The USAF is working with various companies to develop a system that will allow to track the more than 600,000 pieces of space debris that are orbiting the planet. It may seem like a small number compared to the immensity of space, but the fact is that things are getting quite hairy up there. Especially after last February, when two communication satellites—a Russian Cosmo and an American Iridium—collided at 17,000 miles per hour, 490 miles above Siberia.

The system is called the Space Situation Awareness, or Space Fence, and will consist on three networked football field-sized S-band radars, distributed all across the world. The radars will track every single dangerous piece of debris orbiting the planet, keeping it in a continuously updated database. If there is any collision danger, the alert will break, and the astronauts will live to see another day in their shiny white space suits.

Unfortunately, the $2 billion system won't be operational till 2015.

Just before the Discovery docked, the ISS crew was forced to crawl into the Soyuz TMA-13 in anticipation of a possible junk impact. That threat passed, but just days later and with the crew of the Discovery present, another piece of space junk has threatened to punch a hole in NASA's equipment and/or humans.

It bears repeating that this maneuver came in anticipation of possible junk impact. That is to say the survival of the crew of the ISS depended on our ability to detect the position and velocity of a four-inch piece of metal (or, as I suspect, a frozen, smiling Spacebat), which, by my calculations, makes the ISS about 5% less fun. Lasers are sounding more reasonable by the day. [Daily Mail]

In addition to the 19,000+ pieces of space junk floating around, the recent collision of two satellites has substantially increased the dangers of working in orbit. Close calls like this one may become the norm. [NASA Thanks Ryan]

According to the Wall Street Journal, the problem with debris eradication is that there's no money in it. Anybody can cough up a billion or so to launch a telecom satellite, but anyone who wants NASA or the ESA to start cleaning up has to come up with a plan that costs a lot less.

There's no money in it probably because nothing really bad has happened yet. According to that video down below, shuttle pilots have had near misses 12 times with pieces and parts that could've played serious havoc. Like so many busy intersections that are missing stop lights, the problem may require a fatal collision before money is made available. Though nobody died, the recent mid-air collision of US and Russian satellites was at least some kind of wake-up call.

In the meantime, here are some low-budget proposals:

1. Jonathan Campbell at NASA's Marshall Space Flight Center in Huntsville, AL says the answer is lasers, what the WSJ says would be "existing low-power lasers in quick pulses" to "singe the surface of an object in space" to "help point it downward." Campbell calls this Project Orion, as in the great hunter in the sky, but the Orion lasers would be based on land. (Note to self: Don't ever fly over Orion lasers.)

2. Jim Hollopeter, who works for Satellite Communications in Austin, TX, likes water cannons mounted to rockets, or as the Journal says, "aging rockets loaded with water to spray orbiting junk" thereby gradually pushing it towards the atmostphere to burn up, along with the spent rocket itself. "The water would turn to steam," says the Journal.

3. Heiner Klinkrad, head of ESA's Space Debris Office in Darmstadt, Germany, thinks we should give a hoot and just not litter. Rockets should not drop bolts and straps when they separate, and satellites should commit space hara-kiri, by steering themselves toward the atmosphere when their job is done. He's also looking into garbage collection strategies.

What definitely won't work:
• Big magnets - There's no iron in space debris.
• Powerful lasers - Would just make more space junk.
• Strong Nets - Cuz you're in space, not in some meadow chasing butterflies.

Read the full article at the WSJ for more good stuff, or watch their video here:

[WSJ]

About 50 percent of all trackable objects are due to in-orbit explosion events (about 200) or collision events (less than 10).

Yes, we knew that there was a lot of crap out there, but not to this extent. According to the ESA, this is really bad news and urgent measures are needed. Explosions in space are not disastrous on their own, but because of the aftermath. One example: a geostationary satellite travels at 6,213 miles per hour. If it explodes, all the debris stays near the orbit, forming a cloud around the Earth within a few days, as this simulation shows:

The ESA is urging to introduce measures to mitigate this problem, like the complete depletion of fuel in rocket stages (like some Delta launchers already do following NASA's Procedural Requirements for Limiting Orbital Debris) or returning objects to Earth once their mission is complete (perhaps to destroy them on re-entry,) just like SES Americom is going to do with their brand-new AMC-14. This satellite failed to reach its projected altitude and now has to be splashed into the sea because of a dispute with Boeing, which won't let SES Americom use their patented recovery method to put the satellite into the right geostationary orbit.

The impact of these measures could be huge, as reflected by this simulation of how things could look by the year 2112, with and without taking action:

While the idea of bringing back used stages and satellites back to Earth may seem too expensive, in the long run it's clear that leaving all this trash up there is going to have huge consequences to the development of space exploration and colonization. Those concepts may still seem science fiction for many, but as these simulations show, the current and future problem is very real, and could be extremely dangerous.

This is how it looks when orbital debris hits a spaceship, simulated in a laboratory.

[ESA Gallery, Space debris: assessing the risk, NASA, Wikipedia — via Space Travel and Slashdot]