McDowell‏Подлинная учетная запись @planet4589 (https://twitter.com/planet4589) 23 мин. назад (https://twitter.com/planet4589/status/1002929442854002688)

Report that DSLWP-A1 may not be dead after all. (anyone want to translate the Chinese?). What orbit it's in is another matter...

Цитировать(https://img.novosti-kosmonavtiki.ru/186113.jpg)liuyi‏ @LiuyiYiliu (https://twitter.com/LiuyiYiliu) 5 ч. назад (https://twitter.com/LiuyiYiliu/status/1002859309389131776)

message from Harbin Institute of Technology , confirmed already already received the signal from Longjiang1 (DSLWP-A1).

(https://img.novosti-kosmonavtiki.ru/164641.jpg)

(https://img.novosti-kosmonavtiki.ru/185577.jpg)Joe‏ @zzbar (https://twitter.com/zzbar) 17 мин. назад (https://twitter.com/zzbar/status/1002931044381810690)

В ответ @planet4589 (https://twitter.com/planet4589)

Received signal from both Longjiang1 and 2, everything normal, the two has not yet synchronized, Can inhale now!

ЦитироватьChinese data relay satellite nears post over far side of the moon
June 3, 2018 (https://spaceflightnow.com/2018/06/) | Stephen Clark (https://spaceflightnow.com/author/stephen-clark/)

(https://img.novosti-kosmonavtiki.ru/144401.jpg)
Artist's illustration of the Queqiao spacecraft. Credit: China Aerospace Science and Technology Corp.

A Chinese communications satellite carrying a Dutch radio astronomy instrument launched last month is expected to maneuver into position around a gravitationally-stable point beyond the moon in the coming days, ready to relay telemetry and data between Earth and the Chang'e 4 lander set to attempt the first landing on lunar far side late this year.

Launched at 2128 GMT (5:28 p.m. EDT) May 20 from China's Xinhua space center aboard a Long March 4C rocket, the relay probe completed an engine firing as it flew around 60 miles (100 kilometers) from the moon May 25, setting a course for a perch around 280,000 miles (450,000 kilometers) from Earth.

The relay craft is named Queqiao, which means "magpie bridge" and comes from a Chinese folk tale in which a flock of birds form a bridge across the galaxy to reunite two lovers.

Queqiao will park itself in a "halo" orbit around the Earth-moon L2 Lagrange point around 37,000 miles (60,000 kilometers) beyond the moon. At that location, the combined effect from gravity from Earth and the moon will keep Queqiao at roughly the same distance as the moon completes each 28-day orbit.

Спойлер

China developed the Queqiao spacecraft, which weighed roughly 900 pounds (400 kilograms) fully fueled for launch, to link ground controllers and scientists with the Chang'e 4 lander and rover, the country's next robotic mission to the moon.

(https://img.novosti-kosmonavtiki.ru/144570.jpg)
The Queqiao spacecraft launched May 20 (May 21 in China) aboard a Long March 4C rocket. Credit: Xinhua

Chang'e 4 is scheduled for launch in November or December, and it will attempt the first soft landing on the far side of the moon. A direct radio signal between ground controllers and the Chang'e 4 spacecraft will be impossible on lunar far side, which always faces away from Earth.

The Queqiao relay craft will pass data between mission control and Chang'e 4 during the lander's final descent, and during the rover's drives after touchdown. Carrying a 13.8-foot (4.2-meter) deployable antenna which unfurled shortly after launch, the communications satellite will connect with rover and lander in an X-band frequency, and beam signals to a ground station on Earth in S-band.

After its lunar flyby maneuver May 25, Queqiao is expected to arrive on station in its halo orbit around June 10, according to information released by the China Aerospace Science and Technology Corp.

Then ground controllers will ready Queqiao for its role in Chang'e 4's landing late this year.

Using spare hardware built for China's Chang'e 3 lunar lander and rover, which arrived at the moon in December 2013, Chang'e 4 will target Von Karman crater, an impact site located in the moon's South Pole-Aitken basin.

Some of Chang'e 3's science instruments are still functioning, but the rover ceased driving a few weeks after landing. The Chang'e 3 rover, named Yutu and designed to drive up to 6 miles (10 kilometers), traveled around 374 feet (114 meters) before losing its mobility, according to Chinese scientists.

"There are plenty of successful missions with successful landings on the near side of the moon, including Chang'e 3 in Mare Imbrium," said Jun Huang from the Planetary Science Institute at the China University of Geosciences, in a presentation to U.S. scientists in March at the Lunar and Planetary Science Conference in Texas. "This mission has lasted for nearly five years, and it increased our knowledge about the moon greatly, however, we don't have (until Chang'e 4) a mission dedicated to taking precision mesurements of the far side of the moon."

(https://img.novosti-kosmonavtiki.ru/144648.jpg)
Diagram of the Queqiao spacecraft's data relay function between Earth and the Chang'e 4 lander and rover. Credit: CASC

There are some key differences between Chang'e 3 and Chang'e 4. For example, the lander heading for the far side of the moon will not carry a robotic arm or an Active Particle X-ray Spectrometer, an instrument capable to measuring the chemical elements in lunar rocks and soil.

In addition to a suite of cameras on both the stationary lander and rover, the mission aims to deliver a new set of sensors to the lunar surface, some of which are provided by European scientists.

The landing module, which will make a rocket-powered landing on the moon like Chang'e 3, will carry a low frequency radio spectrometer developed by Chinese scientists for astrophysics research. A German-developed neutron and dosimetry instrument will measure radiation levels at the Chang'e 4 landing site, collecting data that could be useful in planning human exploration of the lunar far side, studying solar activity, and gauging the underground water content in Von Karman crater.

The Chang'e 4 rover will host a ground-penetrating radar to study geologic layers buried under the landing site, and a visible and near-infrared spectrometer to gather data on soil composition. Chinese officials approved the addition of a Swedish instrument to study the interaction between the solar wind and the lunar surface, which is not shielded by an atmosphere from the bombardment of charged particles originating at the sun.

Chang'e 4 will also deliver to the moon a student-designed carrier containing potato seeds and silkworm eggs. University students and scientists will monitor the growth of the organisms, which will be housed inside a chamber and fed natural light and nutrients once on the lunar surface.

As soon as next year, China plans to launch Chang'e 5, a robotic mission to retrieve lunar samples and return them to Earth.

(https://img.novosti-kosmonavtiki.ru/143775.jpg)
A camera aboard the Chang'e 3 lander captured this view of the Yutu rover in December 2013. Credit: Chinese Academy of Sciences/NAOC/Science and Application Center for Moon and Deepspace Exploration

Science and technological experiments from the Netherlands and Saudi Arabia are flying on the Queqiao relay craft and two lunar microsatellites that accompanied it to the moon, preceding the international instrument complement on Chang'e 4.

A low-frequency radio receiver on Queqiao was built by a consortium of Dutch companies and research institutions to test the feasibility of using the unique environment near the far side of the moon to probe the ancient universe.

The Dutch payload riding piggyback on the Queqiao mission was developed in less than two years, an unusually fast time for a space instrument, according to Heino Falcke, a radio astronomer at Radboud University in the Netherlands who led development of the Netherlands-China Low-Frequency Explorer.

"This is as much a technological experiment as it is a sociological experiment in collaborating with our Chinese partners," Falcke said in an interview with Spaceflight Now. "This is, to my understanding, the first Western experiment they've had in their exploration program."

It turns out the far side of the moon, and the region of space around it, is prime real estate for astronomers who seek to study a time a few hundred million years after the Big Bang, before the first stars were born, a period known as the cosmic dark ages.

"You had the Big Bang. The universe was cooling, and particles were coming into existence, and at some point it became cool enough that hydrogen was formed, and that's when the universe became optically thin," Falcke said. "So you had this hot plasma, which goes into the neutral hydrogen phase.

