spaceSpace and Physics

The ISS Just Had To Make An Emergency Maneuver To Avoid Space Debris


Katy Evans

Katy is Managing Editor at IFLScience where she oversees editorial content from News articles to Features, and even occasionally writes some.

Managing Editor


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The International Space Station (ISS) had to use its thrusters to move out of the way of a piece of space junk yesterday, and NASA head Jim Bridenstine is pissed.

The then-unknown piece of debris was predicted to come within just over a kilometer of the space station, so the ISS changed its trajectory and moved out of its path. NASA said the crew was never in danger, but all three current ISS crew members were moved nearer to the Soyuz spacecraft for an easy getaway as an extra precaution.


“Because of the late notification of the possible conjunction, the three Expedition 63 crew members were directed to move to the Russian segment of the station to be closer to their Soyuz MS-16 spacecraft as part of the safe haven procedure out of an abundance of caution,” NASA said in a statement. “At no time was the crew in any danger.”

After confirming the maneuver was complete and the astronauts were coming out of safe haven, NASA Administrator Jim Bridenstine took to Twitter to point out this was the third time this year the ISS had had to move out of the way of space junk, and the third potential close encounter in 2 weeks.

"Debris is getting worse!" he wrote. 


Although there was, in NASA's own words, "late notification" of the possible collision, the space agency worked together with Russian controllers to conduct a 150-second boost of the thrusters to change the trajectory of the ISS out of the predicted path of the space debris, which was predicted to come within 1.39 kilometers (0.9 miles) of the space station. The reboost occurred at 5.19pm EDT on Tuesday, and the time of the closest approach for the space junk was 6.21pm EDT.  


With the ISS moving at a speed of 7.66 kilometers per second, or 27,580 kilometers per hour (17,130 miles per hour), even a tiny object could cause damage to the space station or its instruments. 

The space junk has been identified by Jonathan McDowell, an astronomer at the Harvard-Smithsonian Center for Astrophysics, as a piece of the Japanese H-2A F40 rocket that launched GOSAT-2, Japan's second greenhouse-gas observing satellite, in October 2018. The rocket experienced a major break up in February 2019 into at least 77 known pieces.

According to McDowell, at 6.21pm EDT the space junk flew at a speed of 14.6 km/s within a few kilometers of where the ISS would have been if it hadn't moved. 


This isn't the first time the ISS has had to perform this maneuver. According to NASA, 25 such maneuvers have been made between 1999 and 2018. That works out as 0.7 potential collisions a year, and as Bridenstine said this was the third maneuver the space station has made this year, the issue of space junk being a growing threat appears to be stepping up a gear.


There are currently around 500,000 known pieces of space debris (you can see them for yourself here) in low-Earth orbit, 21,000 of them 10 centimeters (4 inches) or over, made up of old satellites, pieces of rockets, paint from spacecraft, and remnants of collisions. With so much orbital debris, there have been surprisingly few disastrous collisions, though they are being monitored from Earth by pretty much all space agencies with contingency plans.

However, there are currently no international space laws to clean up low-Earth orbit, which NASA calls "the World’s largest garbage dump," and with the rise of private space companies and the sheer number of objects being sent into space (we're looking at you, Starlink), sorry Jim, but this looks like something you will have to get used to.


spaceSpace and Physics