The Era of Space Junk: Humanity's Invisible Pollution

A Massive Junkyard in Earth's Orbit: Facts and Figures

Space junk, or orbital debris, is any man-made object in Earth's orbit that no longer serves a purpose. This includes used rocket parts, non-functional satellites, tools lost by astronauts, and even flakes of paint that have peeled off satellites.

According to the U.S. Space Surveillance Network, today there are in Earth's orbit:

• About 27,000 objects larger than 10 cm that are actively tracked.
• About 500,000 objects between 1-10 cm.
• More than 100 million objects larger than 1 mm.

These numbers continue to grow as more and more satellites are launched into space and collisions occur. One such case happened in 2007 when China tested an anti-satellite missile, destroying its old weather satellite. This single test created over 3,000 new fragments.

Kessler Syndrome: Junk Begets Junk

The greatest danger of space debris is its immense speed. In Low-Earth Orbit, objects move at a speed of about 28,000 km/h (17,500 mph). At this speed, even a tiny piece, such as a paint flake, can cause enormous damage.

As early as 1978, NASA scientist Donald Kessler described a theoretical scenario known as Kessler Syndrome. According to this syndrome, a single collision between two objects could create so many new fragments that they lead to a chain reaction of new collisions. As a result, certain orbits could become unusable for decades or even centuries.

The seriousness of this scenario was raised in 2009 when the retired Russian "Kosmos-2251" satellite collided with the American "Iridium-33" satellite. This collision, which occurred over Siberia, created over 2,000 fragments.

Solutions and Hope for the Future

International space organizations and countries are cooperating to solve this problem. Two main approaches are being proposed: prevention and active cleanup.

1. Prevention is the most effective way to combat space debris. It includes new standards that obligate satellite operators to have a deorbit plan for their devices. According to this plan, the satellite must end its mission and safely enter Earth's atmosphere, where it will burn up.
2. Active cleanup (Active Debris Removal - ADR) includes technologies aimed at removing existing debris.

• The Japan Aerospace Exploration Agency (JAXA) tested an electrodynamic tether that can slow down debris, forcing it to enter the atmosphere.
• The European Space Agency (ESA) is developing the ClearSpace-1 mission, which will use a robotic device to capture and remove a non-functional satellite from orbit.
• There are also other proposals, such as using laser beams to vaporize fragments or change their orbit.

"If we keep polluting space at this rate, we will lock ourselves out of it," says NASA specialist Jerome Breitwieser.