Astronauts aboard the International Space Station have carried out an "avoidance manouevre" to ensure they would not be hit by a piece of orbiting debris.
Reporting the manouevre, the US space agency NASA urged better management of objects in Earth's orbit.
Russian and US flight controllers worked together during a two-and-a-half-minute operation to adjust the station's orbit and avoid a collision.
The three crew members - two Russians and an American - relocated to be near their Soyuz spacecraft as the manouevre began so they could evacuate if necessary.
They were able to return to their normal activities after the procedure.
"Maneuver Burn complete. The astronauts are coming out of safe haven," NASA chief Jim Bridenstine said on Twitter.
Maneuver Burn complete. The astronauts are coming out of safe haven.— Jim Bridenstine (@JimBridenstine) September 22, 2020
The threatening scrap was actually a piece of a 2018 Japanese rocket, astronomer Jonathan McDowell said on Twitter. The rocket broke up into 77 different pieces last year.
The debris object that ISS avoided is now available on SpaceTrack as 2018-084CQ, 46477, from the breakup of Japan's H-2A F40 rocket stage. At 2221:07 UTC it passed within a few km of ISS at a relative velocity of 14 6 km/s, 422 km over the Pitcairn Is in the S Pacific pic.twitter.com/2T3yFQoFMT— Jonathan McDowell (@planet4589) September 22, 2020
The ISS usually orbits roughly 420km above the Earth, at a speed of about 27,360km/h.
At such a velocity, even a small object could seriously damage a solar panel or other facet of the station.
This type of manouevre is necessary on a regular basis. NASA said 25 such manouevres had occurred between 1999 and 2018.
Mr Bridenstine wrote on Twitter that this was the third such manouevre on the ISS just this year.
The @Space_Station has maneuvered 3 times in 2020 to avoid debris. In the last 2 weeks, there have been 3 high concern potential conjunctions. Debris is getting worse! Time for Congress to provide @CommerceGov with the $15 mil requested by @POTUS for the Office of Space Commerce.— Jim Bridenstine (@JimBridenstine) September 22, 2020
The operations could become even more frequent as Earth's orbit becomes littered with pieces of satellites, rockets and other objects launched into space over the last 60 years.
Accidental or deliberate collisions, including anti-satellite missile launches by India in 2019 and China in 2007, can break objects apart even further and create added risk.
The Office of Space Commerce is a civilian organisation that supporters want to take over the surveillance of space junk, a task currently carried out by the military.