The largest spot of trash on Earth is in the Great Pacific Garbage Patch, but there is another area over our heads that holds, and continues to gather, huge amounts of junk. Space trash is becoming a problem to anything orbiting the earth, and it also could make our ability for space travel almost impossible.
There are more than 500,000 bits of debris orbiting the earth this very moment. These are pieces that are at least half an inch in size. The number of other bits swirling about that are smaller is largely unknown. This ever increasing amount of space junk poses a problem for spaceflight, satellites, and anything else we may try to put in orbit.
The bits of trash consist of pieces of used up and old satellites, bolts and nuts, and used up thrusters from rockets that flew years ago. Many items burn up on re-entry into the atmosphere, but other pieces simply continue their journey around the earth. The problem posed by these pieces is that they are moving at 17,000 miles per hours or more, a velocity that can tear apart anything they come into contact with. It also makes capturing the objects next to impossible. In addition to the inherent dangers of spaceflight, these rapid pieces of debris only increase the danger.
There are many different orbital positions around the earth. Some are filling up, or are already filled with space junk, making them unusable. Placing a multi-million dollar satellite in orbit in one of these areas would only doom it to being destroyed at some point by a collision.
One of the problems that gave rise to the first accumulation of space junk happened in the ’60s and ’70s. The propellant used in rockets or spacecraft was usually left in the tanks after a mission. Eventually the propellants would explode as they mixed with other chemicals. This would send fragments of material into orbit as the craft was destroyed. By the 1980s, NASA was able to persuade other international space operators to remove propellant from spacecraft before leaving them in orbit, which decreased this occurrence, but two events recently added to the problem of space junk. The Chinese impacted an out of service weather satellite with a demolition type device in 2007, and a US satellite collided with an old Russian satellite in 2009. This sent about 5,000 new bits of junk into orbit that were greater than four inches in size. This represented a third of the now orbiting space debris by size.
|All the space junk currently being tracked by NASA|
Space trash is tracked by the US Department of Defense, mostly the larger objects, and other departments use telescopes and radar to track smaller ones. The NASA Orbital Debris Program is in charge of determining the risk from orbiting trash and ways to anticipate or predict a collision from space debris. They then look ahead days in the future to negate a possible accident.
While debris in low-earth orbit can eventually be dragged into the upper atmosphere where it burns up, many others are in a high-earth orbit and can stay there for many, many years. The build-up of space junk, and the perpetual problems it poses, was examined by a NASA scientist in 1978. Donald J. Kessler proposed what is known as the Kessler syndrome. His scenario stated that the density of objects in low-earth orbit will continue to cascade as objects collided with each other. The increase in space debris would then further the likelihood there would be other collisions. A tipping point would be reached where debris that continued to collide would hit a point that going into low-earth orbit would become impossible. A spacecraft wouldn’t be able to be launched because there would be no room for it to go because of the amount of space debris in orbit. Low-earth orbit would become impassable.
There have been many things accidentally lost while in orbit. Astronaut Heide Stefanyshyn-Piper lost a tool bag during a walk outside the international space station in 2006. A grease gun exploded inside the bag sending it away with another grease gun, putty knife, and cloth mitts. Ed White lost a glove on the first American space walk. A camera was lost during Gemini 10 by Michael Collins, another camera was lost by Sunita Williams on a shuttle trip to the international space station in 2006, and garbage bags from the Soviet space station, Mir, were released, along with a toothbrush, and a wrench.
Unfortunately, the technology hasn’t been developed to handle and clean up the excessive amount of space junk. Going up to retrieve it is currently cost-prohibitive, and the challenge of catching small pieces traveling at 17,000 miles per hour hasn’t been invented. Some ideas for cleaning up the junk have included lasers, walls or sails that would “gather” space junk by allowing it to crash into it, and gels that could catch pieces together. These are only suggestions, and right now there is no apparent solution to the problem. It’s a big problem because if the Kessler Syndrome were to happen, no new satellites could be launched and space travel would stop. Let’s hope that someone wants to really take on the role of a celestial garbage collector.
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