The European Space Agency’s Gaia satellite, designed to create an unprecedentedly detailed 3D map of our galaxy, has been been launched from the European spaceport in Kourou, French Guyana.
Lifted to space aboard the Soyuz rocket, the ten-metre in diameter flying-saucer-like satellite is on the way to the so-called Sun-Earth Lagrangian Point 2 (L2) – a stable spot some 1.5 million kilometres (930,000 miles) from the Earth, where the gravitational pulls of the Sun and the Earth are in equilibrium, allowing an object to stay in a fixed position.
After reaching its destination, Gaia, equipped with the largest digital camera ever flown in space will commence its five-year mission to observe billions of stars of the Milky Way. It is believed that it will discover many more along the way.
In a series of tweets after the launch, ESA, monitoring the progress from its Space Operations Centre in Darmstadt, Germany, confirmed the spacecraft successfully separated from the launcher shortly before 10am GMT, about 40 minutes into the flight. ESA’s ground station in Perth, Australia, acquired the first signal from Gaia about two minutes later.
“After separation, Gaia must still perform a critical automated sequence that includes pressurising its attitude control thrusters and deploying its sunshield, a very delicate step,” Dave Milligan, Gaia Spacecraft Operations manager, said in a pre-launch interview.
During the sequence, Gaia will be in ‘free drift’, meaning that its attitude in space is not controlled and separating from its launcher may cause it to spin or tumble. As a result, it may rotate out of line-of-sight radio communication with the stations below.
“During about 17 minutes, we may lose radio contact, but as long as the on-board sequence runs OK, we’ll regain communications afterwards,” he said, explaining there are only few things satellite controllers and operations engineers like less than not being in touch with their satellites.
The delicate Launch and Early Orbit Phase will be conducted from the Darmstadt centre and is expected to last about four days. The teams will be monitoring the satellite non-stop during this period before commencing regular operations.