“Good, Oliver. You draw up a hit list of near-missers and I will see whether any of the Phobos and Venera series could have passed close to them, maybe even with a side probe fired off.”
Now they were off the scree and running together down lightly wooded hillside. Inside his Eskimo suit, Leclerc was sweating, red-faced.
“Even a fast flyby,” Judy suggested. “Our kamikaze cosmonauts could have—” she raised her hand and they stopped, almost cannoning into each other. “Did you hear that?”
Webb strained his ears.
“Gunfire,” Leclerc said, and sure enough there was a crackle of shooting down and to their right. It seemed as if several weapons were being fired.
“Hunters?” Leclerc wondered, gasping for breath.
“The survivalists,” Webb suggested. “How far have we come?”
“We must have dropped a couple of thousand feet.” Suddenly, even after their exertions, the woods seemed chilly.
“Maybe we should cut off to the left and find the road,” Judy proposed.
“Let’s take five minutes,” Webb said, glancing in alarm at Leclerc’s beetroot face. They sat down on the pine needle carpet and, joy of joys, Judy produced a large bar of chocolate. The gunfire had stopped. They munched quietly for a while, a little uneasy. Leclerc got up and strolled in the direction the gunfire had been. He vanished into the gloom of the woods.
A couple of minutes later Whaler and Webb were relieved to see him strolling back.
“See anything?” Webb asked.
Leclerc gave a Gallic shrug before flopping down again. “I am not sure. Perhaps some animal.”
“Let’s get out of here,” Judy suggested.
They stood up. The Frenchman glanced nervously back in the direction he had come. “We are lost, yes?”
“Somebody knows where we are,” Judy said looking into the trees on the route they had just come down. A man of about twenty, wearing khaki and green battledress and carrying a long-barrelled rifle with a telescopic sight, emerged from the shadows. A country boy, overweight but with an abnormally thin face smeared with black. The dark eyes in the face were set close together. Webb recognized the eyes as he approached. They were xenophobic eyes, intolerant eyes; they were eyes filled with ignorance and suspicion and the superstition of centuries.
“Mo’nin’. You folks from the Fed’ral Gov’ment?” Spoken through tight, disapproving lips.
“No, we’re just visiting,” Webb said, slipping into an exaggerated Oxford accent. Leclerc would lay on the Parisian and Judy would keep her mouth shut.
“But y’all from up top, right?”
“The observatory, yes.”
The man contemplated that, his close-set eyes flickering from Webb to Judy to Leclerc and then back to Judy. He rested his rifle on his forearm.
“One thang I kin shorely tail is y’all ferners.” He paused, his face expressionless. “Y’ain’t bin spyin’ on us, have you now?”
The man stood in shadow, on the floor of the giant bowl, shivering in the cold desert air. Six hundred feet above him, sunlight was illuminating a thin strip of clifftop and creeping down the rock face. He willed it to go faster, but the laws of celestial mechanics remained unmoved. A green lizard looked at him from an eye at the side of its head, and then scurried along an abandoned girder where men long dead had once tried to reach down to the nickel-iron meteorite they thought was buried far under the ground. The chopping sound of the helicopter high above faded as the small, bright blue machine disappeared over the rim of mountain.
The man turned to his companion. “Are there snakes here, Willy? I hate snakes.”
“Welcome to the Barringer crater, Jim,” said Shafer. “Ever been here?”
McNally looked around at the bowl surrounding them. “Seen pictures of it. Please say there are no snakes here.”
“Snakes are not an issue here, Jim. Not like they are in New York, where they smoke crack and carry guns.”
McNally looked relieved. “I believe you, my feel-good index has just gone up.”
“Now the scorpions, that’s another matter.”
“Thanks a million. Why are we here, Willy?”
“I thought a big hole in the ground might lend a little spice
to our deliberations. Anyway, genius makes its own rules. We’re a small club, the rest of you can only look on and wonder. Let’s do the tour.”
McNally turned slowly like a lighthouse, gazing at the circular wall of rock which rose six hundred feet above him on all sides. Then he set out after the physicist, making for the base of the wall a few hundred yards away.
“Some impact,” McNally said.
“A penny firecracker,” said Shafer. “A few megatons about forty thousand years ago. There may have been people around.”
“So where are we at, Willy? Do we smash it to rubble with H-bombs?” McNally asked.
