Danger lurks in Earth's orbit as thousands of rogue objects speed around the planet.
These aren't stray pebbles; they're bits and pieces of all the junk we've shot up there in the 60 years since Sputnik, from tiny specks of metal to larger objects -- all traveling thousands of miles per hour.
A basic step for space operators is to track debris and steer vehicles clear, be they unmanned satellites, rockets with humans, or even the International Space Station. In the future, however, some altitudes may require active cleaning measures.
"It's very easy to get something into orbit," said Bill Ailor, a research fellow at Aerospace Corp. "It's the dickens to get it out."
These speeding objects, some of which top out at 18,000 mph, can circle the globe for hundreds of years. Meanwhile, the clutter in low-earth orbit has grown more rapidly over the past decade.
In January 2007, the Chinese government destroyed an aged weather satellite in a missile test, creating an estimated 2,500 pieces of new debris. That was followed by the February 2009 collision of a defunct 1,900-pound Russian Cosmos satellite with a 1,200-pound Iridium Communications Inc. satellite. That crash, 490 miles above Siberia, generated even more orbiting waste, much of which now blankets the planet.
Over time, this space detritus steadily collecting around the planet, amid more satellite launches and periodic collisions, may approach a critical mass.
The accelerated accumulation of garbage up there raises the possibility of a "collision cascading" effect called the Kessler Syndrome. Named after Donald Kessler, a NASA astrophysicist who described the scenario in a 1978 paper, this phenomenon occurs when flying junk collides and begets more junk, and so on. Eventually, low-earth orbit becomes commercially dubious.
As government-sponsored space exploration slowly gives way to private industry, the business of tracking what's already up there has gone commercial, too. Now, there are some companies contemplating ways to start clearing out our big garage in the sky.
Everyone who has thought about this problem has agreed that it's atrociously expensive to launch satellites merely to intercept and nab junk. This nascent field of inquiry has at least two cardinal rules: Create no further debris, and mind the budget. Most prefer to make the Earth's atmosphere part of the solution by nudging space garbage into a fiery demise.
For example, one proposal is the Brane Craft, an ultrathin, 3-foot-by-3-foot device that weighs just 100 grams. It is the brainchild of Siegfried Janson, a senior scientist at Aerospace Corp., a space researcher and defense contractor based in El Segundo, Calif. The craft would encircle an object, adding sufficient drag to degrade its orbit and send it into the atmosphere. If it had sufficient fuel, the vehicle would then pursue a second object.
A Section on 05/28/2017