Project Solar Sail

by Arther C. Clarke

  He could press the jettison button now, and save his rescuers a few minutes of time. But he could not do so. He wanted to stay aboard to the very end, on the little boat that had been for so long a part of his dreams and his life. The great sail was spread now at right angles to the sun, exerting its utmost thrust. Long ago it had torn him clear of Earth—and Diana was still gaining speed.

  Then, out of nowhere, beyond all doubt or hesitation, he knew what must be done. For the last time, he sat down before the computer that had navigated him halfway to the moon.

  When he had finished, he packed the log and his few personal belongings. Clumsily—for he was out of practice, and it was not an easy job to do by oneself—he climbed into the emergency survival suit.

  He was just sealing the helmet when the Commodore’s voice called over the radio. “We’ll be alongside in five minutes, Captain. Please cut your sail so we won’t foul it.”

  John Merton, first and last skipper of the sun yacht Diana, hesitated for a moment. He looked for the last time around the tiny cabin, with its shining instruments and its neatly arranged controls, now all locked in their final positions. Then he said to the microphone: “I’m abandoning ship. Take your time to pick me up. Diana can look after herself.”

  There was no reply from the Commodore, and for that he was grateful. Professor van Stratten would have guessed what was happening—and would know that, in these final moments, he wished to be left alone.

  He did not bother to exhaust the airlock, and the rush of escaping gas blew him gently out into space; the thrust he gave her then was his last gift to Diana. She dwindled away from him, sail glittering splendidly in the sunlight that would be hers for centuries to come. Two days from now she would flash past the moon; but the moon, like Earth, could never catch her. Without his mass to slow her down, she would gain two thousand miles an hour in every day of sailing. In a month, she would be traveling faster than any ship that man had ever built.

  As the sun’s rays weakened with distance, so her acceleration would fall. But even at the orbit of Mars, she would be gaining a thousand miles an hour in every day. Long before then, she would be moving too swiftly for the sun itself to hold her. Faster than any comet that had ever streaked in from the stars, she would be heading out into the abyss.

  The glare of rockets, only a few miles away, caught Merton’s eye. The launch was approaching to pick him up at thousands of times the acceleration that Diana could ever attain. But engines could burn for a few minutes only, before they exhausted their fuel—while Diana would still be gaining speed, driven outward by the sun’s eternal fires, for ages yet to come.

  “Goodbye, little ship,” said John Merton. “I wonder what eyes will see you next, how many thousand years from now.”

  At last he felt at peace, as the blunt torpedo of the launch nosed up beside him. He would never win the race to the moon; but his would be the first of all man’s ships to set sail on the long journey to the stars.

  ###

  Arthur C. Clarke is from Somerset in England, although he now makes his home in Sri Lanka on the other side of the world. He is well known for his television appearances commenting on the moon flights, as well as for the motion pictures 2001: A Space Odyssey and 2010: Odyssey Two. Yet his reputation rests first upon his excellent science fiction novels like A Fall of Moondust and Childhood’s End, as well as classic short stories such as “The Billion Names of God” and “The Star.”

  When it first appeared, this story was entitled “Sunjammer.” (I didn’t know about the Poul Anderson story of the same title. Besides, I like “The Wind from the Sun” better now.) Many of the bright men and women working to develop solar sails have told me that their lifelong interest began when they first read this story back in the 1960s. Flatterers!

  To Sail Beyond the Sun

  (A Luminous Collage)

  by Ray Bradbury and Jonathan V. Post

  We all are solar sails

  in the tree of heaven climbing free

  And yet in looking back I see

  From topmost part of farthest tree

  A land as bright, beloved, and blue

  As any Yeats found to be true

  home-planet Earth

  As bright as all the summer air

  And in the solar-system’s body, where

  I circumnavigate each cell in you

  Your merest molecule is right and true

  Your moons and planets passing fair

  And so we earn what we shall dare

  Tossed from the central sun

  We with our own concentric fires

  Blaze and burn.

  Burn and blaze, Until we feel

  Once at the hub of wakening

  the vast starwheel

  Of solar system’s body

  A Pegasus of cometary hair

  tended by

  comet grooms like Kepler and

  Galileo Galilee

  Whose short-sight probing light-years

  saw the way for solar sails to go

  To change tomorrow’s clime, its meteor snows.

  Our rocket selfhood grows

  and, rocket-less, more elegantly knows

  And claim from Heaven

  The Garden we were shunted from,

  For now, space-driven

  We fit, fix, force and fuse,

  Re-hub the system vast

  On wings of sunlight, travel fast,

  on vector axle, over vacuum’s floor

  Respoke starwheel

  And at the spiraled core

  Plant foot, full fire-shod

  and stride the stride of God

  whose name is spelled in stars,

  and in whose name

  We clothe ourselves in flame

  Why do we, the solar sails,

  fragile as a feather’s frond,

  silently seek to sail so far?

