Gaia spacecraft in launch configuration before being moved to tanks pressurization test.

The activities on the spacecraft are almost finished. The great achievement of last week was the smooth deployment of the sunshield. The Astrium and Sener teams are now giving the final touch to configure the satellite for flight. This week we will check for the last time the leak tightness of the propellant tanks and then Gaia will be ready to move to another building (called S5A) where it will be fuelled.


Three Soyuz stages in integration centre MIK. The 3rd stage is in the forefront. The 1st and the 2nd stages are already integrated in the background. The 1st stage is constituted by the four lateral conical boosters.

With Gaia almost ready it was time to have a look to other pieces of the puzzle. We therefore paid a visit to the MIK building (MIK is the Russian acronym for the huge hall where the three stages of the Soyuz are assembled). We could see the 1st and 2nd stages mated together and the 3rd one close to them.


Fregat upper stage (4th stage) covered by a protective shroud. This picture was taken before fuelling.




Next was the Fregat upper stage. The Fregat is now fuelled with more than six tons of very poisonous, corrosive and explosive propellant and it is resting in the complex S3B waiting for Gaia.





Fairing which will contain the spacecraft and the Fregat upper stage when integrated.


Last, but not least, we checked the fairing: the two shells which will enclose the spacecraft and the Fregat. It’s ready, and only waiting for the two big stickers featuring the Gaia logo, which will be applied to each shell.

Thee three components – the spacecraft, the Fregat and the fairing – are collectively known as the “upper composite”. The upper composite will be mounted on top of the rocket on the launch pad, five days before launch.