Liftoff for Gaia, Europe’s Billion-star Surveyor
Europe’s Gaia mission blasted off this morning on a Soyuz rocket from Europe’s Spaceport in Kourou, French Guiana, on its exciting mission to study a billion suns.
Gaia is destined to create the most accurate map yet of the Milky Way. By making accurate measurements of the positions and motions of 1% of the total population of roughly 100 billion stars, it will answer questions about the origin and evolution of our home Galaxy.
The Soyuz launcher, operated by Arianespace, lifted off at 09:12 GMT (10:12 CET). About ten minutes later, after separation of the first three stages, the Fregat upper stage ignited, delivering Gaia into a temporary parking orbit at an altitude of 175 km.
A second firing of the Fregat 11 minutes later took Gaia into its transfer orbit, followed by separation from the upper stage 42 minutes after liftoff. Ground telemetry and attitude control were established by controllers at ESA’s operations centre in Darmstadt, Germany, and the spacecraft began activating its systems.
The sunshield, which keeps Gaia at its working temperature and carries solar cells to power the satellite, was deployed in a 10-minute automatic sequence, completed around 88 minutes after launch.
Gaia is now en route towards an orbit around a gravitationally-stable virtual point in space called L2, some 1.5 million kilometres beyond Earth as seen from the Sun.
Tomorrow, engineers will command Gaia to perform the first of two critical thruster firings to ensure it is on the right trajectory towards its L2 home orbit. About 20 days after launch, the second critical burn will take place, inserting it into its operational orbit around L2.
A four-month commissioning phase will start on the way to L2, during which all of the systems and instruments will be turned on, checked and calibrated. Then Gaia will be ready to begin its five-year science mission.
By repeatedly observing a billion stars, with its billion-pixel video camera, the Gaia mission will allow astronomers to determine the origin and evolution of our galaxy whilst also testing gravity, mapping our inner solar system, and uncovering tens of thousands of previously unseen objects, including asteroids in our solar system, planets around nearby stars, and supernovae in other galaxies.
Professor Gerry Gilmore, from the University of Cambridge and UK Principal Investigator for Gaia, said:
“Gaia will be a revolution in our knowledge of the local Universe. For the first time we will have a fair sample of what is out there, where it is, how it is moving, how unseen (dark) matter is distributed, where and when stars formed and where and when the chemical elements of which we are made were created. Gaia will make a huge step towards understanding how the Milky Way came to be formed, and evolved into what we see today. For the first time, we will be able to see the Milky Way in 3-D. In fact in 6-D – where stars are, and how they are moving.”
UK participation in the mission is funded by the UK Space Agency and scientists and engineers from around the UK have played key roles in the design and build of Gaia. The UK Science and Technology Facilities Council (STFC) funded the early development of the project, including the set-up of the data applications centre. STFC’s current support involves the UK exploitation of the scientific data to be yielded from the mission.
The Cambridge Gaia Data Processing Centre will be the front line in processing Gaia’s images, which will also be key to the discovery of many thousands of transient stars and supernovae: these will be made immediately available to schools and the public for their participation in the research.
Dr Chris Castelli, Acting Director of Technology, Science and Exploration at the UK Space Agency, said:
“Gaia is an important space mission for the UK; we’ve won around €80 million of contracts from the European Space Agency to build the spacecraft and are providing a state of the art data centre that will turn the mission’s raw data into the largest stellar catalogue ever made.”
Andy Stroomer, Astrium UK’s Director of Earth Observation, Navigation, and Science, added:
“We are extremely proud of our contribution to the unique Gaia mission – the latest example in a long and successful heritage of supporting ESA science. Stevenage engineers have provided core systems for the Gaia satellite including video processing unit, satellite electrical platform, and mechanical subsystems,”
Once Gaia starts routine operations, around Easter 2014, astronomers will have the challenge of dealing with a flood of data. Even after being compressed by software, the data produced by the five-year mission will fill over 30 000 CD ROMs. This data will be transmitted ‘raw’ and will need processing on Earth to turn it into a calibrated set of measurements that can be freely used by the astronomical community. The cutting edge computer technology developed at the Cambridge Data Processing Centre will be key to this process.
