ISS: U.S. spacewalkers Cassada and Rubio ventured outside the space station on Tuesday

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The first in a series of year-end spacewalks began Tuesday morning outside the International Space Station.

First spacewalkers and NASA astronauts Josh Cassada and Frank Rubio began their excursion outside the space station at 9:14 a.m. ET and ended at 4:25 p.m. ET, lasting 7 hours and 11 minutes.

Cassada wore the red-striped space suit as extravehicular crew member 1, while Rubio was in the unmarked suit as extravehicular crew member 2.

The astronauts mounted a mounting bracket on the starboard side of the space station’s truss against the backdrop of a spectacular view of Earth.

The hardware was delivered to the space station on Nov. 9 aboard a Northrop Grumman Cygnus spacecraft, which safely delivered its payload despite only one of the two solar arrays being deployed post-launch.

This hardware will allow more deployable solar panels called iROSAs to be installed to give the space station a power boost. The first two deployable solar panels were installed outside the station in June 2021. A total of six iROSAs are planned and will likely increase the station’s power generation by more than 30% if they are all operational.

During two more spacewalks on Nov. 28 and Dec. 1, a crew of two astronauts will roll out and install another pair of solar panels once the mounting hardware is in place. The solar arrays will be delivered on SpaceX Dragon’s next commercial resupply mission, currently scheduled to launch on November 21.

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

A thin layer of moisture in excess of the normal expected amount was discovered in Maurer’s helmet when he returned to the airlock after a nearly seven-hour spacewalk. Maurer quickly threw off 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 examination. Officials at NASA determined that the suit did not experience any hardware failures.

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

“Based on the findings, the team has updated operational procedures and developed new mitigation hardware to minimize scenarios where integrated performance results in water build-up, while absorbing any water that appears. These measures will help to keep any liquid inside the helmet to maintain the safety of the crew.”

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

The research team has developed techniques to control the temperature inside 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 are placed in different parts of the helmet, which has already been tested in orbit by the astronauts in the space station.

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

Tuesday’s spacewalk allowed the crew to test the new pads while working outside the space station, before the more complex solar panel installation for spacewalks in the coming weeks.

Meanwhile, a Russian spacewalk is scheduled for Thursday. Cosmonauts Sergey Prokopyev and Dmitri Petelin will begin their walk at 9 a.m. ET to work on the exterior of the Nauka Multifunction Laboratory Module. The duo will prepare a radiator for the transfer of the Rassvet module to Nauka during their seven-hour spacewalk, which will also be streamed live on NASA’s website.