GCOM-C "Shikisai", SLATS "Tsubame" - H-IIA - Танэгасима - 23.12.2017, 01:26:22 UTC

Автор tnt22, 27.10.2017 08:25:16

« назад - далее »

0 Пользователи и 1 гость просматривают эту тему.



ЦитироватьJapanese H-2A rocket lifts off with two satellites
December 22, 2017 Stephen Clark

EDITOR'S NOTE:  Upd ated at 0300 GMT Saturday (10:00 p.m. Friday) with confirmation of a successful launch.

A Japanese H-2A rocket lifts off at 0126:22 GMT Saturday (8:26:22 p.m. EST Friday) from the Tanegashima Space Center. Credit: JAXA

Two research satellites to probe Earth's climate patterns and test ion engine technology to counter atmospheric drag in an unusual low-altitude orbit launched Saturday on top of a Japanese H-2A rocket.

The two Japanese-built spacecraft rocketed away from the Tanegashima Space Center in southern Japan at 0126:22 GMT Saturday (8:26:22 p.m. EST Friday) inside the H-2A's payload fairing.
Liftoff occurred at 10:26 a.m. Saturday Japan Standard Time.

Mounted on a dual-payload adapter fixture, the satellites were released into two distinct orbits a few hundred miles above Earth by the H-2A's upper stage.

First, the hydrogen-fueled launcher deployed the Shikisai climate monitoring satellite into a polar orbit around 500 miles (800 kilometers). Then the rocket's LE-5B upper stage engine reignited twice, targeting a lower altitude for separation of a technological demonstration satellite named Tsubame in an elliptical orbit between 280 and 400 miles (450-643 kilometers) over the planet.

Deployment of the 2.2-ton (2-metric ton) Shikisai satellite, also known as the Global Change Observation Mission-Climate (GCOM-C), occurred around 16 minutes after the H-2A rocket's liftoff from, a facility carved from the rocky coast of an island in southwestern Japan.

The 880-pound (400-kilogram) Tsubame payload, officially named the Super Low Altitude Test Satellite (SLATS), was released from the H-2A second stage at T+plus 1 hour, 48 minutes.

Flying on its 37th flight, the H-2A rocket headed south from Tanegashima and jettisoned two solid rocket boosters around two minutes into the flight.

The launcher's LE-7A main engine, consuming a cryogenic mix of liquid hydrogen and liquid oxygen, fired for about 6 minutes, 38 seconds.

The payload shroud covering the Shikisai and Tsubame satellites separated from rocket at T+plus 4 minutes, 5 seconds.

Once the first stage completed its job, the second stage took over the flight for three engine burns to inject the payloads into the mission's two target orbits.

The H-2A rocket blasted off from Japan 72 seconds before a SpaceX Falcon 9 rocket launched from Vandenberg Air Force Base, California.

The back-to-back liftoffs marked the shortest time between two orbital launch attempts since the dawn of the Space Age, according to Jonathan McDowell, an astronomer at the Harvard-Smithsonian Center for Astrophysics who tracks global space activity.

The previous record for the shortest duration between two orbital launch attempts was set in December 1970, when a Soviet Kosmos 3M booster and a French Diamant-B rocket lifted off from Russia and French Guiana 4 minutes, 44 seconds, apart, McDowell said.

Saturday's successful mission was the sixth H-2A launch of the year, and the 37th straight success for Japan's H-2A/H-2B rocket family.

The Shikisai, or GCOM-C, mission is named for the word for colors in Japanese.

The Shikisai (GCOM-C) mission patch. Credit: JAXA

The satellite follows the Shizuku, or GCOM-W, mission launched by Japan in May 2012 to study Earth's water cycle.

The Shikisai satellite carries a wide-area global imaging instrument package — including a visible and near-infrared radiometer and an infrared scanner — to extend climate observations made by Japan's ADEOS 2 spacecraft, which succumbed to a power failure and ended its mission in 2003.

During its planned five-year mission, the climate monitoring observatory will make "surface and atmospheric measurements related to the carbon cycle and radiation budget, such as clouds, aerosols, ocean color, vegetation, and snow and ice," according to a fact sheet released by the Japan Aerospace Exploration Agency.

