2010 Odyssey Two

author of 2001: A Space Odyssey

Even In this metric age, it was still the 1000-foot telescope, not the 300-meter one. The great saucer set among the mountains was already half full of shadow as the tropical sun dropped swiftly to rest, but the triangular raft of the antenna complex suspended high above its center still blazed with light. From the ground far below, it would have taken keen eyes to notice the two human figures in the aerial maze of girders, support cables and wave guides.

''The time has come,'' said Dr. Dimitri moisevitch to his old friend Heywood Floyd, ''to talk of many things. Of shoes and spaceships and sealing wax, but mostly of monoliths and malfunctioning computers.''

''So that's why you got me away from the conference. Not that I really mind. The view certainly is fantastic--you know, all the times I've been to Arecibo, I've never made it up here to the antenna feed.''

''Shame on you. I've been here three times. Imagine--we're listening to the whole universe, but no one can overhear us. So let's talk.''

''All right, you old Cossack. What do you want to know?''

''First of all, we'll overlook the ridiculous and frankly illegal secrecy with which your peoplé dug up the Tycho monolith--''

''That wasn't my idea.''

There was a gloomy silence while the two men contemplated the black enigma up there on the Moon, still contemptuously defying all the weapons that human ingenuity could bring to bear upon it. Then the Russian scientist continued.

''Anyway, whatever the Tycho monolith may be, there's something more important out at Jupiter. That's where it sent its signal, after all. And that's where your people ran into trouble. Frank Poole was the only one I knew personally. He seemed a good man.''

''Thank you: they were all good men. I wish we knew what happened to them.''

''Whatever it was, surely you'll admit that it now concerns the whole human race--not merely the United States. You can no longer try to use your knowledge for purely national advantage.''

''Dimitri, you know perfectly well that your side would have done exactly the same thing. And you'd have helped.''

''You're absolutely right. With a new President, perhaps wiser counsels will prevail.''

''Possibly. Do you have any suggestions, and are they official, or just personal hopes?''

''Entirely unofficial at the moment. What the bloody politicians call exploratory talks. Which I shall flatly deny ever occurred.''

''Fair enough. Go on.''

''OK--here's the situation. You're assembling Discovery II in parking orbit as quickly as you can, but you can't hope to have it ready in less than three years, which means you'll miss the next launch window--''.

''Don't let anyone know I told you we were afraid of that. But do go on.''

''Because my bosses are just as stupid and shortsighted as yours, they want to go it alone. Which means that whatever went wrong with you may happen to us, and we'll all be back to square one--or worse.''

''What do you think went wrong? We're just as bafiled as you are. And don't tell me you haven't got all of Dave Bowman's transmissions.''

''Of course we have. Right up to that last 'My God, it's full of stars!' We've even done a stress analysis on his voice patterns. We don't think he was hallucinating; he was trying to describe what he actually saw.''

''And what do you make of his Doppler shift?''

''Completely impossible, of course. When we lost his signal, he was receding at a tenth of the speed of light. And he'd reached that in less than two minutes. A quarter of a million gravities!''

''So he must have been killed instantly.''

''Don't pretend to be naïve. Woody. Your space-pod radios aren't built to withstand even a hundredth of that acceleration. If they could survive, so could Bowman--at least until we lost contact.''

''Just doing an independent check on your deductions. From there on, we're as much in the dark as you are. If you are.''

''Merely playing with lots of crazy guesses I'd be ashamed to tell you. Yet none of them, I suspect, will be half as crazy as the truth.''

''Well, Dimitri,'' Floyd said, ''let's get to the point. Just what are you driving at?''

''There must be a vast amount of priceless information stored in Discovery's data banks; presumably it's still being gathered, even though the ship's stopped transmitting. We'd like to have that. And what I propose is cooperation. I'm convinced that's the best idea--but we may have a job selling it to our respective bosses.''

''You want one of our astronauts to fly with Leonov?''

''Yes--preferably an engineer who's specialized in Discovery's systems. Like the ones you're training at Houston to bring the ship home.''

''How did you know that?''

''For heaven's sake. Woody--it was on Aviation Week's video text at least a month ago.''

''I am out of touch; nobody tells me what's been declassified.''

''All the more reason to spend time in Washington. Will you back me up?''

''Absolutely: I agree with you one hundred percent. And--''

''I understand what you're driving at; many thanks. Anything else before we go down? I'm starting to freeze.''

''Don't worry, old friend. As soon as you let all this filter through to Washington--wait a week or so until I'm clear--things are going to get very, very hot.''

