The humanoid who had been imitating Yeh came tumbling over in a series of cartwheels. Mike scratched it behind the ears. Everybody was doing that now. It was hard to keep your hands off them.
“S-t-t-t-ars!” it chirruped in its songbird voice. “S-t-t-ars, s-t-t-ars, t-t-t-we!” The two of them already had picked up a few English and Chinese words, beginning with “no” and “stop” and “don’t touch,” and you could understand them if you listened hard.
“That’s right,” Mike said, patting the silky crest. “We’ll take you home first. Then we’ll visit Alpha Centauri.”
“Hold on there!” Jameson said. “Don’t go off halfcocked. Alpha Centauri’s only four light-years away, and 61 Cygni’s eleven. If we get a starship out of this, the bureaucrats who finance it are going to want instant gratification.”
People were starting to drift over, drinks in hand. Ears had perked up at the sound of what had become the most popular subject aboard the ship.
“That’s right,” Quentin agreed earnestly. “Baby steps first. That’s been the whole history of the space program, ever since Stafford and Cernan and Young circled the moon before they let Armstrong and Aldrin land.”
“Look,” Mike said. “It’s a five-year trip to Alpha Centauri. Two of that is boosting and decelerating up to light-speed, during which you knock off another light-year, right?”
“Yes, but—”
“And it’s a twelve-year trip to 61 Cygni. Same two years to boost and brake. In between you travel at, say, ninety-nine point ninety-nine percent of the speed of light.”
“What about it?”
Mike leaned back, looking smug. “So at that speed, the time dilation effect is a hundred to one, right? Subjective time for the crew is maybe two years and two weeks to Alpha Centauri compared to two years and six weeks to 61 Cygni.” He spread his hands. “So what’s the big deal?”
“You’re missing the point,” Jameson said, egging him on. “Back home in the budget department, they’re waiting ten years to show results from an Alpha Centauri round trip versus twenty-four years for a return from 61 Cygni.”
“You’re missing the point,” Mike said, grinning hugely. “61 Cygni’s a sure thing! Nobody can criticize the maiden voyage. We know there’s life there! And intelligent life at that!” He ruffled the humanoid’s silky fur affectionately. “And we’ve got two friends to introduce us.”
Quentin was still trying. “Yeah, but listen, Mike—”
Mike sat up, an astonished expression on his face. “Hey, it just came to me! All distances are the same! Give or take a couple of months, anyway. We can reach any star within a hundred light-years in about three years of travel. The hell with them back home! If you want to spend five years traveling, you can have any star within three hundred light-years. Hell, make that ten years—no, twelve years…”
He stopped and looked round at the circle of faces.
Kay Thorwald said it for him. “We own all the stars in a thousand light-years. That’s what we traded Jupiter for.”
The celebration had grown suddenly quiet. Into the silence, Jameson said: “What’s the price? Do we dismantle Saturn next?”
“Hell no!” Mike said briskly. “The Cygnans spent six million years traveling with a first-generation technology. We’ll have a second-generation technology. We’ll find a better way.”
Epilogue
“There’s our snowball,” Jameson said. “Let’s see if we can nudge it into the cup.”
Through the forward viewscreen the comet was an enormous sphere of frozen slush, fifty miles in diameter, according to the instruments. Out here in the cometary halo, far beyond the orbit of Pluto, it had no tail. According to Maybury’s calculations, it grew its tail only once every two million years or so, when its elliptical orbit took it close enough to the Sun to vaporize its sherbetlike surface.
“Right on target, Skipper,” Li said from his console in the circular control room. His English had improved a lot in ten years.
It had taken only ten years to build the first starship. Mike had been right. The principle behind the Cygnans’ energized-photon drive was simple. The human race would have had it in another century anyway; the technical and theoretical groundwork already had been laid.
Of course, the humans had made a lot of improvements.
Sue lifted her head from the communications console to admire the view outside. The ten years had fine-etched her face, making it even more striking. Jameson was glad their daughter looked like her, not him.
“Will that really take us all the way to 61 Cygni?” she said.
“Sure,” said Mike Berry. “It’s mostly water ice. Some methane, ammonia, carbon dioxide dissolved into it, of course, but the engine’s only going to eat the hydrogen anyway. There’ll even be enough of it left at the end to keep shielding us from interstellar hydrogen. We’ll use any of that it picks up, too. Who needs a Jupiter? We don’t have to boost as much mass as the Cygnans, and we don’t have to push it as hard.”
“We’ll never run out of interstellar fuel,” Jameson said. “There’s a hundred billion cometary nebulae out here beyond Pluto. All our starships’ll have to do is come out and chase them down. And we can do that on a tank of water.”
At constant one-g acceleration, it had taken less than three weeks to reach the fringes of the cometary halo and find their snowball. There would be similar swarms of unborn comets around every star, extending light-years into space and mingling with the cometary halos of their neighbors. There would always be a refueling stop. Man would never have to vandalize the planets, as the Cygnans had done.
The two feathery humanoids chattered excitedly. They were temporarily free of their engine-room duties, and Jameson had invited them up to the control room for a look. This was a big moment for them.
Slowly, the first human starship drifted toward the comet’s frozen core. It was a mere two hundred meters long, a slender needle with a hundred-meter cup at one end, so that it resembled nothing so much as a gigantic golf tee.
“Contact!” Jameson said.
The snowball settled into the cup, or the ship landed head first on the comet, depending on how you wanted to look at it. The important thing was that the tail of the ship was pointed in the right direction. Before they’d gone very far, the ship would be half buried.
By the time they got ready for turnaround, the snowball would be down to a more manageable size. The ship would be somewhere in the center of the comet by then, firing its photons through a tunnel melted through miles of snow. All that mass around it would be more than adequate to shield it from the diminishing hail of impinging radiation, and the drive beam itself would handily ward off the interstellar hydrogen directly ahead.
There was no spin section. They would be in free fall for only a few weeks, subjective time. Maybe later ships, with farther to go, would work out a spinning cage or some other device pivoted along the axis of the needle.
The forward screen went blank. The ship’s other senses took over. The humanoids had a drink with them to celebrate, then went back to the engine room.
“We’ve got us some friends,” Mike said, watching the pink creatures scamper down the companionway. “Wait till their people start working on their own version of the star drive. In another ten years, we’ll be roaming the galaxy together.”
Jameson switched on another outside pickup, and the viewscreen was suddenly filled with the splendor of the Great Nebula in Andromeda, a whirlpool of stars sparkling with gems of many colors.