"That's 390,000 years after the Big Bang, and that's when you get the cosmic microwave background radiation," he said, referring to the faint heat fingerprint left over from the Big Bang. "Then, for a few hundred million years, there's essentially nothing but this atomic hydrogen, and there's nothing to be seen. It's just an ocean of hydrogen, more or less, with some dark matter in the background. No stars, no planets, no heat or light, except the cosmic microwave background radiation."

Astronomers need to detect low-frequency waves to investigate this part of the universe's ancient past, and Earth's atmosphere blocks most of the signals from reaching ground-based radio observatories. And interference from Earth's own radio emissions introduce noise to listening posts that could be launched into Earth orbit.

The far side of the moon is a "radio quiet" zone free of such interference, and the Netherlands-China Low-Frequency Explorer, or NCLE, aboard the Queqiao spacecraft will demonstrate the potential of sending future radio astronomy missions to such an observation post.

(https://img.novosti-kosmonavtiki.ru/144649.jpg)
Three antennas for the Queqiao spacecraft's Netherlands-China Low-Frequency Explorer stowed before launch. Credit: ASTRON

The idea for the Dutch-Chinese collaboration hatched in 2015 during a trade mission to China by Dutch King Willem-Alexander, Falcke said. By early 2016, the plans came together and Dutch scientists received the formal go-ahead for the roughly $3.5 million (3 million euro) instrument.

But teams had to design and build the instrument, which includes three extendable low-frequency antennas, without the use of U.S. components. U.S. export restrictions prevent U.S.-built space hardware from launching on Chinese rockets.

Falcke said the antennas for such an experiment would typically purchased from a U.S. contractor.

"They're the main experts for low-frequency antennas," Falcke said. "But that wasn't possible, so we had to build them from scratch."

The three monopole antennas will unfurl to a length of more than 15 feet — about 5 meters — in early 2019, once the Queqiao spacecraft's prime data relay mission is complete, allowing the radio astronomers' tech demo campaign to commence.

Lessons learned from the Dutch-led experiment could help scientists and engineers design more sensitive equipment to fly on future spacecraft, but Falcke said the payload on Queqiao might shed some light on astronomers' long-held questions about the nature of the universe before the first stars formed.

"If we integrate long enough, we could see it," Falcke said. "The reason why I'm careful to not claim that we can is because we have not demonstrated that we can do this ... It's a new receiver, of course, but we are on this satellite on which we don't really know its properties, its electromagnetic properties. It has not been particularly designed to be very radio quiet."

Two microsatellites, dubbed Longjiang 1 and Longjiang 2, accompanied Queqiao on its May 20 launch.

Developed by the Harbin Institute of Technology, the twin Longjiang spacecraft, also known by the acronym DSLWP, were programmed to loop into orbit around the moon as Queqiao flew by en route to its operating station beyond the moon.

Both microsatellites carry amateur radio transmitters, the first such payloads to fly in lunar orbit. But engineers and enthusiasts listening to the Longjiang radio broadcasts apparently lost contact with one of the satellites — Longjiang 1, or DSLWP-A — shortly after it was to enter orbit around the moon, according to a GB Times report.

Amateur radio enthusiasts later reported detecting signals from both microsatellites, suggesting they are healthy after arriving in lunar orbit.

The twin Longjiang spacecraft are designed to fly in formation to validate technologies for low-frequency radio astronomy observations, similar to the objectives of the Dutch experiment aboard the Queqiao relay craft.

The microsatellites also carry optical cameras from Saudi Arabia, another example of the Chinese space program's expanding portfolio of international partnerships.

[свернуть]

ЦитироватьRelay satellite for Chang'e-4 lunar probe enters desired orbit
Source: Xinhua | 2018-06-14 11:55:14 | Editor: Yurou

BEIJING, June 14 (Xinhua) -- The relay satellite for the planned Chang'e-4 lunar probe, which is expected to land softly on the far side of the Moon at the end of this year, has entered its mission orbit, the China National Space Administration announced Thursday.

The satellite, named Queqiao, or Magpie Bridge, launched on May 21, entered the Halo orbit around the second Lagrangian (L2) point of the Earth-Moon system about 65,000 km from the Moon at 11:06 a.m. Beijing Time Thursday after a journey of more than 20 days.

"The satellite is the world's first communication satellite operating in that orbit, and will lay the foundation for the Chang'e-4, which is expected to become world's first probe soft-landing and roving on the far side of the Moon," said Zhang Hongtai, president of the China Academy of Space Technology.

ЦитироватьСпутник-ретранслятор для лунного зонда "Чанъэ-4" вышел на ожидаемую орбиту
2018-06-14 14:20:11丨Russian.News.Cn

Пекин, 14 июня /Синьхуа/ -- Спутник-ретранслятор для лунного зонда "Чанъэ-4", который будет запущен в конце нынешнего года и, как ожидается, совершит мягкую посадку на обратной стороне Луны, вышел на намеченную орбиту, сообщило в четверг Государственное космическое управление КНР.

Спутник "Цюэцяо" /"Сорочий мост"/, который был запущен 21 мая с космодрома Сичан на юго-западе Китая, вышел на гало-орбиту вокруг точки Лагранжа L2 системы Земля-Луна примерно в 65 тыс. км от Луны 14 июня в 11:06 по пекинскому времени.

Это первый в мире спутник связи, который находится на этой орбите и заложит фундамент для миссии лунного зонда "Чанъэ-4", который предположительно совершит первую в истории человечества мягкую посадку на обратной стороне Луны, сказал президент Китайской академии космических технологий /CAST/ Чжан Хунтай.

Спойлер

Как сообщается, лунный зонд "Чанъэ-4" совершит первую в истории человечества посадку на обратной стороне Луны, но прямая связь с обратной стороны Луны невозможна, и решить эту проблему поможет спутник-ретранслятор, который будет отвечать за передачу сигналов между "Чанъэ-4" и наземной станцией.

[свернуть]

ЦитироватьRelay satellite for Chang'e-4 lunar probe enters orbit
Source: Xinhua | 2018-06-14 15:00:38 | Editor: mmm

BEIJING, June 14 (Xinhua) -- The relay satellite for the planned Chang'e-4 lunar probe, which is expected to land on the far side of the Moon at the end of the year, has entered orbit, the China National Space Administration (CNSA) announced Thursday.

The satellite named Queqiao (Magpie Bridge) launched on May 21 and entered the Halo orbit around the second Lagrangian (L2) point of the Earth-Moon system, about 65,000 km fr om the Moon, at 11:06 a.m. Thursday after a journey of more than 20 days.

"The satellite is the world's first communication satellite operating in that orbit, and will lay the foundation for the Chang'e-4, which is expected to become the world's first soft-landing, roving probe on the far side of the Moon," said Zhang Hongtai, president of the China Academy of Space Technology.

The concept of the Halo orbit around the Earth-Moon L2 point was first put forward by international space experts in 1950s.

While in orbit, the relay satellite can see both the Earth and the far side of the Moon. The satellite can stay in the Halo orbit for a long time due to its relatively low use of fuel, since the Earth's and Moon's gravity balances the orbital motion of the satellite.

"From Earth, the orbit looks like a halo of the Moon, which is wh ere it got its name," said Zhang Lihua, project manager of the relay satellite.

He said the Halo orbit was a three-dimensional irregular curve. It is extremely difficult and complex to maintain the satellite in orbit.

"If there is a tiny disturbance, such as gravitational disturbance from other planets or the Sun, the satellite will leave orbit. The orbit period is about 14 days. According to our current plan, we will conduct orbit maintenance every seven days," Zhang said.

