It is estimated that there are more than 750,000 pieces of
debris are currently orbiting the Earth, traveling at speeds up to 17,500 mph. This
debris is called “space junk”?—?and it includes not only abandoned satellites
but also spent rocket stages, fuel tanks, everyday rubbish from past space stations
and other random objects. One of the most famous pieces of space junk is the glove
lost by astronaut Ed White during his historic 1965 spacewalk.
Space junk results from thousands of launches conducted since
the beginning of the space age. Gradual wear and tear or sudden collisions of orbiting
satellites and the rockets that shot them into place cause them to disintegrate
into tiny fragments. Satellite interceptions by surface-launched missiles have
also been a major contributor in the recent past.
The main problem with space junk is the risk it poses to International
Space Station, working satellites, and manned spacecraft. Since they are moving
so quickly, even tiny pieces of debris can be deadly. The average impact speed
of a piece of orbital debris running into another object is 22,370 miles per
hour. At that speed, a one-millimeter piece of debris can damage a
satellite if it hits a vulnerable area and a ten-centimeter projectile would be
comparable to 7 kilograms of TNT.
Even more concerning is that space junk could cause Kessler Sydrome, a collision that could
cascade into a snowball effect of collisions. Each time a collision occurs it
creats an incredible amount of debirs fragments, and each of those fragments
then goes on to trigger further collisions until LEO is completely clogged. That
would dramatically impact our way of life back on Earth – no phone services, no
internet, no GPS, and no accurate weather forecasting.
While space junk has been recognized as a huge concern for
us, there is still no concrete solution to getting rid of it. The current
strategy used by NASA is to curb future debris and to possibly clean up the
trash already there. Scientists are working on a range of clean-up technologies
and here are a few ideas:
Robotic arms and nets to help remove debris;
Radar-based ‘space fences’ to detect space
Space harpoons to fire from one satellite to
another to tow it out of the way to a safer orbit;
Self-Destructing Janitor Satellites – designed to capture pieces of space junk and tug them down
into Earth’s atmosphere where both the satellite and the space would be
destroyed during the heat and friction of re-entry.