Report Warns of Space Junk Reaching a Tipping Point

intellitech sends this excerpt from a Reuters report: "The amount of debris orbiting the Earth has reached a tipping point for collisions, which would in turn generate more of the debris that threatens astronauts and satellites, according to a U.S. study released on Thursday (PDF). ... The amount of orbital debris tracked by the U.S. Space Surveillance Network jumped from 9,949 cataloged objects in December 2006 to 16,094 in July 2011, with nearly 20 percent of the objects stemming from the destruction of the Chinese FENGYUN 1-C satellite, the National Research Council said. ... the panel made two dozen recommendations for NASA to mitigate and improve the orbital debris environment, including collaborating with the State Department to develop the legal and regulatory framework for removing junk from space. The study, 'Limiting Future Collision Risk to Spacecraft: An Assessment of NASA's Meteoroid and Orbital Debris Programs,' was sponsored by NASA."

EDDE

[anti11es]

It looks like they've worked out a possible solution to clearing out debris in LEO [space.com].

A small fleet of net-flinging spacecraft could clear every big piece of space junk out of low-Earth orbit within a dozen years, according to a researcher working on the concept. Each spacecraft, known as an ElectroDynamic Debris Eliminator (EDDE), would capture orbital debris in a net, then drag the junk down out of harm's way. The EDDEs would draw their power from the sun and from Earth's magnetic field rather than rely on costly chemical propellants, helping keep costs down, said Jerome Pearson, president of Star Technology and Research, Inc.

Kessler Syndrome

[JoshuaZ]

There's an idea dating back to the late 1970s of "Kessler Syndrome" http://en.wikipedia.org/wiki/Kessler_syndrome [wikipedia.org] in which repeated collisions of objects in orbit will result in so many debris objects that they will become a self-reinforcing problem (since when debris collides with other bits of debris the result is a lot more smaller pieces now in different orbits from the original large pieces). The level at which things become inconvenient is well before where we hit full on Kessler syndrome, but it may well be that one won't get much warning before Kessler syndrome starts to take hold.

There's a very real danger at this point that we will soon run into a real Kessler syndrome situation in low-Earth orbit. This would be really bad since this is both a really useful area to have satellites and the area where it is cheapest to put them in orbit. We have taken a few steps to help matters. For example, it became apparent that the Delta rockets were causing a lot of space debris and the more recent versions have been redesigned to minimize those issues. Unfortunately, many rockets from other countries and some other US rockets still have serious problems. There's no indication that China is taking any serious steps to minimize space debris. There have been some attempts to require people who put up satellites to have plans for either deorbiting them or parking them in graveyard orbits. That's now being done for most civilian satellites, but we don't know what if anything is being done for military satellites. This is in some sense one massive tragedy-of-the-commons type situation.

The current engineering solutions for removing space debris are also lacking. There's a proposal to use lasers to ablate small bits of debris but this is politically not great since lasers powerful enough to do that could be used as weapons. Most of the other proposals have other problems or have the same problem: essentially any method of easily deorbiting objects is going to be a threat to satellites, and so for obvious reasons governments don't want other governments to have that sort of capability.

One point which this new study makes that I had not seen before is the point that the calculated cost of satellite collisions is underestimated because not only do satellites collisions destroy satellites but they also create more debris which can then endanger other satellites and requires further tracking.