"Queqiao is like a little kid running wild in orbit. If there's even the slightest negligence by our team, the satellite will be lost forever," said Guan Bin, a designer for the satellite's control system.

"It's a new type of orbit, we don't have any experience. We ran a number of simulations to make sure the design is feasible and reliable," Zhang said.

In order to set up a communication link between Earth and the planned Chang'e-4 lunar probe, astrophysicists must keep the satellite stable and control its altitude, angle and speed with high precision.

Next, the team will test the communication function of the relay satellite.

ЦитироватьХВ. пишет:
Тем не менее, кто -нибудь может подсказать: по какой орбите вокруг L2 движется спутник-ретранслятор? (возможно где-то об этом уже сказано).

ЦитироватьThe concept of the Halo orbit around the Earth-Moon L2 point was first put forward by international space experts in 1950s. 

While in orbit, the relay satellite can see both the Earth and the far side of the Moon. The satellite can stay in the Halo orbit for a long time due to its relatively low use of fuel, since the Earth's and Moon's gravity balances the orbital motion of the satellite. 

"Fr om Earth, the orbit looks like a halo of the Moon, which is wh ere it got its name," said Zhang Lihua, project manager of the relay satellite. 

He said the Halo orbit was a three-dimensional irregular curve. It is extremely difficult and complex to maintain the satellite in orbit.

Цитировать(https://img.novosti-kosmonavtiki.ru/30820.jpg)BG2BHC‏ @bg2bhc (https://twitter.com/bg2bhc) 19 мин. назад (https://twitter.com/bg2bhc/status/1007206364727291904)

Image from DSLWP-B Saudi camera payload, downlink from x-band some days ago @AMSAT (https://twitter.com/AMSAT) @AmsatUK (https://twitter.com/AmsatUK) @m6sig (https://twitter.com/m6sig) @AJ_FI (https://twitter.com/AJ_FI) @ea4gpz (https://twitter.com/ea4gpz) @n6rfm (https://twitter.com/n6rfm) @dk3wn (https://twitter.com/dk3wn) @cgbassa (https://twitter.com/cgbassa) @supertrack_it (https://twitter.com/supertrack_it) @uhf_satcom (https://twitter.com/uhf_satcom)

(https://img.novosti-kosmonavtiki.ru/165169.jpg)(https://img.novosti-kosmonavtiki.ru/165171.jpg)(https://img.novosti-kosmonavtiki.ru/165170.jpg)

Цитировать(https://img.novosti-kosmonavtiki.ru/29906.jpg)Andrew Jones‏ @AJ_FI (https://twitter.com/AJ_FI) 2 мин. назад (https://twitter.com/AJ_FI/status/1007211169768144897)

This is kind of incredible. Images of the Earth and Moon, taken by a small Saudi camera on a small 45 kg Chinese satellite in lunar orbit (Longjiang-2/DSLWP-B), as part of the Chang'e-4 relay satellite launch.

(https://img.novosti-kosmonavtiki.ru/165172.jpg)

Спойлер

(https://img.novosti-kosmonavtiki.ru/165173.jpg)
(https://img.novosti-kosmonavtiki.ru/165174.jpg)
(https://img.novosti-kosmonavtiki.ru/165175.jpg)

[свернуть]

Цитировать14.06.2018          "Цюэцяо" достиг точки либрации L2 (http://novosti-kosmonavtiki.ru/news/36428/)
       
 Китайский спутник-ретранслятор "Цюэцяо" ("Сорочий мост"  ;)  в четверг успешно вышел в точку Лагранжа L2 на обратной стороне Луны, став первым в мире спутником, функционирующим на этой гало-орбите, говорится в сообщении Национального космического управления Китая.

Цитировать"... на практике полеты по гало-орбитам в настоящее время были реализованы американцами по проекту ARTEMIS. Это примерно 2-3 года назад. Там два космических аппарата летали в окрестностях точек L1 и L2 с поддержанием соответствующих орбит. Один аппарат совершил перелет из точки L2 в точку L1. Вся эта технология на практике реализована.

 ... первый полет в точку L1 в системе Солнце - Земля был осуществлен в 1978 году. С тех пор было реализовано несколько космических миссий."

ЦитироватьChina, Saudi Arabia unveil lunar images gained from space cooperation
Source: Xinhua | 2018-06-14 19:16:40 | Editor: ZX

BEIJING, June 14 (Xinhua) -- China and Saudi Arabia on Thursday jointly unveiled three lunar images acquired through cooperation on the relay satellite mission for Chang'e-4 lunar probe.

This is an important cooperation achievement between China and Saudi Arabia in the relay satellite mission, the China National Space Administration said in a statement.

The relay satellite for the Chang'e-4 lunar probe, named Queqiao or Magpie Bridge, was launched on May 21 and entered the Halo orbit around the second Lagrangian (L2) point of the Earth-Moon system, about 65,000 km from the Moon, at 11:06 a.m. Thursday after a journey of more than 20 days.

An optical camera, developed by the King Abdulaziz City for Science and Technology of Saudi Arabia, was installed on a micro satellite, named Longjiang-2, which was launched together with Queqiao.

The micro satellite is orbiting around the Moon. The camera, which began to work on May 28, has conducted observations of the Moon and acquired a series of clear lunar images and data.

According to a memorandum of understanding signed between China and Saudi Arabia on March 16, 2017, the two countries will share the scientific data in this cooperation.

China is pushing forward space cooperation with countries participating in the Belt and Road Initiative.

ЦитироватьMicro satellite developed by Chinese university starts to work around Moon
Source: Xinhua | 2018-06-14 19:26:43 | Editor: ZX

BEIJING, June 14 (Xinhua) -- A micro satellite, developed by the Harbin Institute of Technology in northeast China's Heilongjiang Province and sent into an orbit around the Moon, has started to transmit data back to Earth.

Two micro satellites, Longjiang-1 and Longjiang-2, were sent into space on May 21 together with the Chang'e-4 lunar probe's relay satellite from southwest China's Xichang Satellite Launch Center.

Longjiang-2 successfully reached its destination near the Moon on May 25, and entered a lunar orbit with the perilune at 350 km and the apolune at 13,700 km. However, Longjiang-1 suffered an anomaly and failed to enter lunar orbit, according to the China National Space Administration (CNSA).

Longjiang-2, weighing 47 kg, has become the world's first lunar orbiter developed by a university.

It carries an optical camera developed by the King Abdulaziz City for Science and Technology of Saudi Arabia, as well as a low-frequency radio detector developed by the National Space Science Center of Chinese Academy of Sciences.

The scientific instruments on the satellite have all started to work, CNSA said.

ЦитироватьChang'e-4 relay satellite enters halo orbit around Earth-Moon L2, microsatellite in lunar orbit
by Andrew Jones (http://spacenews.com/author/andrew-jones/) — June 14, 2018

(https://img.novosti-kosmonavtiki.ru/155796.jpg)
The far side of the Moon and distant Earth, imaged by the Chang'e-5 T1 mission service module in 2014 Credit: Chinese Academy of Sciences

HELSINKI, Finland — The relay satellite which will facilitate China's Chang'e-4 lunar far side landing mission late in 2018 has entered its intended halo orbit around Earth-Moon Lagrange point 2.

The Beijing Aerospace Command and Control Center (BACC) sent commands for the spacecraft to fire its engines at 11:00 p.m. EDT June 13, with the burn complete at 11:06 p.m.

The satellite will now undergo on-orbit testing of its communications functions, while maintaining a complex Lissajous orbit, which is a three-dimensional irregular curve, rather than a two-dimensional halo.

The relay satellite was launched from Xichang, southwest China, on May 20, and performed a braking maneuver May 25 when passing within 100 kilometers of the lunar surface, sending it on a trajectory towards the second Earth-Moon Lagrange point, some 65,000-80,000 kilometers beyond the moon.