•

Mission Profile

English Version

To: Captain Tanya Orlov, Commander. Spacecraft Cosmonaut Alexei Leonov

From: U. S. National Council on Astronautics, Pennsylvania Avenue, Washington. D.C.

Commission on Outer Space, U.S.S.R. Academy of Science, Korolyov Prospect. Moscow

Mission Objectives

The objectives of your mission are, in order of priority:

1. To proceed to the Jovian system and remdezvous with U. S. spacecraft Discovery:

2. To board this spacecraft and obtain all possible information relating to its earlier mission:

3. To reactivate spacecraft Discovery's on-board systems and, if propellant supplies are adequate, inject the ship into an Earth-return trajectory:

4: To locate the Jupiter monolith encountered by Discovery and to investigate it to the maximum extent possible by remote sensors:

5. If it seems advisable and Mission Control concurs, to rendezvous with this object for closer inspection:

6. To carry out a survey of Jupiter and its satellites, as far as this is compatible with the above objectives.

It is realized that unforeseen circumstances may require a change of priorities or even make it impossible to achieve some of these objectives. It must be clearly understood that the rendezvous with spacecraft Discovery is for the express purpose of obtaining information about the monolith; this must take precedence over all other objectives, including attempts at salvage.

Crew

The crew of spacecraft Alexei Leonov will consist of:

Captain Tanya Orlov (Engineering/Propulsion)

Dr. Vasili Orlov (Navigation/Astronomy)

Dr. Maxim Brailovsky (Engineering/Structures)

Dr. Alexander Kovalev (Engineering/Communications)

Dr. Nikolai Ternovsky (Engineering/Control Systems)

Surgeon-Commander Katerina Rudenko (Medical/Life Support)

Dr. Irina Yakunin (Medical/Nutrition)

In addition, the U.S. National Council on Astronautics will provide the following three experts:

Dr. Sivasubramanian Chandrasegarampillai (Engineering/Computer Systems)

Dr. Walter Curnow (Engineering/Control Systems) (continued on page 206) 2010 Odyssey Two (continued from page 92)

Dr. Heywood Floyd (Technical Advisor)

•

Floyd was rapidly acquiring his space legs; by the time he reached Dr. Vasili Orlov, he was maneuvering almost as confidently as his guide. The chief scientist greeted Floyd warmly.

''Welcome aboard, Heywood. How do you feel?''

''Fine, apart from slowly starving to death.''

For a moment, Orlov looked puzzled; then his face split into a broad smile.

''Oh, I'd forgotten, Well, it won't be for long. In ten months' time, you can eat as much as you like.''

Hibernators went on a low-residue diet a week in advance; for the last 24 hours, they took nothing but liquid. Floyd was beginning to wonder how much of his increasing lightheadedness was due to starvation and how much to zero gravity.

''So there you are, Dr. Floyd,'' said an authoritative female voice. ''Why didn't you report to me?''

Floyd rotated slowly on his axis by gently torquing himself with one hand. He saw a massive, maternal figure wearing a curious uniform adorned with dozens of pockets and pouches; the effect was not unlike that of a Cossack trooper draped with cartridge belts.

''Nice to meet you again, doctor--I'm still exploring.''

''Now, Dr. Floyd, you're going to have plenty of time later to explore our little ship. My colleagues are too polite to say this, but they've work to do and you're in the way. I'd like to get you--all three of you--nice and peaceful as quickly as we can. Then we'll have less to worry about.''

''I was afraid of that, but I quite see your point of view. I'm ready as soon as you are.''

''I'm always ready. Come along, please.''

The ship's hospital was just large enough to hold an operating table, two exercise bicycles, a few cabinets of equipment and an X-ray machine. Dr. Rudenko gave Floyd a quick but thorough examination; then she gave him a painless injection with a gas-gun hypodermic and told him to come back as soon as he was sleepy. That, she assured him, would be in less than two hours.

''Meanwhile, relax completely,'' she ordered. ''There's an observation port on this level--Station D.Six. Why don't you go there?''

It seemed a good idea, and Floyd drifted away with a docility that would have surprised his friends.

When he reached the D.6 viewport, Floyd found Drs. Chandra and Curnow already there. They looked at him with a total lack of recognition, then turned back toward the awesome spectacle outside.

A totally unfamiliar planet hung there, gleaming with glorious blues and dazzling whites. ''How strange,'' Floyd told himself. ''What has happened to the Earth?'' Why, of course--no wonder he didn't recognize it! It was upside down! What a disaster; he wept briefly for all those poor people falling off into space....

He barely noticed when two crew members removed Chandra's unresisting form. When they came back for Curnow, Floyd's own eyes were shut, but he was still breathing. When they returned for him, even his breathing had ceased.

