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Since humans have ventured into space, we’ve embraced “The Big Sky Theory.” The Theory holds that space is so big, you could launch anything into orbit, and it wouldn’t collide with anything else.

In 1978 Donald Kessler (ret.), of NASA’s Orbital Debris Office, predicted that within 3 decades random collisions between manmade objects would create smaller debris that would become increasingly hazardous to spacecraft. Known as the Kessler Syndrome, a resulting chain reaction would create exponentially expanding clouds of debris. Even if we don’t launch anything else into space, an orbiting belt of debris could very well alter space exploration as we know it.

Over the last 50 years, we’ve launched several thousand satellites into space. Yet there are only around 1,000 spacecraft that are operational at this time. Once an object stops functioning, we simply leave it in orbit.

That’s a whole lot of junk: It’s estimated that LEO contains 6,000 tons of space junk. And GEO is home to 400 dead satellites, parked into a higher graveyard orbit, where they will remain for millions of years.

Manmade satellites fall out of orbit and burn up in the atmosphere regularly. However, not all objects decay upon reentry. Those that survive fall to earth at very high speeds. Fortunately, 70% of the earth’s surface is water, greatly reducing the chances that a piece of space junk will fall in a populated area.

Upper stage rocket bodies weighing several tons make up a good portion of the junk in space… as do mission-related objects like cast-off bolts or o-rings. The rest are miscellaneous fragments: exploded rockets, left over fuel, and the list goes on.

In LOW EARTH orbit, or LEO, they often experience what satellite operators refer to as “close approaches” -- two satellites passing within just a few short miles of one another. Amazingly, that can happen around 1,500 times a day.

NASA's Orbital Debris Program Office – Accomplishments:
Since 1979, measured increasing amounts of hazardous debris that was too small to be detected by conventional tracking methods.

NASA's Orbital Debris Program Office – Accomplishments:
Obtained international agreements on new rules of space operations that slowed the growth in the debris population.

NASA's Orbital Debris Program Office – Accomplishments:
Contributed to spacecraft designs and operations that have reduced the risk from debris, both in space and on the ground.

NASA's Orbital Debris Program Office – Accomplishments:
Concluded that debris removal is necessary to prevent future growth in the debris population.