Спойлер

The relay satellite is a precursor mission to the launch of the Chang'e-4 lander and rover, which will attempt to land in the vicinity of the Von Kármán crater within the South Pole-Aitken Basin on the lunar far side around November or December. No such mission has been attempted before.

As the lunar far side at no time faces the Earth, due to the moon's orbital period matching its rotational period, a relay satellite is required to facilitate communications with the Earth.

"The satellite is the world's first communication satellite operating in that orbit, and will lay the foundation for the Chang'e-4, which is expected to become world's first probe soft-landing and roving on the far side of the Moon," Zhang Hongtai, president of the China Academy of Space Technology (CAST), told Xinhua news agency.

Named Queqiao ('Magpie Bridge'), a name taken from a Chinese folklore tale that sees two lovers reunited once a year when a flock of magpies form a bridge across the Milky Way, the satellite will orbit around the Lagrange point, with an orbital radius allowing it line-of-sight with both the far side of the most moon and tracking stations on Earth at all times.

It will use a 4.2-meter parabolic antenna to relay telecommands from the ground to the Chang'e-4 lunar spacecraft and transmit data and telemetry back to Earth via S-band, while using X-band to communicate with the lander and rover.
The relay satellite is also equipped with the Netherlands-China Low-Frequency Explorer (NCLE), a low-frequency, space-based astronomy pathfinder experiment that will attempt to detect radio signals from the cosmic dark ages, before emission of light by the first stars in the universe.

The three 5-meter-long antennas will be deployed after the lander and rover section of the mission, which is designed to last a minimum of three months.

Longjiang microsatellite operating in lunar orbit

The State Administration for Science, Technology and Industry for National Defense (SASTIND), which oversees China's space activities, on June 14 also provided an update on the pair of microsatellites launched along with Queqiao.

(https://img.novosti-kosmonavtiki.ru/155802.jpg)
An image captured by the Saudi camera aboard the Longjiang-2 microsatellite shows a portion of the northern hemisphere of the far side of the moon near Petropavlovsky crater, and the distant Earth. Credit: China Lunar Exploration Project (CLEP)

Unlike the relay satellite, the two 47-kilogram satellites developed by the Harbin Institute of Technology were intended for lunar orbit.

The report states that Longjiang-2, also known as DSLWP-B, successfully entered an elliptical lunar orbit using its own propulsion May 25, while Queqiao headed towards Earth-Moon L2.

SASTIND confirmed however that Longjiang-1 (DSLWP-A) had suffered an anomaly during Earth-Moon transfer and did not enter lunar orbit. This was the first official acknowledgement that the spacecraft had been lost.
Longjiang-2 carries a low-frequency antenna and has been facilitating out amateur radio experiments while in lunar orbit. It was also to test space-based interferometry with Longjiang-1.

The China Lunar Exploration Project (CLEP) today also released images from the small camera payload aboard Longjiang-2, developed by the King Abdulaziz City for Science and Technology (KACST) of Saudi Arabia, capturing the surface of the moon with the Earth in the background.

Despite the loss of one of the microsatellites, Jonathan McDowell, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics, says that the mission is a harbinger of things to come.

McDowell told SpaceNews that the Longjiang/DSLWP probes mark the beginning of ambitious plans for small deep space probes, with the even smaller NASA MarCO probes currently on their way to Mars.

"I think in the decade to come, we'll continue to see ambitious, large planetary probes, like the European-Japanese Bepi-Colombo and China's Chang'e-4 which are both preparing for launch, but we'll also see the flourishing of these small, simple and highly focussed probes," McDowell said.

"Fifteen years after the first cubesat we're seeing the first large constellations now. Perhaps in 10 years we'll see big smallsat constellations in the inner solar system for interplanetary comms, GPS, space weather and asteroid searches."

Professor Ping Jinsong of the National Astronomical Observatories of China and principal investigator for the Low Frequency Spectrometer payload on the Chang'e-4 lander, told SpaceNews that future plans are being considered.

"To fly a low-cost constellation in lunar space or at the Sun-Earth L1/L2 points area, with EMC quiet platform for each satellite unit, and with space Very-long-baseline interferometry (VLBI) working mode...should be a reasonable choice in the near future," Ping said.

[свернуть]

ЦитироватьВидеозонд Саудовской Аравии, установленный на китайском микроспутнике "Лунцзян-2", сделал первые снимки Луны
Пекин, 14 июня /Синьхуа/ -- Как сообщили в Государственном управлении оборонной науки, техники и промышленности КНР и Государственном космическом управлении КНР, самостоятельно разработанный Харбинским промышленным университетом орбитальный микроспутник сверхдлинноволнового наблюдения "Лунцзян-2" в настоящий момент вышел на окололунную орбиту. Установленный на спутнике оптический видеозонд Саудовской Аравии начал работу и сделал несколько четких снимков лунной поверхности в видимом спектре. Сегодня во второй половине дня в Пекине Государственное космическое управление КНР и Научно-технический центр им. короля Абдулазиза Саудовской Аравии совместно представили 3 снимка, полученных с помощью видеозонда. -0- Фотографии Синьхуа/предоставлены Государственным управлением оборонной науки, техники и промышленности КНР
 (https://forum.novosti-kosmonavtiki.ru/forum/file/85103)  (https://forum.novosti-kosmonavtiki.ru/forum/file/85105) (https://forum.novosti-kosmonavtiki.ru/forum/file/85106)

ЦитироватьДимитър пишет:
А что с Лунцян-1?

ЦитироватьThe State Administration for Science, Technology and Industry for National Defense (SASTIND), which oversees China's space activities, on June 14 also provided an update on the pair of microsatellites launched along with Queqiao.
...
SASTIND confirmed however that Longjiang-1 (DSLWP-A) had suffered an anomaly during Earth-Moon transfer and did not enter lunar orbit. This was the first official acknowledgement that the spacecraft had been lost.

Цитировать

Китайский микроспутник успешно передал на Землю первые снимки Луны
2018-06-16 21:00:10丨Russian.News.Cn

Пекин, 16 июня /Синьхуа/ -- Китайский микроспутник сверхдлинноволнового наблюдения "Лунцзян-2" успешно передал на Землю первые снимки Луны. Об этом сообщили информагентству Синьхуа в Государственном управлении оборонной науки, техники и промышленности КНР и Государственном космическом управлении КНР.

Спутник "Лунцзян-2" весом 47 кг разработан Харбинским промышленным университетом. Его полезная нагрузка включает миниатюрный видеозонд Саудовской Аравии.

21 мая этого года китайский спутник-ретранслятор "Цюэцяо" /"Сорочий мост"/ с двумя микроспутниками "Лунцзян-1" и "Лунцзян-2" был запущен с космодрома Сичан в провинции Сычуань на юго-западе Китая.

Спустя 113-часовой полет "Лунцзян-2" в 22:00 часа 25 мая по пекинскому времени вышел на окололунную орбиту, параметры которой -- 13700 км апоселений, 350 км периселений. Из-за неполадок в управлении вывести на окололунную орбиту его компаньона "Лунцзян-1" не удалось.

"Лунцзян-2" стал первым в мире микроспутником, который самостоятельно вышел на окололунную орбиту и совершил полеты вокруг Луны, отметили в ведомствах.

Видеозонд Саудовской Аравии на борту микроспутника был включен 28 мая. По оценкам экспертов, снимки лунной поверхности в видимом спектре, снятые указанным аппаратом, отвечают техническим требованиям, разработанным Китаем и Саудовской Аравией.

Государственное космическое управление КНР и Научно-технический центр им. короля Абдул-Азиза Саудовской Аравии на днях в Пекине совместно представили три из вышеупомянутых снимков.

Документ о сотрудничестве между Китаем и Саудовской Аравией был заключен в марте 2017 года.

