Nine astronauts on the space station briefly moved to their docked return spacecraft late Wednesday (June 26) when a satellite in low Earth orbit disintegrated.
The crew of Expedition 71 of the International Space Station (ISS) took off to their three spacecraft, including Boeing Starliner, shortly after 9:00 PM EDT (02:00 GMT), according to a brief NASA update on X, formerly known as Twitter. Because the ISS follows a time zone identical to GMT, the astronauts were likely in their sleep period when the incident occurred, according to the European Space Agency.
The procedure was a “precautionary measure,” NASA officials added, stating that the crew remained in their spacecraft for only about an hour before they were “cleared to leave their spacecraft and the station resumed normal operations.”
NASA did not specify which satellite was involved in the incident, but satellite monitoring and collision detection company LeoLabs identified a “debris-generating event” that same evening. “Early indications are that a non-operational Russian spacecraft, Resurs-P1 [or] SATNO 39186 has released some fragments,” the company wrote on X.
Related: How often does the International Space Station have to dodge space debris?
US Space Command also reported the Resurs-P1 event, saying on X that more than 100 pieces of traceable debris were generated. The military said it “has not observed any immediate threats and continues to conduct routine combination assessments.” (A conjunction refers to a close approach of two objects in orbit around each other.)
Resurs-P1 was launched on June 25, 2013 and operated until December 2021 – longer than its expected lifespan, according to RussianSpaceWeb. The Earth observation satellite was used for applications ranging from defense to emergency monitoring to agriculture, NASA says.
The amount of space debris in orbit is a growing concern in general. As of today, the North American Aerospace Defense Command (NORAD) is tracking a total of more than 45,300 space objects, according to SpaceTrack.org. However, this does not apply to untraceable items. The Union of Concerned Scientists also lists 7,560 operational satellites orbiting the Earth, a figure that belies the number of non-operational satellites that cannot be monitored.
NASA works with the US military to monitor the area around the ISS. The space station is typically tasked with moving (if there is time) when trackable pieces about 5 centimeters in size come within a “pizza box”-shaped region of space around the ISS’s orbit. That box is about 2.5 by 30 by 30 miles (4 by 50 by 50 kilometers), with the ISS in the center, according to agency officials.
NASA procedures also dictate that astronauts be allowed to shelter in their reentry spacecraft if the hazard, usually very small in statistical terms, involves the likelihood that they will have to evacuate the ISS. This happened, for example, after Russia deliberately destroyed a satellite in November 2021 as part of a surprise anti-satellite test that other countries (including the United States) condemned.
The new NASA update did not specify how close the satellite pieces came to the ISS. LeoLabs stated that the debris event it monitored was fragments released between 9:05 a.m. EDT (1305 GMT) and 8:51 p.m. EDT Wednesday (0051 GMT Thursday, June 27).
Related: NASA confirms that space debris in North Carolina came from the SpaceX Crew Dragon return
The incident illustrates what NASA officials have emphasized about the Boeing Starliner spacecraft, which has been more than three weeks into what was expected to be a 10-day Crew Flight Test mission. Starliner is on a test mission with two astronauts and has permission to leave the ISS in an emergency. (The other two crewed spacecraft docked with the ISS are a SpaceX Dragon with four astronauts on board, and a Russian Soyuz with three people on board.)
However, Starliner’s nominal departure date has not yet been released pending assessment and testing of the thrust systems and helium supply, as problems with these two aspects of the spacecraft were discovered on June 6. NASA Starliner astronauts Butch Wilmore and Suni Williams are now doing maintenance work on the ISS after conducting those tests, according to several NASA updates on the space station’s blog. NASA officials did not respond to a Space.com request for a Starliner update sent early afternoon EDT Wednesday.
On Friday (June 21), NASA said Starliner’s departure will be sometime after July 2, following an expected spacewalk on that day. But it’s also unclear whether that spacewalk will go ahead, as a coolant leak shut down extravehicular activity on Monday (June 24). ISS astronauts then conducted a “spacewalk assessment,” NASA officials said, and have since reviewed procedures and examined the affected spacesuit.
Boeing and NASA officials have said development missions like Starliner often fall off planned schedules because of the unexpected. And United Launch Alliance, the Atlas V rocket supplier to Starliner, a joint venture between Lockheed Martin and Boeing, gave a positive update to reporters yesterday (June 26) during an unrelated conference call on future launches of ULA’s new Vulcan Centaur rocket.
“They are all safe and sound,” ULA CEO Tory Bruno told reporters during the conference call. He was talking about the Starliner crew, both former U.S. Navy test pilots accustomed to development programs.
“I understand that the helium leaks that have been in the news are stable and that there is a very, very large supply of helium on board the vehicle, so there is no urgency for its return,” Bruno added. ‘There are a lot of supplies on the space station. So again, there is no urgency.”
As NASA officials have said, Bruno noted that apart from one thruster that shuts down during undocking, the other 27 in the reaction control system are still operational. Five thrusters showed anomalies during docking; while one is offline, issues with the other four thrusters have been “largely resolved,” he said.
Bruno added that consideration is still being given to what to do next. “NASA and Boeing will bring them [the astronauts] home when they’re done with work and when they’re ready and everything is safe.”