On Wednesday, about six hours before NASA’s Crew-3 mission launched to orbit, the International Space Station was forced to maneuver itself to avoid a piece of debris spawned by a Chinese antisatellite weapon test in 2007.
The piece of junk was projected to enter what’s called the “pizza box,” a square-shaped zone 2.5 miles deep and 30 miles wide, where the station sits in the middle. NASA officials keep close eyes on the zone using data models on the location of objects in space kept by the U.S. Space Command.
Faced with a threat to the zone, the agency worked with Russia’s space agency in Moscow to fire station thrusters that raised its altitude by just under a mile.
“It just makes sense to go ahead and do this burn and put this behind us so we can ensure the safety of the crew,” Joel Montalbano, NASA’s space station manager, told reporters during a news conference on Tuesday.
The debris is a remnant of China’s Fengyun-1C, a weather satellite that launched in 1999 and was decommissioned in 2002 but remained in orbit. In 2007, China targeted the defunct satellite with a ballistic missile on the ground, blowing the satellite to smithereens and creating over 3,000 pieces of debris. The missile test drew condemnation from the United States and other countries at the time.
The wreckage from the satellite was expected to make its close pass of the space station this coming Thursday night, according to Jonathan McDowell, a Harvard astronomer who tracks objects in space. But now that the station has moved, the threat of a collision is minuscule.
A large portion of that debris cloud is expected to stay in orbit for decades, threatening the space station and other spacecraft.
The station has carried out 29 such avoidance maneuvers since 1999, a year after its construction began. In some instances, astronauts had to board their spacecraft and brace for an emergency departure in case the station was hit and sustained damage.
Only the United States, Russia, China and India have launched antisatellite tests. The most recent occurred in 2019, when India blew up a defunct satellite, an effort to signal its capability for projecting military force in space.
The SpaceX mission that carried four astronauts for NASA, Japan and France to the space station in April had a space debris scare. SpaceX mission control alerted the astronauts that a piece of space debris was projected to whiz by the capsule, although nothing came close, and the crew safely reached the space station on April 24.
Days later, U.S. Space Command determined that the alert was the result of a “reporting error” and “that there was never a collision threat because there was no object at risk of colliding with the capsule.” Still, the incident renewed discussion about the growing threat of space debris and other clutter in low-Earth orbit.