Experts say the main worry is that such debris will hit a space station, satellite or other equipment. Space debris orbits around the Earth very fast - about 25,000 kilometers per hour in low-Earth orbit. The junk could cause major damage if it hits satellites or spacecraft.

Collisions with debris have become a hazard to spacecraft; the smallest objects cause damage akin to sandblasting, especially to solar panels and optics like telescopes or star trackers that cannot easily be protected by a ballistic shield.

The amount of debris in space threatens both crewed and uncrewed spaceflight. The risk of a catastrophic collision of a space shuttle with a piece of space debris was 1 in 300. (For missions to the Hubble Space Telescope, with its higher and more debris-filled orbit, the risk was 1 in 185.)

Orbital debris threatens this progress. Since these pieces of debris — of which there are approximately 1 million pieces 1 cm and larger — travel several times faster than a bullet, a collision between the debris or with active satellites could be devastating, destroying entire missions or creating large new debris fields.