Gaia – Soyuz-STB/Fregat-MT (VS06) – Куру/Синнамари – 20.12.2013 09:12 UTC

[чайник17]

Нашел http://www.jhuapl.edu/techdigest/TD/td1703/schuster.pdf
Действительно, механика. Зеркала направляют лучи на нужный фильтр.

Это что-то экзотическое, обычно просто вращающийся диск:
http://solarsystem.nasa.gov/deepimpact/tech/instruments.cfm
На картинке подписан "filter wheel"

[Azteckium]

С пикселями все понятно. Но меня «забили» в др. теме, по поводу того, что стекловолокно трудно применить из-за сумасшедшей вибрации. Как матрица выдерживает изгибы?
Может быть:
- под каждым ПЗС элементом механическая прецизионная юстировочная установка, которая выбирает сдвиг за счет остаточного изгиба.
- 20 кГ конструкции не страшны изгибы и они исчезнут в невесомости.
- вибрация мала.
- ПЗС элементы произвольно сместятся во время пуска, но их конструкция рассчитана на свободное положение относительно фокусной плоскости за счет внутренней структуры ПЗС элемента.

Матрицы юстируются однократно (жестко) на подложке.
Вибрации при запуске не приводят к разрушению матрицы или разъюстировке.
Если правильно помню, подложка не из карбида кремния, а из керамики на основе нитрида алюминия

[ZOOR]

http://ria.ru/science/20110729/409029210.html

Российский телескоп на МКС проведет новую перепись звезд[/size]

14:46 29/07/2011

МОСКВА, 29 июл - РИА Новости, Илья Ферапонтов. Российские астрономы создают новый космический телескоп "Лира-Б", который, как планируется, будет в 2015 году установлен на борту МКС. Этот инструмент будет сканировать небо и собирать данные для нового всеобъемлющего каталога, в который войдут около 300 миллионов звезд и других объектов, сообщил РИА Новости Михаил Прохоров, заведующий лабораторией космических проектов Государственного астрономического института имени Штернберга МГУ (ГАИШ).
...

На сегодня самым точным фотометрическим каталогом является каталог, составленный с помощью европейского спутника Hipparcos, работавшего с 1989 по 1993 год. Его задачей было очень точное измерение координат примерно 120 тысяч ярких звезд. Из-за сбоя при запуске спутник не вышел на запланированную орбиту и поэтому провел измерения с худшей точностью, но полученный им каталог остается лучшим.
...

Данные "Лиры" помогут дополнить информацию с европейского астрометрического спутника Gaia, запуск которого планируется на 2013 год.

По словам Прохорова, этот европейский проект "урезали" - высокая точность определения координат осталась, но качество определения спектральных характеристик звезд было значительно ухудшено.

"Естественно возникает мысль объединить астрометрию Gaia и фотометрию "Лиры" в единый "супер-каталог". И это обязательно надо сделать", - заключил ученый.[/size]

[ZOOR]

Дела у европейцев медленно, но движутся

2011-12-07 Sunshield deployment test successfully completed

Gaia has passed a critical test: the spacecraft sunshield has been deployed successfully. During October 2011, the Flight Model (FM) Deployable Sunshield Assembly (DSA) was delivered to Astrium and integrated with the FM Service Module and Thermal Tent and a mass-representative model of the payload module. Once integrated, the first deployment test of the DSA mounted on the spacecraft took place in Astrium on 21 October. This test demonstrated correctness of alignment, confirmed the deployment functionality and verified the flatness of the deployed DSA

2011-09-15 Gaia mirrors ready to shine
Gaia has passed another major milestone after the completion of 10 state-of-the-art mirrors. The integration of the last two mirrors is now ongoing.
http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=49199

2011-09-01 Gaia Payload Module vibration testing completed
In late June, mechanical testing of the Gaia Payload Module was performed at the facilities of Intespace in Toulouse, France, under the direction of the Prime Contractor, Astrium. The results have been analysed and the testing declared successfully completed.
http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=49071

http://www.rssd.esa.int/index.php?project=GAIA&page=index

[Dude]

четыре элемента выделены для контроля качества изображений и слежения за тем, чтобы угол между двумя телескопами Gaia, равный 106,5˚, не изменялся.

как-то смысл расположения этих 4-х ПЗС-элементов и щели мне не очевиден. Зачем эта щель и сдвинут элемент? Края искать?

[чайник17]

как-то смысл расположения этих 4-х ПЗС-элементов и щели  мне не очевиден. Зачем эта щель и сдвинут элемент? Края искать?