ЦитироватьКитайский спутник-ретранслятор "Цюэцяо" вышел в точку Лагранжа L2 на обратной стороне Луны

CGTN на русском (https://www.youtube.com/channel/UCA2WHG4EpVqul3TYjAF0k2A)

Опубликовано: 15 июн. 2018 г.

Китайский спутник-ретранслятор "Цюэцяо" вышел в точку Лагранжа L2 на обратной стороне Луны. Это первый космический аппарат, работающий в этом секторе лунной орбиты, который позволяет передавать радиосигнал и на Землю, и на темную сторону ее спутника.

Цитировать(https://img.novosti-kosmonavtiki.ru/30820.jpg)BG2BHC‏ @bg2bhc (https://twitter.com/bg2bhc) 6 ч. назад (https://twitter.com/bg2bhc/status/1026015756197146626)

Images from DSLWP-B student camera developed by @duke_SORA (https://twitter.com/duke_SORA): Mars & Capricornus on 4 Aug, and Mare Nubium on 30 Jun. UHF received from @radiotelescoop (https://twitter.com/radiotelescoop) @cgbassa (https://twitter.com/cgbassa) @tammojan (https://twitter.com/tammojan) , Beijing, @I0LYL (https://twitter.com/I0LYL) and Harbin BY2HIT @LittleQ_Huang (https://twitter.com/LittleQ_Huang) . Thanks to @fsphil (https://twitter.com/fsphil) for ssdv and much help from @ea4gpz (https://twitter.com/ea4gpz)

(https://img.novosti-kosmonavtiki.ru/166906.jpg)
(https://img.novosti-kosmonavtiki.ru/166907.jpg)
(https://img.novosti-kosmonavtiki.ru/166908.jpg)
(https://img.novosti-kosmonavtiki.ru/166909.jpg)

Цитировать(https://img.novosti-kosmonavtiki.ru/35114.png)Cees Bassa‏ @cgbassa (https://twitter.com/cgbassa) 12 авг. (https://twitter.com/cgbassa/status/1028559755118346241)

Lots of lost packets because of the flowchart crashing, but here is a #DSLWP (https://twitter.com/hashtag/DSLWP?src=hash) image of the Sun with lots of lens flare!

(https://img.novosti-kosmonavtiki.ru/168333.jpg)

Цитировать(https://img.novosti-kosmonavtiki.ru/29906.jpg)Andrew Jones‏ @AJ_FI (https://twitter.com/AJ_FI) 12 авг. (https://twitter.com/AJ_FI/status/1028566732351397888)

The Moon's Mare Nubium imaged by a student-developed camera (not the Saudi KACST imager) aboard the 47 kg Longjiang-2/DSLWP-B lunar microsatellite launched along with China's Chang'e-4 relay satellite in May.

(https://img.novosti-kosmonavtiki.ru/168350.jpg)

Цитировать(https://img.novosti-kosmonavtiki.ru/29726.jpg)Joseph Remis‏ @jremis (https://twitter.com/jremis) 25 сент. (https://twitter.com/jremis/status/1044559824556621825)

43473 Decay predicted for today at UTC 10h32mn (USSTRATCOM TIP) is not due to drag but to a close approach of the moon 15 days ago.


25 сент. (https://twitter.com/jremis/status/1044562984352337920)

43473 was the Long March 4C third stage for the launch of Chinese Longjiang 1, Longjiang 2 and Queqiao satellites on mai 20, 2018

Цитировать(https://img.novosti-kosmonavtiki.ru/67516.jpg)Jonathan McDowell‏Подлинная учетная запись @planet4589 (https://twitter.com/planet4589) 2 мин. назад (https://twitter.com/planet4589/status/1045085869223399426)

After launching the Queqiao probe to the region of the Moon, the CZ-4C Y27 rocket stage was left in a 13000 x 442000 km x 18 deg Moon-crossing orbit. It reentered Sep 25 over the Pacific after lunisolar perturbations lowered its perigee.

Цитировать(https://img.novosti-kosmonavtiki.ru/185672.jpg)Tammo Jan Dijkema‏ @tammojan (https://twitter.com/tammojan) 8 ч. назад (https://twitter.com/tammojan/status/1051455085203648512)

New image of lunar farside just recorded @radiotelescoop (https://twitter.com/radiotelescoop) (@cgbassa (https://twitter.com/cgbassa) and me) and @yl3ct (https://twitter.com/yl3ct). Earth is just outside image. Color correction not yet done. @bg2bhc (https://twitter.com/bg2bhc)

(https://img.novosti-kosmonavtiki.ru/171141.jpg)

Цитировать(https://img.novosti-kosmonavtiki.ru/35114.png)Cees Bassa‏ @cgbassa (https://twitter.com/cgbassa) 5 ч. назад (https://twitter.com/cgbassa/status/1051493157056249856)

During today's @radiotelescoop (https://twitter.com/radiotelescoop) observing session of the @bg2bhc (https://twitter.com/bg2bhc) #DSLWP (https://twitter.com/hashtag/DSLWP?src=hash)-B lunar orbiter we (@tammojan (https://twitter.com/tammojan) and I) downloaded two new images. Showing the lunar far side, as well as Earth. These images have been slightly colour corrected. Originals at https://bit.ly/2yE1gQV  (https://t.co/mlI1IEy1d3).

(https://img.novosti-kosmonavtiki.ru/171147.jpg)(https://img.novosti-kosmonavtiki.ru/171148.jpg)

Цитировать(https://img.novosti-kosmonavtiki.ru/184902.jpg)haibaraemily‏ @haibaraemily1 (https://twitter.com/haibaraemily1) 30 нояб. (https://twitter.com/haibaraemily1/status/1068537651890769921)

I guess you might want to know what does Queqiao (the relay satellite of Chang'e 4) look like? This is a 1:3 scale model of Queqiao satellite exhibited at China International Aerospace Exhibition, Zhuhai this year. You can see the beautiful umbrella-shaped antenna.

(https://img.novosti-kosmonavtiki.ru/172860.jpg)
(https://img.novosti-kosmonavtiki.ru/172859.jpg)
(https://img.novosti-kosmonavtiki.ru/172858.jpg)

Цитировать(https://img.novosti-kosmonavtiki.ru/184888.jpg)LaunchStuff‏ @LaunchStuff (https://twitter.com/LaunchStuff) 5 ч. назад (https://twitter.com/LaunchStuff/status/1081089795777015808)

Earth and Moon as seen from Queqiao's cameras (Chang'e 4 Relay)

(https://img.novosti-kosmonavtiki.ru/125583.png)：https://www.weibo.com/1851755225/Han6Y89L8 ... (https://t.co/E6i1IZBLLK)

(https://img.novosti-kosmonavtiki.ru/173781.jpg)(https://img.novosti-kosmonavtiki.ru/173782.jpg)

ЦитироватьReader пишет:
На РККЭ объекты, подобные Цюэцяо, приказано называть ЭЛОИ - Элементы Лунной Орбитальной Инфраструктуры  :)

ЦитироватьФеликс пишет:

ЦитироватьReader пишет:
На РККЭ объекты, подобные Цюэцяо, приказано называть ЭЛОИ - Элементы Лунной Орбитальной Инфраструктуры  :)  

Почему не Меж-Орбитальные Радиотрансляционные Лунные Обьекты Космической Инфраструктуры?

ЦитироватьФеликс пишет: 
Почему не Меж-Орбитальные Радиотрансляционные Лунные Обьекты Космической Инфраструктуры?

ЦитироватьChina Focus: Relay satellite Queqiao plays key role in exploring moon's far side
Source: Xinhua | 2019-01-06 17:12:19 | Editor: ZX
 
BEIJING, Jan. 6 (Xinhua) -- China's Chang'e-4 probe has started the exploration on the far side of the moon thanks to the relay satellite that provides a communication link with ground control.

