Photo credit: Warner Brother Movie
If you are a movie junkie like I am, you may have associated spacejunk with the movie Gravity. For those of you who haven’t watched it, the key events in this movie involves a variety of junk that causes the destruction of a space shuttle, causing them to be stranded in outer space.
Off the giant screen, is this problem a major concern? Can it ever cause the many strides that we made to travel to great distances in space be hampered by our own litter?
How did it get there?
Spacejunk is a collection of natural and artificial objects that orbit the Earth at extremely high speeds. These objects may include debris, fragments of space craft or other space mission-related objects that are discarded in space. For instance, they can be:
Photo credit: http://www.geosats.com/spacedebris.html
Lost equipment Occasionally, astronauts lose their items during their space walks. The first American to walk in space, Astronaut Edward Higgins White, lost his space glove in 1965. Other items include a lost camera that was used by Astronaut Sunita William in 2006.
Garbage bags Cosmonauts from the Mir Space station threw their garbage out of the space station instead of returning it to Earth.
Destruction of satellites Cosmonauts from the Mir Space station threw their garbage out of the space station instead of returning it to Earth.
Fallen parts In 2009, two satellites, the Iridium 33 and Kosmos-2551 collided and created over 100 pieces of debris that had many pieces that were over 10 cm in diameter.
The Kessler Syndrome
With of of these items, it does show a cause of concern. Travelling at very high speeds, these objects can collide with one another fairly easily. In 1978, a NASA scientist, Donald J. Kessler proposed a theory called the Kessler Syndrome. It states that when the desity of space objects reaches a certain level, it will lead to a continual chain of collisions. A possible implication of this is that it could render space travel impossible in the future.
What can we do to solve this problem?
Eventually, the junk falls out of orbit and burns up in Earth’s atmosphere. Generally it falls at a rate of one objects per day but it may not be able to keep with an increase in man-made debris. Hence, this would make future space missions unpredictable and dangerous due to the risks of collision.
One of the proposed solution was to develop janitor satellited to help remove the space junk during orbit. These satellited will retrieve the objects and nudge the towards Earth so thet gravity can pull it and these objects burn up in Earth’s atmosphere.
In 2007, the United Nations created a set of orbital debris mitigation guidelines through one of its committees, “Committee on Peaceful Uses of Outer Space”. Many countries that are active in space travel have also issued guidelines on minimizing space junk.