Stephen Baxter: Ark

Kenzie came bustling back into the room.

As they walked back to the table Patrick asked Liu, “Do you still hope to bring your wife here someday?”

“It is a dream. But to find her in the great chaos of the flood, even if she survives, and to bring her here-it may be easier to fly to the stars, Mr. Groundwater.”

Liu opened the discussion of his “Category Two.” He brought up graphs and tables and artists’ renderings of exotic worlds. Liu said, “Like many other programs, the work of ‘planet-finding’ was pretty much curtailed by the flood. That is, using advanced telescopic and photographic techniques, including telescopes in space, to detect and study the planets of other stars. Nevertheless several hundred such ‘exoplanets’ were found before the flood came, and more have been found since. And of these, several dozen are like Earth. They have masses similar to Earth’s, and appear to have water oceans-”

“Some of them have life,” Jerzy Glemp said, grinning. “We know that from atmospheric signatures-oxygen, methane. Spectroscopic records of photosynthetic chemicals.”

Patrick was stunned. “We found life on other planets? I didn’t know that.”

Kenzie said dryly, “These days the news agenda tends to be dominated by domestic issues.”

“Think of the irony,” Jerzy said. “We finally discovered life beyond Earth just as we are becoming extinct on Earth itself.”

Liu said, “These worlds are ‘Earthlike’ only in as much as they are more like Earth than Mars is, say. Nevertheless-”

“Nevertheless,” Kenzie said, “if one of them was floating around the solar system we’d fire our kids over there like a shot. Correct? So how far away are these things?”

Jerzy Glemp shrugged. “Well, there’s the rub. The nearest star system is Alpha Centauri-four light-years away. That’s a distance hard to grasp. It’s around forty trillion kilometers. A hundred million times further away than the moon is from Earth.”

Kenzie waved that away. “And the nearest Earth-like world? How far to that?”

Liu said, “The nearest reasonable candidate is sixteen light-years away.”

“Oh, that all? OK, so how do we get there? I’d guess from our previous discussion about the domes on Mars that you guys wouldn’t think we could run a space mission, unsupported, of more than a few years. A decade, tops. So that’s the timescale. Have I got that right? So how do we get to the stars in a decade? I take it chemical rockets, the shuttle and the Saturn, are out. If it took three days for Apollo to fly to the moon-”

Patrick grinned. “Only three million years to Earth II!”

Glemp said, “An alternative is to use electricity to throw ions, charged atoms, out the back as your exhaust. A much higher exhaust velocity gives you a better performance…”

But Liu quickly dug out a whiskery study that suggested that even an ion rocket would need the equivalent of a hundred million supertankers of fuel to reach Alpha Centauri in a century or less.

“Nuclear engines, then,” Glemp went on. “Back in the 60s NASA developed a ground-based test bed of a fission engine-hydrogen heated up by being passed through a hot nuclear fission pile and squirted out the back…” NERVA had worked. But again, as they paged through theoretical studies from the archives, they quickly found that the fuel demands for an interstellar mission on the timescales they required were impossibly large. They did find some useful material, such as a NASA study on lightweight nuclear engines meant to power a generation of unmanned explorers of Jupiter’s moons, probes that never got built; Glemp and Liu flagged such material for further study.

Glemp said, “Look-you don’t actually need any fuel at all to reach the stars. You can use a solar sail…” A sail kilometers across, made of some wispy, resilient substance that would gather in the gentle, unrelenting pressure of sunlight, of solar photons bouncing off a mirrored surface. “Such a craft would take mere centuries to reach the stars.”

“Too long!” Kenzie snapped. “We’re drifting here, guys.” He pushed back his chair and walked around the room. He paused briefly by the kids, who, with Harry patiently filming them, were acting out a siege of their plastic fort. Kenzie said, “Captain Kirk never had this trouble. Where’s a warp drive when you need one?”

They laughed, all save Liu, and Patrick wondered if that was because he’d never heard of Star Trek. But the Chinese said, “That of course would be the solution. A faster-than-light drive.”

“No such thing exists,” said Kenzie.

Jerzy Glemp said firmly, “No such thing can exist. According to Einstein the speed of light is an absolute upper limit on velocity within the spacetime of our universe.”

“True,” Liu said. “But spacetime itself is not a fixed frame. That is the essence of general relativity. In the early moments of the universe, all of spacetime went through a vast expansion. During the interval known as inflation, that expansion was actually faster than light.”

Patrick was lost, but Jerzy Glemp was intent. “What are you suggesting? That we ride a bubble of inflating spacetime?”

“I don’t know,” Liu Zheng said. “I have a faint memory, of a study long ago… May I check it out?” Kenzie waved his permission, and Liu began to scroll through screens of references and citations.

Kenzie said, “You know, maybe we need to step aside from the core problem for a minute. We are after all talking about starting up a space program here in Colorado. However we travel to the stars we’re going to need launch facilities to get to orbit in the first place: gantries, blast pits, liquid oxygen factories, communications, a Mission Control, the whole Cape Canaveral thing. Jerzy, we need to find ourselves some space engineers. And some real-life astronauts, to train our guys. Got to be some of them around.”

“Canaveral itself is long drowned,” Patrick said. “Went under with Florida. There was an alternate launch facility in the west.”

“Vandenberg,” Kenzie said. “Run by the air force. Must be flooded too, but maybe more recently. If we have to salvage equipment from one or other of these places, Vandenberg might be the better choice.”

“But that’s a huge commitment,” Patrick said. “A whole new space program! At such a time of crisis, how can you expect to get the government to back you?”

Kenzie smiled. “There’s always national defense. Look-one effect of the flood has been to knock out our national war-making capabilities. Oh, we’ve been moving nuke-tipped ICBMs out of flooded silos in Kansas. But the basic infrastructure has been hit too. NORAD in Cheyenne Mountain is still operating, not far from here. But all Cheyenne did was gather data and feed warnings to Raven Rock on the Pennsylvania-Maryland border, the Pentagon’s deep-bunker control hub, which has now been lost. Meanwhile our satellites are degrading one by one. Even our deep-defense radar systems are failing, now that the bases in Britain and Canada are flooded out. And you have warlike noises coming out of China and Russia and India. What if those guys decide they need a bit of lebensraum over here in the US of A? What are we going to do about it? I think the federal government could be sold the need for a space launch facility, here on the high ground, to give us the means to launch recon sats and to retaliate in case of any strike against us.”

“Isn’t that kind of cynical?”

Kenzie just grinned. “The space program has always run off the back of the military programs. The first astronauts rode honest-to-God ICBMs to orbit. And anyhow, isn’t it for a good cause? Joe-make a note. Start working on fixing me an appointment with the President as soon as we have a reasonable shopping list-”