SPACECRAFT COMMISSIONING PHASE

With Euclid on its way to L2, the other spacecraft systems and cameras can be switched on. One week after launch the high-power antenna that transmits the science images to ground is deployed. This antenna has a narrow beam and is steered to point at the ground station receiving the data. With the high-power antenna switched on and the storage system available, the instruments can be activated and start taking images.

After 13 days the spacecraft has cooled and the VIS instrument is working correctly. The telescope will be focused through a painstaking process of searching for the best focus, moving the mirror motor mechanism by tiny amounts and measuring stars in VIS images. The Fine Guidance System uses the telescope to track the positions of stars in the sky and with the telescope in focus it can be activated to achieve the necessary precise pointing performance. With all elements in place, the spacecraft, instruments, and telescope work together to capture Euclid's pristine images of the extra-galactic sky.