Low-cost attitude determination system and imager with embedded compression

The Space Astronomy Laboratory has built and flown a very- low-cost (approximately 50K) star tracker and digital imaging system with embedded compression. The star tracker is suitable for all rocket and spacecraft applications, and provides pitch, yaw, and roll updates at rates up to 10 Hz. The digital imaging subsystem uses a novel NASA-funded scheme of `progressive image transmission' in which the image is sent out over a very-low-bandwidth channel, such as a telemetry downlink, in such a way that it can be reconstructed `on the fly' and updated as more data arrive. Large (768 X 474) useful images can be obtained over a 4- kbit/s downlink in as little as 10 seconds. This device can act as an aspect camera, a deployment monitor, or a science imager in situations where low bandwidth is desired or high bandwidth is not available.