The first Gaia science will be discoveries of new sources – supernovae, extreme variable stars and blazars – which will be discovered at the Cambridge processing centre, and immediately made available for study by both professionals and the interested public. Gaia will discover many new sources which are bright enough for amateurs, and schools with access to public robotic telescopes, to become the first to confirm and obtain more information.
Schools and amateurs will be able to load their data onto the Gaia web site (http://gaia.ac.uk) where it will be used in scientific analyses, and fully credited.
“A school class can be the first to `adopt a supernova’, observe it with robotic telescopes, such as the Faulkes, and provide critically important science information which we need to understand the new sources. That class will be doing original science, and will be credited for their research contributions” says Dr Heather Campbell, a scientist at Cambridge who is part of the Gaia science alerts analysis team.
“By participating in the Gaia Alerts programme, and remotely controlling the Faulkes Telescopes to observe exciting targets discovered just hours beforehand, UK schools will be making real contributions to the research side of this project.” added Professor Paul Roche, Director of the FT project at the University of South Wales.
Notes for editors
The UK has two major roles in the Gaia mission: building the spacecraft, and delivering the science.
UK industry and science institutes won some €80 million of industrial contracts to build Gaia, with leadership roles in building the heart of Gaia, the array of 106 CCDs, the control avionics and the critical micro-propulsion system, as well as playing a critical role in the development of the Gaia spectrometer.
Astrium at Stevenage was responsible for the spacecraft’s super precision guidance and control system as well as the powerful on-board computers needed to process the torrent of data it will produce.
The ‘eye’ of Gaia’s camera has the most sensitive set of light detectors ever assembled for a space mission. It is also the largest focal plane array ever to be flown in space and contains a mosaic of 106 large area, high performance Charged Coupled Device (CCD) CCD91-72 image sensors, which are custom designed, manufactured and tested by UK company e2v. Without these image sensors the Gaia mission would not be possible. These detectors were calibrated with the Gaia electronics at Mullard Space Science Laboratory.
SciSys UK Ltd is responsible for the spacecraft’s operational simulator.
Gaia data will be processed and analysed ready for release to the scientific community and public at six data centres, including one in the UK, operating software developed and tested by a consortium of 400 people across Europe, including some 50 people at 6 Institutes in the UK (Cambridge, UCL-MSSL, Leicester, Edinburgh, The Open University, STFC RAL Space and Bristol)
University College London’s Mullard Space Science Laboratory (MSSL) has a major role in spectroscopic science, and in conjunction with The Open University, is involved in software development including architecture, integration and validation, pre-processing development, spectra extraction and calibration.
The UK hosts the Cambridge data processing centre, where the Gaia imaging data are processed. These data provide brightness, colour, and position information, which enable the core Gaia science, determining distances motions and the intrinsic properties of each star. Gaia also has a spectrograph, to measure the radial velocities of 300 million stars, delivering their complete 3-D positions and 3-D velocities. The spectra will be processed at the French data centre, using software in part developed in the UK.
Quotes
Professor Gerry Gilmore from Cambridge’s Institute of Astronomy (IoA) and the Principal Investigator for UK involvement in the mission:
“The results from Gaia will revolutionise our understanding of the cosmos as never before.”
“Our understanding of what’s out there has been driven by looking at what we can see. We’ve never had a genuine opportunity to look at everything, to know what’s there, and to know where they are in relation to each other. We don’t even know how much we don’t know – there are sure to be objects out there that don’t even have names yet, since we don’t yet realise how strange they are.”
“There are literally hundreds of questions like this – why is the universe the way it is? Where did the Milky Way come from? What’s it really made of? Exactly how much does it weigh? How did it get to be like it is?”
“We will go beyond what we can see to understand reality. We are going to discover completely new things, things we would think are impossible.”
Dr Floor van Leeuwen, Manager of the Gaia data processing activities in the UK:
“The sensors on board the spacecraft will be able to detect objects so faint the human eye would have to be nearly 4,000 times more powerful to see them. This accuracy is equivalent to measuring a shirt button on the moon as seen from the Earth. It means we have to have the highest-capability computers to analyse the data.”
“Perhaps as exciting as the other projected discoveries is the ability of Gaia’s scientific harvest to be used to test some of the fundamental premises of astronomy. With Gaia, we can ‘calibrate the calibrators’ on which our cosmic knowledge is built. If you provide a major improvement in the accuracy of the foundations in astronomy, this works its way all the way through the field for decades to come.”
