Due to the recent failure of the Ericsson VHF radio in the ISS Columbus module, the Amateur Radio on the International Space Station (ARISS) APRS packet system that normally operates 145.825 MHz has not been available. Crew member Shane Kimbrough, KE5HOD, has activated an ARISS UHF radio that had been in storage on the ISS, and it is now operational on 437.550 MHz.
The packet system uses the same protocol as the VHF system. Operators using the system should adjust for increased Doppler shift at UHF.
The ARISS team is currently working on Kenwood TM-D710GA models to replace all Amateur Radio transceivers on board the ISS. The target date for delivery is late 2017. — Thanks to ARISS