Hokkaido Institute of Technology’s HIT-SAT satellite has joined several other CubeSats carrying Amateur Radio payloads in space. The tiny satellite launched successfully September 23 (Japan Standard Time) from the Uchinoura Space Center in Japan, and its CW telemetry was copied around the world on the satellite’s initial orbits. Over the weekend, HIT-SAT’s CW telemetry was halted as a power-saving measure during attitude control procedures, and it remained silent after attitude control should have ended. But on September 27, ground controllers were able to restore the CW telemetry.
“Although the cause was still unknown, we hope the transmission of CW continues normally,” the HIT-SAT team said on its Web site. “We appreciate the cooperation and help of radio amateurs all over the world. Please hear the beat of our satellite’s heart.” HIT-SAT’s FM packet transmitter has been operating normally from the time the spacecraft reached orbit, and ground controllers have been able to obtain telemetry data from it.
Like other university-built CubeSats, HIT-SAT was constructed using mostly off-the-shelf parts. The 1200 bps FM packet downlink is on 437.425 MHz, while the CW telemetry downlink is on 437.275 with a transmitter power of 100 mW. The CubeSat uses a VHF uplink. The HIT-SAT team is seeking reception reports, including audio files. The satellite’s call sign is JR8YJT.
Once it’s fully operational, HIT-SAT will permit Earth station operators to request certain parameters by transmitting DTMF commands on the 145.980 MHz uplink. The satellite can report back time/date, temperature and power supply voltages and thank the Earth station by call sign. Only HIT-SAT ground station controllers can access the satellite at this point, however.
The diminutive satellite is a project of the Hokkaido Institute of Technology’s ham radio club. HIT-SAT hitchhiked on the M-V-7 vehicle that carried the Solar-B satellite into orbit. The satellite is in a sun synchronous orbit with an orbital altitude of 250 km at perigee and 600 km at apogee and an inclination of 97.79 degrees. A 12-cm square cube, HIT-SAT weighs 2.2 kg.