Space junk is becoming an increasing problem in Earth’s orbit. As our usage of space technology advances and we send more devices into space, our outer atmosphere is now overflowing with hazardous debris. In the past few decades, our orbit has slowly become a scrap yard that threatens both satellites in space and the environment on Earth.
What is Space Junk?
Space junk is defined by the National Aeronautic and Space Administration (NASA) as “all man-made objects orbiting Earth that no longer serve any useful purpose.” Common items that make up space debris include lower-stage rocket bodies, debris from explosions or collisions between satellites, parts of probes and satellites, tools, used-up rocket fuel, and broken fragments of spacecraft.
Sources of Space Junk
The sources of space junk can be broadly classified into two groups: natural and man-made phenomena. Natural sources include dust, cometary nuclei, meteoroids, and micro-meteoroids. Man-made sources include anything from space technology created and produced by humans. This would include broken satellites, utilized rocket stages, flakes of paint, and other human-made tools.
Effects of Space Junk
Space junk has a myriad of dangerous effects, most notably on the environment on Earth and satellites in space. In the atmosphere, astronauts and cosmonauts are at a higher risk of encountering space debris, which can cause substantial damage to their equipment, thereby endangering their missions and their lives. Secondly, this debris can also cause collisions between satellites, which in turn creates even more hazardous debris that accumulates as a result.
This debris can also fall back onto the Earth, causing harm to people and to the environment. It has been reported that space objects larger than 10 centimeters can survive the journey down to the planet’s surface and may cause physical damage or release toxic substances. Furthermore, even smaller particles can damage the planet’s atmosphere when heated up by friction.
Furthermore, the presence of large amounts of debris in Earth’s orbit can make it difficult for new satellites and spacecraft to launch, as the debris must first be tracked and moved away from the launch site. This can lead to significant delays and increase the cost of space missions.
How Do We Track Space Junk?
The main tool used to monitor and track space debris is the debris catalog maintained by the United States Space Surveillance Network. This system has been in operation for over 60 years and currently monitors more than 29,000 objects in outer space. Satellites and tracking stations continually observe the sky and report any changes to the catalog.
The catalog is used to determine the trajectories of space objects and potential threat of collision with other objects. Scientists are able to use this information to evaluate the threat of space junk to manned spaceflight missions and to suggest strategies to prevent damage.
Clean-up Strategies
Due to the dangerous nature of space debris, scientists are working on strategies to clean up our orbit.
The European Space Agency (ESA) is one of the groups leading research in this field. They have proposed several methods of debris removal, such as:
• Use of nets and robotic arms that can grapple larger pieces of space junk and direct them into the Earth’s atmosphere.
• Harpoons are being developed that could attach themselves to larger pieces of debris and drag them down to the planet’s lower atmosphere for them to burn up on re-entry.
• Lasers can be used to push small objects out of orbit and towards Earth, where they will safely burn up in the atmosphere.
Similarly, NASA has come up with a concept to clear the large amount of debris from Earth orbit which is called the “RemoveDebris” mission. The RemoveDebris mission tests technologies intended to remove hazardous debris from space using a mixture of techniques including a harpoon, net, and a de-orbiting sail.
Space Junk is an increasing problem, and without viable clean-up solutions, our orbit will continue to become more and more of a scrapyard. Government organizations and research labs around the world are developing technologies for debris removal, and will hopefully soon make them a reality. In the meantime, the catalog maintained by the U.S. Space Surveillance Network and other similar systems will remain the best ways to track, monitor, and reduce the risk of space junk.
