SSTI Clark ACS Technology Demonstrations

SSTI Clark, one of two spacecraft built under NASA's Small Satellite Technology Initiative, includes seven ACS technology demonstrations. The technologies redefine the performance cost envelope, providing improved sensor and actuator performance at reduced costs. Six sensing technologies are being flown consisting of both hardware and algorithmic demonstrations: autonomous star tracker, hemispherical resonating gyro, GPS attitude determination, miniature horizon sensors, low cost course sun sensors, and gyroless rate estimation. Although technology demonstrations themselves, combining the star tracker and gyro in a Kalman filter scheme, provides a relatively accurate "absolute" reference against which quantitative measurements of GPS attitude knowledge, horizon sensor and coarse sun sensor performance are to be compared. To round out the suite of technology demonstrations, a pair of low cost reaction wheels are being flown.