The astronauts of NASA have completed the fifth spacewalk of 2018 from International Space Station. They have spent about 6 hours 31 minutes in space in which they have undertaken the maintenance work of the space station.
Flight Engineers Drew Feustel and Ricky Arnold of NASA’s Expedition 55 has carried the work of the Pump Flow Control Subassembly (PCFS) and replace it with a new spare part with the help of the station’s truss robotic arm. The work of the PCFS is to control the flow of ammonia gas through the exterior portions and keep the station cool.
Two astronauts have checked the two external cooling boxes which are named as Leaky and Frosty. The box size is about the size of a mini-refrigerator or Window AC unit. It plays an important role in keeping the batteries of the orbiting lab cool. As they operated in the highly toxic ammonia, spacewalkers have taken precaution to avoid getting that to their suits.
The main danger in this maintenance is the spelling of ammonia. This a high-grade ammonia which runs through the cooling loops. It is about ten times more powerful than ammonia that is used in the household cleaners. Vareha said, “It is something that we are very respectful of because we don’t want that coming inside the vessel on the suits at the end of the spacewalks.”
The duo also removed the camera group and replaced with it a new camera and a degraded Space to Ground Transmitter Receiver Controller and other tasks. Till now, the spacewalkers have spent a total of 54 days, 16 hours and 40 minutes by working outside the International Space Station for maintenance of the laboratory. This spacewalk is the 210th walk which was taken from ISS.