The GAIA satellite has not yet begun its mission. Yet engineers and scientists at the Toulouse Space Centre (CST) have been busy at their stations in recent days. The purpose of the exercise was to train and prepare for handling the vast volumes of astronomy data that GAIA will be returning every day.
"Here at the CST, the rehearsal went as planned," says Véronique Valette, CNES project leader for the GAIA mission. "We successfully received and processed a continuous stream of up to 120 gigabytes of simulated data per day, in coordination with the five other European data processing centres."*
Scientists at the CST had a dual objective: verify that the stars were positioned with the required degree of precision and ensure that the software is able to rapidly identify any objects of interest in the GAIA data.
"Over the months, GAIA will locate hundreds of millions of stars," says Olivier La Marle, astrophysics programmes coordinator at CNES. "But the satellite will also detect other events, such as asteroids or variable stars, which will need to be reported to astrophysicists within 24 hours, not six months later."
1 billion stars to chart
To compile this map, powerful software programs, in particular the software at the CST, must process and make sense of all these data—which is no mean feat," he adds. "Over 6,000 processing cores will thus be needed in order to perform 6,000 billion operations per second for the seven years."
After seven years of gathering and processing all these data, scientists will have the most precise map ever produced, with the positions of over 1 billion stars and other objects—the ideal tool for studying the history and evolution of the Universe.
The GAIA satellite is scheduled to launch on 20 November atop a Soyuz rocket. "The satellite is now in Kourou," says Olivier La Marle. "But the first data won't be arriving until January 2014, so the scientists still have a few months to fine-tune the software and be ready!" concludes Véronique Valette.
*ESAC in Madrid, Institute of Astronomy in Cambridge, University of Barcelona, Data Processing Centre – Turin and ISDC in Geneva.
**Objects that are too low in mass to be considered as stars.