By Chelsea Nevin
Imagine laying on a blanket in the middle of a cool summer night, a light breeze tickles your cheek as you look up in the sky, the stars twinkling alongside the beams of a full moon. The last thing most people think about are the pieces of debris that is behind the beautiful celestial scene, polluting the orbit with every crash and collision.
“Space junk”, properly known as space debris are non- functioning, manmade materials that can be found in the low earth orbit, twelve hundred miles from Earth’s surface. Depending on the altitude it orbits at, debris can take years before falling back to the Earth’s surface. In other cases, it can stay in orbit for centuries. It is estimated about thirteen thousand to twenty thousand pieces of debris revolve around the Earth. These objects can be anything from discarded pieces from a rocket stage to the chip of paint from a spacecraft. These pieces can travel up to 17,500 miles per hour. At such speeds chipped paint has the remarkable power to break the windows on a spacecraft. Though not life-threatening, it can be a burden to fix.
The danger with space debris are the thousands of unaccounted pieces that cannot be tracked by satellite catalogs. Though the Department of Defense and NASA work together characterizing and tracking debris, it can only track objects as small as two inches in diameter.
The risk of a collision is only 1 and 300, however, the threat of orbiting debris can be catastrophic if it collides with a spacecraft or satellite.
The first collision due to debris was recorded in 1996, where a French microsatellite collided with an upper stage rocket, a piece responsible for propelling the rocket into space. Luckily, this caused no significant damage and the satellite was able to continue functioning properly. In 2011, the Chinese destroyed a weather satellite, breaking it into three thousand pieces. In other words, the debris from this one satellite contributes to about twenty percent of the total space debris in orbit. Its effects were seen when the Russians sent a laser ranger satellite, whose mission was cut short because of “a sudden change in orbit,” that was caused by fragments from the Chinese weather satellite.
With the increasing number of particles, there is a higher chance of pieces colliding with one another. The increase in particles stems from objects collide and shatter into smaller pieces, polluting the atmosphere even more. Scientists are racing for solutions to reduce the amount of debris in orbit. Multiple attempts have been made to solve the problem. Some try to burn all the fuel in the rocket state to prevent explosions and other, specifically the Germans, have tested different materials to determine the impact debris has on a particular metal.
The European Space Agency (ESA) is currently working on a contraption to safely remove space degree giving its sporadic movements. They use the example of trying to take hold of bus spinning uncontrollably down the hallway. Scientists do not know the momentum, the weight, or even the speed of the debris, making the capture more difficult. The job of the satellite would be to mimic the orbiting object and capturing it without hurting the satellite. The ESA hopes to use a robotic arm or a net to secure the object where they can burn it safely as the satellite comes back to earth.
References:
Garcia, Mark, “Space Debris and Human Spacecraft NASA. September 26 2013. Updated August 7 2017. https://www.nasa.gov/mission_pages/station/news/orbital_debris.html
Gregersen, Erik. “Space Debris” Encyclopedia Britannica N.D https://www.britannica.com/technology/space-debris
“How Do We Take Space Debris Out of Orbit?” Youtube, uploaded by European Space Agency, ESA March 26 2018. https://www.youtube.com/watch?v=VbEjYyu1H5M