Gaia Deployable Sunshield Assembly (DSA) integrated onto the spacecraft and undergoing deployment testing at Astrium Toulouse. Since the DSA will operate in microgravity, it is not designed to support its own weight in the one-g environment at Earth's surface. During deployment testing, the DSA panels are attached to a system of support cables and counterweights that bears their weight, preventing damage and providing a realistic test environment. The support system is clearly visible in the video.
As the DSA deploys, the flight model thermal tent comes into view and the mechanically representative dummy payload can be seen through the aperture in the tent. Towards the end of the deployment sequence, the flight model service module comes into view.
This test demonstrated correctness of alignment following integration, confirmed the deployment functionality and verified the flatness of the deployed DSA.
The video shows an edited, time-lapse sequence from the deployment of the DSA during a recent test campaign; the entire deployment sequence takes about 20 minutes.
For more information, visit the ESA Science & Technology pages.