January 8, 2014
ESA’s Gaia Ready To Start Operational Orbit
Brett Smith for redOrbit.com - Your Universe Online
Launched from the ESA’s facility in Kourou, French Guiana on December 19, Gaia is now in a gravitationally stable point called ‘L2,’ orbiting nearly 1 million miles from Earth.
“Entering orbit around L2 is a rather complex endeavor, achieved by firing Gaia’s thrusters in such a way as to push the spacecraft in the desired direction whilst keeping the Sun away from the delicate science instruments,” said David Milligan, Gaia spacecraft operations manager.
“After a beautiful launch from Kourou last month, we are very happy to now have reached our destination, and we are looking forward to starting our science operations in the coming months,” said Giuseppe Sarri, ESA’s Gaia project manager.
Once Gaia’s instruments have been properly calibrated and tested, processes that began on the way to L2, the observatory will begin a five-year operational phase. Gaia’s mission involves making extremely precise observations of one billion stars, tracking their exact positions and movements, as well as their temperatures, brightness and compositions. This interstellar census aims to create the most accurate 3D map of the Milky Way to date.
While in operation, Gaia will spin slowly, passing its two telescopes across the cosmos and focusing their light concurrently onto a single, billion-pixel digital camera – the largest ever sent into space. The craft will watch each star an average of 70 times over the course of its five-year mission.
Once the mission is complete the data archive generated by Gaia will exceed one million gigabytes. The herculean task of processing and analyzing this data will be performed by the Gaia Data Processing and Analysis Consortium, which includes over 400 individuals at scientific institutes across Europe.
“Our Gaia discovery machine will keep us busy throughout the mission, with the final results coming only after the five years of data have been analyzed,” said Timo Prusti, ESA’s Gaia project scientist. “But it will be well worth the wait, ultimately giving us a new view of our cosmic neighborhood and its history.”
The ESA had delayed Gaia’s launch due to a glitch found in another satellite already in orbit. The technical issue pushed back the initial Gaia launch date from November 20 to December 19.
Because Gaia shares some of the same components involved in the technical glitch found in the working satellite in space, ESA said engineers working on the final preparations for Gaia had to take some precautionary measures.
The glitch involved components used in two transponders on Gaia that generate timing signals for downloading the science telemetry. These were replaced in order to avoid any future problems that could occur while in orbit.
After the transponders were removed at the Kourou facility, the satellite was shipped to Europe where the components were replaced and verified. After the ESA replaced the faulty equipment, they conducted a final verification test to ensure its ability to work effectively.