Monday, July 27, 2009

Dealing with hazardous space debris

As I've written before, trash collection is space has the potential to be a profitable business for some bright entrepreneurs.
Building an Electronic Fence to Track Space Junk | Popular Science:
"Thousands of manmade pieces of space junk orbit the Earth, threatening astronauts and unmanned missions alike. Now the U.S. Air Force Space Command wants an electronic 'space fence' that could track any orbital object larger than two inches in width.

Such a surveillance system would require a global network of sensitive S-band radar stations that operate in the gigahertz range of the electromagnetic spectrum. The U.S. Air Force currently relies on a system dating back to 1961, which only covers the continental United States, and can only track objects 20 inches in width or larger.

The growing cloud of space debris in Earth orbit includes more than 16,000 pieces of debris larger than four inches in width. And that only seems likely to grow . . . "

Beyond tracking the debris, some folks are coming up with a variety of methods to destroy or collect it. I'm in favor of collecting the debris to sell as souvenirs, but that technology may be too pricey.
Taking Out the Space Trash | Popular Science:
"Scientists at NASA and private companies have devised several ways for clearing the sky. Although some methods are admittedly outlandish, says Nicholas Johnson, the chief scientist for orbital debris at NASA’s Johnson Space Center in Houston, Texas, a few are possible with today’s technology.

One early idea was to have robotic trash collectors shove large pieces of junk through the atmosphere so that they mostly burn up before hitting the ground. But the fuel costs for destroying a significant amount of debris with such craft has quashed this approach.

A more feasible plan is to attach miles-long “electrodynamic tethers,” wound on a spool, to all new satellites. Once a satellite ends its mission, it would deploy the cable and Earth’s magnetic field would induce an electric current in it. This interaction imparts a force on the craft that pushes it through the atmosphere until most of it burns up harmlessly,"

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