The Mashable.com article TESS is about to become your new favorite NASA mission shows a beautiful photo of the TESS spacecraft in a state that looks like it is nearly ready to launch.
There is a panel with array of what looks like mirrors on one side. What are they for? How do they work? Are they related to or the same as the large panels shown in the question What are these very large, square panels on Inmarsat 5's? or something completely different?
below: TESS on Earth. Cropped from Mashable.com. Credit: NASA
below: "A look at TESS inside the PHSF at NASA's Kennedy Space Center in Florida." Cropped from Space.com's NASA's TESS Exoplanet-Hunting Mission in Pictures. Credit: Kim Shiflett/NASA
below left: TESS on Earth. Mashable.com. Credit: NASA. right: Screenshot of YouTube video NASA’s New Planet Hunter: TESS Click for full size.