A malfunctioning antenna outside the ISS (International Space Station) was replaced by two NASA astronauts on the spacewalk, re-establish one of the orbiting outpost’s communication channels with Earth.
Tom Marshburn as well as Kayla Barron of Expedition 66 conducted the extravehicular activity (EVA) that lasted 6-hour, 32-minute on December 2, replacing a damaged S-band Antenna Subassembly (SASA) on station’s backbone truss with a spare SASA stowed on an external pallet.
Marshburn and Barron started the spacewalk at exactly 6:15 a.m. EST, converting their EMU spacesuits to the internal battery power soon before departing the station’s U.S. Quest airlock. The astronauts then proceeded to their first scheduled workstations after obtaining their individual tools.
Barron made her approach to the ExPRESS Logistics Carrier-3 (ELC-3) platform placed on Port 1 (P1) truss, where spare antenna was housed, while Marshburn collected portable foot restraint to mount to end of station’s Canadarm2 robotic arm. Barron made preparations for spare SASA for the removal from pallet and temporarily storing the items she and Marshburn might need for the replacement.
Meanwhile, Marshburn positioned the base of the 58-foot (17.6-meter) Canadarm2 near the unsuccessful SASA. From inside the station, NASA space explorer Raja Chari as well as European Space Agency (ESA) astronaut Matthias Maurer controlled robotic arm’s controls to be able to move Marshburn into place.
The SASA is utilized to send and receive low-bandwidth voices and data from the ground. The antenna on P1 truss stopped transmitting signals to Earth through NASA’s Tracking and Data Relay Satellite System (TDRSS) in September. Even though another unit was still operational and the space station could still broadcast video using its KU-band communications system, mission officials decided to repair the defective antenna in order to maintain redundancy.
Before removing the degraded SASA from truss and provisionally securing it to ELC-3, Marshburn fitted stabilizing gimbal locks. He and Barron then unwrapped a thermal blanket that had been covering the spare SASA while it was stowed, allowing the new unit to be removed from the platform.
With a laugh, Barron added to the blanket, “I’m thankful we’re not attempting to put it back on.” “It’s just a bunch of Velcro in very specific spots.”
Marshburn bolted the replacement SASA into place on the Canadarm2’s P1 truss, ran cables, and unlocked gimbal locks which will enable the antenna to progress. He and Barron then went back to the ELC to examine the malfunctioning SASA and correctly place it on the pallet.