The relay satellite, named Queqiao, meaning Magpie Bridge, after a Chinese legend, was launched on May 21, 2018, and became the first communication satellite operating in the halo orbit around the second Lagrangian (L2) point of the earth-moon system, nearly 500,000 km from the earth.

The maximum distance between the satellite and the Chang'e-4 probe on the far side of the moon is 79,000 km. The satellite processes data from the probe and transmits it to earth, said Sun Ji, a designer of the satellite from the China Academy of Space Technology.

The satellite can stay in its orbit for a long time due to its relatively low fuel consumption, as the earth's and moon's gravity balances its orbital motion, said Zhang Lihua, chief designer of the satellite.

While in orbit, it can "see" both the earth and the far side of the moon. From earth, the orbit looks like a halo on the moon, said Zhang.

The concept of deploying a relay satellite in the halo orbit was first put forward by U.S. space experts in the 1960s, but was realized by Chinese space engineers.

"We will let Queqiao work as long as possible. It could also provide communication for probes from other countries if they intend to explore the moon's far side within the lifetime of the satellite," said Ye Peijian, an academician of the Chinese Academy of Sciences and a senior space expert.

"And that will be a Chinese contribution made to the world," Ye said.

The relay satellite will also be used for scientific and technological experiments.

It has a low-frequency radio spectrometer, jointly developed by Dutch and Chinese scientists, to help astronomers "listen" to the deeper reaches of the cosmos.

It also carries a reflector developed by the Sun Yat-sen University, in south China's Guangdong Province, to conduct the world's longest laser-ranging test between the satellite and an observatory on the ground.

Researchers hope to use the cameras on the satellite to capture asteroids hitting the far side of the moon, said Sun Ji.

"It's extremely difficult, but we hope to try," Sun said.

To control the cost of the Chang'e-4 mission, the relay satellite was designed to be relatively small, weighing about 400 kg.

Chinese experts designed several antennas for it, including one shaped like an umbrella with a diameter of almost 5 meters.

"We learned from textile technologists and watchmakers in the development of the metal mesh and ribs on the antenna," Zhang said.

"It must endure temperature changes of more than 300 degrees centigrade. We conducted countless experiments for that."

His team had just 30 months to develop the satellite, putting them under tremendous pressure.

To promote public interest in space exploration, the China National Space Administration invited people to write down their wishes for lunar and space exploration, and the relay satellite carries the names of tens of thousands of participants and their messages.

ЦитироватьКитай приветствует использование международным сообществом спутника-ретранслятора "Цюэцяо" для космических исследований
2019-01-16 14:21:29丨Russian.News.Cn

Пекин, 16 января /Синьхуа/ -- Китайский спутник-ретранслятор "Цюэцяо" /"Сорочий мост"/, который сейчас обеспечивает связь между севшим на обратной стороне Луны зондом "Чанъэ-4" и Землей, в последствии должен проработать еще от трех до пяти лет. Китай приветствует использование международным сообществом данного спутника для дальнейших космических исследований. Об этом заявил ответственный секретарь и официальный представитель Китайского национального космического управления /China National Space Administration, CNSA/ Ли Гопин.

Спойлер

В интервью журналистам он отметил, что CNSA приветствует участие коллег из разных стран в последующей работе по реализации китайских программ исследования Луны и глубокого космоса в таких формах сотрудничества, как совместные научно-технические разработки, использование китайских космических аппаратов для вывода в космос собственных экспериментальных приборов, а также совместное проведение научных исследований.

В ближайшем будущем Китай приступит к реализации миссии по посадке на Южном полюсе Луны, тогда он будет готов предоставить международному сообществу возможность отправить на борту китайского орбитального аппарата и посадочного модуля приборы - общим весом по 10 кг на каждом, проинформировал Ли Гопин.

По его сообщению, CNSA в апреле 2015 года официально начало принимать заявки от международного сообщества на установку на борту китайских космических аппаратов экспериментальных приборов. Всего были получены заявки более чем от 10 стран, желающих размесить на китайских космических аппаратах около 20 приборов. В результате отбора было решено принять заявки Германии, Нидерландов, Швеции и Саудовской Аравии. Оборудование названных стран было размещено соответственно на посадочном модуле "Чанъэ-4", луноходе "Юйту-2", спутнике-ретрансляторе "Цюэцяо" и спутнике "Лунцзян-2". Китай планирует совместно с этими странами создать международную команду ученых, которая будет работать над использованием данных, полученных с помощью установленных на китайских аппаратах приборов, для проведения научных исследований.

В рамках миссии "Чанъэ-4", кроме иностранных приборов, также были выведены в космос девять научных приборов китайской разработки. CNSA намерено поделиться данными, полученными с помощью этих приборов, с космическими структурами, НИИ, а также исследователями-любителями из разных стран, заявил Ли Гопин.

[свернуть]

Цитировать(https://img.novosti-kosmonavtiki.ru/30820.jpg)BG2BHC‏ @bg2bhc (https://twitter.com/bg2bhc) 2 ч.2 часа назад (https://twitter.com/bg2bhc/status/1088466672896303104)


DSLWP-B has successfully made a maneuver to reduce its perigee. The sat will end up with an impact to the moon in about August this year to avoid space junk.

Цитировать(https://img.novosti-kosmonavtiki.ru/186419.jpg) (https://mobile.twitter.com/hfalcke) Heino Falcke @hfalcke (https://mobile.twitter.com/hfalcke) · 8 ч (https://mobile.twitter.com/hfalcke/status/1100324005762994176)

Tonight the #NCLE (https://mobile.twitter.com/hashtag/NCLE?src=hashtag_click) radio astronomy antenna onboard #Change4 (https://mobile.twitter.com/hashtag/Change4?src=hashtag_click) #moon (https://mobile.twitter.com/hashtag/moon?src=hashtag_click) relay satellite #Queqiao (https://mobile.twitter.com/hashtag/Queqiao?src=hashtag_click) was fully switched on. All systems work. Antennas still stowed. We will perform first calibration measurements now. Congratulations @MarcWolt (https://mobile.twitter.com/MarcWolt) and team @RadRadioLab (https://mobile.twitter.com/RadRadioLab) @isis_space (https://mobile.twitter.com/isis_space) @ASTRON_NL (https://mobile.twitter.com/ASTRON_NL)

(https://img.novosti-kosmonavtiki.ru/160149.jpg) (https://mobile.twitter.com/hfalcke/status/1100324005762994176/photo/1)(https://img.novosti-kosmonavtiki.ru/160150.jpg) (https://mobile.twitter.com/hfalcke/status/1100324005762994176/photo/2)

Цитировать(https://img.novosti-kosmonavtiki.ru/29906.jpg)Andrew Jones‏ @AJ_FI (https://twitter.com/AJ_FI) 1 ч. назад (https://twitter.com/AJ_FI/status/1121693941357842432)

The Queqiao relay satellite, which facilitates communications between Chang'e-4 spacecraft on the always-hidden lunar far side and Earth, can operate for around 10 years, up from initial planned lifetime of 5 years, chief designer Zhang Lihua says.

https://mp.weixin.qq.com/s/s7TRZPwjvwLQB-H0EkNIVA ... (https://t.co/rD29opXUMP)

(https://img.novosti-kosmonavtiki.ru/161181.jpg)

Спойлер

(https://img.novosti-kosmonavtiki.ru/161180.jpg)
(https://img.novosti-kosmonavtiki.ru/161182.jpg)
(https://img.novosti-kosmonavtiki.ru/161183.png)

[свернуть]

1 ч. назад (https://twitter.com/AJ_FI/status/1121693944151183361)

Queqiao, or 'Magpie Bridge', needs 80 grams for station-keeping manoeuvres and has nearly 50 kilograms of hydrazine left, according to the article.


