One might assume that the largest space debris would be the most dangerous. While high budget films and fantastical scenarios may lead one to this conclusion, it is actually the smaller space debris which can do the most damage.
For large debris, the International Space Station and other satellites can take evasive maneuvers and avoid impact. However, the smaller the debris, the harder it is to spot. With a lot of super-small debris moving just as fast as large debris, this brings up a dangerous scenario. Suppose that a piece of space junk only a centimeter in size were to hit the ISS traveling at 17,000 mph. Sure, a small hole can be fixed. But at that velocity it would still do a lot of damage, and it’s likely that this would not be a one-off event. Check out what even the smallest orbital debris can do to the ISS’s kevlar shielding.
Solving this issue is no easy feat, but RIKEN’s EUSO team has an approach which is very promising. The JEM-EUSO (Japanese Experiment Module-Extreme Universe Space Observatory) telescope was originally designed to detect high-energy particles from ultra-high energy cosmic rays entering the Earth’s atmosphere at night. However, the telescope can also be used to detect space debris at around a centimeter in size, potentially the most dangerous and abundant. Mounted on the ISS, it can provide a wide field-of-view for detecting incoming debris.
However, spotting the debris is only half the battle. That’s where the CAN (Coherent Amplification Network) laser comes in. The laser actually consists of many smaller lasers, working together as one powerful beam. This beam would vaporize a thin layer of the debris, creating high-speed plasma, which would propel the debris downward in a decay orbit to burn up in the Earth’s atmosphere.
While this does not solve the problem of large debris, it does have the potential to make a significant impact of the amount of small space junk. By detecting and disrupting small debris, this method can protect the ISS and other satellites while also helping to clean up our orbits.