  We walk the air from here to planet out beyond

  Because we’re more than fond of life and what we are.

  We are the energy of Shakespeare’s verse,

  we are what mathematics wants to be—

  The Life Force in the Universe

  That longs to See!

  That would Become

  and give a voice to matter that was dumb.

  We are, to the gates of gravity, the keys

  We are the Abyss Light that comes from Pleiades

  We are the melody of futures flying soon

  And what the song, the tune?

  To fashion fires and thus outrace the Moon

  West is West, and East is East,

  but we sail on perpendiculars

  To grow man ten ways tall to feast

  On Universe and stars

  And why did Engineering bend

  the force of light to give us play?

  To landfall Time, give man Forever’s Day

  And free us from well-bottom’s cave

  Unlock the doors of light-year grave

  Fling wide the portal;

  Give man the gift of stars

  And so, as solar sail, while children sleep

  in atmospheric blanket curled

  I bury all the stars in Cosmic Deep

  So, listen, world . . .

  Is this the setting of the sun of Earth?

  No, this is what the future brings:

  A million-dozen multitudes of summer things!

  O child, they said, avert your eyes.

  What does a solar sailor feel?

  Avert my eyes? I said, what, from wild skies

  Where stars appear and wheel.

  And so a sail takes flight

  beyond the airy skirts of old Earth-mother

  And fills my heart and make me feel as if I might

  This night and then another and another

  Live forever and not die.

  This is life itself, to onward fly

  A boy alone with Universe

  who knows that he must go into the dark.

  God minds m
e to be so. He put the bright sparks in my blood

  and taught me to run,

  and run again after I fall

  Small sparks, large sun—

  All one, it is the same.

  Large flame or small

  as long as my heart is young

  the flavor of the night lies on my tongue . . .

  The Universe is thronged with fire and light,

  And we but smaller suns which, skinned, trapped and kept

  where we have dreamed, and laughed, and wept

  Enshrined in blood and precious bones,

  with heartbeat’s rhythms, passion’s tones

  Hold back the night

  Somewhere a band is playing

  Where the moon never sets in the sky

  And the sun sets never

  And Time . . . goes on forever

  And hearts then continue to beat

  to the pulse of the future coming

  To the sound of the old moon-drum drumming

  And the glide of Eternity’s feet

  Infinity my destination,

  until my course is run,

  Light hierarchies of Time and, one by one,

  With mighty Ra, fall in that final sun

  Billions of years ago, Big Bang began the flight

  of galaxy from galaxy that was to be

  A thousand tigers’ eyes fireworked the night

  Quadrillions of years hence,

  the suns burnt out, we solar sails still drift

  Gone blind from stars and dark of moon

  thinned by evaporation from our metal flesh

  And saw in X-ray warp and mesh

  A sigh of polar-region breath

  At first there was but sea and tides by night

  fingerboard space with silver starlight frets

  and souls’ pure jets.

  At first, we dandelion sails were still as death

  At first there was no captain to the ship

  But: God obtruded, rose and blew his breath

  and we went spinning outward from His lip

  Sailed . . . through wild dreams

  In free-fall fell

  God, Nature, Space, all Time, now stand aside we said

  Illumine Heaven and relight the coals of Hell

  Past Uranus we sailed, that tilted planet saw

  And knocked the world half off its axis into awe

  What size is Space? A thimble!

  No! outside of a sun!

  pocked by sun-spots in which gods

  could bathe themselves in ion streams

  and sleep in plasma magnet dreams . . .

  What is this dream of Cosmos

  Born from a senseless yearning

  Of molecules for form,

  Birthed from a mindless burning

  Of solar fire-storm—

  The Universe, in Needing,

  Made flesh of empty space,

  And with a mighty seeding

  Made pygmy human race . . .

  Which now on fires striding

  the solar sails to give

  on solar lightbeams riding

  Wakes up the stars to live

  Then off they glide on rafters

  of centripetal force

  with sails as light as laughters

  Of stars like skating ponds.

  The ice between the stars

  is gravity’s weak bonds

  Twin mirror selves of seeing,

  each soul to soul responds.

  We dance, and spin, and play

  We live Forever’s Day

  And spawn the Cosmic rivers,

  in billions celebrate

  with out-from-sunward spinning

  No Ending or beginning

  Behold! The Mystery stirring . . .

  Here in space our dreams are truly ours

  Here they lie—in countries where the spacemen

  Flow in fire and much desire the Moon

  And reach for Mars

  on thin metallic wing

  And teach the fiery atoms how to sing

  Mind’s quest makes footfall here

  leaving cradle Earth behind

  To transfer across Space to lift Mankind

  beyond the reach of ancient fear

  The thought that birthed itself to Space

  is the thought that knows it knows it knows

  Across the solar system’s face

  Where now Man goes

  Grand Things to Come? Yes! Things to Come!