Для датчиков волнового фронта (2 из четырёх), просто нужно место для крепления, IMHO.
Вот тут на картинке видно (Fig. 1):
http://congrex.nl/icso/Papers/Session%203b/FCXNL-10A02-1982820-1-VOSTEEN_ICSO_PAPER.pdf
http://144.206.159.178/FT/CONF/16436189/16436219.pdf
Принцип описан в мурзилке:
http://en.wikipedia.org/wiki/Shack-Hartmann

[чайник17]

Если правильно помню, подложка не из карбида кремния, а из керамики на основе нитрида алюминия

Наверняка неправильно помните, в свежей статье (октябрь 2010)
http://congrex.nl/icso/Papers/Session%203b/FCXNL-10A02-1982820-1-VOSTEEN_ICSO_PAPER.pdf
несколько раз упоминается SiC.

[Dude]

как-то смысл расположения этих 4-х ПЗС-элементов и щели  мне не очевиден. Зачем эта щель и сдвинут элемент? Края искать?

Для датчиков волнового фронта (2 из четырёх), просто нужно место для крепления, IMHO.

спасибо, действительно, место для крепления WFS оставили.

http://sci.esa.int/science-e-media/img/06/Gaia-focal-plane_20090720_small.jpg

[ZOOR]

http://www.rssd.esa.int/index.php?project=GAIA&page=index

Gaia

News & Announcements

2012-02-03 Release of the new issue of the DPAC Newsletter
The DPAC Newsletter no. 15 is available from early this week and there you will find information about some DPAC participating institutes like the one in Slovenia, the alignment between the VLBI and Gaia frames or the modelling of the RVS background signal arising from point sources. For more information, visit the http://www.rssd.esa.int/SA/GAIA/docs/DPAC/web/DPAC_NL_015.pdf

2012-01-31 Open vacancy for a Java software developer at ARI Heidelberg
ARI/ZAH has a vacancy for a Java software developer till end of 2013. The position starts early/mid 2012; the precise time can be negotiated. The successful applicant will work on the preparation of the scientific data processing for the Gaia astronomy mission of the European Space Agency ESA, due for launch in late 2013. More details can be found in the http://www.ari.uni-heidelberg.de/gaia/vacancy-developer-2012.php

2012-01-31 Open vacancy for a Gaia-related postdoc at ARI Heidelberg
ARI/ZAH has a vacancy for a two- to three-year postdoctoral position to do Gaia-related research and to contribute to the Gaia mission preparation. The position starts early/mid 2012; the precise time can be negotiated. More details can be found in the http://www.ari.uni-heidelberg.de/gaia/vacancy-postdoc-2012.php

Никто в Heidelberg поработать не желает?

[PIN]

Хайдельберг - прекрасный город, но эта вакансия - чернорабочего и временная

[instml]

Gaia

Gaia will conduct a census of a thousand million stars in our Galaxy, monitoring each of its target stars about 70 times over a five-year period. It will precisely chart their positions, distances, movements, and changes in brightness. It is expected to discover hundreds of thousands of new celestial objects, such as extra-solar planets and failed stars called brown dwarfs. Within our own Solar System, Gaia should also observe hundreds of thousands of asteroids. Additional scientific benefits include the detection and characterisation of tens of thousands of extra-solar planetary systems, a comprehensive survey of objects ranging from huge numbers of minor bodies in our Solar System, through galaxies in the nearby Universe, to about 500 000 distant quasars. It will also provide stringent new tests of Albert Einstein's general relativity theory.

http://www.youtube.com/watch?v=BCGX1EXQj5c

[instml]

Gaia checks out of antenna testing

2 July 2012

Entombed by the distinctive foam pyramids typical of test chambers, the main antenna of the Gaia billion-star surveyor has been put through its paces ahead of launch next year.

The antenna will send Gaia's precious science data to Earth from its location 1.5 million kilometres away.

Over five years, Gaia is expected to download 200 TB of data – the equivalent of nearly 45 000 standard DVDs – as it makes precise measurements of the positions of a billion stars.

The information will be used to create a 3D map of stars in our home Galaxy, revealing information about its composition, formation and evolution.

Since the spacecraft rotates in space, a complex antenna steered electronically is required to ensure the beam is always directed towards Earth.

By comparison, a conventional mechanical antenna would create tiny vibrations that would impair the performance of the mapping telescope.

The photo shows the 1.5m diameter Gaia antenna panel in the test facility at EADS CASA, Madrid. The chamber's walls are covered with pyramids of non-reflective foam that absorb reflected radio waves to simulate the boundless nature of space.

The chamber also blocks all external signals, such as aircraft radar and cell phones.

As the panel has to radiate the heat generated by the satellite and received from the Sun, it is covered with mirrors.

