ISS Ham Radio Project Engineer Kenneth Ransom, N5VHO, says the Amateur Radio on the International Space Station (ARISS) transceiver has been switched to the PCsat frequency of 145.825 MHz for a few days to conduct some joint packet operational tests.
”ISS will have several extended periods when the satellites will be in view of each other,” he said. ”This will be a temporary move to take advantage of PCsat being operational due to full sun and the favorable alignment of orbits between the two spacecraft.”
Ransom says the challenge for Earth stations is to try to relay a signal through both spacecraft–a double hop. ”Trying to do this via two space-based satellites is a bit trickier, since they are only in view of each other for a short time,” he said. ”The fact that these satellites also have to deal with Doppler relative to each other increases the difficulty.”
PCsat controller Bob Bruninga, WB4APR, says both spacecraft will operate as conventional APRS digipeaters using the alias of WIDE. ”This should double the opportunities for QSOs for the next eight days and also allow some potential double hops,” Bruninga commented.
He and Ransom emphasized that Earth stations should only undertake attended operations and not transmit any beacon any more often than once a minute. In addition, stations should avoid jamming the uplink, not conduct any operations after dark and not digipeat via W3ADO-1. ”If that call sign appears, it means PCsat has reset, and we only have one orbit to recover or we may lose her.”
Ransom says the ISS should remain on 145.825 MHz until February 10. ”Bottom line,” he added, ”try to get your packet signal to go through ISS and then PCSAT–or the other way around–and see if you can work folks outside of the footprint you are currently in.”