•

And they told us we wouldn't dream, thought Heywood Floyd with more surprise than annoyance. The glorious pink glow that surrounded him was very soothing; it reminded him of barbecues and the crackling logs of Christmas fires. But there was no warmth; indeed, he felt a distinct though not uncomfortable coldness.

Voices were murmuring just too softly for him to understand the words. They became louder, but still he could not understand.

The lovely glow faded; he opened his eyes and had a blurred glimpse of a flashlight being withdrawn from his face. He was lying on a couch, held against it by elastic webbing: figures were standing around him, but they were too out of focus to identify.

Gentle fingers closed his eyelids and massaged his forehead.

''Don't exert yourself. Breathe deeply ... again . . . that's right. . . . Now how do you feel?''

''I don't know . . . strange . . . lightheaded . . . and hungry.''

''That's a good sign. Do you know where you are? You can open your eyes now.''

The figures came into focus--first Dr. Rudenko, then Captain Tanya Orlov.

''So I made it,'' Floyd said. ''We've arrived at Jupiter.''

Tanya looked at him somberly. ''No, Heywood,'' she said. ''We're still a month away. Don't be alarmed--the ship's fine and everything's running normally. But your friends in Washington have asked us to wake you up ahead of time. Something very unexpected has happened. We're in a race to reach Discovery--and I'm afraid we're going to lose.''

•

H. Floyd's Transmission to Washington

''I still find it hard to believe; in some ways, it doesn't even make sense. The Chinese can't possibly have enough fuel for a safe return to Earth; we don't even see how they can make the rendezvous.

''We never saw them, of course. Even at its closest, Tsien was more than fifty million kilometers away. They had plenty of time to answer our signals if they wanted to, but they ignored us completely. Now they'll be much too busy for a friendly chat. In a few hours, they'll hit Jupiter's atmosphere--and then we'll see how well their aerobraking system works. If it does its job, that will be good for our morale. But if it fails--well, let's not talk about that.

''The Russians are taking it remarkably well, all things considered. They're angry and disappointed, of course--but I've heard many expressions of frank admiration. It was certainly a brilliant trick, building that ship in full view and making everyone think it was a space station until they hitched on those boosters.

''Well, there's nothing we can do, except watch. And at our distance, we won't have a much better view than your best telescopes. I can't help wishing them luck, though, of course, I hope they leave Discovery alone. That's our property, and I bet the State Department's reminding them of it, every hour on the hour.''

•

The image of Jupiter, with its ribbons of white cloud, its mottled bands of salmon pink and the great red spot staring out like a baleful eye, hung steady on the flight-deck projection screen. It was three quarters full, but no one was looking at the illuminated disk; all eyes were focused on the crescent of darkness at its edge. There, over the nightside of the planet, the Chinese ship was about to meet its moment of truth.

Tsien had closed down all voice, video and data circuits two hours before, as the long-range antennas were withdrawn into the protective shadow of the heat shield. Only the omnidirectional beacon was still transmitting, accurately pinpointing the Chinese ship's position as it plunged toward that ocean of continent-sized clouds. The shrill beep . . . beep . . . beep . . . was the only sound in Leonov's control room. Each of those pulses had left Jupiter more than two minutes earlier; by this time, their source might already be a cloud of in-candescent gas, dispersing in the Jovian stratosphere.

The signal was fading, becoming noisy. The beeps were getting distorted; several dropped out completely, then the sequence returned. A plasma sheath was building up around. Tsien and would soon cut off all communications until the ship re-emerged. If it ever did.

They could see that the tiny elongated spark had moved appreciably away from the sunward face of the planet and would soon disappear into the nightside. By then, if all had gone according to plan, Jupiter would have captured the ship, destroying its unwanted velocity. When it emerged from behind the giant world, it would be another Jovian satellite.

The spark flickered out. Tsien had rounded the curve of the planet and was heading over the nightside. There would be nothing to see or to hear until it emerged from shadow--if all went well, in just under an hour. It would be a very long hour for the Chinese.

Vasili switched off the computer display, spun around in his chair, loosened his seat belt and addressed the patiently waiting audience.

''Earliest reappearance is in forty-two minutes. Why don't you spectators go for a walk, so we can concentrate on getting all this into good shape? See you in thirty-five minutes. Shoo! Ukhodite!''

Reluctantly, the unwanted bodies left the bridge--but, to Vasili's disgust, everyone was back again in little more than 30 minutes. He was still chiding them for their lack of faith in his calculations when the familiar beep . . . beep . . . beep . . . of Tsien's tracking beacon burst from the loud-speakers.

