MIT researchers develop technique to identify materials of space debris using laser radars

There are hundreds of millions of pieces of debris in space, that are moving around the Earth at speeds of roughly 28,163 kilometers per hour. NASA and the US department of defence are tracking over 17,000 individual pieces of debris using laser radars, or ladars. The position and velocity of the pieces of space junk are tracked to prevent any potential disastrous collisions with useful objects in space, such as the international space station. Two major collision events in the past ten years have significantly increased the amount of debris in space. Now, researchers from MIT have developed a new technique based on laser polarimetry that will allows ground based stations to track what kind of material the space junk is made out of. The method works by analysing the properties of the light reflected back from the space debris. The researchers found out the characteristics of the reflected light in lab conditions, on commonly used materials in satellites. This allows ground based stations to find a match of the reflected light from debris with the known characteristics of materials. Knowing whether the debris is made up of aluminum, titanium or Teflon will allow better guesses on how badly a collision will affect a spacecraft, satellite or space station. The researchers have published their findings in IEEE Transactions on Aerospace and Electronic Systems. Kerri Cahoy, one of the co-authors of the paper says agencies “want to know where these chunks of debris are, so they can call the International Space Station and say, ‘Big chunk of debris coming your way, fire your thrusters and move yourself up so you’re clear.’”