Scientists say Shikisai's observations will improve their understanding of climate change, and help numerical climate models predict future changes. The imager will also track phytoplankton, aerosol, and vegetation activity to map fisheries, monitor the transport of dust, and estimate crop yields, according to JAXA.

The smaller of the two satellites launched Saturday was named Tsubame, the Japanese word for swallow, after a public competition.

JAXA said Tsubame is "a perfect nickname for the thin, elongated satellite in super low orbit with a se t of solar array wings – what can describe it better than the small, familiar bird flying low?"

Tsubame will use aerodynamic drag to eventually drop into an orbit below 166 miles (268 kilometers), and an ion engine powered by electricity and xenon gas will maintain its altitude between 111 miles (180 kilometers) and 166 miles, counteracting air resistance from the thicker atmosphere at that height.

Designed with aerodynamic stability in mind, Tsubame was built to operate at least two years. The small spacecraft's ion engine produces thrust equivalent to the weight of a small coin, but it burns little fuel, allowing it to fire for weeks to months continuously.

Artist's concept of the Tsubame (SLATS) satellite. Credit: JAXA

"An orbit with an altitude lower than 300 kilometers (186 miles) is referred to as "super low orbit," and it is an unexplored region which has yet to be fully utilized by existing satellites," JAXA said in a fact sheet for the SLATS mission. "Satellites in a super low orbit will bring benefits such as higher resolution optical observation imagery, lower transmission power for active sensors, and cost reductions in satellite manufacturing and launches."

A European Space Agency satellite named GOCE flew in a super-low orbit with the aid of an ion engine to measure Earth's gravitational field and ocean circulation before running out of fuel in 2013 after a four-year mission.

The Tsubame satellite carries a camera to take pictures of Earth from orbit, and an experimental coating on the craft's thermal insulation to prevent damage from atomic oxygen, a gas present at the orbiting testbed's planned altitude. Atomic oxygen is known to damage the multi-layer insulation typically used on satellites, according to JAXA.

Japanese engineers want to know how the satellite responds to years of exposure to conditions at the mission's unusual operating altitude.


Completion of Critical Operations Phase, SHIKISAI and TSUBAME
December 24, 2017 (JST)

National Research and Development Agency
Japan Aerospace Exploration Agency (JAXA)

JAXA received telemetry data fr om SHIKISAI and TSUBAME, confirming that their satellite attitude control system had transitioned to the steady state. Current status of both satellites is stable.

Subsequently, the following procedure occurred – power generation that supports the satellites' operation by the deployed solar array wings, ground communications and sound attitude control that maintains those operations. Combined by the completion of the series of other operations, such as powering up of the bus and mission equipment, the satellites have entered the state where they can be sustained in orbit. This concludes their critical operations phase*¹.

SHIKISAI and TSUBAME will move on to the next operations phase*², wh ere the functions of the satellites' onboard apparatus will be examined approximately in the next three-month period.

JAXA conveys deep appreciation for the support by all for the satellites' launch and tracking.

*¹ Critical operations phase: the phase that follows satellite's separation from a launch vehicle, solar array deployment, and powering up of instruments for the satellite's regular operations. The critical operations phase comes to an end at the start of the satellite's control mode for nominal operation.

*² Next operations phase: during this phase, the entire satellite, its observation/mission sensors and other onboard equipment are scrutinized.
Оригинал на японском - http://www.jaxa.jp/press/2017/12/20171224_shikisai_tsubame_j.html


Видео NVS (2-я камера, 500 м от СК)
ЦитироватьH-IIAロケット37号機 「しきさい」/「つばめ」打ち上げ(リモートカメラ)


Опубликовано: 24 дек. 2017 г.
https://www.youtube.com/watch?v=ULgEZMr6XzIhttps://www.youtube.com/watch?v=ULgEZMr6XzI (1:02)


Пуск и отделение SRB-A на высоте примерно 60 км
ЦитироватьH-IIA Rocket F37 Launch ./ H-IIAロケット 37号機打ち上げ 【4K】


Опубликовано: 25 дек. 2017 г.

