Courtesy of Warner Bros. Pictures
The Space Junk Disaster In 'Gravity' Is A
Real Threat
By Robin Johnston, Published on Oct. 28, 2013
at http://www.businessinsider.com/the-spacejunk-disaster-in-gravity-is-a-real-threat-to-earth2013-10
Many moviegoers were recently introduced to the
dangers of space debris by Alfonso Cuaron's science-fiction thriller "Gravity."
In the film, a group of astronauts on a spacewalk to repair the Hubble Space Telescope must try and escape a cloud
of deadly shrapnel following a Russian missile strike on a dead satellite.
The debris sets off a chain reaction and destroys their shuttle, leaving them stranded and out of communication with
ground control.
The events depicted in "Gravity" are fictional, but are grounded in a very real hazard: space debris.
NASA currently monitors 17,000 objects orbiting our planet, 10,000 of which are spent rocket components, dead
satellites, and fragments from previous explosions and collisions. They estimate that there are around 200,000 pieces
of space junk the size of a softball, 500,000 objects larger than a marble and hundreds of millions of shards at least 1
millimeter in diameter.
Traveling at incredible velocities, even the smallest of these items has the ability to put future launches, like the next
Mars rover planned for 2020, or one of the 1,000 or so operational satellites in orbit at risk. With modern society
dependent upon satellites like the GOES-12 that tracks weather patterns across North America and the HughesNet
EchoStar XVII that provides Internet service to rural areas, the need to find ways to clean up Earth's orbit has never
been greater.
Each item of existing junk has the potential to increase the problem as every collision generates even more debris. In
2009, an extra 2,000 items of space junk were created when a collision occurred between a U.S. communications
satellite and a dead Russian spy satellite. Similar collisions are a constant worry as more launches take place and
orbits become increasingly congested.
Roughly 10 objects pass within 2 kilometers (1.2 miles) of vital communications satellites every week, triggering
collision warnings and forcing operators to maneuver satellites to safety. The debris field has also been enlarged by
military testing in space similar to the incident depicted in "Gravity."
In 2007, China's military conducted an anti-satellite missile test that created a vast cloud of debris which still
plagues space agencies to this day.
Several solutions have been proposed to both limit the creation of new pieces of space junk and remove existing
debris. By venting pressure tanks, depleting all remaining fuel reserves, and switching off batteries before a satellite
is dead, space programs can prevent objects from accidentally exploding. Aging satellites can also be maneuvered
out of high traffic orbits while still under human control to prevent collisions.
For larger debris, special retrieval craft will need to engage in missions to actively remove these objects from orbit.
Using robotic arms or special net systems, these craft will first attach to the dead satellite or object and then use their
thrusters to force them into a controlled reentry where they can be recovered from the ocean and disposed of
properly.
The problem of space debris needs to be addressed before it grows into more than just a good story.