Space Debris – Top 10 Facts on Earth’s Orbital Junk

What Are Space Debris in Our Orbit

Space debris in the Earth’s orbit are considered to be all man-made objects that have no useful purpose. Here at Science Facts, we will discuss the Top 10 Facts on orbital junk. Some examples include:

  • Derelict spacecraft parts and components such as empty fuel tanks
  • Various waste disposed by astronauts – human waste, food packaging and similar
  • Wreckage created as a result of space shuttle or upper stage explosions or collisions
  • Flecks of paint released by thermal stress or small particle impacts

Top 10:

More than 35,000 orbital debris larger than 10 cm (4 inches) are known to exist in our orbit. The rough number of space debris that float around the Earth is estimated at 500,000 elements that range between 1 and 10 cm in diameter, and over 100 million other debris less than 1cm. Pretty crowded!

Large debris over 10cm are monitored by the U.S. Space Surveillance Network, whilst the smaller particles can be detected by ground-based radars. Other space debris that are smaller than 1cm are calculated by examining impact features on the surfaces of returned spacecraft.

According to the European Space Agency (ESA) the number of collision alerts (satellites vs debris) has doubled in the past decade to 1,200 per year. The study suggests that this number will quadruple over the next 5 years – if we don’t find a solution.

Fengyun-FY-1C is a Chinese weather satellite launched into our orbit in 2007 that was later destroyed deliberately to test the anti-satellite weapon. It contributed to over 2,000 pieces of junk bigger than 10cm, and around 35,000 of particles more than 1cm across.

Most space junk can be found within 2,000 km (1200 miles) of the Earth’s surface, but the highest concentration of waste is found 750 to 800 km above our heads. The vast majority of space debris travel at the speed of 7 to 10 km per second (4 to 10 miles per second).

The International Space Station (ISS) is required between 1 to 3 times per year on average to maneuver away from a collision course with debris – or if the chance of a possible impact exceeds 1 in 10,000. The U.S. Space Surveillance Network spends nearly $400,000 per year on tracking debris that could harm ISS despite the fact that the Station is the most heavily shielded spacecraft ever flown.

The junk left in orbits below 600 km (370 miles) will normally fall back to Earth within several years, however debris above 1,000 km (600 miles) will continue to orbit us for centuries.

Tsinghua University scientists in Beijing, China are working on a spacecraft that will turn orbital waste into fuel, just like we have witnessed DeLorean DMC-12 in the “Back To The Future” series. The plan is to turn debris into a plasma of positive ions and electrons by heating it to high temperatures

The biggest orbital piece of junk made by humans is the American Vanguard I that was launched into Earth’s orbit in 1958. It’s also the oldest surviving man-made space debris still in orbit.

There are almost 10,000 operational satellites in the orbit, 19,000 shuttle-like known large objects (in terms of size), and more than 30,000 spacecraft launched by humans.

Until next time!

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