2017.12.23 10:26:22 H-IIA Rockey F37 Lanch at Tanegashima Space Center

https://www.youtube.com/watch?v=gSsTUJYXNBchttps://www.youtube.com/watch?v=gSsTUJYXNBc (3:10)


JAXA выпустило отчёт по работе SLATS (на яп.яз)

Профиль траектории движения

(1) Компактный оптический датчик высокого разрешения (SHIROP)

Компактный оптический датчик высокого разрешения (SHIROP) является датчиком для демонстрации того, что разрешение может быть значительно улучшено наблюдением с чрезвычайно низкой высоты (от 200 до 300 км). В будущем мы стремимся к получению более тонких изображений наблюдения за счет снижения высоты «Ласточки».

Рисунок 1-1 представляет собой изображение SHIROP вокруг города Нагоя, префектура Аити около 11:19 25 марта 2018 года (японское время). Высота орбиты спутника на момент съемки составляет 398 км. На рисунке 1-2 показан увеличенный вид перемычки верхней части Тамайама (Камиясиро), которая может идентифицировать легковые автомобили и дорожки. Масса SHIROP составляет 19,4 кг, диаметр 20 см, для сравнения приведено изображение, полученное оптическим датчиком диаметром 30 см (PRISM), установленным на спутнике наблюдения Земли «Дайчи» (ALOS) * 3, запущенном в январе 2006 года. По сравнению с изображением наблюдения оптического датчика (PRISM) (рис. 1-3), состояние поверхности земли фиксируется более детально и четко.

(2) Компактный оптический датчик (OPS)

Компактный оптический датчик (OPS) представляет собой компактный и легкий оптический датчик цветного изображения с широкой областью с диаметром 2 см. На рисунке 2 показано изображение города Нагоя, префектура Аичи, около 11:19 25 марта 2018 года (японское время). Высота орбиты спутника на момент съемки составляет 398 км.

Рисунок 2 Изображение ОПС вблизи Нагоя, префектура Аичи



Снимки камерой КА GCOM-C, сделанные 21 мая с.г. (о-ва Хонсю и Сикоку)
ЦитироватьJAXAサテライトナビゲーター‏ @satellite_jaxa 5 ч. назад

2018年5月21日に「#しきさい」が取得した中国・四国地方、中部地方の画像。 #中部 #四国 #中国地方 #GCOM-C #宇宙 #雲


Shikisai Data Stream Exploratory Measures Initiated for JAFIC
August 3, 2018 (JST)

National Research and Development Agency
Japan Aerospace Exploration Agency(JAXA)
General Incorporated Association
Japan Fisheries Information Service Center (JAFIC)
JAXA has undertaken the initial checkout and calibration*1 of Shikisai, originally known as Global Change Observation Mission-Climate (GCOM-C), to start the satellite-derived data stream service in December 2018. The operation of the Shikisai satellite has been nominal since the launch on December 23, 2017. On July 25, JAXA started the test stream service measures and has provided Japan Fisheries Information Service Center (JAFIC) with three types of nearly real time data including sea surface temperature.

Observation images fr om Shikisai can yield higher resolution images compared with other Earth observation satellites which provide data used for fisheries. Additionally, the satellite's multiple remote sensing, capable of simultaneous observation of ocean color and water temperature, will make the data applicable both to fisheries and marine research. Sea surface temperature in the fishing grounds and other detailed information pertaining to marine environment are expected to advance searching for productive fishing grounds. Data fr om Shikisai is also expected to enhance the monitoring of coastal environment, making it possible to observe seaweed beds, tidal flats, and algal blooms. It will contribute to the management of coastal marine resources and studies.

JAFIC will cooperate with JAXA in calibration and verification of the data by supplying on-site surface temperature and other data. The Center will also use the test data distribution to implement the service that provides information with stakeholders such as those engaging in commercial fishing and research institutions. JAXA will use on-site measurements for comparison provided by JAFIC and other sources and continuously ensure the ongoing checkout and calibration of the satellite.

*1: the initial checkout and calibration: satellite operation to check the accuracy of derived data and make data correction by comparing with the ground observation data

Boso Peninsula

Image: Surface water temperature and the seine fishing ground as observed by Shikisai

In this image, the coolest waters appear in blue, and the warmest temperatures appear in red. Red circles are fishing spots for Japanese pilchard (Sardinops melanostictus). A band of waters at high temperature (in red) along the Japan current lies on the south of the fishing ground. Warm water (orange to green) veers north, countercurrent, off fr om the Japan current. Cold water (blue) is distributed along Kashima coast. This suggests fishing grounds are formed wh ere warm waters move north.

