Friday, November 21, 2008

Why Should I Care About This Space Trash Problem, Anyway (1 of 9)

The Effect of the Uncontrolled Growth of Space Debris on the Current and
Future Space Use of Artificial Satellites

The space around Earth is empty, isn’t it? Just occupied by the moon, a few comets and satellites, right? But the earth’s orbit has over 680.4 tons (3 million kilograms) of space debris, unusable man-made material speeding in Earth’s orbits; space “junk” made up of not only items accidentally lost during space missions, such as a glove lost on the first American spacewalk, a camera lost near the spacecraft Gemini 10 and so forth, but also discarded rocket stages, dead satellites and other abandoned spacecraft that are beyond their usefulness but cannot be sent back to earth (Tufte, 1990). But much of the debris is made up of the shattered fragments of such deserted spacecraft, due to collisions with other debris or normal wear and tear of use. For example, all 31 of the nuclear-powered Radar Ocean Reconnaissance satellites (RORSATs), launched from 1967 to 1988 by the Soviet Union, still orbit the Earth unused, but, due to a construction error they create a much bigger problem. 16 of the satellites leak liquid sodium-potassium reactor coolant, making tens of thousands of coolant droplets speeding around after the abandoned satellites, making the orbit extremely hazardous to any human use. But while the RORSAT problem is unique, the fact of debris has become commonplace. After 45 years of space use, there are known to be 17,000 objects larger than 3.9 inches in orbit, which is confirmed by debris monitoring by the US and other countries. But the projected amount of objects between .4 and 3.9 inches in diameter is greater than 200,000, and the numbers of particles smaller than .4 inches, such as paint flakes and metal splinters, probably exceed 10,000,000. (Stansbury, 2005) This is in addition to thousands of orbital satellites that currently have considerable use.

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