THREE decades into the space age, it's time that space-faring nations cleaned up their orbital act. What should be a pristine environment for astronauts, orbiting telescopes, and other satellites is a junked-up mess. A new study led by NASA and the US Department of Defense warns that, unless the debris accumulation is curtailed, it could seriously threaten both manned and unmanned spacecraft.
This echoes warnings made over the past several years by other groups, including the European Space Agency. Indeed, an international meeting of space scientists in Britain last summer concluded that the situation could become intolerable within a decade if debris accumulated at its present rate. There's an immediate need to learn more about the trash now up there. NASA has asked industry to come up with radar by 1991 that can track centimeter-size objects in low Earth orbit. That's equivalent to tracking an American dime several hundred miles high.
The cloud of space junk has tens of thousands of metal, plastic, and paint bits that are that small or smaller, as well as some 7,000 larger objects. Orbiting at speeds on the order of 17,000 miles an hour, even one of the dime-size fragments could seriously damage - or even destroy - a spacecraft.
But more than tracking is needed. The debris is building up rapidly, already adding to the cost of space operations. The Hubble Space Telescope, to be launched this year, is now three times as likely to take a hit in its first two years of operation as its designers estimated half a decade ago. Shielding is being added to new satellites which increases cost and reduces useful payload. NASA, for example, added 12,000 pounds of extra shielding to inhabited parts of its planned space station.
Nations using Earth orbital space must act now to reduce the junk they create, if they can't eliminate it entirely. Rockets and spacecraft can be designed to reduce fragmentation. Satellites can be designed for retrieval. If antisatellite tests are carried out, they can be conducted low enough that resulting debris will quickly reenter the atmosphere.
Nations should also start cooperative development of ways to clean up existing trash. This includes a rising inventory of dead satellites, some with nuclear reactors on board. Many of these satellites are parked out of the way in higher orbits. Nevertheless, as near-Earth orbital space becomes more heavily used over the next two decades, these derelicts will be a dangerous nuisance.
The few nations now working in near-Earth space have no right to clutter it up, especially as other nations will soon be wanting to use it also. The United States and Soviet Union should lead a formal effort to negotiate an environmental protection treaty for the space surrounding our planet.