Session
Technical Session XI: Educational Programs
Abstract
A communications system operating in the 2.4GHz ISM unlicensed band was developed for GeneSat-1, an innovative technology demonstration mission intended to validate the use of research quality instrumentation for in situ biological research and processing. As a key underlying mission-enabling technology, and responding to a lowcost, quick turn-around philosophy, this communications system is based on commercial-of-the-shelf components not originally intended for space flight. The system utilizes a frequency hopping spread spectrum technique widely used in wireless phones, Internet hubs and other devices. This approach provided exceptional benefits relevant to small satellite missions: low cost, highly integrated hardware resulting in small volume, ready commercial availability, plug and play integration, and simple licensing requirements. As a comparison with typical amateur band systems widely used in spacecraft of this class, besides avoiding the restrictions on the nature of the mission, it has the potential for higher throughput and includes security features such as addressing and encryption. Challenges in using this component included the accommodation of Doppler frequency shift, coordinating propagation delays with a time-division multiplexing architecture, and establishing suitable interface requirements for the Earth communication station. GeneSat-1 is a “triple-CubeSat” vehicle launched into LEO in December 2006. Its main mission objectives were successfully achieved during the first few weeks of operation This paper presents a description of the comprehensive analysis and testing produced to attain space qualification and measures of onorbit performance collected during spacecraft operations, including link availability, effective telemetry throughput and link margin.
Presentation Slides
A Flight-Proven 2.4GHz ISM Band COTS Communications System for Small Satellites
A communications system operating in the 2.4GHz ISM unlicensed band was developed for GeneSat-1, an innovative technology demonstration mission intended to validate the use of research quality instrumentation for in situ biological research and processing. As a key underlying mission-enabling technology, and responding to a lowcost, quick turn-around philosophy, this communications system is based on commercial-of-the-shelf components not originally intended for space flight. The system utilizes a frequency hopping spread spectrum technique widely used in wireless phones, Internet hubs and other devices. This approach provided exceptional benefits relevant to small satellite missions: low cost, highly integrated hardware resulting in small volume, ready commercial availability, plug and play integration, and simple licensing requirements. As a comparison with typical amateur band systems widely used in spacecraft of this class, besides avoiding the restrictions on the nature of the mission, it has the potential for higher throughput and includes security features such as addressing and encryption. Challenges in using this component included the accommodation of Doppler frequency shift, coordinating propagation delays with a time-division multiplexing architecture, and establishing suitable interface requirements for the Earth communication station. GeneSat-1 is a “triple-CubeSat” vehicle launched into LEO in December 2006. Its main mission objectives were successfully achieved during the first few weeks of operation This paper presents a description of the comprehensive analysis and testing produced to attain space qualification and measures of onorbit performance collected during spacecraft operations, including link availability, effective telemetry throughput and link margin.
