Nine space station astronauts briefly moved to their docked return spacecraft Wednesday evening (June 26) as a satellite broke up in low Earth orbit.
The Expedition 71 crew aboard the International Space Station (ISS) boarded its three spacecraft, including the Boeing Starliner, shortly after 9 p.m. EDT (0200 GMT), according to a brief update NASA Day on X, formerly known as Twitter. As the ISS follows a time zone identical to GMT, according to the European Space Agency, the astronauts were likely asleep when the incident occurred.
The procedure was a “precautionary measure,” NASA officials added, specifying that the crew remained in their spacecraft for only about an hour before being “allowed to leave their spacecraft and that the station has resumed normal operations.
NASA did not specify which satellite was associated with the incident, but satellite monitoring and collision detection company LeoLabs identified a “debris event” that evening. “Early indications indicate that a non-operational Russian spacecraft, Resurs-P1 (or) SATNO 39186, released a number of fragments,” the company wrote on X.
Related: How often does the International Space Station have to avoid space debris?
US Space Command also reported the Resurs-P1 event, saying on X that more than 100 pieces of traceable debris had been generated. The military said it “has not observed any immediate threats and continues to conduct routine assessments.” (A conjunction refers to a close approach of two objects in orbit relative to each other.)
Resurs-P1 was launched on June 25, 2013 and operated until December 2021, beyond its expected lifespan, according to RussianSpaceWeb. The Earth observation satellite has been used for applications ranging from defense to emergency monitoring to agriculture, according to NASA.
The amount of space debris in orbit is of increasing concern. The North American Aerospace Defense Command (NORAD) monitors more than 45,300 space objects in total, according to SpaceTrack.org. However, this figure does not include non-traceable debris. The Union of Concerned Scientists also lists 7,560 operational satellites orbiting Earth, a figure that does not match the number of non-operational satellites that cannot be controlled.
NASA is working with the US military to monitor the area around the ISS. The space station is generally instructed to move (if it has time) if traceable pieces of about 5 centimeters in size are found in a “pizza box” shaped area of space surrounding the orbit of the ISS. This box measures approximately 4 x 50 x 50 kilometers, with the ISS in the center, according to agency officials.
NASA procedures also require that astronauts be able to shelter in their returning spacecraft if there is a danger, usually very minimal in statistical terms, of having 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.
NASA’s new update doesn’t specify how close the satellite pieces came to the ISS. LeoLabs said the debris event it was monitoring released fragments between 9:05 a.m. EDT (1305 GMT) and 8:51 p.m. EDT Wednesday (0051 GMT Thursday, June 27).
Related: NASA confirms space debris in North Carolina came from SpaceX Crew Dragon re-entry
The incident illustrates what NASA officials have emphasized about the Boeing Starliner spacecraft, which is more than three weeks into what was supposed to be a 10-day crewed flight test mission. Starliner is carrying out a test mission with two astronauts and is allowed to leave the ISS in an emergency. (The other two crewed spacecraft docked at the ISS are a SpaceX Dragon carrying four astronauts and a Russian Soyuz with three people on board.)
The Starliner’s nominal departure date has not yet been released, however, pending review and testing of its propellant systems and helium supply, as problems with both aspects of the spacecraft have were discovered on June 6. NASA Starliner astronauts Butch Wilmore and Suni Williams are now on their way. ISS maintenance tasks after completing these tests, according to several NASA updates on the space station blog. NASA officials did not respond to a Space.com request for a Starliner update sent early Wednesday afternoon EDT.
On Friday June 21, NASA announced that Starliner would depart shortly after July 2, following a spacewalk planned for that day. But we also don’t know if this spacewalk will take place, because a coolant leak interrupted extravehicular activity on Monday June 24. The ISS astronauts then performed a “spacewalk review,” NASA officials said, and have since reviewed procedures and examined the affected spacesuit.
Boeing and NASA officials have said that development missions such as Starliner often fall outside of planned schedules due to unforeseen circumstances. And United Launch Alliance, Starliner’s Atlas V rocket supplier, a joint venture between Lockheed Martin and Boeing, provided 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 of whom are former US 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 reserve of helium on board the vehicle, so there is no rush for their return “added Bruno. “There are plenty of supplies on the space station. So again, there’s no urgency.”
As NASA officials said, Bruno noted that except for one thruster that will be shut down during undocking, the other 27 in the reaction control system are still operational. Five thrusters presented anomalies during docking; while one is offline, issues on the other four thrusters “are largely resolved,” he said.
Bruno added that reviews of next steps are still underway. “NASA and Boeing will take them (the astronauts) home when they’re done working, when they’re ready and everything is safe.”