Professor Envisions High-Tech Janitor to Clean Up Space Junk : Orbiter: Inventor says his satellite could clear the space lanes of the most dangerous debris, if he could get NASA interested.

Spent satellites, burned-out rocket boosters and bits of other junk create a mine field that could destroy a space shuttle or satellite.

But what if there were a satellite designed to scour the most-traveled areas around the Earth for dangerous space flotsam?

Kumar Ramohalli, a University of Arizona professor of aerospace and mechanical engineering, says his invention--Space Janitor--could clear the space lanes of the most dangerous debris, if only he could get NASA interested.

The Autonomous Space Processor for Orbital Debris would automatically catch errant satellites or bits of space junk with robot arms, cut off reusable parts like solar panels with a solar-powered torch and dump the rest in a hopper. When it filled up, the satellite would either be emptied by a space shuttle, dive into the atmosphere and burn up, or splash down in the ocean for recovery.

“It’s a janitor that eats the diet that’s on the floor,” Ramohalli said. “A janitor with an appetite for crumbs and junk.”

Ramohalli, formerly of NASA’s Jet Propulsion Laboratory, developed his invention since 1988 with the help of students and a $17,500 annual grant that ended in 1994 from the Universities Space Research Assn. Advanced Design Program.

Orbiting trash is no joke for the National Aeronautics and Space Administration.

Officials have estimated there’s a one-in-five chance the planned space station would be hit by junk if it were launched.

Satellites have been hit by debris. Space shuttles have been hit many times by smaller bits, and shuttles Discovery and Atlantis have had to steer around larger pieces.

“It’s not a minor issue as far as the space station is concerned,” said Donald J. Kessler, senior scientist for orbital debris research at NASA’s Johnson Space Center in Houston.

But NASA officials aren’t ready, he said, to turn to Ramohalli’s approach.

So Ramohalli, who has patented the device and built a one-third scale prototype, finds himself with no market for his product--unless he can interest private entrepreneurs.

NASA and the U.S. military have used radar to catalogue about 7,000 objects in orbit that are softball-size or larger. There are many times more objects too small to detect.

The debris, flotsam from hundreds of satellite launchings since 1957, ranges from spent spacecraft to booster rockets, abandoned fuel tanks, pieces of rockets or satellites that have exploded, even minute paint chips.

Even a small bit of orbiting junk can cause disaster because of the tremendous speed of both the flotsam and the spacecraft, said Leslie Tennen, a Phoenix attorney who practices international law governing space.

“They don’t have to be very large when they’re coming at you at 15,000 m.p.h.-plus,” Tennen said.

The National Academy of Engineering, White House and Department of Defense have had separate studies under way, said Ramohalli.

“It’s a very serious and a very major problem,” said Ramohalli.

Ramohalli estimates that his satellite would cost up to $5 million to build and $15 million to deploy, including launching costs. He envisions a fleet of a dozen or so in orbit.

The satellite could retrieve up to 30,000 pounds over two years placed in a stationary orbit, waiting in one spot in space for bits to drift by and grabbing them with its two robot arms. If it maneuvered with thrusters to chase debris, the Space Janitor could probably last one month, he said.

Rather than sweep up debris, NASA is concentrating on preventing the buildup of more space trash, Kessler said. The agency is working with other space-faring nations to ensure that satellites and boosters are programmed to spiral into the atmosphere and burn up harmlessly, rather than floating forever in the vacuum of space.

Tennen said there is no current international agreement on the definition of debris. That poses a potential problem, since nations that put objects in space retain legal control, Tennen said.

It might be 10 years or so before NASA takes a serious look at retrieving space junk, Kessler said, adding: “It’ll always be nice if some people have done some advanced thinking along those lines.”

But Ramohalli doesn’t want to wait: “If anybody foresees a problem 10 years downstream, it’s obvious that the time to start is now.”