TIME: Almanac 1993/TIME Almanac 1993.iso/time/022089/02208900.006

Text File | 1992-09-23 | 5.5 KB | 111 lines

                z                                                              SPACE, Page 80

A Flap over Reactors in Orbit


Activists want to ban nuclear power but the Pentagon favors it


    Ever since a Soviet nuclear-powered satellite broke apart
over a remote region of northern Canada in 1978, the use of
atomic reactors in space has been highly controversial. Once
again the debate over nukes in orbit has heated up. Last April
the Soviets lost control of another nuclear satellite, raising
fears that it would fall to earth before they managed to boost
the reactor into a safer, high-altitude orbit. Then, at a
scientific conference in New Mexico last month, the Soviets
said they had begun putting a new generation of powerful
reactors in space and were even interested in selling them to
the West.

    The news has upset antinuclear activists and raised
questions about American plans for nukes in space. The U.S. has
not launched a nuclear satellite since 1977, relying instead
mostly on solar-powered models. But Pentagon officials are
planning the eventual use of atomic spacecraft in the Strategic
Defense Initiative, the Government's proposed space-based
defense system. To prevent that idea from going any further,
U.S. Representative George Brown, a California Democrat,
introduced a bill in Congress last week that would bar American
nuclear-power sources from space -- on the unlikely condition
that the Soviets do so first. The only exceptions: projects
like moon bases or trips to other planets.

    The Soviets have launched some three dozen nuclear
satellites over the past two decades. Altogether they contain
almost 3,500 lbs. of radioactive fuel. The only way to halt
that proliferation would be to make space nukes an issue in
U.S.-Soviet arms-control talks. Warns Brown: "If we don't stop
the use of nuclear-power sources traveling over our heads,
we're likely to wake up one day with a nuclear reactor landing
on our heads."

    That nearly happened in 1978, when the Soviets' Cosmos 954
fell from orbit and burned on re-entry, showering northern
Canada with radioactive debris. The only reason no one was hurt
was that the impact site was virtually unpopulated. The
incident persuaded the Soviets to design more effective safety
devices into their nuclear satellites.

    Those safeguards were put to a test last September, when the
nuclear-powered Cosmos 1900, containing about 70 lbs. of
radioactive fuel, began falling out of orbit. But before the
satellite re-entered the atmosphere, an automated safety system
kicked in. The reactor was separated from the satellite and shot
into a higher orbit. If, however, the reactor should collide
with a defunct satellite or some other piece of debris left from
more than 30 years of human activity in space, it could be
knocked out of orbit anyway. Says Daniel Hirsch, director of the
Stevenson Program on Nuclear Policy at the University of
California at Santa Cruz: "The probability of a collision with
space debris is unacceptably high."

    While not admitting that any of their nuclear satellites are
dangerous, the Soviets boast that their new type of space
reactor, called Topaz, is especially safe. Topaz can produce up
to 10,000 watts of power, about ten times as much as previous
models. That enables Topaz-powered satellites to fly at such
high altitudes, say Soviet scientists, that they will remain
safely in orbit for up to 350 years, long enough to lose most of
their radioactivity.

    The Pentagon is less worried about Moscow's new satellites
falling out of orbit than about their mission in space. The
Topaz reactors are likely to power a new generation of
reconnaissance satellites that could track the movements of
American ships more accurately than ever and target them for
destruction in time of war. Eventually nuclear reactors could be
used to power space-based weapons. That is why the development
of antisatellite technology is a central part of the Strategic
Defense Initiative.

    Since George Bush became President, the status of SDI has
grown murky. John Tower, Bush's choice for Secretary of
Defense, has conceded that a complete shield against Soviet
missiles is unattainable, but he still favors partial deployment
of SDI as soon as it is feasible. The Reagan Administration's
farewell budget for 1990 proposes a 50% increase in SDI funding,
to about $6 billion. Bush may trim the increase, but he is not
expected to eliminate it.

    Star Wars strategists envision putting up a network of
satellites with the capability of knocking out enemy spacecraft
and missiles. In the early years of the program, the SDI
satellites would probably be conventional solar-powered models.
But later on, new satellites may be increasingly loaded down
with exotic, power-hungry weapons, such as high-energy lasers,
particle beams and electromagnetic rail guns to launch
projectiles. Such equipment would almost surely require nuclear
reactors. General Electric, with funding from the Pentagon, is
already at work on the SP-100, the first American space reactor
developed since the U.S. abandoned the technology in the 1970s. A
Government audit has suggested that the GE design would produce
a reactor too heavy to lift into space, but the company thinks
the SP-100 will be ready for testing in the mid-1990s.

    That prospect seems ominous to Congressman Brown and other
opponents of nuclear-powered satellites. If the purpose of SDI
is to make the world safer, they contend, then the
proliferation of nukes in space will be dangerously
counterproductive.