Space Debris
Written by Tega Jessa
Map of debris from satellite collision. Credit: Dan Deak and Spaceweather.com
One of the emerging concerns in space exploration is space debris; the outer space equivalent of pollution on Earth. Over the past 40 years, abandoned or obsolete man made space objects have been left in orbit around the Earth. In general we don't worry much about them because most will eventually fall out of their orbit and burn up in the Earth's atmosphere. However, these objects can collide creating the scattered fragments we call space debris.
The problem is further exacerbated by two facts. First, these objects are traveling at very high velocities around the earth. To put this in perspective, a bullet is deadly because it is an object traveling at high speeds; its momentum comes mainly from its high velocity. Now think of much smaller objects traveling at speeds 10 times faster than a bullet; there are thousands of them out there, and they can come from any direction at any time. This is the environment most space craft and astronauts operate under on a regular basis.
The second problem is the proliferation of space debris. As space debris scatters, they collide with other objects to create even more debris and so on. This phenomenon is call the Kessler syndrome. While space debris might be a manageable threat now, it can seriously hinder space exploration in the future if not dealt with.
The seriousness of the situation came with two recent events in space. The International Space Station had to alter its orbit to avoid a particularly dangerous patch of space debris. The damage, even to a station as well armored as this one, would have been in the millions and halted a lot of important research. The second event was the first collision of two satellites in February of 2009. What if this had happened to a major communications satellite? The damage would also have high cost and only further exacerbate the problem with more space debris.
Fortunately, steps are already being taken. The United States Military and NASA both have agencies that monitor debris and are working on solutions to deal with them. One hindrance to implementing some solutions are the political implications. For example, if Strategic Command – the Military Debris monitoring agency – was to use laser to get rid of space debris, the technology would be the first step to a space weapon and raise the concerns of other nations. Hopefully solutions can be found that will agreeable to everyone.
If you enjoyed this article there are several others on Universe Today that you might enjoy. There is an article on space debris with illustrations that show the extent of the problem. There is another article about debris coming dangerously close to the Hubble Telescope.
You can also find other resource about the subject on the internet. Wired.com has an interesting article about how to track space debris online. There is another great article on the Howstuffworks website that goes into detail about the problem.
You can also listen to a podcast on the issue on Astronomy Cast. Episode 82 Space Junk is quite interesting.
Filed under: Astronomy
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