Sign up for CNN’s Wonder Theory science newsletter. Explore the universe with news about fascinating discoveries, scientific advances and more.
The International Space Station received its second solar power boost in a month when two NASA astronauts spacewalked to install a new solar panel. The event comes after a piece of wayward space debris disrupted plans to conduct Wednesday’s spacewalk.
NASA was forced to implement a 24-hour delay to allow the space station to start its engines to avoid the debris, which has been identified as a fragment of an old Russian rocket. Near-misses in space are the order of the day as low-Earth orbit — the area where the ISS orbits — becomes increasingly crowded with satellites and space debris.
“The crew is not in immediate danger,” NASA noted in a blog post Wednesday.
The spacewalk began Thursday around 8:30 a.m. ET and lasted about seven hours.
NASA astronauts Josh Cassada and Frank Rubio installed a new solar array called iROSA outside of the floating laboratory. Rubio serves as crew member 1 outside the vehicle and wears a red stripe suit, while Cassada as crew member 2 outside the vehicle wears an unmarked white suit.
The solar array deployed around 2:00 p.m. ET, completing the primary objective of the spacewalk. Rubio and Cassada returned to the ISS airlock about an hour later, ending the event.
Cassada and Rubio previously installed a solar array outside of the space station during a spacewalk on Dec. 3. And the first two iROSAs were deployed off-station in June 2021. There are plans to add a total of six, which will likely boost the space station’s power generation by more than 30% once all are operational.
Two more arrays were delivered to the space station on Nov. 27 aboard the 26th commercial resupply mission, SpaceX Dragon, which also brought dwarf tomato seeds and other experiments to the orbiting laboratory. Rolled up like a carpet, the arrays weigh 750 pounds (340 kilograms) each.
The solar array installed on Thursday will boost capacity in one of the space station’s eight power channels, located on its port truss. During a spacewalk webcast, a NASA commentator confirmed that the newly installed iROSA is already generating power for the ISS.
When fully deployed, the solar array measures approximately 63 feet (19 meters) long and 20 feet (6 meters) wide.
The original solar arrays on the space station are still functional, but have been providing power for more than 20 years and show signs of wear after prolonged exposure to the space environment. The arrays were originally designed to last 15 years.
Erosion can be caused by engine plume, both from the station’s engines and from the crew and cargo vehicles coming and going from the station, and micrometeorite debris.
The new solar fields are placed in front of the original ones. It’s a good test, as devices of the same design will power parts of the planned Gateway lunar outpost, which will help people return to the moon through NASA’s Artemis program.
The new arrays will have a similar life expectancy of 15 years. However, since it was expected that the deterioration of the original arrays would be worse, the team will be monitoring the new ones to test their longevity because they can last longer.
While US spacewalks continue, Russian spacewalks, conducted by cosmonauts aboard the space station, are suspended following the discovery of a coolant leak the Soyuz MS-22 spacecraft docked with the Russian segment of the space station.
The leak was found on December 14, ahead of a scheduled Russian spacewalk, when the Soyuz leaked liquid.
According to a Dec. 15 update from NASA, the Soyuz external cooling circuit is the suspected source of the leak.
While the crew of the space station remained safe, the investigation into the leak is ongoing. During a Thursday news conference, NASA ISS program manager Joel Montalbano said it’s still not clear what caused a 4-millimeter hole in the spacecraft, although it could have been a piece of space junk or a hardware problem.
NASA and its Russian counterpart Roscosmos are still checking whether the spacecraft is safe to carry a crew.
The Soyuz MS-22 brought NASA’s Rubio and two Russian cosmonauts to the space station on Sep 21 and was scheduled to return them to Earth in March.