STEM News: Space Debris in Low Earth Orbit

On 22nd May, people in Victoria, Australia, oohed and ahhed as a spectacular light show lit up the night sky. But they weren't watching fireworks, a laser light show or even a shooting star streaking across the sky. It was in fact a piece of space junk that fell into Earth's atmosphere! Debris believed to be from a Russian Soyuz rocket re-entered Earth's atmosphere after it put up a satellite. Luckily, the debris burned up and none of it would have hit the ground.

Space junk, however, isn't always a great source of entertainment. Sometimes, it can endanger the lives of astronauts out in space.

Unwanted man-made objects that are hanging around the low Earth orbit are called “space junk”. They can be anything from nuts and bolts, garbage bags, screwdrivers, satellites, and even a spatula. They pose a big risk to satellites in orbit, including the International Space Station. Fortunately, collisions with space junk are rare: the last collision was in 2009.

However, space junk can crash into other objects in space, faster than the speed of a Formula One race car. They collide with the many satellites, telescopes and other things floating in space, and even the tiniest pieces of trash can cause major damage, leaving them battered and bruised.

The first satellite humans launched into space, Sputnik 1, heralded the start of the Space Age, a historic period of time where countries started diving into space exploration and the world was changed by planets, rocket ships and our solar system. And, as always, we humans leave a trail of destruction behind us wherever we go, and space is no exception. Anti-satellite missile tests to try new military technology has inadvertently contributed to the brunt of space junk in the 21st century. For example, China destroyed a weather satellite in one such test in 2007, creating more than 3000 pieces of space junk, contributing to about 20% of all space junk at that time. Just last year, on March 27 2019, India also completed a missile test, creating a new mound of at least 400 pieces of space junk floating around in space, and increasing the risk of space junk collisions with the International Space Station by 44%.

Thankfully, humans have found ways to track space junk and prevent galactic disasters from happening. The Space Surveillance Network detects and monitors debris floating around our planet through a global network of telescopes. They use radars to detect tiny trash and inspect space vehicles to find even tinier pieces of junk. And to invent a way to do a massive clean-up of outer space, Japan’s space agency JAXA is testing the ElectroDynamic Tether, an electrified line to knock trash out of orbit and burn up in Earth’s atmosphere. How cool would that be?