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Authors: Ben Bova

Venus (11 page)

BOOK: Venus
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O
rbiting Venus’s hot, thick atmosphere at slightly more than seven kilometers per second,
Hesperos
fired its retrorockets at precisely the millisecond called for in the entry program.
Strapped into the chair in the observation blister, I felt the ship flinch, like a speeding car when the driver taps the brake slightly.
I leaned forward as far as the safety harness would allow. Through the forward-angled port I could see the rim of the big heat shield and, beyond it, the smooth saffron clouds that completely shrouded the planet.
Except the clouds were no longer smooth. There were rifts here and there, long streamers floating above the main cloud deck, patterns of billows like waves rolling across a deep, deep sea.
Marguerite was turned toward the port also, so I could not see her full face, only a three-quarter profile. She seemed intent, her hands gripping the arms of her chair. Not
white-knuckled, not frightened, but certainly not relaxed, either.
Me, I was clutching the arms of my chair so hard my nails were going to leave permanent indentations in the plastic. Was I frightened? I don’t know. I was excited, taut as the Buckyball cable that had connected us to the old Truax. I was breathing hard, I remember, but I don’t recall any snakes twisting in my gut.
Something bright flared across the rim of the heat shield and I suddenly wished I were up on the bridge, where I could see the instruments and understand what was happening. There was an empty chair up there; I should have demanded that I sit in it through the entry flight.
The ship shuddered. Not violently, but enough to notice. More than enough. The entire rim of the heat shield was glowing now and streamers of hot gas flashed past. The ride started to get bumpy.
“Approaching maximum gee forces,” Duchamp’s voice called out over the intercom speaker in the overhead.
“Max gee, check,” Rodriguez replied, from his position up in the nose.
It was
really
bumpy now. I was being rattled back and forth in my chair, happy to have the harness holding me firmly.
“Maximum aerodynamic pressure,” Duchamp said.
“Temperature in the forward section exceeding max calculated.” Rodriguez’s voice was calm, but his words sent a current of electricity through me.
The calculations have an enormous safety factor in them, I tried to reassure myself. It would have been easier if the ship didn’t feel as if it were trying to shake itself apart.
I couldn’t see a thing through the port now. Just a solid sheet of blazing hot gases, like looking into a furnace. I squeezed my eyes down to slits while the battering, rattling ride went on. My vision blurred. I closed my eyes entirely for a moment. When I opened them cautiously, I could see fairly well again, although the ship was still shuddering violently.
Marguerite hadn’t moved since the entry began; she was still staring fixedly ahead. I wondered if her camera was getting anything or if the incandescent heat of our entry into the atmosphere had fried its lens.
The ride began to smooth out a bit. It was still bumpier than anything I had ever experienced before, but at least now I could lean my head back against the padded headrest and not have it bounce so hard it felt like I was being pummeled by a karate champion.
Marguerite turned slightly and smiled at me. A pale smile, I thought, but it made me smile back at her.
“Nothing to it,” I said, trying to sound brave. It came out more like a whimper.
“I think the worst is over,” she said.
Just then there was an enormous jolt and an explosion that would have made me leap out of my chair if I weren’t strapped in. It took just a flash of a second to realize that it was the explosive bolts jettisoning the heat shield, but in that flash of a second I must have pumped my entire lifetime’s supply of adrenaline into my blood. I came very close to wetting myself; my bladder felt painfully full.
“We’re going into the clouds!” Marguerite said happily.
“Deceleration on the tick,” Duchamp’s voice rang out.
“Heat shield jettison complete,” Rodriguez replied. “Now we’re a blimp.”
Rodriguez was inaccurate, I knew. A blimp has a soft envelope; ours was rigid cermet. It wasn’t often I could catch him in a slip of the tongue. I threw a superior smile to Marguerite as I popped the latch on my safety harness. The instant I stood up, though,
Hesperos
shuddered, lurched, swung around crazily, and accelerated so hard I was slammed right back into my chair.
 
The superrotation.
The solid body of the planet may turn very slowly, but Venus’s upper atmosphere, blast-heated by the Sun, develops winds of two hundred kilometers per hour and more
that rush around the entire planet in a few days. In a way, they’re like the jet streams on Earth, only bigger and more powerful.
Our lighter-than-air vessel was in the grip of those winds, zooming along like a leaf caught in a hurricane. We used the engines hanging outside the gondola only to keep us from swinging too violently, otherwise we would have depleted our fuel in a matter of hours. We couldn’t fight those winds, we could only surf along on them and try to keep the ride reasonably smooth.
