Destroy or Recycle: Let's Fix Space Trash with a GIANT... "LASER."
Picture the final frontier as a pristine and clean place, all deep black nothingness and sparkling stars, like you're seeing it from the bridge of the Enterprise. Bzzt, wrong answer! In reality, the past fifty years of space exploration and satellite launching have left a junkyard of twisted metal encircling our planet (we talked about this on Idea Lab last week. In today's episode of Space Debris, we look at one irresistible solution: a GIANT... "LASER."
Researchers at Arecibo Observatory estimate pieces of debris, large and small, number about one million. Some falls to the atmosphere, hopefully burning up on the way to Earth instead of landing on the elaborate domino spiral you just finished. Most of it will continue to orbit at about five miles per second, splintering anything it hits into even more thousands of fragments. NASA's Orbital Debris office---yep, they have one---can tell you that this kind of space trash has increased by almost 50% since 2007.
One of NASA's most popular ideas to confront this problem is building a massive laser. When is building a giant laser not a popular idea?
But seriously folks, this laser would fire at space debris and push it into a lower orbit so that it burns up in the atmosphere. How does that work? Here's our glib Idea Lab version (a more technical explanation is below).
Anything from a Space Pen to SpaceLab can circle around Earth for-freakin'-ever in high orbit if it isn't kicked around ("perturbed") by powers such as a craft's own engines or, say, some alien space pods that careen in from a nearby wormhole. If the circling objects are in LEO---not the astrological Leo, but "low earth orbit"---they can be encouraged to enter our planet's atmosphere by atmospheric drag.
Like space trash, atmospheric drag is not, unfortunately, the name of a long-lost, Ziggy-era David Bowie album. It's what happens when air molecules snuggle up to satellites, slowing them down. Suppose a laser pushes a blob of space trash closer to the planet. Atmo-drag slows it down, changing how the object is aligned to the big round ball o' atmosphere up there. That helps it pass through said atmosphere, where it'll likely burn up completely. (If a chunk of it survives, we might see it as a shooting star, crashing down to the Earth's surface.)
Will a GIANT... "LASER" solve our space-crap problem? If not, other potential solutions are on the table, too. We'll explore a few next week in our Space Debris series. Until then, try not to burn up in the atmosphere. ---Robin Johnson and Tiffany Lee Brown