Vasili looked astonished and mortified but soon joined in the spontaneous round of applause; Floyd could not see who had first started the clapping. Rivals though they might be, they were all astronauts together, as far from home as any men had ever traveled--''Ambassadors for Mankind,'' in the noble words of the first UN Space Treaty. Even if they did not want the Chinese to succeed, neither did they wish them to meet disaster.

A large element of self-interest was also involved, Floyd could not help thinking. Now the odds in Leonov's own favor were significantly improved; Tsien had demonstrated that the aerobraking maneuver was, indeed, possible. The data on Jupiter were correct: its atmosphere did not contain unexpected and perhaps fatal surprises.

''Well!'' said Tanya. ''I suppose we should send them a message of congratulations. But even if we did, they wouldn't acknowledge it.''

Some of his colleagues were still making fun of Vasili, who was staring at his computer output in frank disbelief.

''I don't understand it!'' he exclaimed. ''They should still be behind Jupiter!''

Another silent dialog was held with the computer; then Vasili gave a long, low whistle.

''Something's wrong. They're in a capture orbit, all right--but it won't let them make a rendezvous with Discovery. The orbit they're on now will take them way beyond Jupiter's moon Io--I'll have more accurate data when we've tracked them for another five minutes.''

''Vasili, will you give me their final orbit as soon as you've worked it out?'' asked Floyd. ''I'm going down to my cabin to do some homework.''

Floyd unlocked his little communications console and called for the information on Tsien that had been transmitted to him from Washington. He stared intently at the excellent photographs of the Chinese ship, taken when it had revealed its true colors and was just about to leave Earth's orbit. There were later shots--not so clear, because by then it had been far away from the prying cameras--of the final stage as it hurtled toward Jupiter. Those were the ones that interested him most; even more useful were the cutaway drawings and estimates of performance.

Granted the most optimistic assumptions, it was difficult to see what the Chinese hoped to do. They must have burned up at least 90 percent of their propellant in that mad dash across the Solar System. Unless it was literally a suicide mission--something that could not be ruled out--only a plan involving hibernation and later rescue made any sense. And Intelligence did not believe that Chinese hibernation technology was sufficiently far advanced to make that a viable option.

With a sigh, Floyd started once more to skim the 500 pages of data, keeping his mind as blankly receptive as possible while diagrams, charts, photographs, news items, lists of delegates to scientific conferences, titles of technical publications and even commercial documents scrolled swiftly down the high-resolution screen.

Some of the items must have been included by accident; they could not possibly relate to the mission. If the Chinese had placed a secret order for 1000 infrared sensors through a dummy corporation in Singapore, that was the concern of only the military; it seemed highly unlikely that Tsien expected to be chased by heat-seeking missiles. And this one was really funny--specialized surveying and prospecting equipment from Glacier Geophysics, Inc., of Anchorage, Alaska. What lame-brain imagined that a deep-space expedition would have any need--

The smile froze on Floyd's lips; he felt the skin crawl on the back of his neck. My God--they wouldn't dare! But they had already dared greatly; and now, at last, everything made sense.

Floyd called the bridge. ''Vasili,'' he said, ''have you worked out their orbit yet?''

''Yes, I have,'' the navigator replied in a curiously subdued voice.

Floyd could tell at once that something had turned up. He took a long shot. ''They're making a rendezvous with Europa, aren't they?''

There was an explosive gasp of disbelief from the other end.

''Chyort voz'mi! How did you know?''

''I didn't--I've just guessed it.''

''There can't be any mistake--I've checked the figures to six places. The braking maneuver worked out exactly as they intended. They're right on course for Europa--it couldn't have happened by chance. They'll be there in seventeen hours. Why should anyone want to land on Europa? What's there, for heaven's sake?''

Floyd was enjoying his little moment of triumph. Of course, he might still be completely wrong.

''What's on Europa? Only the most valuable substance in the Universe.''

He had overdone it; Vasili was no fool and snatched the answer from his lips.

''Of course--water!''

''Exactly. Billions and billions of tons of it. Enough to fill up the propellant tanks, go cruising around all the satellites and still have plenty left for the rendezvous with Discovery and the voyage home. I hate to say this. Vasili, but our Chinese friends have outsmarted us again.

''Always assuming, of course, that they can get away with it.''

•

On Leonov's bridge, Captain Orlov was looking thoughtfully at a dense mass of words and figures on the main display. Floyd had painfully started to transliterate them when she interrupted him.

''Don't worry about the details. These are estimates of the time it will take for Tsien to refill its tanks and get ready for lift-off. Making educated guesses about pipe deployment, drilling through the ice and so on--well, we think they could lift off again in five days.''

