Fox-1B, AO-91 or AMSAT OSCAR 91[3] is a United Statesamateur radio satellite. It is a 1U Cubesat, was built by the AMSAT-NA and carries a single-channel transponder for FMradio. The satellite has a whip antenna for the 70 cm and 23 cm bands (uplink), and a second antenna for the 2 m band (downlink). Fox-1B is the second amateur radio satellite of the Fox series of AMSAT North America.
To facilitate a satellite launch as part of NASA's Educational Launch of Nanosatellites (ELaNa) program, the satellite carries a student experiment conducted by Vanderbilt University's Institute for Space and Defense Electronics. The RadFx experiment at this institute hosts four payloads for the study of radiation effects on commercially available electronic components. So it should be tested electronic components "off the shelf" under space conditions. The payload of AMSAT North America is a single-channel FM converter from Ultra high frequency (UHF) to Very high frequency (VHF). After successful launch, the satellite was assigned the OSCAR number 91.
Launches are separated by dots ( • ), payloads by commas ( , ), multiple names for the same satellite by slashes ( / ). Crewed flights are underlined. Launch failures are marked with the † sign. Payloads deployed from other spacecraft are (enclosed in parentheses).