ASTRONAUTS aboard the International Space Station (ISS) had to flee the craft yesterday after a piece of space junk hurtling at 17,500mph forced an emergency evacuation.
The three crew members – two Americans and one Russian – had to scramble into a Russian Soyuz spaceship docked at the station to seek shelter as the debris, speeding through orbit seven times faster than a rifle bullet, came close to striking the s
tation 220 miles above Earth.
The fragment, measuring just one-third of an inch in diameter, came from a defunct US rocket motor.
Despite its size, such debris is capable of piercing a hole through the station's hull, leading to rapid depressurisation – and death for the crew.
Commander Mike Fincke and Sandra Magnus, both from Nasa, and Russian flight engineer Yuri Lonchakov, huddled in the Soyuz – whose life support systems run independent of the space station – as experts on the ground monitored the fragment's path with telescopes. They were given the all clear at 4:45pm.
"We are reactivating all space station systems so we can get back to business," said Kelly Humphries, a Nasa spokesman.
In the eight years that astronauts have lived there, the space station has had to shift orbit eight times to avoid collisions with dangerous space junk.
But Mr Humphries said: "This is the first time we have had to evacuate and shelter in a Soyuz."
Nasa tracks about 25,000 items of orbiting debris from the ground, ranging from used rocket parts to defunct satellites.
Space junk is considered a serious threat to the 800 or so commercial and military satellites estimated to be operating in space as well as to the International Space Station. There are more than 18,000 pieces of debris catalogued.
The incident occurred only a day after Nasa postponed until Sunday the scheduled launch of the space shuttle Discovery on a mission to the space station. The US space agency blamed a hydrogen leak during fuelling for the postponement.
The purpose of the shuttle flight – the first of five planned for this year – is to deliver a final set of solar power panels to the space station and to transport Japan's first astronaut, who will serve as a member of the station's crew.
The ISS was assembled in space; construction began in 1998 and is expected to be completed by 2011.
The space station is in low earth orbit, currently 220 miles above the planet's surface, and can be seen with the naked eye.
The International Space Station, the largest ever launched into orbit, serves primarily as a research laboratory, but has become a destination for space tourism, with six visitors paying £17 million each to visit.