''Five days!''

''If they're lucky and everything works perfectly. And if they don't wait to fill their propellant tanks but merely take on just enough for a safe rendezvous with Discovery before we do. Even if they beat us by a single hour, that would be enough. They could claim salvage rights, at the very least.''

''Discovery is merely a few billion dollars' worth of hardware. The ship's not important--only the information it carries.''

''Exactly. Information that could be copied and then erased.''

•

Someone was shaking him awake. ''Dr. Floyd--please wake up! You're wanted on the flight deck!''

Reluctantly, Floyd opened his eyes.

''What's the problem, Max?'' he said. ''Is something wrong?''

''We think so--but not with us. Tsien's in trouble.''

Captain, navigator and chief engineer were strapped in their seats on the flight deck; the rest of the crew orbited anxiously around convenient handholds or watched on the monitors.

''Sorry to wake you up, Heywood,'' Tanya apologized brusquely. ''Here's the situation. Ten minutes ago, we had a Class-One Priority from Mission Control. Tsien's gone off the air. It happened very suddenly, in the middle of a cipher message; there were a few seconds of garbled transmission--then nothing.''

''Their beacon?''

''That's stopped as well. We can't receive it, either.''

''Phew! Then it must be serious--a major breakdown. Any theories?''

''Lots--but all guesswork. An explosion--landslide--earthquake: Who knows?''

''And we may never know--until someone else lands on Europa or we do a close flyby and take a look.''

Tanya shook her head. ''We don't have enough delta vee. The closest we could get is fifty thousand kilometers. Not much you could see from that distance.''

''Then there's absolutely nothing we can do.''

''Not quite, Heywood. Mission Control has a suggestion. They'd like us to swing our big dish around, away from Earth toward Tsien just in case we can pick up any weak emergency transmissions. It's--how do you say?--a long shot but worth trying. What do you think?''

''I agree,'' he said. ''Let Earth know what we're doing and start listening. I suppose you'll try all the space-mayday frequencies.''

''Yes, as soon as we've worked out the Doppler corrections. How's it going, Alexander?''

''Give me another two minutes and I'll have the automatic search running. How long should we listen?''

''Listen for fifty minutes and report back to Earth for ten. Then repeat the cycle.''

The 50 minutes seemed like hours. When they were up, Alexander swung the ship's antenna complex back toward Earth and reported failure. While he was using the rest of the ten minutes to send a backlog of messages, he looked inquiringly at the captain.

''Is it worth trying again?'' he said in a voice that clearly expressed his own pessimism.

''Of course. We may cut back the search time--but we'll keep listening.''

On the hour, the big dish was once more focused upon Europa. And almost at once, the automatic monitor started flashing its Alert light.

Alexander's hand darted to the audio gain, and the voice of Jupiter filled the cabin. Superimposed upon that, like a whisper heard against a thunderstorm, was the faint but completely unmistakable sound of human speech.

Alexander played skillfully with fine-tuning and band-width controls, and the words became clearer. The language was undoubtedly English.

There is one combination of sounds that every human ear can detect instantly, even in the noisiest environment. When it suddenly emerged from the Jovian background, it seemed to Floyd that he could not possibly be awake but was trapped in some fantastic dream. His colleagues took a little longer to react; then they stared at him with equal amazement.

For the first recognizable words from Europa were: ''Dr. Floyd--Dr. Floyd--I hope you can hear me.''

•

''Who is it?'' whispered someone to a chorus of shushes. Floyd raised his hands in a gesture of ignorance.

''Know you are aboard Leonov . . . may not have much time . . . aiming my suit antenna where I think. . . .''

The signal vanished for agonizing seconds, then came back much clearer, though not appreciably louder.

''Relay this information to Earth. Tsien destroyed. I'm only survivor. Using my suit radio; no idea if it has enough range, but it's the only chance. Please listen carefully. There is life on Europa. I repeat: There is life on Europa. . . .''

The signal faded again. A stunned silence followed that no one attempted to interrupt. While he was waiting, Floyd searched his memory furiously. He could not recognize the voice; it might have been that of any Western-educated Chinese. Probably it was someone he had met at a scientific conference, but unless the speaker identified himself, he would never know.

''Soon after local midnight. We were pumping steadily and the tanks were almost half full. Dr. Lee and I went out to check the pipe insulation. Tsien stands--stood--about thirty meters from the edge of the Grand Canal. Pipes go directly from it and down through the ice. Very thin--not safe to walk on. The warm upwelling. . . .''

