ISS

The International Space Station (ISS) may have to be manoeuvred out of its path in order to avoid collision with two pieces of debris from an old Russian satellite and a fragment from an Indian spacecraft.

NASA said that the avoidance manoeuvre would be done using the European Space Agency’s (ESA) Automated Transfer Vehicle-3 (ATV-3), which was scheduled to undock from the ISS on 25 September, but had to be postponed due to a communications error.

The debris from Russian military satellite Kosmos 2251 is expected to come close enough to ISS today, while the fragment from an Indian rocket is scheduled to drift by on 28 September.

Kosmos 2251 was launched into space in 1993 and decommissioned two years later.

The Russian spy orbiter collided with US Iridium-33 satellite in February 2009, the first accident of this kind to occur in space. It resulted in the creation of multiple smaller fragments, which pose a risk to not just the ISS but other satellites as well.

“The debris from Russian military satellite Kosmos 2251 is expected to come close enough to ISS today, while the fragment from an Indian rocket is scheduled to drift by on 28 September."

If the chance of a collision is greater than one in 100,000, then the manoeuvre will be carried out.

The three-member Expedition 33 crew is safe from collision threat and the manoeuvre will not impact its scientific research and routine maintenance operations, NASA said.

However, if there is not much time for an avoidance manoeuvre, the three astronauts are likely to move into their Soyuz vehicles.

Space debris in orbit has been a growing threat for satellites and according to NASA and the US military’s Space Surveillance Network there are at least 20,000 known pieces drifting.

Small micrometeoroid frequently hit ISS, but they are not large enough enough to create depressurisation to the orbiting space laboratory.

Meanwhile, the unmanned spacecraft ATV-3 will undock on 28 September to enter Earth’s atmosphere and then burn up over the Pacific Ocean.

Image: The debris from the Russian military satellite Kosmos 2251 is expected to come close enough to ISS today. Photo: courtesy of NASA.