Ever since humanity began routinely slipping the surly bonds of Earth there has been a tremendous amount of, well, junk piling up above our heads. Every satellite launch, station resupply mission, and daring comet rendezvous leaves behind a couple of tons worth of metal fuselage and other rocket components that stick around in Earth’s orbit for weeks, years – decades in some cases. Even the astronomically high-priced satellites circling the globe today, including the satellite beaming the NBA Finals to your dish, will eventually fail and become yet another hunk of metal hurtling through space.
The Great Junkyard in the Sky
Our massive orbital junk pile has been in the making since the 1960s, when the US and USSR started sending people and hardware up into space with some regularity. With every launch, bits and pieces of rocket would be left in orbit, as well as assorted bolts and other detritus that comes loose during the various stages of ascent. These launches were relatively few in number through the 60’s and 70’s, but then came the era of satellite TV, GPS, commercial satellite imagery, and global telecommunications, boosting the number of satellite launches from a few dozen per year to over 100 within a few short decades.
The cumulative result of our 50+ years in space is a field of debris stretching from 100 to 1,250 miles above the planet. The field consists of 500,000 individual pieces of debris zooming around the Earth at 17,500 mph. Of these pieces, 22,000 are larger than a softball, big enough to be tracked by ground-based radar. But the rest are too small to be detectable, posing a far greater risk to astronauts and satellites since no one can even see them coming.
This is a serious problem, as coming into contact with something even as small as a fleck of paint is enough to put a dent in a spacecraft or tear through a spacesuit. The space shuttle fleet even took a couple of hits while it was in service, with a number of shuttles needing new windows after being hit by millimeter-sized debris.
As you’d expect, the ever-increasing volume of junk whizzing over our heads is becoming a concern for space agencies and launch companies alike, and there’s no shortage of zany ideas for cleaning it all up. One team of astronomers in Japan proposes equipping the International Space Station with a laser cannon (let the awesomeness of that image sink in for a moment…got it? OK, proceed) that would be used to push errant debris on a trajectory towards the Earth so it can burn up in the atmosphere.
Even NASA has caught laser fever in recent years. In 2011, the space agency released a study on the feasibility of a ground-based “laser broom” that could push debris out of the path of orbiting satellites. It wouldn’t help reduce the amount of junk in outer space, but it would keep spacecraft and satellites safe from collisions.
Other ideas are less lasery and more physics puzzle. Last March, the European Space Agency experimented with using nets to capture debris and re-directing it towards the Earth. Another team of astronomers is designing a probe with a claw that could grab a piece of debris and drop it towards the Earth like a plush toy. And yet another Japanese team unveiled a novel satellite design that could push debris into a lower orbit by bombarding it with waves of electricity.
No Star Wars Just Yet
As much as the idea of lasers and electrodynamic tethers excites our inner child, none of these solutions for ridding the heavens of trash is even close to being deployed. The reason? Politics of the third kind. There are several international treaties and conventions in place that bar any one nation from putting military hardware in space. Even hardware with a peaceful purpose, i.e junk-zapping lasers, would be a violation of decades of agreements to keep outer space peaceful. What’s more, even with a method of removing space junk, you’d have to contend with the bureaucratic nightmare of identifying, and gaining approval, to nudge another country’s defunct satellite into a lower orbit before it smacks into your own satellite.
Under the current regulatory framework, the launching state has sovereign rights over whatever hardware they put into space, meaning you can’t shoot your orbital laser cannon from the hip. Any contact or interaction with a foreign satellite has to be pre-approved and planned out well in advance. That wouldn’t be entirely impractical if it weren’t for the fact that only 16,000 of the 22,000 pieces of debris currently being tracked have identifiable owners. That leaves 7,000 anonymous solar panels, ammonia tanks, even tool bags, tumbling through the magnetosphere that no one can legally zap, grab, or drag.
There’s also the small problem of funding. The primary focus of the space industry today is to make rockets and space travel a lot cheaper. Which is great for science, discovery, and tourism, but makes cleaning up outer space a secondary priority. But who knows? In the rapidly approaching space economy, there could be a sizable job market for astronauts with a waste management background and a penchant for shooting things with lasers. Just remember to wear your helmet.