Image 2: Chlorophyll concentrations and algal blooms

The lower the chlorophyll concentration the coder the color, the higher, the warmer. Algal blooms, commonly known as red tide occurred in the red circle, based on data from Kumamoto Prefecture Fisheries Research Center HP. High chlorophyll concentrations are visible on north and south along the inner Ariake Bay toward the offshore Kumamoto prefecture. In Isahara Bay, too, chlorophyll concentrations are high. The circle wh ere algal blooms occurred, caused by diatoms and other organisms, is located wh ere chlorophyll concentrations are also high.


Tsubame Transition to Orbit Keeping Operations
March 18, 2019 (JST)

National Research and Development Agency
Japan Aerospace Exploration Agency (JAXA)
National Research and Exploration Agency Japan Aerospace Exploration Agency (JAXA) launched Tsubame*1, The Super Low Altitude Test Satellite, on December 23, 2017. The Tsubame satellite completed its orbit transfer phase and will transition on April 2 to the orbit keeping phase, powered by the ion engines.

Designed to open up the possibilities of satellite use in a super low orbit, Tsubame gradually lowered its altitude using atmospheric drag and the onboard gas jet and has been in good health.

The ensuing orbit keeping operation executes the descent in five stages, 271.5 kilometers, 250 kilometers, 240 kilometers, 230 kilometers, and 220 kilometers. Each altitude is sustained for some time. In an orbit at 180 kilometers, the target altitude, where there is significant atmospheric resistance, the gas jet is turned on in addition to the ion engines to withstand the drag. (See the images of the orbital maintenance operation profile)

On April 2 through May 2, the Tsubame satellite will be sustained at 271.5 kilometers, its recurrent orbit.*2 Stationary measuring is scheduled every day of the month-long period above the Tokyo metropolitan area at high resolution, one advantage that satellite operation in a super low orbit affords. Thereafter, the satellite gradually lowers its altitude and enters the orbit keeping operation through September. During this operation, data is to be acquired of the atmosphere and atomic oxygen in a super low altitude. Photographing by Small and High Resolution Optical Sensor (SHIROP) will also be experimented.

*1: For more information, go to http://global.jaxa.jp/projects/sat/slats/

Tsubame three onboard mission instruments are:
(1) The Small and High Resolution Optical Sensor (SHIROP)
(2) The Optical Sensor (OPS)
(3) The Atomic Oxygen Monitor System (AMO) – comprising of the Atomic Oxygen Monitor (AOFS) and the Material Degradation Monitor (MDM)

*2: A satellite repeats its path, which is called a recurrent or sub-recurrent orbit. This orbit enables the satellite to observe the same area at regular intervals.
【Computer generated image of Tsubame】

【Operational Orbits Profile】

(1) The Small and High Resolution Optical Sensor (SHIROP)
19.4 kg and 20 cm in diameter, the SHIROP is a small optical sensor, less than 10-meter resolution, designed to demonstrate observations at super low altitudes. Compared to 30 cm in diameter and 2.5 meter resolution of the Panchromatic Remote-sensing Instrument for Stereo Mapping (PRISM) onboard Daichi, the Advanced Land Observing Satellite, launched on January 24, 2006, the SHIROP is smaller and has more sensitive resolution, as it observes in a super low orbit.
Below are the images captured by Tsubame on January 2.
On April 2 through May 2, the areas above Tokyo Station and Shinjyuku-gyoen including Akasaka Geihinkan and the New National Stadium will be observed. Atmospheric resistance and other factors may change the satellite's orbit. This may alter the measuring spots, too. Observations will proceed rain or shine, but clouds may prevent getting clear images on the ground.

Captured image above New National Stadium

Above Geihinkan and Akasaka Rikyu
(2) The Optical Sensor (OPS)
The OPS is a 1.9 kg, 2 cm in diameter instrument for wide range photographing. It returns 30 m resolution colored images.

Below are the images above Dubai, the United Arab Emirates, observed on February 4 and 10, 2018.
The right image shows measuring at the lower altitude narrows the range and heightens the resolution.

