ARISS Quick Update 5 March 2021 by Frank Bauer KA3HDO


The following is an ARISS update from the e-mail I sent out on 2 March 2021, which is shown at the bottom of this e-mail:

This past week, astronauts on ISS performed troubleshooting tests on all four Bartolomeo RF cables that were previously installed in the Columbus Module.   The P01 cable, designated for ARISS, and the other three cables, designated for Bartolomeo commercial use, were connected to the ARISS radio system and tested in APRS mode.  No communications were established.

An EVA (spacewalk) is currently in progress.  Both ARISS radio systems on ISS have been shut off prior to this EVA for safety reasons.  As stated below, the ARISS antenna cable swap is a contingency procedure that is planned as the last task in the EVA (as time allows).  Prior to this contingency activity, Kate Rubins and Soichi Noguchi will be working on some other Bartolomeo cable/connector troubleshooting,  The troubleshooting with the Bartolomeo PAPOS connector will occur around 1700 UTC (+/- 30 minutes).  We are cautiously hopeful that the ARISS contingency EVA procedure, planned after the PAPOS troubleshooting, will be successfully completed prior to the end of the EVA.  If you listen to the EVA and want to follow along, Rubins and Noguchi plan to reconnect our ARISS antenna to the J02 connector of the APCU bracket. 

You can watch the EVA at

73,  Frank Bauer, KA3HDO

ARISS International Chair

2 March 2021


The ARISS team has been working very closely with NASA and ESA to identify potential ARISS radio anomaly causes and resolve the radio issues that were observed after the EVA (spacewalk) conducted on January 27.  During this spacewalk, cabling was installed to support the commissioning of the Bartolomeo attached payload capability mounted on the Columbus module.  Part of this cabling rerouted the cabling of the ARISS antenna on Columbus to the ARISS radio system. 

Through a great deal of coordination with NASA and ESA, ARISS will be conducting a set of APRS tests to determine the operational use of the ARISS radio system in Columbus through employment of three different cabling configurations.  Over the next couple of days, ARISS will be performing a series of tests using our APRS capability through the standard 145.825 MHz APRS frequency.  The crew will be periodically shutting down the radio and swapping cables so ARISS can troubleshoot the radio system and the cabling.  ARISS is unsure of the exact swap times as it will be dependent upon the crew’s availability.  We expect these tests to start no earlier than 1600 UTC on March 2 and run through sometime on March 3.  We cannot guarantee that these troubleshooting tests will resolve the radio issue.  But we encourage ARISS APRS operations in this time span.  Additionally, a contingency task has been approved for an EVA planned for this Friday March 5 if these tests are unsuccessful. This EVA task would return the ARISS cabling to the original configuration prior to the January 27 EVA. Being a contingency task means the crew  will only be perform the activity if time allows.  So there is no guarantee that this EVA will be conducted on Friday.

We ask to please not send any “No contact” e-mails or social media responses as this will overwhelm the ARISS team.  But if you definitely hear the packet system working or are able to connect through it, let us know the Date, Time and Grid Square of the occurrence. 

We thank you for your patience as we work through this somewhat complex anomaly.


Frank Bauer, KA3HDO

ARISS, International Chair

Executive Director, ARISS-USA

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