'Sling-Sat' Could Remove Space Junk on the Cheap

[Buster's Uncle]

'Sling-Sat' Could Remove Space Junk on the Cheap
By Leonard David | SPACE.com – 8 hrs ago.. .

A proposed space-junk removal system would hop from one piece of debris to the next without burning much fuel, potentially making a de-clutter mission economically feasible with current technologiy.
 
The TAMU Space Sweeper with Sling-Sat, or 4S for short, would harness the momentum imparted by capturing and ejecting one object to slingshot on to the next chunk of space junk, its developers say.
 
“The goal of this mission is to remove as many pieces of debris with the minimum amount of fuel,” said Daniele Mortari of Texas A&M University.
 


A growing problem
 
Earth is surrounded by a huge and ever-growing cloud of orbital debris — stuff like spent rocket bodies, dead spacecraft and the fragments generated when these objects collide. [The Expanding Danger of Space Junk (Video)]
 
NASA estimates that about 500,000 pieces bigger than a marble and 22,000 as large as a softball whiz around Earth at fantastic speeds. And there are probably hundreds of millions of flecks at least 1 millimeter in diameter.
 
This cloud of junk poses a threat to the satellites and spacecraft circling our planet, including the International Space Station, and many researchers say humanity must act soon to prevent the problem from really getting out of hand.
 
“It is well understood that we are past the point of no return. Relying solely on improved tracking and avoidance is not enough … it is simply a technical form of sticking your head in the sand and crossing your fingers,” Texas A&M PhD student Jonathan Missel told SPACE.com. “We are at a point where the problem needs to be solved, with active removal, not just avoided.”
 


A new idea
 
Many ideas have been put forward over the years to combat the space-junk threat, including schemes that would blast debris with lasers or snare it in a giant net.
 
“While they are interesting to think about, they are often threatening to operating satellites, or need technological advances that are decades out,” Missel said of some of the more ambitious offerings.
 
The most technically and politically sound idea is a simple rendezvous mission, during which a clean-up craft would travel to and de-orbit debris objects one at a time, Missel said. But such a mission would burn loads of fuel to get between widely spaced targets, making it “fatally plagued by inefficiency,” he added.
 
The 4S system, which Missel and Mortari are developing, aims to correct this fatal flaw. It would snare debris at the end of a spinning satellite, then fling the object down to burn up in Earth's atmosphere.
 
The spacecraft would harness the momentum exchanged during both of these actions to cruise over to the next piece of space junk on its list, minimizing fuel use and extending its operational life to the point that such a mission might be practical.
 
Work on 4S this year includes looks at hardware options, Mortari said, and further optimization of the idea.

http://news.yahoo.com/sling-sat-could-remove-space-junk-cheap-100806976.html

[Unorthodox]

Interesting...

Curious to see the actual design. 

[Buster's Uncle]

Europe Takes Aim at Space Junk Menace
By Clara Moskowitz | SPACE.com – 5 hrs ago.. .

Each dot represents a bit of known space junk that's at least 4 inches (10 cm) in low-Earth orbit, where the space station and shuttles roam. In total, some 19,000 manmade objects this size or bigger orbit Earth as of July 2009


An artist's illustration of a satellite collision from space debris in orbit. Space traffic accidents only beget more such accidents.

The European Union has launched a new program to tackle the threat of space junk, which litters the corridors of Earth orbit.
 
Space junk is man-made debris — spent rocket stages, dead satellites and even lost spacewalker tools — orbiting Earth. These bits of detritus pose a risk to orbiting satellites, which even a small piece of space trash could damage or destroy.
 
There are thought to be about 600,000 objects larger than 1 cm (0.39 inches) in diameter orbiting Earth, and at least 16,000 larger than 10 cm (3.9 inches). Satellite operators rely on Earth-based tracking programs to locate this orbital debris in time to maneuver spacecraft out of the way of impending collisions.
 
To better combat the problem, the European Union has proposed that its 27 member countries combine their space-surveillance efforts and work together in alerting satellite operators of collision risks. The European Commission, the executive body of the European Union, announced the new initiative on Feb. 28.[Why Europe is Tackling Space Debris Threat (Video)]
 
"Some EU Member States have national systems, radars or telescopes that could be used for monitoring satellites and space debris, but all in all, European satellite operators almost completely depend on United States SST [space surveillance and tracking] information," European Commission officials said in a statement."However, with increasing space activities, the U.S. will no longer be able to meet the information needs of an increasing number of spacecraft operators."

 European officials propose making contributions toward each country's costs in setting up and operating space junk-surveillance programs.
 
Improved tracking could save satellite operators significant amounts of money. Officials estimate that losses from space junk collisions, plus the risky maneuvers necessary to avoid impacts with space junk, cost European satellite operators €140 million ($182 million) a year, and the costs could rise to €210 million ($273 million) per year within the next decade.
 
"Today, the only effective way satellite operators can mitigate collision risks is to move their satellites out of the way as soon as a collision risk has been identified," officials said."Each such avoidance maneuver costs fuel and shortens the satellite's lifetime. Some European space agencies operating satellites report that, on average, they carry out one collision-avoidance maneuver every month."
 
And the space junk problem not only affects the companies that operate satellites in Earth orbit. It has repercussions for most of the planet's population, which increasingly relies on satellite technology in everyday life.
 
"Without being aware, European citizens rely on space technologies when they use their mobile phones, make financial transactions, take an airplane, watch the weather forecast or look for the nearest restaurant in their cars," officials said."Any interruption of services which rely on space-based systems can have dramatic economic consequences."

http://news.yahoo.com/europe-takes-aim-space-junk-menace-115853198.html