Preparing Gaia's Deployable Sunshield Assembly at Kourou
Engineers from SENER and Astrium (not visible in this photograph) inspect the alignment and movement of the long poles or "arms" that are the skeleton of the Deployable Sunshield Assembly (DSA), at the S1B cleanroom at Kourou in French Guiana. Once inspected, they will be covered in multi-layer insulation (MLI) to provide the thermal shield.
The structural skeleton of the DSA is made up of 12 frames of carbon fibre tubes, split into 4 quarters of 3 frames each. Each of the 12 frames is hinged at 2 points at its base, where it is attached to the spacecraft, and can be deployed 90 degrees. When all the frames are deployed and thermal blankets are added to cover the structural skeleton, the sunshield will form a flat disc at the base of the spacecraft, which will shade the Gaia telescope from the Sun.
Before adding the thermal blankets, the frames are deployed one by one, and a laser tracker is used to measure the position of several points on each frame to check that once deployed they will all form a perfectly flat plane.
The Prime Contractor for Gaia is Astrium SAS, based in Toulouse, France. SENER (Spain) is responsible for the development and manufacture of the Deployable Sunshield Assembly. The thermal blankets are provided by RUAG Aerospace Austria and the carbon fibre frames come from RUAG Aerospace Switzerland.