ISS: American spacewalkers Cassada and Rubio venture outside the space station

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Things are about to get busy on the International Space Station as the first in a series of end-of-the-year spacewalks kicked off Tuesday morning.

First-time spacewalkers and NASA astronauts Josh Cassada and Frank Rubio began their excursion outside the space station at 9:14 a.m. ET, with live coverage on NASA’s website. The event is expected to last for about seven hours.

Cassada is wearing the spacesuit with red stripes as extravehicular crew member 1, while Rubio is in the unmarked suit as extravehicular crew member 2.

The astronauts will assemble a mounting bracket on the starboard side of the space station’s truss. The hardware that will be installed during the spacewalk was delivered to the space station on November 9 aboard a Northrop Grumman’s Cygnus spacecraft, which safely delivered its cargo despite only one of its two solar arrays deploying after launch.

This hardware will allow for the installation of more rollout solar arrays, called iROSAs, to give the space station a power boost. The first two rollout solar arrays were installed outside the station in June 2021. Six iROSAs total have been planned and will likely boost the space station’s power generation by more than 30% once all are operational.

During two more spacewalks on November 28 and December 1, a two-astronaut crew will unroll and install another pair of solar arrays once the mounting hardware is in place. The solar arrays will be delivered on the next SpaceX Dragon commercial resupply mission, currently slated for launch on November 21.

Spacewalks are part of the space station crew’s routine as they maintain and upgrade the aging orbital laboratory, but Tuesday’s spacewalk is NASA’s first since March. The agency’s spacewalks came to a halt after European Space Agency astronaut Matthias Maurer ended his first spacewalk with water in his helmet.

A thin layer of moisture that exceeded the normal, expected amount was discovered in Maurer’s helmet once he returned to the airlock after a nearly seven-hour spacewalk. Maurer quickly shed the helmet, in an event deemed “a close-call” by NASA, and water samples, suit hardware and the spacesuit itself were returned to Earth for investigation. Officials at NASA determined the suit didn’t experience any hardware failures.

“The cause for the water in the helmet was likely due to integrated system performance where several variables such as crew exertion and crew cooling settings led to the generation of comparatively larger than normal amounts of condensation within the system,” according to NASA in a blog post update.

“Based on the findings, the team has updated operational procedures and developed new mitigation hardware to minimize scenarios where integrated performance results in water accumulation, while absorbing any water that does appear. These measures will help contain any liquid in the helmet to continue to keep crew safe.”

Officials at NASA gave the “go” for spacewalks to resume after concluding the review in October.

The investigation team has developed techniques to manage temperatures in the suit and added new absorption bands to the helmet, said Dina Contella, operations integration manager for the International Space Station Program.

The thin orange pieces have been placed in different parts of the helmet, which has already been tested on orbit by the astronauts inside the space station.

“We’ve taken several different models of this up and the crew on board sloshed water around, essentially tried to inject water into the helmet at the same rate that would be kind of a worst, worst case. And we found that these pads were very, very effective,” Contella said.

Tuesday’s spacewalk will allow the crew to test the new pads as they work outside of the space station before the more complex solar array installation spacewalks within the next couple of weeks.

Meanwhile, a Russian spacewalk is scheduled to take place on Thursday. Cosmonauts Sergey Prokopyev and Dmitri Petelin will begin their walk at 9 a.m. ET to work on the outside of the Nauka multipurpose laboratory module. The duo will prepare a radiator for transfer from the Rassvet module to Nauka during their seven-hour spacewalk, which will also stream live on NASA’s website.