The seven-person crew living on the International Space Station resumed normal operations Wednesday, two days after closing off parts of the complex as precaution following a widely-condemned Russian anti-satellite test that created a new cloud of space debris.
NASA says the debris field, which U.S. Space Command says numbers more than 1,500 trackable objects, will continue to pose a risk to the space station. But the most danger was in the first 24 hours after the anti-satellite test early Monday.
The space agency said Wednesday that ground teams are “assessing the risk levels to conduct various mission activities. Any changes to launches, spacewalks, and other events will be updated as needed.”
The next major event on the space station is the release of a Northrop Grumman Cygnus supply ship from the lab’s Canadian-built robotic arm Saturday. A new Russian node module is scheduled for launch to the space station Nov. 24, and two astronauts are slated to head outside the station for a spacewalk Nov. 30.
A Russian cosmonaut and two Japanese space tourists are training for launch to the space station Dec. 8 on a 12-day flight. And a SpaceX Dragon cargo capsule is scheduled for launch from NASA’s Kennedy Space Center on Dec. 21 on the final mission to visit the space station this year.
Russia shot down a decommissioned Soviet-era military satellite with a ground-based missile Monday, shattering the Kosmos 1408 spacecraft into thousands of fragments.
Four of the space station crew members sheltered in their SpaceX Dragon ferry ship for two hours Monday, ready to depart the outpost and return to Earth if there was a catastrophic collision with a piece of Kosmos 1408. Three other crew members boarded their Russian Soyuz capsule during the same time period.
The crew closed hatches to the radial, or side-mounted, modules on the space station, and also sealed the passage between the station’s U.S. and Russian segments. The hatch between the U.S. and Russian sections was later reopened after mission control gave the all-clear for the astronauts and cosmonauts to head back into the station from their Dragon and Soyuz safe havens.
The space station continues to pass through or near the debris cloud every 90 minutes, NASA said, but an assessment performed by teams at NASA’s Johnson Space Center in Houston showed the crew only needed to shelter in their lifeboats for two of the highest-risk passes early Monday.
Hatches remained closed for the radial modules, including the European Columbus and Japanese Kibo laboratories, and the Quest airlock, until early Wednesday.
The sealing off of multiple modules interrupted the space station crew’s schedule, preventing work with the lab’s robotic arm and interrupting some experiments. European Space Agency astronaut Matthias Maurer had to vacate his sleeping quarters in the Columbus module and use a sleeping bag in the Harmony module, also known as Node 2.
Maurer tweeted photos Thursday showing NASA astronaut Kayla Barron opening the hatch to Columbus, writing that it “marks the end of our slumber party in Node 2, as I return to my regular crew quarters … in Columbus.”
Mission control informed the station crew late Tuesday that they would could re-open the hatches to the radial modules the next day. Ground teams have kept the crew informed of times when the space station is passing through the Kosmos 1408 debris field.
NASA astronaut Mark Vande Hei said the crew will consider the debris field crossings “routine” going forward.”
“If the hazard gets worse than we experienced in the last 48 hours, then let us know about that,” Vande Hei said Tuesday. “But otherwise, we’re going to consider the debris passings routine, and we’ll press on with the day.”
Maurer and Barron arrived at the space station Nov. 11 on SpaceX’s Crew Dragon Endurance spacecraft, along with commander Raja Chari and pilot Tom Marshburn. Vande Hei flew to the space station in April on a Russian Soyuz spacecraft with cosmonaut crewmate Pyotr Dubrov. Anton Shkaplerov, commander of the station’s Expedition 66 crew, arrived in October on another Soyuz mission.
U.S. Space Command said Monday that the anti-satellite test created more than 1,500 fragments of trackable debris, and likely hundreds of thousands more smaller pieces that can’t be reliably monitored using the military’s array of orbital tracking sensors.
The video below released by AGI, a space services and software company, provides a simulated illustration of the anti-satellite test and the resulting debris field. The video ends showing the International Space Station intersecting the debris cloud.
“This debris cloud that was just created has increased the risk to the station,” NASA said.
“If orbital debris were to strike the station and cause an air leak, the crew would close hatches to the affected module,” the agency said. “If crew members do not have time to close the affected module, they would enter their respective spacecraft and, if necessary, undock from the space station to return to Earth.”
It is likely that the space station, along with other satellites in low Earth orbit, will eventually have to perform avoidance maneuvers to move out of the way of Kosmos 1408 debris. Even if there are no collisions, the effects of the anti-satellite test will cause other spacecraft to use up precious fuel to stay safe.
“The cataloging of the total number of identifiable pieces of debris is ongoing. Once the debris cloud is dispersed and items are tracked and catalogued, NASA will receive notifications of potential conjunction threats to the station and perform maneuvers as necessary,” the space agency said in a statement. “In addition, NASA will continue to perform visual inspections and review telemetry data to ensure vehicle health.”
Email the author.
Follow Stephen Clark on Twitter: @StephenClark1.