After being rendered non-operational following a January 27 spacewalk that was conducted to install an HMU-601 cable for the Bartolomeo commercial platform, the ARISS Columbus Radio Station returned to the air on March 14 with full capabilities.
The station that typically operates as NA1SS suffered technical difficulties following the installation of the HMU-601 cable alongside the ARISS antenna cable (HMU-895) that replaced the existing coax feed line installed onsite 11 years ago. After the install, the radio equipment on the Ham station remained operational but was unable to transmit a signal to the ARISS antenna. The problem became evident when a contact with a school in Wyoming, between ON4ISS on Earth and astronaut Michael Hopkins at NA1SS, failed to hear a downlink signal and was forced to abort.
ARISS scheduled a detailed news conference on March 10 that discussed troubleshooting efforts, highlighted complexities of the issue, and included a proposed action plan for a return spacewalk on March 13 to resolve the problems—and resolve the problems it did.
On March 13, Hopkins installed three PAPOS connectors for the Bartolomeo platform on the Columbus module and then started the ARISS task. Hopkins next removed the HMU-601 cable from the APCU J02 connector reverting the system to the pre-January 27 configuration and restoring full signaling capabilities.
The team of astronauts then turned on the ARISS radio system on Columbus around 1200 UTC and placed it in PM3 (packet mode), which employs a downlink frequency of 145.825 MHz. Shortly after, APRS signals were heard in California, Utah, and Idaho as the ISS passed along the west coast of the U.S. ARISS team member Christy Hunter, KB6LTY, confirmed that she digipeated using NA1SS during the pass. Confirmations from stations in South America and the Middle East were made soon after, and the ARISS Columbus Radio Station was declared to be officially back in action!
