Raytheon has been selected to provide the synthetic-aperture radar (SAR) payload for the US Air Force Research Laboratory's TechSat21 micro-satellite technology demonstration. MicroSat Systems is building three SAR-equipped 150kg (330lb) satellites for the on-orbit demonstration, planned to begin in late 2005.
TechSat21 is intended to demonstrate the feasibility of replacing today's large satellites with constellations of mass-produced micro-satellites that can be reconfigured in orbit to perform multiple missions. Although the focus of the programme is moving target indication from space, the USA Falso plans to demonstrate precision geolocation using the same micro-satellites.
The spacecraft will fly in formation, exchanging position and timing formation via inter-satellite links. Operating in close proximity, with their active-array radars synchronised, the craft will create a virtual satellite with a much larger effective aperture size, increasing SAR resolution. The satellites will typically be 500m apart in "sparse aperture" radar mode, with spacecraft separation increasing to 5km when they are used for geolocation.
The three demonstration micro-satellites are scheduled for launch together in late 2005. MicroSat, a small Denver, Colorado-based company, won the $20 million cost-sharing contract in July 2000 and plans to complete the first satellite by the end of next year. The company is offering the micro-satellite as a bus for other military and civil experiments, says director of business development Scott Norris.
MicroSat is leading a TechSat21 "national team", including General Dynamics, ITT, Lockheed Martin and TRW, providing various technologies including lightweight thin-film solar arrays, micro pulsed-plasma thrusters, and inter-satellite links.
Source: Flight International
