Nemesis (12 page)

Suddenly McNally froze. He raised a hand to silence Shafer, an unformulated thought just out of reach. Then he nodded his head, and he said, “I have a very bad idea.”

“Let’s hear it,” Shafer encouraged him.

“The Europeans have a comet soft lander. It’s called the Vesta. It could reach the asteroid.”

Shafer stopped. “That’s a bad idea?”

“The project’s well along and we’re lending them our telemetry systems. Trouble is, their Ariane Five isn’t powerful enough for a soft land.”

“Oh no,” said Shafer.

“Oh yeah. ESA are shipping Vesta to Byurkan. The Russians are launching it for them with a Proton booster.” McNally narrowed his eyes. “They’re building Vesta at Matra Astrium in Toulouse. If we could somehow get our hands on it, without arousing suspicion, we might lift it with a Saturn–Centaur combination.”

“I agree,” said Shafer excitedly. “It’s a terrible idea. A new procurement policy for NASA. Theft.”

“My career would be ruined. I might have to commit suicide,” said McNally happily, his eyes gleaming.

Shafer stopped and let McNally walk on. The NASA Chief Administrator paced slowly up and down for some minutes, muttering eccentrically to himself. He came back, his eyes narrowed. “Willy, we could bring a bomb up on a Shuttle to save payload on the Saturn. The crew would rendezvous with Vesta two hundred miles up and transfer the bomb over before the spacecraft goes hyperbolic. Goddard and JPL could handle the trajectory planning if we ever find Nemesis. Lawrence Livermore have experience with mission sensors and the bomb. I could get the Naval Research Lab to look at the overall mission design. We have our Deep Space Network . . .”

“Don’t use it,” Shafer said sharply. “The Russians would pick up the ionospheric backscatter. Once this thing leaves the ground it’s on its own.”

“Where am dat chopper?” McNally started to perform a sort of war dance, whooping and staring up at the crater rim. “If it gets me to Phoenix I could connect with New York this afternoon and then a Concorde to Paris . . .”

“Hey, Jim, calm down. Even if you reached Nemesis you wouldn’t know what to do with it. And something else. Try to acquire Vesta from the Europeans and the Russians will realize we’re on to them. If you’re seen within five hundred miles of Toulouse you’ll trigger a nuclear strike. I’m sorry, Jim, and I’m sorry about your grandchildren, but we’re screwed up before we start.”

“Let me get this straight,” Noordhof said. “First, the West’s finest brains have so far failed to come up with a strategy to find Nemesis in any reasonable timeframe. Second, even if you do find Nemesis, you have come up with no practical means of delivering a punch to it.”

“Be reasonable, Mark, we’re barely in the door,” said McNally. There was a collective murmur of agreement round the conference table.

Noordhof sighed. “But you only have until Friday night. Where are Kowalski and Leclerc?”

“Kenneth’s gone to bed,” Webb said. “He’ll be observing all night.”

“We left André taking a walk round the grounds,” said Judy. “He said he was meditating.”

“Gone to bed; taking a walk; meditating. Jesus wept, do you people understand the situation?”

“Maybe you should shoot one or two of us, to encourage the others,” Shafer suggested.

“You probably meant that as a joke,” said Noordhof grimly.

“I’m here,” Webb said happily. The backwoodsman from
Deliverance
, the one with the Fenimore Cooper rifle and the intolerant, ignorant eyes full of medieval superstition, had turned out to be a philosophy student from the University of
Arizona in Tucson, in his final year of an MS and writing a thesis on the Influence of the Platonic School on Aristotelian Cosmological Doctrine, a fact which had reminded Webb that you can’t always go by appearances. The astronomer’s backside was still sore from the metal floor of the student’s suspension-free Dodge.

Noordhof stared angrily at the astronomer. “That was an unbelievable breach of security. What right do you people have to endanger this operation by wandering off over the mountain?”

“Nobody ever comes here in the winter, Mark. You said so.”

“Has it occurred to you that the Russians might have feelers out? That a place like this might be under surveillance?”

“Astronomers visit observatories, Mark. It can be Hawaii one week, Tenerife the next, Chile after that. No security breach was involved.”

“Allow me to judge that. As of this moment nobody steps more than one hundred metres from this building without my permission, except to go up to the telescopes.” The soldier turned to Shafer. “Okay. You don’t know where it is. You don’t know how far away it is. You guess it’s a kilometre across and closing at maybe twenty kilometres a second. But now the good fairy comes along and she waves her fucking wand and you find Nemesis some time in the next few days. Then she waves it again and McNally rustles up a launcher and gets a probe out to it. Okay Willy, now it’s up to you. Your mission, should you decide to accept it, which of course you do, is to find some way to stop this frigging thing.”

