Miniature Interferometric Star Tracker for Harsh Space Environments

Optical Physics Company (OPC) has been developing a sub-arcsecond accuracy rad-hard interferometric star tracker under AF SBIR sponsorship. Under this SBIR Phase I project, we will investigate options to miniaturize this device by more than an order of magnitude while maintaining the wide temperature range and high radiation tolerance of the original design. The changes for miniaturization involve a smaller dual grating interferometric front end, elimination of the image intensifier and relay optics, and use of an off-the shelf FPA that has been backthinned. Our target weight is 200 gm (15x lighter) in a 3.5x3.5x10 cm volume (12x smaller). The expected performance is 10 arcseconds (3 sigma) at a slew rate of up to 8 deg/sec. During Phase I, we will set up a lab demonstration to build and test a model of the miniaturized star interferometer using our existing star simulating testbed. This will be followed by the anchoring of experimental results to analytic model predictions and Phase II prototype design.