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In 2009, a Russian and an American satellite collided with each other in orbit, creating lots of debris in the process. In recent years, space junk, like that released in the 2009 collision, has increased significantly, endangering future space missions. Space junk is defined as machinery or debris left by humans in space. This could range from dead satellites to small paint flakes from a rocket left over in orbit. Scientists use GoPro cameras fitted inside rockets to study and monitor the amount of debris created during each rocket and satellite launch. While paint flakes and debris may seem quite small, the damage they can cause to orbiting satellites is monumental. This is because space junk doesn’t sit in space motionless. It constantly orbits Earth at speeds reaching around 25,000 kilometres per hour, making a small piece of debris pierce a satellite like a bullet. These satellites orbiting today are essential and control a lot of our daily life from traffic alerts to Google Maps and telecommunication.
The Hubble Space Telescope, launched in 1990, was recently succeeded by the James Webb Telescope. While still operational, Hubble has been repaired and adjusted multiple times to keep it functioning for the sake of science. Unlike James Webb which orbits at Lagrange point 2 approximately 1.5 million kilometres away from Earth, Hubble orbits the Earth in a low Earth orbit. This region is full of space debris and junk which has damaged the telescope on multiple occasions. Low Earth orbits occupy the region of space about 160–1,000 kilometres above the surface of the Earth, where satellites and certain space telescopes orbit. For comparison, most planes fly at 35,000–40,000 feet which is only about 14 kilometres above the Earth’s surface.
Today, with around 2,000 satellites still active, we have amassed about 35,000 pieces of space junk. However, these numbers just include objects over 10 centimetres in size, and there are many more debris pieces so small they go undetected until they cause damage. The International Space Station (ISS), that houses around six astronauts at any given time, orbits the Earth in a low Earth orbit. According to data collected by NASA, the ISS has had to perform 25 debris avoidance manoeuvres since 1999.
Clearing up this mess has become a global priority to prevent the Kessler syndrome, a hypothetical scenario where the low Earth orbits become useless due to the amount of space junk and debris.
…To read the full article, head over to Issue 31: Science in the 22nd Century
Written by Ananya Ganapathy (she/her), a second-year Astrophysics student.
