The development of low-earth-orbit store-and-forward satellites in the Amateur Radio Service

The author discusses several satellites whose primary mission is to provide store-and-forward message relay services for radio amateurs. The primary focus is on the PACSAT-1 satellite owned and operated by the Radio Amateur Satellite Corporation of North America (AMSAT-NA), and the UoSAT-3 and UoSAT-5 satellites constructed and operated by the University of Surrey (England) UoSAT Spacecraft Engineering Research Unit. This paper emphasizes three major areas: a description of the spacecraft; the ground station equipment and software required to utilize the services provided by the satellites; and statistics which describe current usage patterns. A breakdown of downlink usage by data type is given for PACSAT-1. To show how the PACSAT-1 and UoSAT-5 satellites are utilized on a day-to-day basis, graphical summaries of two weeks of PACSAT-1 and UoSAT-5 operation are included