Wednesday, 1 May 2013

Hazards posed by Space Junks and Possible Solutions

Once in space, the biggest threat to astronauts and spacecrafts is space debris. Space debris, also known as space junk or space waste, are potentially dangerous and useless objects in Earth’s orbit. These objects are either man-made (such as spent stages of rockets, broken off pieces of spaceships or equipment, old unusable satellites, and even small flecks of paint) or natural (such as space rocks, ice, and dust). The problem with space debris is how hazardous they can be if they impact a spacecraft or even a spacewalking astronaut.

There are approximately 11,000 pieces of space debris in Earth’s orbit that are larger than three inches and can be currently detected. And there are probably millions or even billions of smaller pieces of space debris that are unable to be detected. Despite the size of these objects, they all have the potential to be lethal because of the speed that they are traveling, especially since most space debris are traveling hundreds or thousands of kilometers per hour. For instance, it has been found that even a single grain of sand has caused serious damage to the heat shields of the space shuttles. Now imagine the catastrophic and deadly impact if a piece of space debris punctures an astronaut’s spacesuit, cracks a window on the space station, or blasts a hole in a spaceship.

Currently, there are three methods to mitigate against space junk.
  1. old satellites are now starting to be returned to Earth where they will hopefully completely burned up in the atmosphere or crash into unpopulated areas. However, some satellites, such as the Hubble Telescope, have no such plans for removing them from orbit. Another piece of space debris could hit these satellites, cause an explosion, and create millions of more pieces of space junk. These pieces of space debris could literally become dangerous and lethal shrapnel.    
  2. Another solution is to put shielding on spaceships and space stations. For instance, the International Space Station is the most fortified habitat ever in space. Unfortunately, not all parts of the space station, such as the solar panels and windows, are able to be shielded. Also, spacesuits have almost no protection from space debris.                                                               
  3. The final solution for space junk is avoidance. Most spacecrafts and satellites are able to move in order to avoid being impacted from space debris. However, since only objects that are larger than 3 inches can be detected, there are a huge number of objects that are not known and thus can never be avoided.
As you can plainly see, the three current methods of mitigating space junk each have major flaws. Furthermore, almost every spacecraft has scars to prove the real threat of space debris. It is only a matter of time before a truly disastrous collision happens. Therefore, more solutions need to found to clean up space debris from Earth’s orbit.

I propose several ways to solve this problem.

Since it is not economically feasible for a spacecraft to pick up all the pieces of space junk, then I recommend a laser that could vaporize or redirect space debris back to Earth. This laser would probably be most easily installed on the International Space Station, since it will need a huge supply of power that I think the space station could be upgraded to provide. Since only large objects can be detected and redirected by the laser, this solution would be limited.

Create massive blobs of aerogel or lightweight surfaces with huge surface areas so that space debris would impact and be stuck to. Since these objects would be in a slow decaying orbit, this would in affect be a large vacuum cleaner removing potential dangerous materials from space. Furthermore, aerogel would be most cost effective to launch into orbit and burn up completely in Earth’s atmosphere.

Instead of tossing trash away in space, like what was recently done onboard the International Space Station, use waste to create huge orbit junkyards surrounding the space station for additional shielding. These junkyards would additionally be storage locations for resources that future space missions could use if needed.
Whatever the space agencies chose, the problem of space debris is becoming a greater problem with each and every mission into space that must be eventually taken care of for the safety of future astronauts and spacecrafts.

by Phil B.

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