The International Space Station was almost hit by Chinese satellite debris

In the station’s 23-year orbital life, there are about 30 close encounters with avoidable orbital debris. Three of them took place in 2020. In May of this year, a success occurred: a small space debris created a 5mm hole in the hand of a Canadian International Space Station robot.

This week’s incident involved the destruction of the Fengyun – 1C dead weather satellite, which was destroyed in China’s anti – satellite missile test in 2007. The satellite exploded into more than 3,500 pieces of debris, most of which are still in orbit. Many have now fallen into the orbit of the International Space Station.

To avoid a collision, the Russian spacecraft Progress, which landed at the station, fired its missiles over six minutes. It changed the speed of the SKS by 0.7 meters per second and increased its orbit by about 1.2 km, which is already over 400 km.

NASA Hubble Space Telescope (from Wikimedia Commons)

As the largest human space station, the International Space Station is the most vulnerable target. It spins at a speed of about 7.66 kilometers per second and travels from Perth to Brisbane in about eight minutes.

Collisions at this speed can cause severe damage, even with a small amount of debris. The relative speed of the satellite and the scrap is important, so some collisions may be slow, while others may be faster and cause more damage.

As LEO becomes more and more crowded, there are more and more things to face. There are currently nearly 5,000 satellites in operation, and many more.

SpaceX alone will soon have more than 2,000 Starling Internet satellites in orbit, reaching its original targets of 12,000 and 40,000.

If it were only about the satellites in orbit, it would not be so bad. However, according to the European Space Agency’s space debris office, there are an estimated 36,500 man-made objects, obsolete satellites and rocket positions with a diameter of 10 cm around the world. There are about 1 million by 1 cm to 10 cm and 330 million by 1 mm to 1 cm in size.

Most of these elements are in low Earth orbit. Due to the high speed, even stains of paint can engrave the ISS window and the marble body can enter the small unit.

The ISS is slightly protected by a multi-layer shield to reduce the possibility of puncture and decompression. However, there is still the risk that such an event could occur before the useful life of the International Space Station expires at the end of the decade.

Of course, no one has the technology to monitor every ruin, and we do not have the opportunity to remove this waste. However, possible ways to eliminate large orbits are being explored.

Meanwhile, companies around the world, such as the US Space Surveillance Network, monitor more than 30,000 objects over 10 centimeters.

Here in Australia, space waste monitoring is part of an increasing process. Several organizations are involved, including the Australian Space Agency, photovoltaic systems, the UN Space Agency, the Space Surveillance Radar System, the Industrial Science Group and the Australian Machine Learning Institute funded by SmartSat CRC. In addition, the German Aeronautics and Space Center (DLR) at the Mount Kent Laboratory at the University of Southern Queensland has the SMARTnet facility to monitor Earth’s orbit at an altitude of about 36,000 km, including several communications satellites used by Australia. .

One way or another, if we want to continue to use nearby “final boundary” areas, we must eventually clean up our space environment.