• Space debris consists of discarded launch vehicles or parts of a spacecraft, which float around hundreds of miles above Earth.
  • Every satellite that enters space has the potential to become debris.
  • Russia's satellite the Kosmos 1408 from 1982 was recently destroyed in a test, which created 1,500 pieces of "trackable orbital debris".
  • Concerns have been raised for the crew of the ISS, whose safety during future space activities may have been compromised as a result.
  • Japan's Aerospace Exploration Agency (JAXA) and the European Space Agency have formed partnerships with start-ups to help remove space debris.

Russia's test to blow up one of its own satellites in space has drawn criticism for endangering the crew of the International Space Station and, experts say, created a debris field that has increased risks to space activities for years.

What is space debris and where does it come from?

Space debris, or space junk, consists of discarded launch vehicles or parts of a spacecraft that float around in space hundreds of miles above the Earth, risking collision with satellites or a space station.

Debris can also be caused by an explosion in space or when countries conduct missile tests to destroy their own satellites by missiles. Apart from Russia, China, the United States and India have shot down satellites, creating space debris.

As space debris orbits around the earth at tremendous speeds - about 15,700 miles per hour (25,265 kph) in low Earth orbit - it could cause significant damage to a satellite or a spacecraft in case of a collision.

"Every satellite that goes into orbit has the potential of becoming space debris," Professor Hugh Lewis, head of the Astronautics Research Group at the University of Southampton, said in an interview.

With the launch of more satellites from companies such as Elon Musk's Starlink and OneWeb satellite constellation, near Earth space will likely see more space debris.

a diagram showing how space debris is made
Space debris consists of discarded launch vehicles or parts of a spacecraft, which float around hundreds of miles above Earth.
Image: Space Safety

How big is the debris?

The U.S. government tracks about 23,000 pieces of debris larger than a softball orbiting the Earth.

There are half a million pieces of debris larger than 1 centimetre and 100 million pieces of debris about one millimetre or larger.

Debris, particularly near the International Space Station, orbits the Earth 15 to 16 times a day, increasing the risk of collision.

The European Space Agency (ESA) estimates the total mass of all space objects in Earth orbit weigh more than 9,600 tonnes.

In a few decades, if the build-up of space debris continues, some regions of space might become unusable, Holger Krag, head of the ESA's Space Safety Programme Office, said in an interview.

What was the impact of the current test?

The Kosmos 1408 satellite that was destroyed was launched in 1982 and weighed more than 2,000 kg (4,410 lbs), creating a significant amount of space debris.

The test generated more than 1,500 pieces of "trackable orbital debris" and would likely spawn hundreds of thousands of smaller fragments, the U.S. Space Command said in a statement.

The crew of the space station were directed to take shelter in their docked spaceship capsules for two hours after the test in case they needed to leave due to a collision with debris.

"The event happened at an altitude just 80 kilometres (50 miles) from the space station altitude," Krag said. "So the risk for the space station will be increased, perhaps even doubled, compared to what it was before."

Will space debris affect space travel?

While space debris is unlikely to affect space travel, it will lead to significant problems for spaceflight around Earth.

The risk would be highest for objects orbiting at an altitude of around 1,000 kilometres (620 miles), which is used for communications and Earth observation.

"We will still be able to travel to Mars because we will transit very fast through this problematic region," Krag said.

"But if you want to operate and stay for years in this problematic region, that might not be possible anymore in a few decades from now," he said.

Can space debris be removed?

According to NASA, debris in orbits below 600 kilometres will fall back to Earth within several years, but above 1,000 kilometres it will continue circling the Earth for a century or more.

"If we want to try and solve the space debris problem, we have to start to remove that type of object," Lewis said.

Japan's Aerospace Exploration Agency (JAXA) and the European Space Agency have partnered with start-ups to help with removal of space debris.

While JAXA has launched a six-month demonstration project with Astroscale for the world's first debris removal mission, ESA is working with Swiss start-up ClearSpace for launching a mission in 2025.


What's the World Economic Forum doing to tackle air pollution?

Over 50% of countries have established national ambient air quality standards, but we must do more to protect citizens and our planet.

During COP26 the World Economic Forum and the Clean Air Fund launched the first global private sector initiative to tackle air pollution.

Image: Jane Burston/ World Economic Forum

Founding members of the Alliance for Clean Air are committed to measuring and decreasing their air pollution emissions, creating healthier communities around the world.

Members of the Alliance for Clean Air will:

  • Establish air pollution footprints on nitrogen oxides, sulphur oxides, particulate matter within 12 months
  • Pinpoint where they are being emitted to track human exposure
  • Set ambitious targets and objectives to reduce the air pollution emissions, with a clear action plan
  • Act as champions for clean air by raising awareness among employees, customers and communities about the impact of air pollution. They will also help them to reduce their exposure and support them to take action to reduce pollution
  • Use their assets innovatively to accelerate clean air solutions

Also at COP26, a practical guide for businesses on how to measure air pollution across value chains is being introduced by the Climate and Clean Air Coalition and Stockholm Environment Institute, in co-operation with IKEA. The guide will support companies to understand their impact on air quality and to take necessary actions to reduce their emissions.

If your company is committed to improving air quality contact us to express interest in working with us.

Not only a hazard, space debris increases the cost for satellite operators.

Satellite operators in the geostationary orbit have estimated protective and mitigation measures account for about 5-10% of mission costs and for lower-Earth orbits the cost is higher, according to an OECD study.