One of the most commonly discussed topics in space science today is the space junk problem, in which space junk collides with objects to create space debris, which can range in size. Space debris larger than a baseball can be detected and avoided as spacecraft use automated maneuvers to jump out of the way, but smaller space debris is substantially more common, and nearly impossible to detect or avoid.
While a tiny piece of space debris may not seem all that intimidating at first glance, it’s the orbital velocity that makes it so dangerous. Something as small as a fleck of paint traveling tens of thousands of miles per hour can generate enough energy on impact to leave a crater in something as heavily armored as the space shuttle’s window. Larger objects that are still smaller than a baseball can be even more dangerous.
To protect astronauts on the International Space Station, the Earth-orbiting space lab is covered in whiffle shields that are designed to mitigate impact energy. Still, some pieces of space debris sometimes strike the station’s weak spots, such as the solar array.
Developing technologies that can resist space debris impacts is particularly challenging because of how difficult it is to produce orbital velocity impacts on Earth. Doing do necessitates a light-gas gun, which can be used to eject a projectile up to 19,000 miles per hour onto a target surface. A projectile doesn't exit the muzzle of a traditional firearm with anywhere near as much speed.
While difficult, progress has been made in developing new shield technologies for spacecraft in space, including the football field-sized International Space Station. With a little luck, perhaps we’ll be better shielded from space debris in the future than we already are now.