“Where did you get that from, Jim, your Los Alamos Workshop or a bad movie? Say you tried that and you ended up with a thousand fragments. Each one maybe a hundred yards across and coming in at maybe seventy or eighty thousand miles an hour. The bits would drift apart slowly but they’d keep close to the old trajectory. By the time they reach us they’d come in as a spray, countrywide. Instead of a rifle bullet you get buckshot, coming in over a few hours. So you don’t get a million megaton shot, you get a thousand impacts instead, each one with fifty thousand times the energy of the Hiroshima bomb. Ungood.”
“I’m still trying to get a handle on this,” McNally admitted.
“Think of America on the receiving end of a nuclear attack. Then multiply by fifty.”
“So let’s take it a stage further, literally pulverize it. Could it be done?”
Shafer started to scramble up the steeply sloping inner wall. “Depends who you listen to,” he called down. “One school of thought says the Earth-crossers are just dried-out comets, maybe even just dust balls. In that case, maybe you could. That’s the Webb line. Sacheverell thinks otherwise. He says they’re strays from the main belt asteroids between Mars
and Jupiter. In that case they could be rock or iron and no way could we deliver the energy to smash one up into dust.”
“What’s your view?” McNally asked.
“There was this Crusader,” said Shafer, sitting down. “He wants to show off his strength to a Saracen. So he gets this iron bar and swipes it with his two-handed sword, and the iron bar breaks in two, and he says beat that if you can. So the Saracen gets a silk handkerchief and he throws it up in the air. He holds the blade of his scimitar upwards, and when the handkerchief floats down over the blade it splits in two.”
“That is very poetic, Willy. I like poetic stuff, I didn’t know you were a poet as well as a genius. Maybe if I had a Nobel prize too and a head full of parables I would get your drift, but you see just being an ordinary Joe with an ordinary-sized hat who’s frantically trying to save his country, the significance of this poetic story passes me by.”
Shafer grinned and threw a fist-sized stone playfully down at the NASA administrator. “That comes from running big bureaucracies. Loosen up, Jim, think lateral. So if the asteroid is rocky, when it comes in it hits us like a two-handed sword and we’re blasted to hell. If it’s a dust ball, and we turn it into a powder with bombs, the dust floats gently down like a Saracen’s handkerchief and cuts off our sunlight. We could end up with a few billion tons of dust dumped into the stratosphere. If it’s sub-micron, like condensation from vaporized rock, it blocks out sunlight and we go around in deep gloom. It takes a year for dust to settle out and meantime we’ve killed off commercial agriculture. So our food chain collapses. Experience shows that people without food eventually die. That’s your Saracen option, Jim.”
“If I could corner the market in canned beans . . . is that lateral enough?”
Shafer clambered down and the two men began a circuit of the Barringer crater. “Forget about pulverizing Nemesis,” said the physicist. “The only way we can handle this is to
knock Nemesis off course the same way it was knocked on. We need a controlled explosion.”
“You mean use the debris from the explosion like a rocket exhaust?”
“You got it.”
“How much would we need?”
Shafer glanced at his watch. “I’ll be showing some calculations. If we had ten years’ advance warning, we’d only need to shift Nemesis by a centimetre a second, about the speed of a fast snail. The long-term orbital drift does the rest.”
“Snail’s pace,” repeated McNally. “I like snails, right from the time I was a boy I liked them. My feel-good index has just jumped again. Tell me what you need from NASA. Maybe we could just smash a heavy spaceship into it.”
“Depends how big Nemesis is. I think we have to assume a one-kilometre asteroid, enough to take out the States comfortably. In that case you could do it with a three hundred ton spaceship. It would be a kamikaze mission, crashing into the asteroid at twenty kilometres a second.”
“Three hundred tons!” McNally exclaimed. “NASA doesn’t run to the Starship
Enterprise
, Willy. And we don’t have ten years, right? Say we reach Nemesis a couple of months before it’s due to hit us.”
“Then you have to shift it at a brisk walking speed.”
“What would that take?” McNally asked.
“Forget kamikaze. Hitting it with the Starship
Enterprise
fails by a large margin. We’d need to eject billions of tons of asteroid. For medium-strength rock or hard ice, we’d need maybe ten million tons of high explosive.”
“Or its nuclear equivalent. Ten megaton bombs surely exist. So we bury one at some optimum depth . . .”
