The signal from the digital amateur television (DATV) transmitter aboard the International Space Station (ISS) cannot be detected on the ground, Amateur Radio on the International Space Station (ARISS) has reported. The unit indicates that it is functioning, however. So far, ARISS has been at a loss to pin down the problem.

“A series of steps are currently being undertaken to try to diagnose the problem,” a May 10 announcement from ARISS said. “However, if an actual failure occurred, only a ground-based evaluation will fully diagnose the problem. The ARISS International team is working diligently to bring [the system] back to full operation as soon as practical.” The ISS DATV system is known variously as “HamVideo” and “HamTV.”

ARISS said it has begun coordination with its space agency partners and sponsors to “expeditiously troubleshoot the issue onboard and, if necessary, troubleshoot and repair the device on the ground.”

The DATV transmitter has proved to be a valuable educational asset that ISS crew members have enjoyed employing over the past couple of years during ARISS school and group contacts. Astronauts Tim Peake, KG5BVI; Paolo Nespoli, IZ0JPA; and Thomas Pesquet, KG5FYG, in particular, made routine use of the DATV system to enhance the ARISS ham radio contact experience for students and educators.

Ground stations in Australia and Europe have functioned to receive and distribute the Amateur Radio TV signal from the ISS. Ground stations are under development in the US. Several hams in Japan have set up ground stations that have received the DATV signal from the ISS.

Peake inaugurated formal use of the DATV system for a 2016 ARISS school contact with students at a Royal Masonic School, in Rickmansworth, England, home of GB1RSM. The DATV system, located in the Columbus module of the ISS, allowed students at the school to see as well as listen, as Peake, operating as GB1SS, answered their questions about life in space. The one-way DATV downlink took place near 2.4 GHz, while the two-way FM audio component was maintained on 2 meters.

The DATV system was first proposed more than 17 years ago. The IK1SLD ground station received the DATV signal. It was commissioned during a series of tests in 2014.