Two cosmonauts conducting a spacewalk outside the International Space Station (ISS) on Wednesday (Oct. 25) had a close encounter with a coolant leak. Oleg Kononenko got so close to the growing “blob” or “droplet” of pooling ammonia that his tether became contaminated. It had to be bagged and left outside the space station when the spacewalk ended. Kononenko and his fellow spacewalker, Nikolai Chub, began the extravehicular activity (EVA) at 1:49 p.m. EDT (1749 GMT) on Wednesday. One of their first tasks was to isolate and photograph the radiator, which had been observed leaking coolant on Oct. 9. The radiator is a backup for the main body radiator that regulates the temperature inside Russia’s Nauka multipurpose laboratory module. The cosmonauts successfully cut off the external radiator from its ammonia supply by configuring a number of valves.
After completing this task, Kononenko noticed a growing deposit of liquid coolant and observed a myriad of small holes on the radiator’s panels. He described the holes as having even edges as though they were drilled. The “blob” was believed to have formed from residual ammonia that was disturbed during the valve closing. To prevent bringing any toxic material back inside the space station, the cosmonauts wiped down their spacesuits and tools with tissues and cloths. Russian engineers will analyze the data collected during the spacewalk to determine the cause of the leak and how to address it in the future.
In addition to the radiator inspection, Kononenko and Chub also installed a synthetic radar communications system and released a nanosatellite to test solar sail technology. The installation of the radar, which will be used to monitor Earth’s environment, marked the first science payload mounted on Nauka’s exterior. However, the radar’s panels only partially deployed, and attempts to fully deploy them were unsuccessful. The nanosatellite, developed by a team at Bauman Moscow State Technical University, was designed to test experimental solar sail deployment but did not extend its solar wings as planned.
The spacewalk lasted 7 hours and 41 minutes and ended with the hatch being closed to the Poisk module airlock at 9:30 p.m. EDT (0130 GMT on Oct. 26). This EVA was the 268th in support of space station assembly, maintenance, and upgrades. It was the first for Chub and the sixth for Kononenko, who has now spent a total of 41 hours and 43 minutes working in Orlan spacesuits in the vacuum of space.