Dr Nicholas Walton, a member of the ESA Gaia Science team, and astronomer at the University of Cambridge:
“Through the Gaia GREAT network the UK has taken a leading role both in training the next generation of researchers in the sophisticated techniques required to fully exploit the data from Gaia, and enabling networking between researchers across Europe to use Gaia to answer some of the most fundamental questions concerning our place in the Universe.”
e2v spokesperson
“We are immensely proud and excited to finally see our image sensors embark on this mission. All the hard work, dedication and expertise that has been put into our sensors and into the mission will finally come to fruition. Our products will now play their part in history as we help increase our understanding of our universe.”
Images
Artist’s impression of Gaia
http://spaceinimages.esa.int/Images/2013/08/Artist_s_impression_of_Gaia2
http://spaceinimages.esa.int/Images/2013/08/Artist_s_impression_of_Gaia3
Deployment of Gaia’s DSA
http://spaceinimages.esa.int/Images/2013/10/Deployment_of_Gaia_s_DSA6
http://spaceinimages.esa.int/Images/2013/10/Deployment_of_Gaia_s_DSA14
Gaia Service Module
http://spaceinimages.esa.int/Images/2013/06/Gaia_Service_Module
Gaia antenna in test chamber
http://spaceinimages.esa.int/Images/2012/06/Gaia_antenna_in_test_chamber
Videos and animations
http://spaceinvideos.esa.int/Videos/2013/11/Gaia_-_unlocking_the_Milky_Way
http://spaceinvideos.esa.int/Videos/2013/11/Gaia_Mission_VNR
http://spaceinvideos.esa.int/Videos/2013/11/Gaia_technology
http://spaceinvideos.esa.int/Videos/2013/11/Gaia_History_Hipparcos
http://spaceinvideos.esa.int/Videos/2013/10/Gaia_sunshield_deployment_time_lapse_sequence
http://spaceinvideos.esa.int/Videos/2013/10/Gaia_solar_array_and_sunshield_deployment
http://spaceinvideos.esa.int/Videos/2013/06/Gaia_scanning_the_sky
http://spaceinvideos.esa.int/Videos/2013/06/Gaia_telescope
http://www.youtube.com/watch?v=h_fjlec5Wqs&list=SPhQpDGfX5e7CSp3rm5SDv7D_idfkRzje–
http://www.youtube.com/watch?v=cot680thsdQ&list=SPhQpDGfX5e7CSp3rm5SDv7D_idfkRzje–
Contacts
Julia Short
Press Officer
UK Space Agency
Tel: +44 (0)1793 418069
Mobile: +44 (0)7770 276721
Email: julia.short@ukspaceagency.bis.gsi.gov.uk
Prof Gerry Gilmore FRS
UK Gaia Principal Investigator
Institute of Astronomy, Cambridge University
Tel: +44(0)1223337506
Mob: +44(0)7712774522
gil@ast.cam.ac.uk
Dr Floor van Leeuwen
Manager of the Gaia data processing activities in the UK,
Institute of Astronomy, Cambridge University
+44 (0)1223 766654
fvl@ast.cam.ac.uk
Dr Heather Campbell
Supernova science expert
Institute of Astronomy, Cambridge University
+44 (0)1223 746462
hcc@ast.cam.ac.uk
Dr Anna Hourihane
Gaia science expert
Institute of Astronomy, Cambridge University
+44 (0)1223 766667
aph@ast.cam.ac.uk
UK Space Agency
The UK Space Agency is at the heart of UK efforts to explore and benefit from space. It is responsible for all strategic decisions on the UK civil space programme and provides a clear, single voice for UK space ambitions.
The Agency is responsible for ensuring that the UK retains and grows a strategic capability in the space-based systems, technologies, science and applications. It leads the UK’s civil space programme in order to win sustainable economic growth, secure new scientific knowledge and provide benefits to all citizens.
The UK Space Agency:
• Co-ordinates UK civil space activity
• Encourages academic research
• Supports the UK space industry
• Raises the profile of UK space activities at home and abroad
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• Licences the launch and operation of UK spacecraft
• Promotes co-operation and participation in the European Space programme
