General Science

Attack of the Space Junk!

posted: 06/07/16
by: Eileen Marable
Space Junk

By Dillon Fernando

On Earth, there is a lot of concern about conserving the environment by not using up resources, polluting, or pushing our landfills to maximum capacity, but what about space? People might not realize it, but space has its own trash heap called space junk and it's starting to stink.

Here is what you need to know about space junk and what scientists and engineers are doing about it.

What is Space Junk?

Scientists refer to the collection of non-functional fragments orbiting our Earth as space debris--or more endearingly, space junk. The "junk" encompasses over 500,000 pieces of debris the size of marbles, 20,000 pieces larger than a softball, and millions upon millions of debris bits that can be as small as a fleck of paint.

While the junk includes natural debris like meteorites, the large majority of the debris that circles our earth was caused by the hand of mankind, and is non-functional. Only about 7% of the space junk is actually functional.

The first piece of man-made space junk dumped in 1957 was the rocket body that was used to launch the USSR's Sputnik, the first artificial Earth orbiting satellite. From there, countries like the U.S. and China have helped add to the junk tally by depositing spacecrafts, abandoned launch vehicle stages, and other debris as a result of space missions. As of 2013, the largest space debris risk in orbit was the 85-foot satellite ENVISAT that lost contact with with Earth in 2012.

Why is it a Problem?

One of the biggest problems space junk brings is damage to functional satellites orbiting Earth like the International Space Station (ISS). The debris can travel at speeds reaching 17,500 mph, which can do some major damage upon collision. As you can imagine, a rock or metal object through the window of your house is miserable enough, imagine in your space craft. Even junk the size of paint flecks can damage windows on a shuttle in a way some describe as similar to sand blasting.

The high concentration of space junk in the Earth's lower orbit led NASA scientist Donald J. Kessler to believe that eventually, the amount of space trash would become so great that collisions would become inevitable and start a domino-effect of crashes in space. This idea has been subbed the Kessler syndrome and poses the danger that the "belt of debris" formed around our planet would hinder our future space ventures.

Surprisingly, there have been few instances where major damage accrued. In 1996, a French satellite was damaged by French rocket debris from a decade earlier. In 2009, the Russian satellite broke a functioning U.S. Iridium commercial satellite into 2,000 pieces. The 2007 Chinese anti-satellite tests destroyed an old weather satellites adding 3,000 pieces to the space junk collection.

Regardless, the Department of Defense and NASA scientists are currently tracking all satellites as small as 2 in. in diameter about three times a day. Using radar, NASA monitors if any debris that may fall close to a rectangular box, or pizza box, 30 by 30 miles. around the ISS. In the case of possible collision, NASA has protocols in place to maneuver the ISS out of the collision trajectory using its thrusters and moving crew members to different parts of the station or in emergency life boats.

For every ten years the ISS in orbit, there is a 20% chance that a space debris collision could be fatal for the crew or majorly destroy parts of the station. The odds of being in a fatal transportation accident on Earth is 1 in 47, 718.

How do we fix it?

Whether we reach the point where the Kessler Syndrome becomes a reality, scientists are trying to clean up the debris.

The obvious solution would be to wait for the space junk to slow down and fall out of orbit and burn up in the atmosphere. While that works for some objects that are in orbit closer to Earth, much of the junk is located a couple hundred miles higher up where the atmosphere is thin and could orbit for a long, long time.

Some scientists are proposing using lasers to throw the junk off its orbit and potentially causing it to burn up. The CleanSpace One Space project is aiming for a solution that launches clean-up satellites by 2018. This cleaning crew essentially engulfs space debris and brings it back into the atmosphere to burn up. Other groups in the Space Debris Elimnation project are looking at using pulses of atmospheric gas that fosters a momentary drag, almost "pulling" the debris into the atmosphere.

Want to learn more? Check out this clip from Space's Deepest Secrets - Attack of the Space Junk.

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