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The International Space Station is set to receive its second solar power boost in a month during a spacewalk on Thursday. The event comes after wayward space junk interfered with plans to carry out the spacewalk on Wednesday.
NASA was forced to implement a 24-hour delay so the space station could ignite its thrusters to steer clear of the debris, which was identified as a fragment of an old Russian rocket. Near-misses in space are common, as low Earth orbit – the area in which the ISS orbits – becomes increasingly cluttered with satellites and space debris.
“The crew is not in immediate danger,” NASA noted in a blog post on Wednesday.
The spacewalk began around 8:30 a.m. ET on Thursday and is expected to last about seven hours. Live coverage began at 7 a.m. ET on the NASA website.
NASA astronauts Josh Cassada and Frank Rubio work on installing a solar panel outside the floating lab. Rubio serves as Extravehicular Crewman 1 and wears a red striped suit, while Cassada wears an unmarked white suit as Extravehicular Crewman 2.
Thursday’s spacewalk is one of many designed to install deployment solar panels, called iROSAs, to boost the space station’s electrical power.
The first two deployment solar panels were installed outside the station in June 2021. The plan is to add six iROSAs, which will likely increase the space station’s power output by more than 30% once that they will all be operational.
Two more arrays were delivered to the space station Nov. 27 aboard the 26th SpaceX Dragon commercial resupply mission, which also carried bush tomato seeds and other experiments to the orbiting lab. Rolled up like carpet, the panels weigh 750 pounds (340 kilograms) each and are 10 feet (3 meters) wide.
Cassada and Rubio have already installed one outside the space station during a spacewalk on December 3.
During Thursday’s spacewalk, the pair will install a solar panel to boost the capacity of one of the space station’s eight power channels, located on its port beam.
Once the array is deployed and bolted in place, it will be approximately 63 feet (19 meters) long and 20 feet (6 meters) wide.
The space station’s original solar panels are still working, but they’ve been providing power for over 20 years and are showing signs of wear after long exposure to the space environment. The arrays were originally designed to last 15 years.
Erosion can be caused by thruster plumes, which originate both from the station’s thrusters and those from crew and cargo vehicles traveling to and from the station, as well as from micrometeorite debris.
The new solar panels are placed in front of the original ones. It’s a good test because equipment using this same design will power parts of the planned Gateway lunar outpost, which will help humans return to the moon through NASA’s Artemis program.
New berries will have a similar life expectancy of 15 years. However, since the degradation of the original berries was expected to be worse, the team will monitor new to test their longevity as they may last longer.
While US spacewalks continue, Russian ones conducted by cosmonauts aboard the space station are suspended following the discovery of a coolant leak the Soyuz MS-22 spacecraft, which is docked with the Russian segment of the space station.
The leak was discovered on Dec. 14 ahead of a planned Roscosmos spacewalk, when liquid began gushing out of the Soyuz.
The Soyuz’s external radiator cooling loop is the suspected leak source, according to a Dec. 15 update from NASA.
While the space station crew remained safe, the investigation into the leak is ongoing. NASA is expected to give an update on the matter Thursday at 11 a.m. ET.
The Soyuz MS-22 carried NASA’s Rubio and two Russian cosmonauts to the space station on September 21 and is expected to return them to Earth in March.