Two Russian cosmonauts completed a spacewalk to activate a radiator they previously helped relocate outside the International Space Station.
Expedition 69 Commander Sergey Prokopyev and Flight Engineer Dmitry Petelin, both from the Russian federal space corporation Roscosmos, successfully deployed the heat exchanger as their primary task during the 5-hour, 14-minute extravehicular activity (EVA) out of the International Space Station (ISS) on Friday (May 12).
The spacewalk was the third and final in a series that focused on outfitting the exterior of the Russian Nauka multipurpose laboratory module with the radiator and an experimental airlock that was launched with NASA’s onboard Rassvet research mini-module. space shuttle atlantis 13 years ago.
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After opening the airlock in the Poisk module at 11:47 a.m. EDT (1547 GMT) and exiting the station, Prokopyev and Petelin proceeded to the Nauka module to remove the remaining restraints that kept the radiator closed. As the bolts were loosened, the radiator began to fan out to its full length.
“The radiator is deployed,” Prokopyev said a short time later, after using a crowbar to fully extend the three-paneled wing.
With the hardware in place, the two spacewalkers set about opening the first set of valves to begin charging the radiator with coolant, a process that in total was estimated to take around two hours.
While waiting for the coolant to flow into the radiator, Prokopyev and Petelin installed two wrenches on the European Robotic Arm (ERA). The manipulator was previously used to transfer the radiator and airlock from Rassvet to Nauka during the April 18 and May 3 spacewalks.
The two cosmonauts also completed some “breakthrough” tasks for future spacewalks, installing a pair of handrails connecting Nauka’s lab to Prichal’s docking node.
Prokopyev and Petelin then opened a second set of valves to complete the coolant charge for the radiator. With no reported leaks, Russian flight controllers were able to confirm that the radiator had been successfully integrated into Nauka’s thermal control system.
The spacewalkers then began clearing their work area to return inside, having completed all the tasks set for them about an hour ahead of schedule. After discarding the towels used to wipe errant coolant from their spacesuits, Prokopyev and Petelin finished their spacewalk at 5:01 p.m. EDT (2101 GMT).
With Friday’s EVA, Prokopyev has now spent 42 hours and 16 minutes on six spacewalks. Petelin has now completed four sorties, logging 26 hours and 45 minutes out of the station.
The spacewalk was the sixth of the year and the 263 dedicated to the assembly and maintenance of the International Space Station.