Truax
, up in a safe, stable orbit, was supposed to keep track of our position by monitoring our telemeter beacon. This was for two reasons: to stay in constant communications contact with us and to plot the direction and speed of the superrotation wind, with
Hesperos
playing the same role as a smoke particle in a wind tunnel. But
Truax
hadn’t deployed the full set of communications satellites around the planet by the time we got caught in the superrotation. Without the commsats to relay our beacon, they lost almost half our first day’s data.
And if anything had gone wrong, they wouldn’t know it for ten, twelve hours.
Fortunately, the only trouble we had was a few bruised shins as
Hesperos
lurched and swirled in the turbulent winds. It was like being in a racing yacht during a storm: you had to hold on to something whenever you moved from one place to another.
It was scary at first, I admit. No amount of lectures, videos, or even VR simulations can really prepare you for the genuine experience. But in a few hours I got accustomed to it. More or less.
I spent most of those hours right there in the observation blister, staring out as we darted along the cloud tops. Marguerite got up and went back to her lab; crew members passed by now and then, stumbling and staggering along the passageway, muttering curses every time the ship pitched and they banged against the bulkhead.
At one point Marguerite came back to the blister, a heavy-looking gray box of equipment in her hands.
“Shouldn’t you be checking the sensors up forward?” she asked, a little testily, I thought.
“They’re running fine,” I said. “If there were any problems I’d get a screech on my phone.” I tapped the communicator in the chest pocket of my coveralls.
“Don’t you want to see the data they’re taking in?”
“Later on, when the ride settles down a little,” I said. It had always nonplussed me that many scientists get so torqued up about their work that they have to watch their instruments while the observation is in progress. As if their being there could make any difference in what the instruments are recording.
Marguerite left and I was alone again, watching the upper layer of the cloud deck reaching for us. Long, lazy tendrils of yellowish fog seemed to stretch out toward us, then evaporate before my eyes. The cloud tops were dynamic, bubbling like a boiling pot, heaving and breathing like a thing alive.
Don’t be an anthropomorphic ass, I warned myself sternly. Leave the similes to the poets and romantics like Marguerite. You’re supposed to be a scientist.
Of sorts, a sardonic inner voice scoffed. You’re only playing at being a scientist. A real scientist would be watching his sensors and data readouts like a tiger stalking a deer.
And miss the view? I answered myself.
We were dipping into the clouds now, sinking down into them like a submarine sliding beneath the surface of the sea. Yellow-gray clouds slid past my view, then we were in the clear again, then more mountains of haze covered the port. Deeper and deeper we sank, into the sulfuric-acid perpetual global clouds of Venus.
The ride did indeed smooth out, but only a little. Or maybe we all became accustomed to the pitching and rolling. We got our sea legs. Our Venus legs.
It was eerie, sailing in that all-enveloping fog. For days on end I stared out of the ports and saw nothing but a gray sameness. I wanted to push ahead, to go deeper, get beneath the clouds so we could begin searching the surface with telescopes for the wreckage of my brother’s vessel.
But the mission plan called for caution, and despite my eagerness I understood that the plan should be followed. We were in uncharted territory now, and we had to make certain that all of
Hesperos
’s systems were performing as designed.
The mammoth cermet envelope above us had been filled (if that’s the right word) with vacuum. Its hatches had been open to vacuum all the time of our flight from Earth orbit, then sealed tight when we entered Venus’s atmosphere. What better flotation medium for a lighter-than-air vessel than nothingness?
Now we were slowly filling the envelope with hydrogen gas, sucked out of the clouds’ abundant sulfuric acid through our equipment that separated out the wanted hydrogen and released the unwanted sulfur and oxygen. On Earth hydrogen’s flammability would have been dangerous, but Venus’s atmosphere contained practically no free oxygen, so there was no danger of explosion or fire. The envelope itself was a rigid shell of cermet, a ceramic-metal composite that combined toughness and rigidity yet was lighter than any possible metal alloy.
To go deeper, we would vent hydrogen overboard and replace it with atmospheric gas: mainly carbon dioxide. When the time came to rise again, we intended to break down the carbon dioxide into its component elements of carbon and oxygen, vent the carbon overboard, and let the lighter oxygen buoy us upward. Higher up we intended to dissociate the sulfuric acid molecules of the clouds again and refill the envelope with hydrogen.
