Amateur Radio on the International Space Station (ARISS) and its partners are troubleshooting the failure of the on-board NA1SS amateur station in the ISS Columbus module. ARISS was alerted of the problem when a contact with a school in Wyoming, between ON4ISS on Earth and astronaut Mike Hopkins, KF5LJG, at NA1SS, had to abort when no downlink signal was heard.
“Today was a tough one for ARISS,” ARISS-International Chair Frank Bauer, KA3HDO, began in a message on January 28 to the ARISS team. Bauer explained that during a January 27 spacewalk to install exterior cabling on the ISS Columbus module, the current coax feed line installed 11 years ago was replaced with another built by the European Space Agency (ESA) and Airbus. It included two additional RF connectors to support the commissioning of the Bartolomeo payload-hosting platform installed last spring on Columbus.
“On January 26, prior to the EVA [extravehicular activity], our Columbus next-generation radio system was shut off and the ISS-internal coaxial cable to the antenna was disconnected from the ARISS radio as a safety precaution for the EVA,” Bauer said. During the spacewalk, an external four-connector coax feed line replaced one with two RF connections.
“This change was made to allow ESA to connect ARISS and three additional customers to Bartolomeo, as compared to ARISS and one additional RF customer,” Bauer explained.
With the spacewalk completed, the ISS crew restarted the ISS ham radio station on January 28, but no voice repeater or automatic packet repeater system (APRS) downlink reports were heard. During a scheduled school contact at 1746 UTC, no downlink signal was heard either, and the attempted contact had to be terminated.
“Clearly, there is an issue,” Bauer continued. “More troubleshooting will be required. It may be the new external RF cable that was installed during yesterday’s EVA. It might also [have been caused by] the connect and disconnect of the interior coaxial (RF) cable. So, the interior cable cannot be totally discounted yet.”
Read more – via American Radio Relay League | Ham Radio Association and Resources http://www.arrl.org/news/view/ariss-and-partners-are-investigating-space-station-ham-radio-failure