NASA Delays Spacewalk, Citing Space Debris Threat to Astronauts

NASA officials called off a Tuesday spacewalk late Monday night for two of the agency’s astronauts after receiving alerts that nearby space debris could endanger the crew. It was the latest abrupt change to the International Space Station’s operations since Russia blew up one of its old satellites in space earlier this month.

“Due to the lack of opportunity to properly assess the risk it could pose to the astronauts, teams have decided to delay the spacewalk planned for Tuesday, Nov. 30 until more information is available,” NASA said in a statement it posted on Twitter early Tuesday morning.

Tom Marshburn and Kayla Barron, two U.S. astronauts who arrived at the orbital outpost earlier this month, were scheduled to don their spacesuits and scale the laboratory’s exterior at 7:10 a.m. Eastern time on Tuesday. Their mission of about six hours was to replace a broken communications antenna.

The agency did not specify where the debris came from, and a NASA spokeswoman did not answer requests for comment. Officials said the spacewalk was rescheduled to Thursday.

Mark Vande Hei, a NASA astronaut on the space station, checked in with mission control in Houston after waking up to an email that showed the spacewalk had been canceled.

“Sorry for the news,” a NASA official in Houston replied to Mr. Vande Hei over the ground-to-space channel. “We’re probably almost as disappointed as the crew members today, but I know it’s a little bit harder for you guys waking up to this news.”

“It’s just real life, this is how things work out sometimes, and I’m really glad people are looking out for our safety,” Mr. Vande Hei said.

Earlier this month, Russia struck a defunct Soviet-era satellite with an antisatellite missile, spawning thousands of untraceable smithereens that could remain in orbit for decades. The widening field of hazardous space debris created new threats to the space station and could jeopardize other satellites in orbit, according to the U.S. Space Command.

The initial debris cloud from the Russian satellite strike came dangerously close to the space station, which housed a crew of seven astronauts, including two from Russia. A NASA mission control official in Houston abruptly awoke the agency’s astronauts soon after the strike, urging them to take shelter in their spacecraft in case they needed to return to Earth. The crew kept certain hatches on the station closed for days following the incident and opened them when the immediate danger had abated.

“There are about 1,700 new objects, larger objects that are being tracked,” Dana Weigel, NASA’s deputy manager of the space station, said on Monday during a news conference that previewed the scheduled spacewalk. “It will take a few months to get all of those cataloged and into our normal debris tracking process, where we can then assess miss distances and how close these items get to the I.S.S.”

Ms. Weigel said that the Russian weapon test doubled the size of the background debris environment for the space station. She said that the new field of wreckage raised the risk to spacewalking astronauts by about 7 percent. But she said that “falls within the family” of similar risk calculations for past spacewalks.

The Russian missile test, which lifted off from the Plesetsk launch site, roughly 650 miles north of Moscow, angered U.S. officials and drew condemnation from other countries, including Australia, Canada and Britain.

Bill Nelson, NASA’s administrator, said shortly after the test that it was “pitiful that the Russians would do this.”

The spacewalk delay came a day before the White House will convene the first meeting of the National Space Council during the Biden administration. In a letter sent to the council on Monday, lawmakers on the Senate Commerce Committee urged Vice President Kamala Harris, the council’s chairwoman, to act on the Russian antisatellite test and “work to develop international dialogue on norms of responsible behavior in space.”

There have been a dozen spacewalks this year, many of which added new components and solar panels to the space station’s exterior. NASA intends to keep the 21-year-old orbital laboratory running until 2030, pending congressional approval. But the station has already shown signs of its age, like cracks and air leaks that were discovered on a key module in 2019.