Again a long silence. Floyd wondered if the speaker was moving and had been momentarily cut off by some obstruction.

''No problem--five kilowatts of lighting strung up on the ship. Like a Christmas tree--beautiful, shining right through the ice. Glorious colors. Lee saw it first--a huge dark mass rising up from the depths. At first, we thought it was a school of fish--too large for a single organism--then it started to break through the ice.

''Dr. Floyd, I hope you can hear me. This is Professor Chang; we met in 'Oh-two--Boston I.A.U. conference.''

Instantly, incongruously, Floyd's thoughts were a billion kilometers away. He vaguely remembered that reception, after the closing session of the International Astronomical Union Congress--the last one that the Chinese had attended before the Second Cultural Revolution. And now he recalled Chang very distinctly--a small, humorous astronomer and exobiologist with a good fund of jokes. He wasn't joking now.

''Like huge strands of wet seaweed, crawling along the ground. Lee ran back to the ship to get a camera; I stayed to watch, reporting over the radio. The thing moved so slowly I could easily outrun it. I was much more excited than alarmed. Thought I knew what kind of creature it was--I've seen pictures of the kelp forests of California--but I was quite wrong.

''I could tell it was in trouble. It couldn't possibly survive at a temperature a hundred and fifty below its normal environment. It was freezing solid as it moved forward--bits were breaking off like glass--but it was still advancing toward the ship, a black tidal wave, slowing down all the time. . . .''

''Is there any way we can call him back?'' Floyd whispered urgently.

''No--it's too late. Europa will soon be behind Jupiter. We'll have to wait until it comes out of eclipse.''

''Climbing up the ship, building a kind of ice tunnel as it advanced. Perhaps this was insulating it from the cold--the way termites protect themselves from sunlight with their little corridors of mud.

''Tons of ice on the ship. The radio antennas broke off first. Then I could see the landing legs beginning to buckle--all in slow motion, like a dream.

''Not until the ship started to topple did I realize what the thing was trying to do--and then it was too late. We could have saved ourselves if we'd only switched off those lights.

''Perhaps it's a phototrope, its biological cycle triggered by the sunlight that filters through the ice. Or it could have been attracted like a moth to a candle. Our floodlights must have been more brilliant than anything that Europa has ever known. . . .

''Then the ship crashed. I saw the hull split, a cloud of snowflakes form as moisture condensed. All the lights went out except for one swinging back and forth on a cable a couple of meters above the ground.

''I don't know what happened immediately after that. The next thing I remember, I was standing under the light, beside the wreck of the ship, with a fine powdering of fresh snow all around me. I could see my footsteps in it very clearly. I must have run there; perhaps only a minute or two had elapsed. . . .

''The plant--I still thought of it as a plant--was motionless. I wondered if it had been damaged by the impact; large sections--as thick as a man's arm--had splintered off, like broken twigs.

''Then the main trunk started to move again. It pulled away from the hull and began to crawl toward me. That was when I knew for certain that the thing was light-sensitive: I was standing immediately under the thousand-watt lamp, which had stopped swinging now.

''Imagine an oak tree--better still, a banyan, with its multiple trunks and roots--flattened out by gravity and trying to creep along the ground. It got to within five meters of the light, then started to spread out until it had made a perfect circle around me. Presumably, that was the limit of its tolerance--the point at which photo-attraction turned to repulsion. After that, nothing happened for several minutes. I wondered if it was dead--frozen solid at last.

''Then I saw that large buds were forming on many of the branches. It was like watching a time-lapse film of flowers opening. In fact, I thought they were flowers--each about as big as a man's head.

''Delicate, beautifully colored membranes started to unfold. Even then, it occurred to me that no one--no thing--could ever have seen these colors before; they had no existence until we brought our lights--our fatal lights--to this world.

''Tendrils, stamens waving feebly. . . . I walked over to the living wall that surrounded me so that I could see exactly what was happening. Neither then nor at any other time had I felt the slightest fear of the creature. I was certain that it was not malevolent--if, indeed, it was conscious at all.

''There were scores of the big flowers in various stages of unfolding. Now they reminded me of butterflies just emerging from the chrysalis, wings crumpled, still feeble . . . I was getting closer and closer to the truth.

''But they were freezing--dying as quickly as they formed. Then, one after another, they dropped off from the parent buds. For a few moments, they flopped around like fish stranded on dry land--and, at last, I realized exactly what they were. Those membranes weren't petals: they were fins or their equivalent. This was the free-swimming larval stage of the creature. Probably it spends much of its life rooted on the sea bed, then sends those mobile offspring in search of new territory. Just like the corals of Earth's oceans.