“There you go again, Jim, getting your ideas from old movies. Truckloads of mining gear, diesel engines running on oxygen, engineers holding on to a spinning asteroid like the Keystone Kops. No, on any timescale likely to be available to us, burial is not a practical option. We’ll have to be
guided by Judy on what a surface burst can achieve. And we still need to know what the asteroid is made of. Say it had the strength of cigarette ash? You’re back to the Saracen option.”
“So test it on the hoof. Zap it with a laser as we approach and get the composition from the spectrum of the vapour, like the Russians did with the Martian satellites. Then use an onboard computer to work out your bomb-placing strategy as you close.”
The physicist shook his head doubtfully. “Even with a nanosecond-pulse laser you’d be lucky to vaporize anything at over a hundred kilometres’ range. That gives your spacecraft maybe three seconds to analyse the spectrum of the vapour, work out the size and composition of the asteroid, calculate the optimal position for the bomb and then actually get itself into a corrected position which might be miles away. Forget it.”
Sunlight was now halfway down the crater wall and a light dew was steaming off, but down at the floor, the bowl was still in shadow and the desert air was freezing. McNally was beginning to feel a sense of oppression, as if the walls were closing in on him.
“How can we?” asked the NASA Director. “You’re telling me Nemesis might be approaching at twenty kilometres a second. We have no launch vehicles which could get out there fast and then slow down to match an approach speed like that.”
“In which case America is about to be exterminated.”
“Damn you, Willy, I have six grandchildren.”
“I’m just as fond of my dog.”
They paced on in silence. After some minutes Shafer said: “What about your big heavyweight, the Saturn Five? As I recall it could just about match the Soviets in booster power. I know you phased it out when the Shuttle came on line, but you must still have the blueprints and the launch infrastructure.”
McNally pulled the collar of his jacket up around his neck. “Sure. The blueprints are on microfilm at Marshall, and Federal Archives in East Point hold three thousand cubic feet of old Saturn documents. And sure, the old launch pads were converted for Shuttle use, but we might convert one back again with a little help from Superman. But Willy, where do we find firms to supply sixties vintage hardware? It would take so long to redesign for modern hardware and modify a pad, we’d be as well starting from scratch with a clean sheet design. You’re talking years.”
Shafer kicked thoughtfully at a stone. “By which time we’re dead.”
“Willy, there are two ways we can approach this. With an unmanned module, or a manned one.” Shafer nodded encouragement, and the NASA Chief continued: “We could build fast from an existing manned module design, or even revamp one from the Smithsonian Aerospace, and get it aloft on a Saturn/Centaur combination.”
“How long?”
McNally pondered. “The moon landings were a child’s game by comparison. The Phase A study alone would take nine months in normal circumstances. I might cut that to three or four. Acquisition planning a month, systems engineering and testing another year. Life support systems are a lot of sweat. Absolute minimum a year to launch.”
“By which time we’re dead,” Shafer repeated. They walked on. The silence in the big bowl was becoming tomblike.
“A shuttle carries people,” said Shafer. “Stuff its cargo bay with fuel. Once the astronauts are in low Earth orbit they could blast themselves into interplanetary space.”
McNally shook his head. “The Mark Three can lift eighty tons of payload into a low orbit. Even if that was pure fuel it still wouldn’t be enough. Look, Willy, ideas for boosting the lift capability of the baseline shuttle are coming out of NASA’s ears. Liquid boosters, carrier pods under the external
tank, carrier pods above it, extra side-mounts etcetera. They all need more time than we’ve got.”
Shafer persisted; his voice was beginning to acquire an anxious edge: “Half a dozen shuttle launches, each time with a booster tank in the cargo hold. Fix it so the crews can take the boosters and join them on to a single shuttle like Lego. Skip the test phase”—McNally’s eyes widened with disbelief—“that way you use off-the-shelf systems all the way and all you need is a plumber.”
They were halfway round the circumference. Another lizard scurried away from them, its reptilian legs a blur of speed. McNally threw a stone after it and missed. “I’m sorry, Willy, but you’re now into fantasy.”
The familiar egg-beater sound began to echo off the crater walls as the helicopter appeared, and sank down towards them. McNally waved it away with a grand sweep of the arm, and it tilted alarmingly before veering out of sight. The sunlight had almost reached the floor of the crater.