More than 2 dozen QB50 constellation CubeSats have been deployed from the International Space Station (ISS), including three carrying Amateur Radio transponders. Built by student groups from 23 countries, the string-of-pearls QB50 constellation aims to study the lower thermosphere 200-380 kilometers above Earth. The satellites were launched to the ISS onboard an Atlas V rocket in March.

In all 28 QB50 2U and 3U CubeSats were released into orbit between May 16 and May 25. These included LilacSat-1 (ON02CN), which includes an Amateur Radio VHF/UHF FM to Codec2-BPSK digital voice transponder, APRS digipeater, and a camera; X-CubeSat (ON01FR) and SpaceCube (ON05FR). LilacSat-1’s transponder’s FM uplink is 145.985 MHz (67 Hz CTCSS tone); the Codec2 9600 bps BPSK downlink is 436.510 MHz. The uplink frequency for both X-CubeSat and SpaceCube is 145.860 MHz (210.7 Hz CTCSS tone). Downlinks are 437.020 MHz for X-CubeSat and 436.880 MHz for SpaceCube.

LilacSat-1 was developed at the Harbin Institute of Technology. Its primary payload is an ion and neutral particle mass spectrometer, developed by the University of London, to measure the mass and distribution of charged and neutral atoms. Shortly after its deployment LilacSat-1 took a picture of the ISS solar panels, and the image was received by students on 70 centimeters, using 9,600 bps BPSK.

Eight other QB50 CubeSats will be placed into orbit from India onboard Polar Satellite Launch Vehicles (PSLVs). No launch campaign has been announced for another four QB50 CubeSats. All of the QB50 CubeSats have downlinks between 435.8 and 438 MHz, and reports from radio amateurs are welcome.

In 2014, two precursor QB50 CubeSats were launched — QB50p1 (EO-79/FunCube-3) and QB50p2 (EO-80). Both carried Amateur Radio transponders.