Two astronauts conducting a spacewalk outside the International Space Station (ISS) on Wednesday (October 25) got a close-up view of a coolant leak that was first observed flowing from an external radiator earlier this month.
Oleg Kononenko got so close to the growing “bubble” or “droplet” — as the collected ammonia was described — that one of his tethers became contaminated, necessitating it being bagged and left outside the space station when the spacewalk was over.
Kononenko and fellow Expedition 70 cosmonaut Nikolai Chub, also of Russia’s federal space corporation Roscosmos, began extravehicular activity (EVA) at 1:49 p.m. EDT (1749 GMT) on Wednesday, marking one of their first missions The radiator, which was first observed to be leaking coolant, was isolated and photographed on October 9. It was used as a backup to the temperature-regulating main body cooler inside a multi-purpose Nauka laboratory unit in Russia, and Kononenko and Chubb configured a number of fuses to cut off the external power. Coolant of ammonia supply.
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After this was completed and before the increasing buildup of coolant was noticed, Kononenko reported seeing countless small holes on the surface of the radiator panels.
“The holes have very even edges and are drilled through them,” Kononenko said over the radio to flight controllers working at Mission Control in Moscow. “There are a lot of them. They are spread out chaotically.”
It is believed that the “bubble” formed from residual ammonia that was disturbed when work was completed on closing the valves. Knowing in advance that they might come into contact with the coolant, the astronauts were equipped with wipes and cloths to wipe down their spacesuits and instruments so as not to bring any toxic materials back inside the space station.
Russian engineers on Earth will use the data collected by the astronauts to further determine the cause of the leak and what steps can be taken to restore the coolant for future use.
In addition to investigating the coolant, Kononenko and Chub also worked on installing a synthetic radar communications system and launched a nanosatellite to test solar sail technology. The radar, which will be used to monitor Earth’s environment, was the first scientific payload to be installed on the outside of Nauka. The radar panels were only partially deployed, and the astronauts’ attempt to deploy them completely was unsuccessful.
The small, cube-shaped satellite, developed by a team at Moscow’s Bauman State Technical University, was designed to test a way to deploy an experimental solar sail. With a little persuasion, the nanosatellite emerged from its envelope and slowly fell away from the space station, but the solar wings did not extend as planned.
The 7-hour, 41-minute spacewalk ended with the hatch to the Poisk module’s airlock closing at 9:30 PM EDT (0130 GMT on October 26).
The EVA was the 268th supporting space station assembly, maintenance and modernization. It was Chub’s first spacewalk and the sixth for Kononenko, who has now logged a total of 41 hours and 43 minutes working in Orlan spacesuits in the vacuum of space.
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