''I knelt down to get a closer look at one of the little creatures. The beautiful colors were fading now to a drab brown. Some of the petal fins had snapped off, becoming brittle shards as they froze. But it was still moving feebly, and as I approached, it tried to avoid me. I wondered how it had sensed my presence.

''Then I noticed that the stamens--as I'd called them--all carried bright blue dots at their tips. They looked like tiny star sapphires or the blue eyes along the mantle of a scallop--aware of light but unable to form true images. As I watched, the vivid blue faded; the sapphires became dull, ordinary stones. . . .

''Dr. Floyd--or anyone else who is listening--I haven't much more time; Jupiter will soon block my signal. But I've almost finished.

''I knew then what I had to do. The cable to that thousand-watt lamp was hanging almost to the ground. I gave it a few tugs and the light went out in a shower of sparks.

''I wondered if it was too late. For a few minutes, nothing happened. So I walked over to the wall of tangled branches around me and kicked it.

''Slowly, the creature started to unweave itself and to retreat back to the canal. I followed the creature all the way back to the water, encouraging it with more kicks when it slowed down, feeling the fragments of ice crunching all the time beneath my boots. As it neared the canal, it seemed to gain strength and energy, as if it knew that it was approaching its natural home. I wondered if it would survive to bud again.

''It disappeared through the surface, leaving a few last dead larvae on the alien land. The exposed free water bubbled for a few minutes until a scab of protective ice sealed it from the vacuum above. Then I walked back to the ship to see if there was anything to salvage. I don't want to talk about that.

''Jupiter will be cutting us off in a few minutes. I wish I knew whether anyone was receiving me. Anyway, I'll repeat this message when we're in line of sight again--if my suit's life-support system lasts that long. . . .''

The signal faded abruptly, came back for a moment, then disappeared completely below the noise level. Although Leonov listened again on the same frequency, there was no further message from Professor Chang.

•

Back on Earth, Dr. Chang was already a hero and his countrymen had, with obvious embarrassment, acknowledged countless messages of sympathy. One had been sent in the name of Leonov's crew--after. Floyd gathered, considerable redrafting in Moscow. The feeling on board the ship was ambiguous--a mixture of admiration, regret and relief. All astronauts, irrespective of their national origins, regarded themselves as citizens of space and felt a common bond, sharing one another's triumphs and tragedies. No one on Leonov was happy because the Chinese expedition had met with disaster; yet at the same time, there was a muted sense of relief that the race had not gone to the swiftest.

The unexpected discovery of life on Europa had added a new element to the situation: Did this life have any connection with the Tycho monolith and with the still more mysterious monolith in orbit near Io?

No time remained for much speculation or discussion, for the ship was gaining speed at last, on the downhill run toward Jupiter. The crew was busy almost nonstop, preparing for the encounter and the brief onset of weight after months in free-fall. All loose objects had to be secured before the ship entered Jupiter's atmosphere.

In the hours immediately before encounter. Floyd saw little of captain or navigator. The Orlovs scarcely left the bridge as they continually checked the approach orbit and made minute refinements to Leonov's course. The ship was now on the critical path that would just graze the outer atmosphere; if it went too high, frictional braking would not be sufficient to slow it down and it would go racing out of the Solar System, beyond all possibility of rescue. If it went too low, it would burn up like a meteor. Between those two extremes there was little margin for error.

The Chinese had proved that aerobraking could be done, but there was always the chance that something would go wrong.

Floyd retreated to his cabin. Now there was nothing to do but wait. His sleeping bag was slung in preparation for the return of gravity when deceleration commenced, and he had only to climb into it--

''Antennas retracted, all protective shields up,'' said the intercom speaker. ''We should feel first braking in five minutes. Everything normal.''

''That's hardly the word I'd use,'' Floyd muttered to himself. ''I think you mean nominal.''

Now it was too late for second thoughts. From far, far away came the first faint whisper of sound, like the wailing of some lost soul. At the same moment, the ship gave a barely perceptible jerk: the sleeping bag began to swing around and its suspension tightened. After weeks of weightlessness, gravity was returning.

Within seconds, the faint wail had risen to a steady roar as the ship decelerated; already it was difficult to breathe.

Floyd wondered how the rest of the crew was faring, and he gave a momentary thought to Chandra and Curnow, sleeping peacefully through it all. They would never know if Leonov became a meteor shower in the Jovian sky. He did not envy them; they had missed the experience of a lifetime.

Tanya was speaking over the intercom: her words were lost in the roar, but her voice sounded calm and perfectly normal, just as if she were making a routine announcement. Floyd managed to glance at his watch and was astonished to see that they were already at the mid-point of the braking maneuver. At that very moment, Leonov was at its closest approach to Jupiter.

