Last week, the International Space Station (ISS) was forced to maneuver to avoid a potential collision with space junk. Given that there was an astronaut crew on board, an urgent orbital change was necessary.
During the station's 23-year orbital lifetime, there were approximately 30 close encounters with orbital debris and required evasive action. Three of them came close to happening in 2020.
As quoted from Science Alert, Monday (11/15/2021) last May, there was a small piece of space junk that punched a hole in the Canadian-made ISS robot arm.
Last week's collision incident involved a piece of debris from the defunct Fengyun-1C weather satellite that was destroyed in 2007 by a Chinese anti-satellite missile test.
The satellite exploded into more than 3,500 pieces of debris, most of which are still in orbit. Many are now falling into the orbit of the ISS.
To avoid a collision, the Russian Progress spacecraft docked at the station firing its rockets for more than six minutes. This changes the speed of the ISS by 0.7 meters per second and increases its orbit, which is already over 400 km, by about 1.2 km.
Orbit is getting full of trash
Space debris is a major concern for all satellites orbiting Earth, not just the ISS which is the size of a football field. In addition to well-known satellites such as China's smaller Tiangong space station and the Hubble Space Telescope, there are thousands of other man-made space objects in Earth's orbit.
As the largest inhabited space station, the ISS is the most vulnerable target. The ISS orbits at 7.66 kilometers per second. A collision at that speed with even a small piece of debris could cause serious damage. The relative velocities of satellites and debris greatly impact, so some collisions can be slower while others can be faster and more destructive.
As the Earth's low orbit becomes denser, the more it has to pass. There are currently nearly 5,000 satellites in operation, and many more are under construction.
