Star Tracker 5000
The Star Tracker 5000 (ST5000) is a device used by NASA to provide attitude and guidance signals to suborbital rockets and high-altitude balloons.
The ST5000 is an imaging device that provides autonomous (”Lost in Space”) inertial attitude determination, 10 Hz star tracking, and digital imaging with embedded compression. The attitude determination subsystem uses a 30-square degree field of view and an embedded star catalog to determine the Right Ascension and Declination of its line of sight to about 1 arcsecond.
The star tracking subsystem generates inertial attitude quaternions at 10 Hz. The digital imaging subsystem uses a scheme of "progressive image transmission" in which the image is sent out over a very-low-bandwidth channel, such as a spacecraft telemetry downlink, in such a way that it can be reconstructed "on the fly" and updated as more data arrive. Large (> 1 Mb) useful images can be obtained over a 4-kbit downlink in as little as 10 seconds.