The ship was now rocking noticeably, like a small boat on a choppy sea. Was that normal? wondered Floyd. Just for a moment, he had a vision of the walls' suddenly glowing cherry red and caving in upon him. Like the nightmare fantasy of Edgar Allan Poe's The Pit and the Pendulum, which he'd forgotten for 30 years.

But that would never happen. If the heat shield failed, the ship would crumple instantly, hammered flat by a solid wall of gas. There would be no pain: his nervous system would not have time to react before it ceased to exist. He had experienced more consoling thoughts, but that one was not to be despised.

The buffeting slowly weakened. There was another inaudible announcement from Tanya. Now time seemed to be going much more slowly; after a while, he stopped looking at his watch, because he could not believe it. The digits changed so slowly that he could almost imagine himself in some Einsteinian time dilation.

Suddenly. Floyd became aware of an almost postorgasmic drowsiness, as if he had been emotionally drained by the encounter. He had to fight to remain awake. . . .

And then he was falling . . . falling . . . falling . . . it was all over. The ship was back in space, where it belonged.

•

When Floyd reached the observation deck, Jupiter already seemed farther away. But that must be an illusion based on his knowledge, not the evidence of his eyes. They had barely emerged from the Jovian atmosphere, and the planet still filled half the sky.

And now they were--as intended--its prisoners. During the last incandescent hour, they had deliberately jettisoned the excess speed that could have carried them right out of the Solar System and on to the stars. Now they were traveling in an ellipse that would shuttle them back between Jupiter and the orbit of Io. 350,000 kilometers higher. If they did not--or could not--fire their motors again, Leonov would swing back and forth between those limits, completing one revolution every 19 hours. It would become the closest of Jupiter's moons--though not for long. Each time it grazed the atmosphere, it would lose altitude, until it spiraled into destruction.

Floyd had never really enjoyed vodka, but he joined the others without any reservations in drinking a triumphant toast to the ship's designers, coupled with a vote of thanks to Sir Isaac Newton. Then Tanya put the bottle firmly back in its cupboard: there was still much to be done.

Although they were all expecting it, everyone jumped at the sudden muffled thud of explosive charges and the jolt of separation. A few seconds later, a large, still-glowing disk floated into view, slowly turning end over end as it drifted away from the ship.

''Look!'' cried Max. ''A flying saucer! Who's got a camera?''

There was a distinct note of hysterical relief in the laughter that followed. It was interrupted by the captain, in a more serious vein.

''Goodbye, faithful heat shield! You did a wonderful job.''

Everyone applauded those noble sentiments as the jettisoned shield cooled to yellow, then to red and finally became as black as the space around it. It vanished from sight only a few kilometers away, though occasionally the sudden reappearance of an eclipsed star would betray its presence.

''Preliminary orbit check completed,'' said Vasili. ''We're within ten meters a second of our right vector. Not bad for a first try.''

There was a subdued sigh of relief at the news, and a few minutes later, Vasili made another announcement.

''Changing attitude for course correction: delta vee six meters a second. Twenty-second burn coming up in one minute.''

They were still so close to Jupiter it was impossible to believe that the ship was orbiting the planet; they might have been in a high-flying aircraft that had just emerged from a sea of clouds. There was no sense of scale; it was easy to imagine that they were speeding away from some terrestrial sunset: The reds and pinks and crimsons sliding below were so familiar.

And that was an illusion; nothing here had any parallels with Earth. Those colors were intrinsic, not borrowed from the setting sun. The very gases were utterly alien--methane and ammonia and a witch's brew of hydrocarbons, stirred in a hydrogen-helium caldron. Not one trace of free oxygen, the breath of human life.

The clouds marched from horizon to horizon in parallel rows, distorted by occasional swirls and eddies. Here and there, upwellings of brighter gas broke the pattern, and Floyd could also see the dark rim of a great whirlpool, a maelstrom of gas leading down into unfathomable Jovian depths.

''Correction completed. We're now on interception orbit with Io. Arrival time: eight hours, fifty-five minutes.''

Less than nine hours to climb up from Jupiter and meet whatever is waiting for us, thought Floyd. We've escaped from the giant--but he represents a danger we understood and could prepare for. What lies ahead is utter mystery.

And when we have survived that challenge, we must return to Jupiter once again. We shall need his strength to send us safely home.

The exciting conclusion to ''2010: Odyssey Two'' will be featured in our December issue.

'''Something unexpected has happened. We're in a race to reach Discovery--and we're going to lose.'''