The OPS images captured at different altitudes


ЦитироватьMar. 1, 2019 Updated
New Dataset Release: GCOM-C/SGLI

JAXA GCOM-C (Global Change Observation Mission - Climate "SHIKISAI") satellite was launched on Dec. 23rd, 2017 to conduct long-term and continuous global observations in order to elucidate the global warming mechanisms related to fluctuations in radiation budget and/or carbon cycles etc.

The onboard sensor SGLI (Second Generation Global Imager) can observe 19 bands of radiations from near-ultraviolet to thermal infrared region (380 nm-12 µm), which yield various physical properties related to cloud, water, snow, ice, aerosol, sea, land, vegetation, biomass, chlorophyll a, and photosynthesis. The spatial resolution and swath of SGLI are 250m and greater than 1,000 km respectively and the whole globe can be scanned approximately in every two days.

SGLI can observe 15 Essential Climate Variables (ECV) such as cloud, aerosols, vegetation, etc. and its data are expected to contribute to improve the projection accuracy of climate change and also to predict fishing grounds, yellow sands, red tides, etc.

The released products can be downloaded via JAXA G-Portal ( https://gportal.jaxa.jp/ )

Contact Point: JAXA G-portal help desk: z-gportal-support@ml.jaxa.jp

1. Events after the launch

The data was released as scheduled according to the following operations.
December 23, 2017 Launch of GCOM-C (SHIKISAI)
January 1, 2018 Obtained First Light images
March 28, 2018 Started initial calibration and validation operations
December14, 2018 Completed initial calibration and validation operations
2. The overview of Initial calibration and validation operations

To detect tiny climate change signals, higher accuracy products are needed. JAXA performed calibration with GCOM-C function using solar light, internal lamps, black body, lunar light and others, and compared (calibration and validation) GCOM-C observation value with ground observation data acquired in cooperation with ground observation networks (Skynet, AERONET and AsiaFlux) and collaborating research institutes (universities, Meteorological Research Institute, JAMSTEC and NOAA). As a result of the calibration, JAXA confirmed that the accuracy of 29 types of products covering land, atmosphere, ocean and cryosphere is attained to start data utilization.

3. GCOM-C/SGCLI Standard Products

Further information for the definition of the product and sample data is available at;
1) Chlorophyll-a Concentration

Global chlorophyll-a concentration (average of October 201  8)  
2) Aerosols

Polarization radiance at 867nm (average from August 11 to 20, 2018)
3) Global vegetation index (NDVI)

The image is a map of global normalized difference vegetation index (NDVI) derived from SGLI observation data acquired during January 1st to 9th 2018. NDVI becomes high at active vegetation with high density, indicating the spatial distribution of vegetation on the global scale.


Цитировать Jonathan McDowell‏ Подлинная учетная запись @planet4589 50 мин. назад
On Jul 20 JAXA's Tsubame satellite, designed to operate at low orbital altitudes, descended to a 218 x 221 km orbit (Tsubame: red;  H2A Stage 2: blue)


Цитировать Jonathan McDowell‏ Подлинная учетная запись @planet4589 44 мин. назад

The @JAXA_jp Tsubame  (SLATS) low altitude test satellite, launched in 2017, has reached a 163 x 166 km orbit. This plot shows how its orbit has been actively lowered in stages:


Цитировать Joseph Remis‏ @jremis 2 ч. назад

Obj. 43066 SLATS decay prediction: October 01, 2019 UTC 016h48mn ± 6h. Assuming orbit control using ion engine system is over.


Цитировать Jonathan McDowell‏ Подлинная учетная запись @planet4589 17 мин. назад

JAXA's Tsubame (SLATS) low orbit test satellite confirmed to have reentered between 1420 and 1500 UTC Oct 1 from a final 133 x 147 km orbit.


ЦитироватьJapanese satellite re-enters atmosphere after experiments in ultra-low orbit
October 15, 2019 | Stephen Clark

Artist's concept of the Tsubame satellite, also known as the Super Low Altitude Test Satellite (SLATS). Credit: JAXA

An experimental Japanese satellite has ended its mission after proving it could operate at super-low altitudes, testing an Earth-imaging camera and using ion propulsion to fight against aerodynamic drag at an altitude of 112 miles (181 kilometers).

The Japan Aerospace Exploration Agency's Tsubame satellite, named for the Japanese word for barn swallow, re-entered the atmosphere Oct. 2 after a nearly three-year mission.

