The TESS instrument comprises four identical cameras. Each camera contains seven lenses and four CCD sensors that convert light into digital signals. Each CCD in the TESS cameras images a sky area that could hold 576 full Moons, and each camera captures an area as large as the constellation Orion. The cameras are bolted to a common plate and aligned so they capture a single wide swath of the sky. A sunshade encloses the cameras to protect them from the Sun. The cameras have lens hoods to shield them from stray light from Earth and other sources. In its first two years, TESS will survey 85 percent of the sky.