International Space Station with ATV-5

The International Space Station was threatened by space debris last week but ESAs Automated Transfer Vehicle saved the day by firing its thrusters to push the orbital outpost and its six occupants out of harms way.

Station with ATV-2

This is the first time the Stations international partners have avoided space debris with such urgency.

Ground stations continuously track space junk leftover hardware from defunct satellites for potentially life-threatening collisions. A fleck of paint can cause major damage travelling at 28 800 km/h. When they raise the alarm, ground teams can move the Station to a safer orbit.

The calculations sometimes take hours this is rocket science but fortunately, most of the time, the radar network gives ample warning. Sometimes a dangerous object can slip through the net or its erratic behaviour makes accurate predictions difficult.

ATV-5 approaching Station

This is where Europes ATV Georges Lematre came in on 27 October. A piece of Russias Cosmos-2251 satellite that broke up after colliding with another satellite in 2009 was on a collision course with the International Space Station. The object was around the size of a hand and calculations showed it would pass within 4 km too close for comfort.

Just six hours before potential impact, the five space Station agencies agreed to an emergency manoeuvre. The ATV Control Centre team in Toulouse, France, triggered a boost of 1.8 km/h, enough to raise the 420-tonne Station by 1 km and out of harms way.

Progress and Soyuz spacecraft docked to Station

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ESA space ferry moves Space Station to avoid debris / ATV ...