We Should Probably Stop Leaving Our Rubbish All Over Space

Rubbish from the International Space Station about to be unloaded. (Photo via)

Space is big. You just won't believe how vastly, hugely, mind-bogglingly big it is. It's so big that if you were to lay all the clichés and ropey metaphors in popular science end-to-end, you'd have achieved nothing beyond writing the proposal for Malcom Gladwell's next book.

Still, as the new film Gravity shows, we’ve put quite a lot of stuff up there. No less than 14 missions are en-route or in progress across the solar system, visiting asteroids, comets, Mars, Jupiter, Saturn, Mercury and even Pluto. But that number pales into insignificance against the constellation of stations and satellites spinning their way around our planet. A database maintained by the Union of Concerned Scientists lists over a thousand satellites currently operating in Earth's orbit.

All of these objects are moving fast – orbiting means going sideways so fast that you miss the planet before you fall into the ground – and maintaining low Earth orbit (an altitude between 160km to 2,000km) means moving at a speed of several kilometers per second. The International Space Station (ISS), for example, orbits at around 27,500km per hour. Any substantial collision at that speed means obliteration and a vast cloud of debris, which could in turn strike other satellites, causing more debris, and so on. In theory, if the space around our planet gets too congested, one small collision could trigger a vast chain reaction – a phenomenon ominously named the Kessler Syndrome.

The consequences of this would be catastrophic. In the short term, the debris would obviously pose a terrible threat to astronauts who aren’t standing behind Sandra Bullock, whose superpowers in Gravity apparently include a debris deflection shield and the ability to pilot all known human vehicles. Beyond those immediate problems, satellite technology could become essentially unusable, and we could lose the ability to enter space for generations. That means no GPS, no satellite links and a lot of very pissed off RunKeeper users.

In Gravity, that chain reaction is set off by the Russians blowing up a satellite in a missile test. That fictional mission echoes a real-life incident in which China blew up its own Fengyun 1C satellite in a demonstration of its anti-satellite missile capability. Debris from that test took out a Russian BLITS nano-satellite earlier this year, which isn’t quite as bad as destroying the ISS and George Clooney, but still worrying.

It’s the United States, however, who were responsible for the most absurd episode of space littering: a Cold War-era programme known as Project West Ford. At the turn of the 1960s, the Cold War was in full swing and the US Army had identified a key strategic weakness in their operations. At the time, global communications relied entirely on undersea cables, stretching across the word’s oceans. These were – and still are – incredibly vulnerable to attack, with the potential to cause severe disruption. With that fear in mind, the Americans began looking to the skies for a plan B.

It was 1961, a time before communication satellites filled our skies. SCORE the world’s first communications satellite – had been launched a couple of years before, using a tape recorder to store messages for broadcast. But the first active satellite wouldn’t be in operation until late 1962, and geostationary satellites were still a few years away. It was also a time before the rise of popular concern about pollution and the environment. Even in that context, though, the plan the US Army came up still seems insane.

The Americans intended to create a ring around the earth. A satellite would be launched, carrying a payload of hundreds of millions of copper needles – tinier even than the tears that were shed for whoever the third character in Gravity was. A controlled release of the needles would scatter them out along the satellite’s orbit, creating a tenuous ring of what were effectively millions of tiny antennae, stretching around the world. Once in place, radio communications could be broadcast up to the ring and bounced around the world to wherever they needed to be received.

Even in the 1960s, people were up in arms. Scientists around the world protested about what they felt was almost an act of vandalism. Many, such as Harvard’s William Liller, warned of serious consequences for astronomy: "Substantially increased dipole densities, as the operational belts will very likely have, will make any research on faint astronomical objects most difficult except from above these belts," he wrote – a problem compounded by the location of the ring being classified.

The West Ford project was reviewed in the latest edition of a fascinating newsletter from NASA – "Orbital Debris Quarterly News". Two attempts were made to create the ring, with launches in October of 1961 and May of 1963. The first mission reached orbit at an altitude of around 3,500km, but "due to design characteristics and unanticipated thermal effects" the needles came out in several big clumps, all of which remain in orbit to this day. One paper published a few months later suggests mechanical malfunction was to blame, though details are frustratingly scanty.

The second mission fared a little better, but not much. Nobody knows exactly how many needles were deployed, but an estimate puts it in the 120 to 215 million range – so a lot. Their orbits were intended to decay over a few years, but in the decades since, over 144 small objects – believed to be clumps of needles – have been detected in associated orbits. "Today, 46 clumps remain in Earth orbit," according to NASA's newsletter. No benefits for communication were ever realised.

One unintended side effect of the failed project was a far greater awareness in the scientific community about the problems of space debris: "Following the failed first Project West Ford mission, the Committee on Space Research (COSPAR) of the International Council of Scientific Unions (ICSU) established the Consultative Group of Potentially Harmful Effects of Space Experiments. That group evolved into today’s Panel on Potentially Environmentally Detrimental Activities in Space (PEDAS), which is the home of COSPAR discussions on orbital debris."

These days, satellite missions tend to be designed with clean-up in mind, but even small amounts of debris have a tendency to stick around, and even a fleck of paint moving at 17 miles per second can cause minor damage. According to NASA, there are more than 20,000 pieces of debris "larger than a softball" in orbit, and more than half a million bigger than a marble; and they’ll be there for a long time, often generations.

We could probably clean some of it up with enough time and money. Some scientists have proposed a "laser broom", a high energy ground laser that could zap particles in orbit. This wouldn’t destroy the debris, but cause it to move just enough for its orbit to decay over time. The Swiss "Clean-mE" project – so ridiculously neighbourly it’s almost Canadian in nature – hopes to deploy nano-satellites that could grapple and deorbit some of the larger items. So, at the moment, we're relying on ground-based laser brooms or orbiting Roombas.

But the best thing to do, probably, is to not create a mess in the first place; whether it’s blowing up your own satellite because you like showing off your giant missile, or trying to create a gigantic ring of copper in Earth's orbit.

Follow Martin on Twitter: @mjrobbins

Previously – Calling Bullshit On Richard Dawkins and His Little Pot of Honey