The Terma HE-5AS Star Tracker is a fully qualified design, offering a favorable combination of arc-second performance at an affordable price. Robust algorithms provide full autonomy in initial attitude acquisition and attitude update. Terma quality standards, documentation and component screening meet the requirements of discerning customers including the European Space Agency and the U.S. Department of Defense.

The Camera is separate to make it easier to accommodate on the satellite, and to minimize heat dissipation (<1.5W) near the sensor. The camera is a very compact unit, weighing less than 1.0 kg. The optics provides a 22º field of view and – although compact – provides enough aperture to track across the entire celestial vault. A cable provides digital data-link (LVDS) and power supply from the processor unit. The Camera can be supplied with a thermo-mechanically stable bracket.

Custom or standard baffles are available providing a Sun exclusion half angle as low as to 30º.

The processing unit houses the star catalogue and the software algorithms for initial attitude determination and continuing attitude update. Also, the unit provides power to the camera. The interface towards the spacecraft is redundant RS-422 or MIL-STD-1553, and a power supply voltage from +22 V to +34 V. Dissipation is 5.5 W.