We had tested the equipment for splitting the carbon dioxide and sulfuric acid molecules before we ever took off from Earth, and now, inside the globe-girdling cloud deck of Venus, we put it to work to fill the gas envelope with hydrogen.
Eager as I was to go deeper, I was perfectly happy to see that the equipment worked in Venus’s clouds. I had no desire to be stuck down at the surface with no way to come back up,
So we coasted along in the uppermost cloud deck, patiently filling the big shell above us and testing our equipment. Once in a while it seemed to me that we weren’t moving at all, that we were stuck in place like a ship run aground on a reef. All we could see out the ports was that perpetual yellowish-gray sameness. But then some strong current in the atmosphere would grab us and the gondola would tilt and groan like a creaking old sailing ship and my insides would flutter just a little bit.
I was constantly worried about Fuchs, of course, but the IAA reports on his activity showed that he was also moving cautiously. He had entered the atmosphere several hours before we did, but so far had not gone much deeper than we had. Like us, he was floating in the upper reaches of the top cloud deck, pushed around the planet by the superrotation winds.
“He’s no fool,” Duchamp told me as we sat together in the spartan little galley. It was the only place aboard
Hesperos
where two or three people could sit together, other than the bridge.
“Lars takes risks,” Duchamp said, “but only when he’s certain the odds are in his favor.”
“You know him?” I asked.
She made a thin smile. “Oh, yes. Lars and I are old friends.”
“Friends?” I felt my brows hike up.
Her smile faded. “I first met him just after he had lost his business and his wife. He was a pretty desperate man then. Hurt and angry. Bewildered. Everything he had built up in his life had been snatched away from him.” She exhaled a puff of air through her nostrils, something between a grunt and a sigh.
The expression on her face told me she knew perfectly well that the man who had destroyed his company and taken
his wife was my father. She didn’t have to say it; we both knew.
“But he pulled himself up again, didn’t he?” I snapped. “He’s done fairly well in asteroid mining, hasn’t he?”
Duchamp looked at me for a long silent moment, the kind of look a university professor gives to an especially dense and hopeless student.
“Yes,” she said. “Hasn’t he.”
A
t least, during those first days coasting through the clouds, I had an excuse to stay close to Marguerite. I was supposed to be a planetary scientist, I kept reminding myself, and even though she was a biologist we began to work together, sampling the clouds.
Marguerite’s lab was too crowded for both of us to use it at the same time, and it would have been impossible for us to work together in either her quarters or mine; each of us had nothing more than a narrow berth with a privacy screen shuttering it. We could have both fit in either berth, but no scientific research would have been done. Indeed, I found myself wondering what it would be like to have Marguerite cupped beside me in my berth. Or hers.
But she had no romantic interest in me, that was clear. Instead, we turned the observation post up in the gondola’s nose into a makeshift laboratory where we took samples of the cloud droplets and analyzed them.
“There really is water in the clouds!” Marguerite exclaimed
happily, after a long day of checking and rechecking the results of our spectral analyses.
“Thirty parts per million,” I grumbled. “It might as well be zero for all the good—”
“No, no, you don’t understand,” she said. “Water means life! Where water exists, life exists.”
She was really excited. I was more or less playing at being a planetary scientist but to Marguerite the search for life was as thrilling and absorbing as Michelangelo’s drive to create great works of art out of rough slabs of marble.
We were sitting cross-legged on the metal decking up in the gondola’s nose section because there was no room for chairs and nobody had thought to bring any cushions aboard. The transparent quartzite nose itself showed only the featureless yellowish gray of the eternal cloud deck; it might just have well been spray-painted that color for all that we could see out there. Two mass spectrometers sat to one side of us, half a dozen hand-sized computers were scattered on the deck plates, and a whole rack of equipment boxes—some gray, some black—hummed away along the bulkhead beside me.
“The presence of water,” I pointed out, “does not automatically mean the presence of life. There is a good deal of water on the Moon, but no life there.”
“Humans live on the Moon,” she countered, with mischief in the lilt of her voice.
“I mean native lunar life, you know that.”
“But the water deposits on the Moon are frozen. Wherever there’s
liquid
water, like under the ice crust on Europa—”
“The water vapor in these clouds,” I interrupted, jabbing a finger toward the observation port, “hardly constitute a supply of liquid water.”
“They do to microscopic organisms.”
I had to hold back a laugh. “Have you found any?”
Her enthusiasm didn’t waver one iota. “Not yet. But we will!”