Shafer rubbed a day-old stubble. “Say it’s coming in on a bullseye geocentric orbit. To miss the Earth, we have to deflect it so that by the time it gets here its orbit has shifted by at least one Earth radius. Six thousand kilometres.” He moved to the blackboard and picked up chalk. A blackboard was the logical way for everyone to follow his logic, but
Webb suspected it was also the way he liked to work. “Say we intercept it a week from impact.”

“A week!” McNally gasped incredulously.

“If
is the radius of the Earth and
t
is the time before deflection, you need a velocity increment δ
V
=
/
t
if you want to punch it sideways. A transverse movement of say seven thousand kilometres in seven days comes to one thousand kilometres a day, or forty kilometres an hour.”

“But Nemesis won’t be going in a straight line. The Earth’s gravity will curve it in,” objected Sacheverell.

Webb joined Shafer at the blackboard and they both started to scribble. Webb got there first. “Hey, Herb finally got something right. Gravitational focusing will add to the Earth’s target area. The gravitational target area exceeds the geometric one by 1 + (
V
_E
/V
)
²
where
V
_E
is the escape velocity from the Earth and
V
is the Nemesis approach speed.”

“But we don’t know
V
,” McNally complained. “We don’t know how fast Nemesis will come in.”

“We guess.
V
_E
is about eleven kilometres a second and a typical Earth-crosser might hit us at twice that speed. That adds twenty-five per cent to Willy’s estimate. Intercept Nemesis a week out and you need to deflect at over fifty kilometres an hour.”

“Okay,” Noordhof said. “So what does Nemesis weigh?”

Webb and Shafer scribbled, and this time Shafer got there first: “Pretend it’s a rocky sphere a kilometre across, say with density 2.5 grammes per cc. Okay, that means we’re dealing with about—yes, 10
¹⁵
grammes. A billion tons.”

“To be knocked sideways at 30 mph,” said Noordhof.

“Without breaking it up,” Webb added. “We can’t shower the Earth with fragments.”

Noordhof said, “Nuke it.”

McNally was looking worried. “That’s what I said. But I’ve been wondering about the legalities of that. As I recall Article Four of the Outer Space Treaty forbids the placing or use of nuclear weapons in space.”

“So how do you think the Russians deflected Nemesis? With a pea-shooter?”

“But the ABM Treaty of 1972 . . .”

“Jim, hear this. Screw all treaties. I include in the screwing thereof the Outer Space Treaty of 1967, the Nuclear Non-Proliferation Treaty of 1968, the Convention on Registration of Objects Launched into Outer Space of 1978 and any other protocols and codicils I haven’t thought of or don’t know about. Let’s just find Nemesis and nuke it.”

Judy Whaler said, “That’s the kind of talk I’ve been waiting to hear. We can blow a big hole in its side, and use the recoil from the ejecta to deflect it. A rocket effect.”

Noordhof said, “You people tell me how big a hole we need.”

McNally said, “With a week’s notice, nobody outside a Bruce Willis movie is drilling holes in it.”

Noordhof said, “In that case you have a surface burst. We surely have empirical data from the Nevada H-bomb tests.”

The NASA Director asked, “With a one megaton bomb, what weight are you asking me to launch?”

“A ton,” Judy replied without hesitation, moving over to a terminal. McNally nodded his satisfaction. They waited as she tapped her way into a web site. “My home page. It’s full of goodies.” She moved the cursor to an icon and clicked the mouse. A table of numbers appeared.

“Here we are. The Nevada tests.”

“But these are tiny explosions,” Leclerc said, looking over her shoulder.

Judy nodded. “Schooner was 35 kilotons, Sedan a tenth of a megaton. But I agree, mostly like Jangle or Teapot they were just a kiloton or two. You don’t want the neighbours screaming when you set off your A-bombs.”

“Can you do a least squares fit?” McNally asked.

“It’s been done.” She clicked again, and a graph appeared on the screen. Shafer got there first: “So, if we believe the fit, a one-megaton surface bomb excavates a crater six or seven
hundred metres across. The crater could be as big as Nemesis. We’d shatter it.”

“Maybe, maybe not,” Sacheverell said.

“Let’s run with a megaton for a while,” Webb proposed.

“It is not enough to know the size of the crater,” Leclerc pointed out. “We need also to know its depth before we know the volume excavated.”

Back to the table. A red-painted fingernail traced along a row. “Jangle S was a surface burst. It had a depth about half its diameter.”

Sacheverell said, “These bomb craters were made in terrestrial gravity. How can we trust these results on Nemesis?”

Leclerc was scribbling on the back of an envelope. “Shall we ignore details like gravity? If we extrapolate Judy’s figures we find we could excavate maybe fifty million tons of Nemesis with a megaton bomb.”

“We can also get at it from the crushing strength of rock,” Webb said, “Assuming Nemesis is made of rock. If it takes
5 × 10
⁸
ergs to crush a gramme of medium-strength rock, and a megaton is 4 × 10
²²
ergs, Willy’s bomb has the energy to excavate eighty million tons.”