Tuesday, July 7, 2015

HF Returns to Ham Radio Satellites

An amateur radio satellite with HF capabilities is in orbit and operating for the first time in at least 15 years. Two cubesats recently launched by the U.S. Naval Academy - BRICsat (Naval Academy OSCAR-83) and PSAT (NO-84) carry 300-milliwatt PSK-31 transponders with uplinks on 10 meters
(28.120 MHz) and downlinks on 70 centimeter FM (435.350 MHz). The PSK transponder is NO-84's primary mission, according to the ARRL Letter, designed to allow dozens of simultaneous users to operate full duplex and keep up a continuous group dialog throughout a pass. It is the first time an amateur satellite has had either an uplink or downlink on the HF bands since the Russian RS-series satellites went silent around the turn of the century.
The two satellites were launched May 20. They both also operate APRS on VHF (NO-84)/UHF (NO-83), which is not surprising since their design team was led by APRS developer Bob Bruninga, WB4APR.

In a related story, NASA's next mission to Mars, due for launch next year, will include two non-amateur cubesats. According to the AMSAT News Service, it will be the first time these microsatellites have flown in deep space. The ultimate mission goal, in addition to seeing if cubesats can make it through interplanetary space, is to use them as communication relays for future Mars missions between the time a lander enters the planet's atmosphere and touchdown.