1 ч. назад (https://twitter.com/AJ_FI/status/1121693952367824897)

Chang'e-7 will require a relay satellite, but perhaps with upgrades and new astronomy equipment. One idea would be to send Queqiao to check for hypothetical Trojan asteroids at the other Earth-Moon Lagrange points (L4, L5) using the spacecraft's imager

(https://img.novosti-kosmonavtiki.ru/161186.jpg)

Спойлер

(https://img.novosti-kosmonavtiki.ru/161187.jpg)
(https://img.novosti-kosmonavtiki.ru/161185.jpg)
(https://img.novosti-kosmonavtiki.ru/161184.jpg)

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Цитировать(https://img.novosti-kosmonavtiki.ru/185952.jpg)Daniel Estévez‏ @ea4gpz (https://twitter.com/ea4gpz) 6 мая (https://twitter.com/ea4gpz/status/1125503390321119235)

New blog post: DSLWP-B deorbit and mission end. The collision of DSLWP-B with the Moon is expected on July 31, putting an end to the mission.

https://destevez.net/2019/05/dslwp-b-deorbit-and-mission-end/ ... (https://t.co/Cz5OL9rosv)

(https://img.novosti-kosmonavtiki.ru/161136.jpg)

Цитировать(https://img.novosti-kosmonavtiki.ru/185952.jpg)Daniel Estévez‏ @ea4gpz (https://twitter.com/ea4gpz) 9 мая (https://twitter.com/ea4gpz/status/1126597121673695237)

New blog post: DSLWP-B lunar impact prediction. Calculation of the future impact point of DSLWP-B on the surface of the Moon. It falls in the far side of the Moon, so not observable from Earth.

https://destevez.net/2019/05/dslwp-b-lunar-impact-prediction/ ... (https://t.co/iY5bmSzyod)

(https://img.novosti-kosmonavtiki.ru/161440.png)

Цитировать(https://img.novosti-kosmonavtiki.ru/29906.jpg)Andrew Jones‏ @AJ_FI (https://twitter.com/AJ_FI) 5 мин. назад (https://twitter.com/AJ_FI/status/1137073341490171904)

Cool new pics of the Moon & Earth from the student camera on the Longjiang-2/DSLWP-B microsatellite in elliptical lunar orbit. (Taken on June 3, so before the Moon 'became part of Mars', or whatever is going on rn...). Info: https://destevez.net/2019/06/report-for-dslwp-b-june-imaging/ ... (https://t.co/1b95gECY7E)

(https://img.novosti-kosmonavtiki.ru/161909.jpg)
(https://img.novosti-kosmonavtiki.ru/161910.jpg)
(https://img.novosti-kosmonavtiki.ru/161911.jpg)
(https://img.novosti-kosmonavtiki.ru/161912.jpg)


5 мин. назад (https://twitter.com/AJ_FI/status/1137073364777013248)

And here's a gif (https://video.twimg.com/tweet_video/D8eyL38XoAARmbe.mp4) made with corrected images by @bg2bhc (https://twitter.com/bg2bhc)

https://video.twimg.com/tweet_video/D8eyL38XoAARmbe.mp4 (https://video.twimg.com/tweet_video/D8eyL38XoAARmbe.mp4)

Цитировать(https://img.novosti-kosmonavtiki.ru/29906.jpg)Andrew Jones‏ @AJ_FI (https://twitter.com/AJ_FI) 3 ч. назад (https://twitter.com/AJ_FI/status/1146313331940188160)

Fantastic! This is yesterday's solar eclipse as seen from lunar orbit by a small camera on a tiny 45 kg satellite.

(https://img.novosti-kosmonavtiki.ru/166566.jpg)


3 ч. назад (https://twitter.com/AJ_FI/status/1146314172306771968)

Another eclipse image from the DSLWP-B satellite, launched with the Queqiao relay satellite for the Chang'e-4 mission in May 2018. The satellite will soon impact the Moon to prevent possible future collisions in lunar orbit.

(https://img.novosti-kosmonavtiki.ru/166625.jpg)


3 ч. назад (https://twitter.com/AJ_FI/status/1146321488548704256)

Another spectacular image of the #SolarEclipse (https://twitter.com/hashtag/SolarEclipse?src=hash) from lunar orbit from the DSLWP-B microsatellite. #Eclipse2019 (https://twitter.com/hashtag/Eclipse2019?src=hash)

(https://img.novosti-kosmonavtiki.ru/166705.jpg)


(https://img.novosti-kosmonavtiki.ru/185672.jpg)Tammo Jan Dijkema‏ @tammojan (https://twitter.com/tammojan) 3 ч. назад (https://twitter.com/tammojan/status/1146323440057667584)

В ответ @AJ_FI (https://twitter.com/AJ_FI) @radiotelescoop (https://twitter.com/radiotelescoop) и еще 3

Wow, we're getting Earthrise + eclipse! Unfortunately some missing chunks, so not sure we'll finish this image today (window ends at 8 UTC).

(https://img.novosti-kosmonavtiki.ru/166713.jpg)


(https://img.novosti-kosmonavtiki.ru/29906.jpg)Andrew Jones‏ @AJ_FI (https://twitter.com/AJ_FI) 2 ч. назад (https://twitter.com/AJ_FI/status/1146338348157587456)

Wow. This an #Earthrise (https://twitter.com/hashtag/Earthrise?src=hash) image also capturing the shadow cast by the July 2 total solar eclipse.

(https://img.novosti-kosmonavtiki.ru/166524.jpg)


(https://img.novosti-kosmonavtiki.ru/185672.jpg)Tammo Jan Dijkema‏ @tammojan (https://twitter.com/tammojan) 1 ч. назад (https://twitter.com/tammojan/status/1146341211504041985)

В ответ @AJ_FI (https://twitter.com/AJ_FI) @bg2bhc (https://twitter.com/bg2bhc) и еще 3

Here's the color-corrected version of the Earthrise image featuring the solar eclipse shadow. Color-corrected by @bg2bhc (https://twitter.com/bg2bhc).

(https://img.novosti-kosmonavtiki.ru/166592.jpg)

Цитировать(https://img.novosti-kosmonavtiki.ru/35114.png) Cees Bassa‏ @cgbassa (https://twitter.com/cgbassa) 8 ч. назад (https://twitter.com/cgbassa/status/1156575266153648128)
There is a new crater on the Moon... We are already 5 minutes past the moment DSLWP-B would've appeared from behind the Moon if it had not crashed. The fact that we are no longer receiving signals means it has impacted the lunar surface. RIP DSLWP-B.


(https://img.novosti-kosmonavtiki.ru/175777.jpg)

Цитировать(https://img.novosti-kosmonavtiki.ru/67516.jpg) Jonathan McDowell‏ Подлинная учетная запись @planet4589 (https://twitter.com/planet4589) 23 мин. назад (https://twitter.com/planet4589/status/1156732417950048256)
The Chinese Longjiang-2 (DSLWP-B) lunar orbiting spacecraft completed its mission on Jul 31 at about 1420 UTC, in a planned inpact on the lunar surface.

ЦитироватьChina's micro lunar orbiter crashes into Moon under control
Source: Xinhua | 2019-08-02 16:28:11 | Editor: huaxia

BEIJING, Aug. 2 (Xinhua) -- China's micro lunar orbiter Longjiang-2 has crashed into the Moon under ground control after it completed its mission, according to the Lunar Exploration and Space Program Center of the China National Space Administration.

The micro satellite crashed into a predetermined area on the far side of the Moon at 10:20 p.m. on July 31 (Beijing Time), the center said Friday.

