Inertial Stellar Compass (ISC) was a proposed[1] instrument for an advanced navigation system designed to allow spacecraft to operate more autonomously by enabling precise attitude determination with an accuracy of better than 0.1 degrees across all three axes.
The ISC was developed by NASA as part of New Millennium program's Space Technology 6 project in collaboration with Charles Stark Draper Laboratory.
It uses a wide field-of-view active pixel star camera and a micro electromechanical system to determine the real-time stellar attitude (orientation) of the spacecraft.
[4] In 2007, it was successfully deployed and fully operational in space aboard the TacSat-2 spacecraft.
[6] As the New Millennium Program had its budget cancelled in 2009,[7] it is unclear whether development of this instrument is ongoing.