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Will space junk ever fall back to Earth?

Category: research Video duration: Will space junk ever fall back to Earth?
On this episode of Engineering Explained…

What is space junk or space debris? Is it dangerous? What is the future of space junk? Does space junk or debris eventually come back to earth? Are we collecting, tracking, or removing space junk?

Samantha Parry Kenyon shares her expertise on space instrumentation and space debris. With a number of organizations and companies planning on launching large amounts of satellite systems, the amount of real estate inside of low-Earth orbit is called into question. By designing satellites with the intent of burning up in the atmosphere during the end of their life cycle, we can create a safer, cleaner area around Earth's atmosphere.

Curious about space? Learn more below: https://www.space.vt.edu/
Objects in war's orbit are moving at about 17,000 miles per hour. Even a small object can act like a bullet or punch through an existing satellite. Space junk or space debris is any object that's in space. There's about 40,000 objects in orbit that are currently being tracked that are 10 centimeters or larger. Only about a third to a half of those are actually operational. Some are spent rocket bodies, some are satellites, but it's anything that humans have made that are now in orbit around the Earth. But anything below 10 centimeters is a bit tricky to track, and there's a lot of objects that are in that centimeter or even a millimeter scale, and that all constitutes as space debris. The way that we can manage space debris is twofold. We can do things now for future launches that can help mitigate the number of objects that are not being used in space, especially in really popular areas of Earth orbit, like in low Earth orbit. So these are altitudes less than 2,000 kilometers. We can do things to prevent the overcrowding of those areas now, one of which is preventing satellites who have finished their missions from existing there further. There are some regulations that the US government as well as the UN have passed to make sure that when satellites are done that they have a deorbit strategy. The most popular, especially for low Earth orbit, those satellites that are really close to us, is to allow them to burn up in the atmosphere to avoid low Earth orbit from getting too crowded. Space debris that is in orbit can eventually deorbit and come down to the ground. It is not very common. A lot of objects, due to the density of the atmosphere, the heat and the compression allows them to get burned up. For some of the much larger objects or depending on the materials that they're made out of, yes, technically, some can fall to the Earth, but I believe the number is about one to three per day of material that humans have put in space come down from space. The United States has the space surveillance network that we use to track objects in space. The probability of these objects going into populated areas of the Earth is pretty low. About 70% of the Earth is water, which is helpful, and the majority of the population live in pockets. So the probability of it affecting where humans are and stuff is low, but there technically is a non zero chance. There's about 25,000 satellites in low Earth orbit with a projection of the number of companies and other groups that are planning on launching large satellite networks and constellations of satellites to enable this what they call proliferated low Earth orbit. There's going to be a two to three times increase in that number, so up to 60,000 satellites within the next ten to 20 years that we're expecting a low Earth orbit. In order to enable for that to happen, we need to make sure that we're removing satellites that are done and possibly removing old satellites or rocket bodies that could increase the probability of collision. I'm Samantha Kenyon. I'm a research assistant professor in the aerospace and ocean Engineering Department at Virginia Tech, and this is space degree explained.