Spacewalking astronauts replace faulty antenna at ISS

European Space Agency astronaut Thomas Marshburn rides the robotic Canadarm2 to the SASA work area. NASA astronaut Kayla Barron assisted him in replacing the failed S-band antenna. The two astronauts spent about 6.5 hours outside the outpost. Credit: NASA
Two astronauts have successfully completed a spacewalk at the International Space Station to repair a faulty S-band Antenna Sub-assembly, or SASA, during U.S. EVA-78 as part of the seven-person Expedition 66 mission.
The faulty antenna was first noticed during routine testing in September. Mission Control in Houston experienced issues while testing S-Band string 2 at both high and low data rates, yielding anomalous signatures. NASA made the determination that the SASA would need to either be repaired or replaced, with the latter being the more economical option.

Astronauts Thomas Marshburn, left, and Kayla Barron prepare their suits for their spacewalk. Credit: NASA
The event was originally scheduled to take place Tuesday, Nov. 30, 2021, however NASA made the last minute decision to reschedule the outing due to a possible collision risk posed by on-orbit debris.
It has not been confirmed if the debris event was related to the test-firing of a Russian anti-satellite weapon that forced the station crew into emergency configuration approximately two weeks ago.
The spacewalk began at approximately 6:15 a.m. EST (11:15 UTC) Dec. 2. European Space Agency astronaut Thomas Marshburn, acting as EV1 wearing red stripes, and NASA astronaut Kayla Barron, acting as EV2, began the activity at the Quest airlock.
Over the course of 6 hours, 32 minutes, the two astronauts quickly got ahead of their scheduled SASA replacement tasks on the Port 1 truss segment where the faulty antenna was located.
The duo were even able to perform several get-ahead tasks on the Port 4 truss segment, which included resetting torque on a set of bolts, according to NASA.
“Kayla and Tom, I asked you to crush it but man, you all triple crushed it,” astronaut Mark Vande Hei radioed from inside the station before the spacewalkers returned to the airlock.
This spacewalk, which officially ended at 12:47 p.m. EST (17:47 UTC), was the 13th at the ISS in 2021. While it was Barron’s first extravehicular activity, it was Marshburn’s fifth, bringing his cumulative time outside a spacecraft to 31 hours and 1 minute.
In total, this was the 245th spacewalk in support of ISS assembly and maintenance over the last 21 years. According to NASA, space station astronauts and cosmonauts have collectively spent 64 days, 12 hours and 26 minutes outside the orbiting laboratory.
Cullen Desforges
Having a life-long interest in crewed space flight, Desforges’ passion materialized on a family vacation in 1999 when he was able see the launch of Space Shuttle Discovery on STS-96. Since then, Desforges has been an enthusiast of space exploration efforts. He lived in Orlando, Florida for a year, during which time he had the opportunity to witness the flights of the historic CRS-4 and EFT-1 missions in person at Cape Canaveral. He earned his Private Pilot Certificate in 2017, holds a degree in Aviation Management, and currently works as an Operations Analyst in the aviation industry in Georgia.