Tsubame, also known as the Super Low Altitude Test Satellite, demonstrated controlled flight in an unusually low orbit, skimming through the rarefied layers of the upper atmosphere where aerodynamic drag typically causes spacecraft to quickly drop out of orbit and burn up.

JAXA's Tsubame satellite carried an ion thruster, powered by electricity and fueled by xenon gas, to counteract the effect of atmospheric drag. The spacecraft also had an on-board camera to demonstrate the capability to collect high-resolution images of cities and landforms from an altitude as low as 112 miles.

These two images were taken by the same camera aboard JAXA's Tsubame satellite. The image on the left shows a major intersection in Tokyo from an altitude of 236 miles (381 kilometers), while the more detailed image on right shows the same intersection from an altitude of 112 miles (181 kilometers). Credit: JAXA

With some exceptions, most Earth-imaging satellites typically fly at altitudes between 300 and 400 miles (500-650 kilometers).

Built by Mitsubishi Electric Corp., Tsubame launched aboard an H-2A rocket in December 2017 into an elliptical, or egg-shaped, orbit with a low point around 280 miles (450 kilometers) above Earth, then maneuvered into a 243-mile-high (392-kilometer) orbit in early 2018. Ground controllers allowed aerodynamic drag to gradually lower Tsubame's orbit to an altitude of 168 miles (271 kilometers).

At that altitude, Tsubame activated its ion engine to maintain its orbit for one month. Then Tsubame switched off the xenon thruster to allow the spacecraft to drop into lower orbits at 155 miles (250 kilometers), 149 miles (240 kilometers) and 142 miles (230 kilometers), stopping to maintain each altitude for around one week using the ion engine.

Tsubame used its low-thrust ion engine to hold altitude at around 134 miles (217 kilometers) for approximately one month, then lowered its orbit to 112 miles (181 kilometers) in September for one week, again maintaining altitude using its xenon thruster.

The satellite then stabilized its orbit at 104 miles (167 kilometers) for several days. At that altitude, Tsubame had to use its liquid-fueled higher-thrust rocket jets to in conjunction with the ion engine to counteract drag.

The satellite re-entered the atmosphere earlier this month after completing its experiments, JAXA said.

Future satellites operating in such low orbits could offer several advantages to developers, including reduced costs for their imaging instruments and launch services.

A smaller camera on a low-altitude satellite could capture the same quality of images as a more powerful camera on a spacecraft in a higher orbit. An Earth-imaging satellite launched into a lower orbit might also need a less expensive rocket, according to JAXA.

A European Space Agency satellite named GOCE flew in a super-low orbit with the aid of an ion engine to measure Earth's gravitational field and ocean circulation before running out of fuel in 2013 after a four-year mission.

But Tsubame is the first satellite to test an Earth observation instrument while using electric propulsion to maintain such a low orbit.

Tsubame also carried an experimental coating on the craft's thermal insulation to prevent damage from atomic oxygen, a gas present at the orbiting testbed's low operating altitude. Atomic oxygen is known to damage the multi-layer insulation typically used on satellites, according to JAXA.

JAXA said knowledge gained from the Tsubame mission will be useful in future space applications in science and technology.


;)  До жирафов быстрей добегает... Не прошло и года...

ЦитироватьЯпонский спутник установил рекорд сверхнизкой орбиты полета
12:24 25.12.2019

ТОКИО, 25 дек - РИА Новости. Японское аэрокосмическое агентство (JAXA) сообщило, что испытательный спутник "Цубамэ" совершил полет и наблюдения за Землей на сверхнизкой орбите в 167,4 километра и был занесен в Книгу рекордов Гиннеса.

Как отметило агентство, на сегодняшний день нет ни одного спутника, которому бы удалось облететь планету на меньшей высоте. Чем ниже полет, тем детальнее космическому аппарату удается произвести наблюдения и съемку, однако на высоте ниже 300 километров возрастает сопротивление воздуха и ускоряется износ оборудования.

Спутник "Цубамэ", что в переводе означает "ласточка", был запущен в 2017 году. В апреле этого года он достиг орбиты в 271 километр, а затем снизился до 167,4 километра и сумел удержаться на этой высоте в течение семи дней, после чего срок его эксплуатации был завершен.