Over the past century, human beings have polluted the environment in every way possible. The seas are replete with plastics, the land is contaminated with poisonous pesticides, and the air is filled with harmful gases. We have taken this habit outside of the Earth as well, with space being polluted in an increasingly dangerous way.
NASA estimates that there are more than 500,000 pieces of garbage in space, most of which are untraceable. Just a small piece would be lethal enough to harm satellites and other assets orbiting the Earth. Space junk travels at a speed of 22,300 mph. As such, an object as small as 5 cm would be enough to damage a satellite or spacecraft. Something with a size of just 10 cm would hit with an energy that is equivalent to 300 kg of TNT.
Many countries irresponsibly create space junk, with little consideration given to the consequences. In 2007, China blew up its Fengyun-IC weather satellite to test its anti-satellite missile. It is believed to have created the largest debris cloud ever recorded. “The destruction of Fengyun-IC creates an estimated 300,000 objects 1cm or larger — big enough to be fatal to a satellite mission. More than 3,000 pieces of debris are at least 10cm long — large enough to be tracked,” according to South China Morning Post.
The U.S. Department of Defense tracks space debris through the Space Surveillance network, which is tasked with identifying, cataloging, and monitoring such garbage through a network of telescopes. Ground-based radars allow the tracking of objects up to 0.12 inches in size. Items greater than 4 inches in size are noted and routinely tracked.
Countries are also getting more responsible for their launches. When India tested its anti-satellite weapon in March this year, they targeted a low orbit satellite due to which the resulting debris entered the Earth’s atmosphere and burned up. However, the rapid growth of private space companies threatens to increase the amount of garbage we dump in space. As more companies compete with each other, the risk of explosive growth in space garbage increases exponentially.
“Computer simulations of the next 200 years suggest that during that time debris larger than about 8 inches across will increase by 1.5 times. But the smaller particles will increase even more. Junk between 4 inches and 8 inches is expected to multiply 3.2 times and debris less than 4 inches will grow by a factor of 13 to 20,” according to National Geographic.
Cleaning up space
To solve the issue of space debris, a team of scientists from Japan and Australia is developing a helicon plasma thruster. The system uses bi-directional plasma beams that counteract each other. One beam shepherds the satellite while the other beam directs the junk to Earth. Both the beams are powered by a single energy source.
“The helicon plasma thruster is an electrodeless system, which allows it to undertake long operations performed at a high power level… This discovery is considerably different from existing solutions and will make a substantial contribution to future sustainable human activity in space,” Kazunori Takahashi, an associate professor at Tohoku University in Japan, said to Universe Today.
The Japanese space agency, JAXA, is developing an ElectroDynamic Tether (EDT). This will be a 2,300-foot-long, 44-pound electrified line. Once deployed, the agency hopes that the EDT will act as a space whip and knock out debris toward the Earth, where it will burn upon entering the atmosphere.