Kepler (spacecraft) - Kepler Spacecraft

Kepler Spacecraft

The spacecraft has a mass of 1,039 kilograms (2,290 lb), has a 0.95-meter (37.4 in) aperture, and a 1.4-meter (55 in) primary mirror – at the time of its launch, this was the largest mirror on any telescope outside of Earth orbit. The spacecraft has a 115 deg2 (about 12 degree diameter) field of view (FOV), roughly equivalent to the size of one's fist held at arm's length. Of this, 105 deg2 is of science quality, with less than 11% vignetting. The photometer has a soft focus to provide excellent photometry, rather than sharp images. The mission goal is a combined differential photometric precision (CDPP) of 20 ppm for a m(V)=12 solar-like star for a 6.5 hour integration, though the observations so far fall short of this objective (see mission status). An Earth-like transit produces a brightness change of 84 ppm and lasts for 13 hours when it crosses the center of the star.