A tiny piece of a defunct Russian satellite zipped by the International Space Station Tuesday, but was far enough away that outpost's two-man crew did not have to strap into their lifeboat to wait out the close shave, NASA officials said.
The debris — a small piece of a Cosmos satellite less than four inches (10 cm) wide — zoomed by the station at 1:19 p.m. EST (1819 GMT) and came less than a mile (1 km) of the outpost at its closest point.
"Updates showed that it would not come close enough to the space station to require any change in the processes onboard or require precautionary measures," said NASA spokesperson Kylie Clem.
NASA detected the object too late to move the space station clear of the incoming space trash by firing its thrusters.
Instead, NASA told the station's American commander Jeffrey Williams and Russian flight engineer Maxim Suraev that they might have to wake up during their sleep period and take refuge in their Soyuz spacecraft. The Russian-built Soyuz vehicles ferry crews to and from the station, and also serve as lifeboats in case astronauts must leave the orbiting laboratory in an emergency.
But additional analysis of the object's trajectory found that, despite its close pass, the satellite remnant posed no danger of hitting the space station. NASA typically moves the space station if there is a 1-in-10,000 chance of an object striking the $100 billion orbiting laboratory.
Tuesday's space debris event marked the third time in less than a week that station managers kept a watchful eye on debris near the space station. An old piece of an American rocket flew by the station Saturday and part of a defunct experiment payload buzzed the outpost on Monday. Neither of those objects posed a threat to the station — they were several kilometers away — but NASA tracked them anyway to be sure.
Mission Control receives multiple space debris alerts every month for the space station, but most times the orbital junk passes well clear of the orbiting laboratory, NASA spokesperson Kelly Humphries told SPACE.com. While there have been some recent spikes in debris events near the space station, the overall long-term outlook is stable, he said.
NASA works to maintain a clear safety perimeter that extends 15 miles (25 km) around the space station, as well as about a half-mile (0.75 km) above and below it. The orbiting laboratory flies about 220 miles (354 km) above Earth at a speed of about 17,500 mph (28,163 kph).
Williams and Suraev are the only residents aboard the space station after a series of planned spacecraft departures cut the outpost's crew size by two-thirds.
Three members of the station's six-person crew landed earlier today on the frigid steppes of Kazakhstan to end their months-long space mission. Another crewmember returned home last week on NASA's space shuttle Atlantis.
Williams and Suraev will watch over the space station by themselves until late December, when a new Russian Soyuz will ferry three more crewmembers to the orbiting lab and boost its population back up to five people.