  Starlings, eagles, falcons, larks

  we sing from throats no longer dumb

  and spread our wings, and soar in arcs

  Of wheeling orbs and sparks

  From graveyard dirt he shapes a striding man

  To jig the stars and go where none else can.

  What pulls him there in arrow flight of ships?

  A birth of suns that burn from Shakespeare’s flaming lips

  From Stratford’s fortress mind we build and go

  And strutwork catwalk stars across abyss

  The Universe itself is our stage

  and our script reads something close to this:

  Stand here, grow tall, rehearse

  and then surpass the plan.

  Be God-grown-Man.

  Act out the Universe!

  Across the waters of galactic Babylon

  We sail, we solar sails, and sing of Zion.

  Our golden song goes on and on

  The sun whose light we sail upon:

  A blazing summer dandelion.

  ###

  What can I say? We can follow this dream, and so many others like it, if we only lift our heads and go!

  The Canvas of the Night

  by K. Eric Drexler

  As the sun sinks from sight one summer evening, a spark appears in the fading light, rising and moving east. Faint at first, it climbs toward the zenith, shrinks to a line, then opens to a hexagon of brilliance slowly turning, sweeping across the sky to redden and vanish in the shadows of the horizon. The next night, it comes again.

  As night follows night, the hexagon shrinks to a dot, then to a point drifting slowly across the starry vault circling higher and higher, now above both Earth and its cone of shadow. At last it vanishes, no longer circling, a fading glint among the constellations.

  Five centuries after Columbus, the hope of treasure calls once more and a ship sets sail for distant shores. And again, the ship has sails.

  Why, one may ask, should a spaceship use sails? On the seas of Earth, engines replaced sails generations ago, and engines of awesome power launch our spacecraft today. Sails will work in space: Einstein showed that energy has mass, and light exerts force when it bounces off a mirror. The pressure of sunlight, however, is terribly weak; using sails to replace rockets in space may seem a step backward.

  In fact, the two could prove natural partners, each enabling the other to achieve its potential. To understand this, however, we need to skim a little history.

  Rockets are as old as Chinese fireworks. They are compact, powerful, and useful. Unlike sails, they can punch through air and fight strong gravity. Even in the 1930s a few visionaries knew that rockets could lift people to the moon. Rockets were needed for the first big step in space travel, the step off our planet.

  Project Apollo with its first “Moonwalk” was a triumph so great that it seemed to be what “the space program” was all about, yet the triumph was not followed up. The voyage of Columbus opened a frontier by sailing to new lands in a reusable ship. Apollo virtually closed a frontier by surveying a wasteland in a machine built at great expense and then thrown away.

  Beyond the moon, robots with cameras, launched to the planets, replaced the dream of a jungle-clad Venus with the reality of a vast oven of high-pressure poison; they erased the network of lines drawn by wishful earthbound astronomers on the deserts of Mars, and with them went both canals and Martians.

  Many scientists believe Mars does possess water, buried in its dusty permafrost.
Some consider it the next logical step for manned exploration, though not at once for conquest or settlement. Rather, we may find ourselves going there for reasons having to do with earthly concerns . . . to seal a place between East and West, for instance, or to lift our spirits with a common goal.

  But it will be next to impossible to go to Mars the way we went to the moon, using wasteful, throwaway rockets. At least not with rockets alone. The crew themselves may travel that way, but the hundreds of tons of supplies they will need, for a mission lasting two years or more, may be shipped by cheaper means, or the trip may not be made at all. Explorers and scientists will not leave footprints in the red soil until, first, robot freighters have hauled there the means of sustaining life.

  Anyway, to practical men and women, a Mars expedition would be at best a start. Symbolic gestures are less important than winning riches from space.

  Even as the old space program was shriveling and planetary launches had ground to a halt, new opportunities were coming into sight. Today, we have a shuttle and, better, the beginnings of a private launch industry, and we know more about space and our own abilities. There is talk of building important industries in space, where sunlight and vacuum are free and weightlessness offers novel opportunities. Where attention once focused on planets because they were big and bright and somewhat like Earth, people now realize that an asteroid or two could fill a world’s factories and launch a whole new economic frontier.

  Between these two poles lies a common problem. The romance of a Mars mission and the gritty practicality of space industry share one attribute, a need for inexpensive propulsion to supplement flashy, inefficient rockets, a need for systems able to haul great cargos, slowly but surely, across vast reaches of space. Although rockets have been used for centuries, light pressure has been known for scarcely a century.