Stellar Compass on Stardust

The Stellar Compass™ software provided the primary method of attitude measurement during the Stardust spacecraft's (picture below) seven year sample return mission to the comet Wild 2 and back.

The image below was taken by a star camera on Stardust. The image was downlinked on March 11, 1999. It is centered at RA 14 hr 13.14 min, DEC -8.295 deg. It is half in the constellation Virgo, showing both Alpha Virgo (Spica) and Alpha Vibra. The bright object in the image is the planet Mars. The slightly speckled background is from thermal and electronic noise, and from radiation (mostly protons). The Stellar Compass software successfully filtered out Mars and the noise, and was able to produce a solid attitude solution for this image.

As of August 13, 1999, the star camera on Stardust had taken 1,588,830 images. Of those, 804 images did not result in immediate attitude solutions ("outages"). That is a 99.95% performance record. 736 of the outages, or 92%, involved a single image only. In 30 of the outages, or 4%, there were two consecutive missed images. There were thus only 38 times out of 184 days of operation where more than 1 or 2 images were missed.

In mid February 2000, the Stardust spacecraft was on the opposite side of the solar system from Earth. An image taken by the Stardust star camera during this time can be seen here. For most of the mission, the star camera was operating in all-stellar mode, capturing a new star image once per second (that's 3600 images/hour, or 86400 images/day).

The star cameras and optics used by the Stellar Compass were built by Goodrich Aerospace (formerly OCA Applied Optics). The cameras were integrated into the NASA spacecraft by Lockheed Martin Astronautics (LMA), who was also responsible for the rest of the flight software.