A crisis situation arose as rocket boosters discarded from space a while ago and satellites discarded from the Soviet era were closer to within 100m of orbit. If it had collided, both would have been destroyed, exacerbating the problem of mass space debris in orbit.
Space debris is a lot of artificial waste and space waste that surrounds the earth. There is a lot of artificial debris in Earth’s orbit in recent years, and there is concern about the possibility of adverse effects on future space missions and plans such as the international space station.
The incident that the old Chinese rocket booster and the Soviet scrapped satellite almost collided this time highlighted the seriousness of the space debris problem. According to the orbit calculation according to the research team, the re-approach distance on both sides is predicted to be 12m, and the probability of a collision is less than 10%. There are other predictions that are less probable, but again the approach distance is 70m, so it must be approaching considerably. Fortunately, it did not collide, but 10% in space is a very high probability.
If such a large artifact collides and destroys a tiny piece of metal, such as a bolt, flying over fast orbits, it could potentially penetrate the space station and the spacecraft heading there. If you get hit by the astronaut inside, your life could be in danger. In addition, if mass debris spreads in the same direction by a collision, it may be entrained in an orbiting satellite in turn, causing a chain collision like the movie Gravity.
Space debris in orbit cannot be manipulated on the ground, so without external factors, the number continues to increase. In fact, in 2009, a decommissioned Russian military satellite collided with an operational communications satellite Iridium 33, forming 1,800 traceable fragments by October 2010. The number of 1,800 is limited to the size that can be traced from the ground, and countless number of finer, untraceable fragments are considered to be in orbit. In addition, in 2019, India is distributing more than 6,500 pieces of debris that can only be determined by the size of an eraser and destroying satellites through anti-satellite missile tests.
Currently, thousands of small communication satellites, such as SpaceX’s Starlink project, are being launched into orbit one after another, but if these satellites fail or come to life, they are discarded. These satellites decide whether to re-enter the atmosphere before being scrapped or to move to a higher-than-usual orbit, called a grave orbit. However, it is said that about 30% of the abandoned satellites are unable to move to the grave orbit due to rocket fuel exhaustion or failure. Such satellites could one day lead to destructive release of debris in a cascade.
Space agencies in each country foresee this situation and are considering ways to remove debris. However, no functional spacecraft has been developed yet. For reference, when the StarLink satellite reaches its end of life, it departs from orbit using a rocket in 2 to 3 months and disappears from the atmosphere. If the propulsion system fails, it is attracted to the Earth for about 1 to 5 years and falls into the atmosphere. In any case, there were no scrapped rockets and satellite crashes this time, but the likelihood of this happening one day is increasing. Related information can be found here .