I could only shake my head in admiration for her perseverance.
“This proves that there must be at least some volcanic activity down at the surface,” Marguerite said.
“I suppose so,” I agreed.
The reasoning was simple enough: Any water vapor in Venus’s atmosphere quickly boiled up to the top of the clouds, where the intense ultraviolet radiation from sunlight broke up the water molecules into hydrogen and oxygen, which eventually evaporated away into space. So there had to be a fresh supply of water constantly replenishing the droplets. Otherwise they would have all been dissociated and blown off the planet ages ago. The source of the water most likely came from the planet’s deep interior and was vented into the atmosphere by volcanic eruptions.
On Earth volcanoes constantly blow out steam, sometimes in explosions that tear the tops off the mountains. But the water vapor they vent into the atmosphere stays in the atmosphere, on Earth. It’s not lost to space because Earth’s atmosphere gets cold at high altitudes and the water condenses and falls back as rain or snow. That’s why Earth has oceans and Venus doesn’t. Earth’s upper atmosphere is a “cold trap” that prevents the water from escaping the planet. Hothouse Venus doesn’t have a cold trap in its upper atmosphere: at the altitude where on Earth the temperature dips below freezing, Venus is almost four hundred degrees Celsius, four times hotter than water’s boiling point. As a result Venus can’t build up any appreciable water content in its atmosphere.
I wondered what this meant for Greenbaum’s theory about Venus’s whole surface erupting into a planet-wide upheaval. There must be
some
volcanic activity venting at least a bit of the planet’s internal heat into the atmosphere.
“We’ll have to go deeper to find life-forms in the clouds,” Marguerite said, as much to herself as to me. “The UV absorber isn’t that much further down.”
I was still thinking about volcanoes. “We’ve been watching
Venus for more than a century and no one’s seen a volcanic eruption. Of all the spacecraft that we’ve put in orbit and landed on the surface, not one sensor’s picked up a volcano in the process of erupting.”
Marguerite poo-poohed me. “What do you expect? We’ve only sent a few dozen robot spacecraft to orbit Venus and even fewer landers. We’ve ignored the planet terribly.”
I had to agree. “Still, if Professor Greenbaum is right and there isn’t that much active vulcanism …”
“Maybe we’ll catch an eruption,” Marguerite said. “That would be a first, wouldn’t it?”
She was all enthusiasm. But I thought of the ancient Chinese maxim: Be careful what you wish for; you might get it.
 
Fuchs still worried me. Apparently he was still sailing in the clouds, as we were. But aside from his position I could get no information about him from the IAA. For a good reason: He was giving out no information, nothing but his tracking beacon and the standard telemetering data that showed his basic systems to be operating in good order. When I tried to get details about the design of his ship or the array of sensing systems he carried, I drew a blank.
Lucifer
was his ship, his design, built out in the deep darkness of the Asteroid Belt, equipped according to his specifications and no one else’s. He reported the minimum required by the IAA and kept everything else to himself.
One thing I was able to do during those first days in the clouds was to begin to build up a map of the superrotation wind pattern. By recording our position from the ship’s inertial navigation system I was able to generate a three-dimensional plot of where those winds blew, a sort of weather map of Venus’s jet streams. Every time a powerful gust buffeted us and made me grab for a handhold, every time a sudden upwelling bounced us or a cold spot made us drop until my stomach crawled up into my throat, I thought to myself that at least I was getting useful data.
The winds fanned outward from the subsolar point, of
course. That was where the Sun was directly overhead, blazing down on the planet’s atmosphere like a blowtorch. Venus turns so slowly, once in 243 Earth days, that the subsolar spot gets blasted remorselessly. The atmosphere rushes away from there in a gigantic heat-driven flow, setting up currents and convection cells that span the girth of the planet. I measured wind speeds of nearly four hundred kilometers per hour: We were setting a Guinness speed record for lighter-than-air vessels.
Deeper down, where the atmosphere gets thicker and so much hotter, the winds die to almost nothing. At a pressure similar to that of an Earthly ocean a kilometer or so deep, there could be nothing that we would recognize as winds, only sluggish tidal motions.
At least, that’s how the theory went.
My map of the superrotation winds was coming along quite nicely after a few days, and it made me proud to realize that I was making a real contribution toward understanding Venus. When I tried to extend my data down to a slightly lower altitude, though, in an effort to see how far down the winds might extend, the computer program glitched on me. Insufficient data, I thought, peering at the display screen.
