TEXT B As every ancient mariner
knew, traveling by sail is a simple way to go. Though the winds could be fickle
and the boats pokey, the energy source that moved the ship was free, plentiful
and renewable. Now tile same technology that conquered the oceans of Earth may
conquer the ocean of space. This week a Russian and American
consortium will announce plans for an April launch of the first so-called
solar-sail vehicle, a multicasted spacecraft that will use sunlight to push
itself along. To a public raised on smoke-and-fire rocketry, the idea of drawing
energy straight from space seems fanciful. To the people behind the new ship,
however, the technology is not only sensible but inevitable, the easiest way to
reinvent the business of cosmic travel. "This allows us to use very little fuel
to fly very great distances," says Bud Schurmeier, a former NASA engineer and an
adviser to the project. "It’ s an in- triguing concept." The
idea behind solar sailing is simple. Although light is made of massless
particles called photons, such ephemeral things exert real pressure, especially
when they flow so close a source as the sun. Attach a sail of lightweight Mylar
or other material to a spacecraft, set it up in the path of .that outrushing
energy, and you ought to be able to move in almost any direction.
NASA has a keen interest in solar sailing and had budgeted ＄ 5 million to
invest igate 17 possible missions. It may select one as early as next month. But
while the space agency has been mulling plans, the people behind the new ship,
dubbed Cosmos I, have been getting set to fly. The project is the brainchild of
Russia’s Babakin Space Center, near Moscow, and the Planetary Society in
Pasadena, Calif., a think tank founded in 1979 by astronomer Carl Sagan and
others. The two groups had long been developing plans for a solar-sail mission
but got the cash to make it happen only last year when Ann Druyan, Sagan’s widow
and head of the Media Company Cosmos Studios, and Joe Firmage, the founder of US
Web, threw their names and about ＄ 4 million behind the effort. "I had talked to
people about solar sailing before, "says Lou Friedman, former engineer at the
Jet Propulsion Laboratory in Pasadena and director of the Planetary Society,"
but between the Russians’ capabilities and Ann’s vision, I knew this one would
click." The spacecraft is a 3-ft. metal with eight 35-ft.
metallic wings. Mylar petals sprout from it -- though the prototype used in the
April launch will have just two petals. Mounted atop a reconfigured Russian ICBM
and launched from a sub in the B arents Sea, the Cosmos I will fly to an
altitude of 260 miles, where it will deploy the wings and float for a minute of
so. If all goes well, the wings will then be jettisoned and the sphere
aerobraked back to Earth, its bounce-down on Russian soil cushioned by air
bags. By some measures, this cosmic lob shot is not that
impressive, but for solar-sail scientists, the engineering is everything.
Few doubt that when sunlight strikes the wings, the spacecraft will
accelerate; the key is building wings that can open and pivot, allowing the ship
to tack into the solar stream. If this mission works, a more ambitious orbital
flight, using the eight-paneled craft, is set for the end of the year. The
space-craft could circle Earth for months, surfing the sun until designers shut
it down. "There will be a grandeur to it, "says Druyan, "a 70-ft. sail that will
be visible to the whole planet." Grandeur aside, critics wonder
if solar sails have a future. The technique is problematic in Earth orbit, since
the changing position of sun relative to the space-craft makes constant tacking
necessary. Sailing is best used for as the crow- flies shots to neighboring
planets. Even in these cases, progress can be slow, since sunlight exerts, at
most, 2 lbs. of pres- sure per square half-mile, requiring a year or more to rev
a spacecraft to interplanetary speeds. Worse, beyond Jupiter, sunlight flickers
out almost entirely; to go any farther would require energy beamen from Earth
orbit, perhaps by giant laser howitzers. "None of these things has been tested,
"says Mel Monte-merlo, one of NASA’s solar-sailing chiefs. "We have a long way
to go." Whether that will continue to seem such a long way may
depend on the spring-time flight of Cosmos I. A successful mission has a way of
making impossible technologies seem possible -- a big burden for a small rocket
that will, for one day at least, carry the hopes of the world’ s space
community. What does "brainchild" in the paragrapth 4 mean