![The lifetime of a small satellite should be 1 year… After that, it turns into a floating weapon. [Science]](https://file.mk.co.kr/news/facebook_mknews.jpg "The lifetime of a small satellite should be 1 year… After that, it turns into a floating weapon. [Science]")
Space debris refers to a satellite or its fragments that float in orbit at the end of their life. They float in orbit at 8 km/s, 10 times the speed of a bullet. They orbit at a very high speed, interfere with constellations and celestial observations, and collide with active satellites. According to the European Space Agency (ESA), there are currently an estimated 34,000 pieces of such space debris.
It is by far the small satellites that increase worries about space debris. This is because several small satellites are launched simultaneously and have a short lifespan. Medium and large satellites have a lifespan of 10 years or more, while small satellites have a lifespan of only one year. When the life of a small satellite is over, a new satellite is launched. As a result, there is growing concern that a satellite that has reached the end of its life can become space debris. The bigger problem is debris. This is because inactive satellites collide with each other or when they collide with fragments, the satellites break and the fragments that come out become space garbage. It’s at the end of its lifespan, so there’s no way to control it.
Astronomers are most affected by the space debris problem. First of all, the small rays of sunlight reflected off satellites can interfere with astronomers’ observations of celestial bodies. For example, the US Large Synoptic Observation Telescope (LSST), which will study various astronomical phenomena such as dark matter and asteroids from next year, looks into a wide range of sky, so if there is a satellite in the middle, it can be practically affected. In addition, radio waves used for satellite communication are also used for space observation, making it difficult to observe celestial bodies using radio waves.
The slow international agreement on space debris is also pointed out as a problem. The International Space Debris Coordination Committee (IADC) and the United Nations have proposed guidelines for space debris, but they only need to return to Earth within 25 years, and specific standards are lacking.
Dr. Park Chang-soo of the Korea Aerospace Research Institute said, “There are guidelines that must be followed internationally for space debris, but it is pointed out that it may be insufficient because it is a previously established regulation.” There will be no choice but to say,” he explained.
Elon Musk’s SpaceX is said to create the most space debris. This is because of the’Starlink Project,’ which puts tens of thousands of satellites in low Earth orbit. Of course, SpaceX is preparing for this to some extent. First of all, Musk announced plans to paint the satellite black to minimize light reflection. In addition, all Starlink satellites have a propellant, which can dislodge satellites of near-lived life over several months and then pull them into the Earth’s atmosphere and burn them. Even if a satellite fails, SpaceX plans to enter the Earth’s atmosphere and burn it within one to five years.
Various technologies are also being developed to reduce space waste. Currently, a method of shooting a harpoon or a net or collecting garbage with a robotic arm and then entering the atmosphere and burning it is being reviewed as the Space Waste Disposal Act. To this end, ESA plans to launch a space garbage collection satellite in 2025 by signing a contract with a private company,’ClearSpace,’ worth about KRW 113.7 billion.
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