Gaia will be launched in 2013 from Europe's Spaceport in French Guiana, and will have an initial lifetime of five years.

http://www.esa.int/export/esaSC/SEMWFV1VW3H_index_0.html

[instml]

Gaia Phased Array Antenna delivered and integrated

06 Jul 2012 10:38



http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=50523

[instml]

Dialling down the heat on ESA's billion-star surveyor
 
10 September 2012

ESA's Gaia mission to survey a billion stars has passed a gruelling test to prove it can withstand the extreme temperatures it will experience in space when it is launched next year.
 
After arrival at its working position some 1.5 million km from Earth, Gaia will operate at a temperature of –110°C, shielded from the heat of the Sun by a giant shade attached to the spacecraft to keep its instruments in permanent shadow.



The focus of the most recent test was Gaia's service module, which houses electronic units to run the science instruments, as well as the units that provide the spacecraft resources, such as thermal control, propulsion, communication, and attitude and orbit control.

The tests were carried out at Intespace, a spacecraft test facility in Toulouse, inside a barrel-shaped chamber. Here, Gaia was entombed under vacuum conditions and subjected to a range of temperatures.

During the 19-day test, Gaia endured two types of test: the thermal balance and the thermal–vacuum cycle.



In the thermal balance test Gaia's service module units were switched on and their response to a frigid environment of –170°C analysed.

In the thermal–vacuum cycle, the temperatures of the units were pushed to their limits with the aid of heaters, and functional tests verified the instruments could still work properly.

Temperatures between –20°C and +70°C were recorded inside Gaia during the test period.

"The thermal tests went very well; all measurements were close to predictions and the spacecraft proved to be robust with stable behaviour," reports Gaia Project Manager Giuseppe Sarri.

Later this year, the same thermal tests will be carried out on Gaia's payload module, which contains the scientific instruments, for around two months.

The payload module will then be mated to the service module at the beginning of 2013.

Once in space, Gaia will make precise measurements of the positions and motions of a billion stars. The information will be used to create a 3D map of stars in our home Galaxy, the Milky Way, revealing information about its composition, formation and evolution.

"The latest thermal test marks a major milestone achieved in the development of Gaia," says Giuseppe.

"It demonstrated that the service module is compatible with working in space and that we are on track for launch by the end of next year."

http://www.esa.int/esaSC/SEMR69AYT6H_index_0.html

[instml]

http://www.unmannedspaceflight.com/index.php?showtopic=2540&view=findpost&p=196410

According to Spaceflight Now, Gaia is now scheduled for launch on September 29th with a Soyuz rocket at the French Guiana launch site.

Click here for ESA's basic public website

Click here for ESA in depth website

Click here for Gaia advanced scientific community website

[PIN]

instml пишет:
According to Spaceflight Now, Gaia is now scheduled for launch on September 29th

С очень большой вероятностью к 29му будет объявлена launch readiness и по аппарату, и по наземному сегменту управления. А вот сможет ли Арианэспас запустить в сентябре или октябре - пока открытый вопрос.

[Salo]

Уже декабрь.

[Salo]

http://www.redorbit.com/news/space/1112881313/look-into-gaia-mission-062413/

A Look Into The Gaia Mission
                   
June 24, 2013
                                       Image Caption: Artist's impression of Gaia. Credit: ESA                   
                                                        ESA
 
[ Watch The Video Gaia Sunshade Deployment ]
 
Gaia, ESA's billion-star surveyor, will be launched into space towards the end of this year. In the meantime, ESA Space Science has launched a new 'minisite' focused on the Gaia mission.
At www.esa.int/gaia you will find the latest news from the mission, as well as background articles explaining the mission objectives, the spacecraft, its heritage and more.
You'll also find links to in-depth reports and journal entries covering the test campaign as Gaia was put through its paces before being shipped to ESA's launch site in Kourou.
Once in space, Gaia will spend five years determining the precise distances and velocities of a billion stars. It will observe each star about 70 times, recording vital statistics such as brightness, color and temperature.
The resulting census will enable astronomers to identify different generations of stellar populations, and reconstruct their journey through space over time, thus providing the most detailed picture of our Galaxy's structure and its evolution ever achieved.
In the animation presented here, Gaia is shown shortly after launch as it unfolds its 10 m-wide sunshield 'skirt'.
The shield has two purposes: to shade Gaia's sensitive telescopes and cameras, and to provide power to operate the spacecraft. Gaia will always point away from the Sun, so the underside of the skirt is partially covered with solar panels to generate electricity.
New animations like this, along with supporting background articles and topical news items, will be added to the minisite as the launch draws nearer, to explain in more detail the exciting science that Gaia will perform and how it will help us learn more about our place in the Universe.

[PIN]

Salo пишет:
Уже декабрь.

Откуда информация? Миссия готовится к пуску в октябре. Дату не скажу

[G.K.]

SOE пишет:
Откуда информация?

NSF