I had coded the map with false colors, each color indicating a range of speeds. There they were, a network of jet streams all rushing out from the subsolar point, in shades of blue and green. With my VR goggles on, I saw it all in three-dimensional motion. But there was the damned glitch, a swath of red and a few kilometers below our present altitude. Red should have indicated even higher wind velocity than we were in now, but I knew that was wrong. The wind velocities had to get lower as we went down in altitude, not higher. Something was wrong with the program.
I mentioned it to Duchamp and Rodriguez when we met to decide on when we would start down toward the surface.
Our conference center was the observation blister, the only place in our cramped gondola where three or four people could sit comfortably. Duchamp and I sat side by
side, our chairs swiveled away from the observation ports. Rodriguez sat on the floor facing us, his back against the far bulkhead.
“All systems have performed well within their design range,” Duchamp said, tapping a manicured fingernail on the screen of her handheld computer. “Unless I hear otherwise, I declare this phase of the mission completed.”
Rodriguez nodded. “No complaints about that. It’ll be good to get out of this wind and down to a calmer altitude.”
“Calmer,” Duchamp said, “but hotter.”
“We can handle the heat.”
She smiled at him as if they had some private joke going between them.
I spoke up. “My map of the wind system keeps throwing this glitch at me.” I had brought a handheld, too, and showed it to them.
“The red indicates even higher wind velocities than we’re in now,” I said.
“That’s an extrapolation, isn’t it?” Rodriguez asked. “It’s not based on observational data.”
“No, we haven’t gone down that far, so we don’t have any data from that altitude.”
“A computer extrapolation,” Duchamp said, like an art critic sniffing at some child’s lopsided attempt to draw a tree.
“But the extrapolation is based on pretty firm meteorological data,” I pointed out.
“Terrestrial meteorological data?” asked Duchamp.
I nodded. “Modified to take into account Venus’s different temperature, pressure, and chemical regime.”
“An abstraction of an abstraction,” Duchamp said, with a
that’s-that
wave of her hand.
Rodriguez was staring at the smear of red at the bottom of my map. He handed the palm-sized computer back to me and said thoughtfully, “You don’t think there could be some kind of wind shear down at that altitude, do you?”
“A supersonic wind shear?” Duchamp scoffed.
“It’s not supersonic at that pressure,” Rodriguez pointed out.
She shook her head. “All the planetary physicists agree that the superrotation winds die out as you go deeper into the atmosphere and the pressure builds up. The winds get swamped by the increased pressure.”
Rodriguez nodded thoughtfully, then said slowly, “Yeah, I know, but if there really is a wind shear it could be a killer.”
Duchamp took a breath, glanced from him to me and back again, then made her decision.
“Very well,” she said. “We’ll rig for intense wind shear. Check out all systems. Make everything secure and tightened down, just as we did for atmospheric entry.” She turned to me. “Will that satisfy you, Mr. Humphries?”
I was surprised at the venom in her reaction. I swallowed once and said, “You’re the captain.”
“Good.” To Rodriguez she said, “Tommy, this means you’ll have to go outside and manually check all the connectors and fittings.”
He nodded glumly. “Yeah. Right.”
Then, smiling coldly, Duchamp turned back to be. “Mr. Humphries, would you care to assist Tom?”
“Me?” I squeaked.
“We could use the extra hand,” she said smoothly, “and the inspection is actually at your behest, isn’t it? You and your computer program.”
You bitch, I thought. Just because my computer program showed a possible problem she’s blaming me for it. Now I’ve either got to risk my neck or show everybody that I’m a coward.
Rodriguez leaned across the narrow passageway separating us and grabbed my knee in a rough, friendly way.
“Come on, Mr. Humphries, it won’t be so bad. I’ll be with you every step of the way and you’ll be able to tell your grandchildren about it.”
If I live long enough to have grandchildren, I thought.
But I swallowed my fear and said as calmly as I could, “Sure. It ought to be exciting.”
It certainly was.
Basically, our task was to check all the connectors that held the gondola to the gas envelope above us. It was a job that a plumber could do, it didn’t call for any special training. But we’d be outside, in a cloud of sulfuric acid droplets that was nearly a hundred degrees Celsius, more than fifty kilometers above the ground.
Rodriguez spent two intense hours briefing me on what we had to do in the virtual reality simulator. Six main struts had to be checked out, and six secondary ones. They connected the gondola to the gas shell; if they failed under stress we would go plunging down to the red-hot surface like an iron anvil.
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