The Earth is surrounded by human-made orbital debris in all shapes and sizes that includes everything from abandoned satellites and leftover rocket stages to the tiniest paint chips and droplets from spacecraft coolant systems.

The hazard is very much real. Given the ultra-fast speeds of objects in space (satellites in low-Earth orbit fly at 17,400 mph), even the most minuscule bit of rubbish could create havoc if it crashed into a functioning spacecraft.

The question of how best to de-clutter outer space has produced a wealth of proposals: some whacky, whimsical or wanting of a sanity check. Many space junk clean-up ideas have already been proposed, including: catch-all space sweepers, fishing nets and harpoons, tethers, laser blasts, big and small space tugs.