During launch, Gaia is operated from the European Space Operations Centre (ESOC, Darmstadt, Germany), using the ground stations at Perth (Australia) and Kourou (French Guiana).
Once in orbit and during normal operations, ESA’s most powerful ground stations – the 35 m-diameter Deep Space Antennas at Cebreros (Spain) and New Norcia (Australia) – will be used to relay information to and from the spacecraft via ESOC.
Science operations will be conducted from the European Space Astronomy Centre (ESAC, Villafranca, Spain).
Gaia will communicate with Earth for an average of about 8 hours each day. During this time, it will transmit its science data and ‘housekeeping’ telemetry signal. Although the spacecraft is 1.5 million kilometres away, it will be able to maintain its transmission at an extremely high data rate (~ up to 7.5 Mbit/s).
The Gaia Data Processing and Analysis Consortium (DPAC), which consists of more than 400 individuals, will process the data. Over the course of the 5 year mission, Gaia’s data archive will exceed 1 Petabyte (1 million Gigabytes), equivalent to about 200 000 DVDs worth of data.