Weighing 47 kg, Longjiang-2 was sent into space on May 21, 2018, together with the Chang'e-4 lunar probe's relay satellite "Queqiao," and entered the lunar orbit four days later. It operated in orbit for 437 days, exceeding its one-year designed lifespan.

The development of the micro lunar orbiter explores a new low-cost mode of deep space exploration, said the center.

The micro satellite carried an ultra-long-wave detector, developed by the National Space Science Center of the Chinese Academy of Sciences, aiming to conduct radio astronomical observation and study solar radiation.

As a part of the international cooperation behind China's Chang'e-4 mission, Longjiang-2 also carried an optical camera developed by the King Abdulaziz City for Science and Technology of Saudi Arabia. The camera has captured 30 high-definition images of the Moon.

The Lunar Exploration and Space Program Center said it was an important space cooperation achievement for countries participating in the Belt and Road Initiative, and also ushered in more space cooperation between China and Saudi Arabia.

The program also pushed forward non-governmental cooperation between the satellite's developers from the Harbin Institute of Technology in northeast China's Heilongjiang Province and research teams in countries such as Japan, Germany and the Netherlands.

ЦитироватьLongjiang-2 Impact Site Found!

(https://img.novosti-kosmonavtiki.ru/120959.png)
The Longjiang-2 spacecraft (also known as DSLWP-B) crashed onto the lunar farside on 31 July 2019 after completing its orbital mission. This new crater was most likely the result of that impact. Image width 330 meters, north is up, image enlarged by 4x, LROC NAC M1324916226L (NASA/GSFC/Arizona State University).

The Longjiang-2 satellite was launched to the Moon along with the Queqiao communications satellite on 20 May 2018 by the China National Space Agency (CNSA). The small spacecraft (45 kilograms) was designed to work with its twin (Longjiang-1) to validate technologies (https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=2018-045C) for low-frequency radio astronomy observations.

A team led by Daniel Estévez estimated (https://destevez.net/2019/08/trying-to-find-the-dslwp-b-crash-site/) that the small spacecraft impacted somewhere within Van Gent (http://bit.ly/2pCTIwN) crater (16.69°N, 159.52°E). The LROC team used these coordinates to image the area on 5 October 2019 from an altitude of 122 kilometers (M1324916226L). Through a careful comparison of pre-existing NAC images, the LROC team was able to locate a new impact crater (16.6956°N, 159.5170°E, ±10 meters), a distance of only 328 meters from the estimated site! The crater is 4 meters by 5 meters in diameter, with the long axis oriented southwest to northeast. Based on proximity to estimated crash coordinates and the crater size, we are fairly confident that this new crater formed as a result of the Longjiang-2 impact.

(https://img.novosti-kosmonavtiki.ru/120960.gif)
Before and after images of the newly formed crater credited to the impact of Longjiang-2 [NASA/GSFC/Arizona State University].

(https://img.novosti-kosmonavtiki.ru/120961.png)
The new crater is located on a steep slope, greater than 20°, measured from an LROC NAC Digital Terrain Model [NASA/GSFC/Arizona State University].

Read more about the Longjiang-2 spacecraft (https://www.planetary.org/blogs/guest-blogs/2019/longjiang-2-impacts-moon.html) and its mission.

Related Featured Images
Topographic Map of the Chang'e 4 Site (http://lroc.sese.asu.edu/posts/1100)
What a Blast! – Revisiting the Chang'e 3 Landing Site (http://lroc.sese.asu.edu/posts/929)
Chang'e 4 Rover on the Move (http://lroc.sese.asu.edu/posts/1096)
Chang'e 4 Rover Comes into View (http://lroc.sese.asu.edu/posts/1091)
Chang'e 4 Lander Coordinates (http://lroc.sese.asu.edu/posts/1087)
First Look: Chang'e 4 (http://lroc.sese.asu.edu/posts/1090)

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Posted by Mark Robinson (http://lroc.sese.asu.edu/posts?author_id=33) on November 14, 2019 18:46 UTC.

Цитировать(https://img.novosti-kosmonavtiki.ru/35114.png) Cees Bassa‏ @cgbassa (https://twitter.com/cgbassa) 14 мин. назад (https://twitter.com/cgbassa/status/1195064058141184002)

The #DSLWP (https://twitter.com/hashtag/DSLWP?src=hash)-B impact crater has been found on the Moon! On July 31st, the small @BY2HIT (https://twitter.com/BY2HIT) lunar orbiter crashed (as planned) into the surface of the Moon. Thanks to analysis by @bg2bhc (https://twitter.com/bg2bhc), @tammojan (https://twitter.com/tammojan), @ea4gpz (https://twitter.com/ea4gpz) and myself we predicted where it crashed. We were off by only 328 meters!

(https://img.novosti-kosmonavtiki.ru/178188.jpg)

Цитировать(https://img.novosti-kosmonavtiki.ru/29906.jpg) Andrew Jones‏ @AJ_FI (https://twitter.com/AJ_FI) 1 ч. назад (https://twitter.com/AJ_FI/status/1198365022386307073)

The three 5-metre-long antennae of the Netherlands-China Low-Frequency Explorer aboard the Queqiao relay satellite for the Chang'e-4 mission have been fully extended. These could eventually seek to detect signals from the cosmic Dark Ages.  https://mp.weixin.qq.com/s/PVjHTqNzV9zBLySjnJcuaQ ... (https://t.co/6qd6gh2SsB)

(https://img.novosti-kosmonavtiki.ru/178333.jpg)

Цитировать16 ноября все три большие антенны NCLE были успешно развернуты, видеокамера зафиксировала весь процесс развёртывания. С этого момента Цюэцяо получает данные от всех трех антенн, что поможет исследовать тайны вселенной, продолжая при этом обеспечивать связью посадочный модуль и луноход на Луне с Землей.

ЦитироватьНа борту спутника-ретранслятора "Цюэцяо" заработал детектор китайско-голландской разработки
2019-11-26 19:17:32?Russian.News.Cn
Пекин, 26 ноября /Синьхуа/ -- Запущена работа детектора китайско-голландской разработки, который находится на борту спутника-ретранслятора "Цюэцяо" /"Сорочий мост"/. Об этом сообщили в Государственном космическом управлении Китая.
По информации ведомства, антенны спектрометра для низкочастотных радионаблюдений на борту спутника-ретранслятора развернуты, и благодаря аппарату, как ожидается, астрономы получат информацию из еще более отдаленных районов космического пространства.
Детектор разработан для исследований радиоизлучений Земли, Юпитера и других планет, а также поисков экзопланет. При этом его можно использовать для наблюдения совместно с радиоспектрометром на борту спускаемого аппарата "Чаньэ-4", уточнили ученые.

"ранее"

21 мая 2018 года Китай запустил спутник-ретранслятор, предназначенный для установки связи между Землей и лунным зондом "Чанъэ-4".
"Цюэцяо" выведен на орбиту вокруг точки Лагранжа L2 системы Земля-Луны. Таким образом, он стал первым в мире спутником связи, работающим на этой орбите.
При помощи спутника-ретранслятора китайский зонд "Чанъэ-4" 3 января этого года совершил мягкую посадку на обратной стороне Луны. Космический аппарат прилунился в районе кратера Карман в южном полушарии Луны и, таким образом, стал первым в мире космическим аппаратом, успешно севшим на обратную сторону естественного спутника Земли.

[свернуть]

Цитировать(https://img.novosti-kosmonavtiki.ru/29906.jpg) Andrew Jones‏ @AJ_FI (https://twitter.com/AJ_FI) 26 мин. назад (https://twitter.com/AJ_FI/status/1246785595613069314)

This is cool. The far side of the Moon and distant Earth from the Queqiao communications relay satellite for the Chang'e-4 mission. [Image: CAST]

(https://img.novosti-kosmonavtiki.ru/181225.jpg)