A single instrument aboard SNAP, the proposed SuperNova/ Acceleration Probe, will make it unique among satellites: its billion-pixel astronomical camera, the GigaCAM - the largest and most sensitive astronomical CCD imager ever constructed.
Standard astronomical CCDs are fragile affairs, and their ability to obtain high-quality images degrades quickly in the hostile radiation environment of space -- one reason why astronauts have already replaced all of the Hubble Space Telescope's original imaging instruments.