by Les Johnson
Inertial Confinement Fusion (ICF) is considered a promising approach to fusion propulsion. In ICF the charged reaction products themselves are turned directly into thrust via magnetic nozzles. This process leads to far fewer thermodynamic losses and enables much of the fusion energy to be channeled to create thrust for the spacecraft. The Daedalus spacecraft was to be powered by ICF.
The Project Icarus group has identified no less than seventeen unique approaches to nuclear fusion, including plasma jet driven magneto-inertial confinement fusion, z-pinch fusion, antimatter catalyzed fusion and electrostatic inertial confinement fusion. At the current phase in the project, no one method has yet shown to be a favorable fusion technique that would prove ideal for an interstellar mission. However, research continues, and in the future a candidate will be selected.
***
Further Reading
Alan Bond and Tony R. Martin, “Project Daedalus Reviewed”, JBIS, V39, pp. 385-390, 1986.
A. Bond & A. Martin, Project Daedalus: The Final Report on the BIS Starship Study, JBIS, special Supplement, S1-S192, 1978.
Terry Kammash, “Fusion Energy in Space Propulsion”, Progress in Astronautics and Aeronautics, V167, 1995.
DESIGN FLAW
Louise Marley
Proceed as far into the future as you like, possibly even to the glorious day when we are wandering quietly around the solar system, basking in its wonders, and we will undoubtedly discover that some of the worst aspects of our tribal instincts are still with us, especially the one that divides people by religious belief, ethnic background, or even the baseball team they root for. One particularly irritating aspect that promises to resist going away may well be the way in which males with ego problems treat women. After all, it’s probably the only thing they have.
***
“Hey, Itty Bit! Haul ass, would ya?”
Isabet floated up into the maintenance tube, pushing with her feet until she could grasp the first hand rung. “You think you could do it faster, Tie Dye?”
He gave an irritated grunt. “That’s Mr. Dykens to you, Tech.”
“Yeah,” she muttered, wriggling herself further along the tube. “When you call me by my name, I’ll call you Mister. Maybe.”
“What was that?” he shouted behind her.
“Or maybe not,” she added, under her breath. “Fat bastard.”
It wasn’t as if he—or any of the other engineers—could come after her. The tube was no more than twenty inches in diameter, and Dykens wore an extra-large utility suit. The other engineers were not as big as he was, but not one of them could have squeezed into the tube, and certainly not with a tool belt strapped around him. It was up to her and the other ring techs, Ginger and Skunk and Happy and the others, to slither along the maintenance tubes, to check the joints and monitor the ’stats and the flow meters. Tie Dye could yell at her all he wanted to, but if anything went wrong with the containment ring, the North America would be dead in space, antimatter leaking out every which way. Dykens’s big butt would be as dead as anyone else’s, stuck out here halfway to the habitat, in orbit around Ganymede, whining as their food and air ran out. It was obvious he had never huddled in a shelter for days without food.
She sure as hell had.
Isabet blew out an angry breath as she slid deeper into the tube. She kept telling herself it didn’t do any good to be pissed at him. It was just the way he was. He wasn’t the only one, either. It was true of a lot of the crew. For one thing, most of them thought ring techs were superfluous. They conveniently forgot the failure of the North America’s first containment ring and the resulting discharge of expensive antimatter, all because the mechanical sensors were off by a fraction of a millimeter. And then, leaving aside their short memories, the other crew members seemed to think that because ring techs were small, they could push the techs around. Crew members grinned when they saw them, as if the ring techs were kids playing grown-up. The other crew members patted their heads and made jokes about their extra-extra-small utility suits. Ring techs were housed in quarters barely big enough to stand up in. They slept in cots so cramped the techs called them coffins. They were allowed only three showers a week, while the rest of the crew got five.
Command didn’t seem to particularly care that three hundred crew depended on six techs. It was Government that insisted on the use of human monitors as backup. Command had to do as it was told, but as far as Isabet and the others could tell, once the ship was under way, the ring techs had been all but forgotten.
It made her blood pound to think about it, but then, a lot of things made her blood pound.
It took ten minutes to reach the ’stat that was on her assignment list, and by the time she did, she felt better. She liked the solitude of the tube. No one could get to her, no one could bother her. It was calming. She flipped up the cover of the ’stat and eyed it. It wasn’t part of the protocol, but she always did a visual scan first. Tie Dye would be surprised to know how much Isabet understood of what the ’stats recorded about the containment ring. She could have told him all about pressure differentials and temperature variations and magnetic flux. She didn’t, though. She tried not to talk to him any more than she had to.
Everything looked fine. She pulled the remote from her belt, pinning herself to one side of the tube in order to get her hand down and then up again. She clamped the remote into its holder, and waited the three seconds it took to record the reading. Finished, she started the long backward slide back to Engineering.
She meant to ignore Tie Dye when she got there. She really did. But when he took the remote from her to pass on to the chief, he brushed her chest with his big, freckled hand. It wasn’t an accident. His fingers lingered on the front of her utility suit at least a full second.
“Back off!” she spat at him. She slapped at his hand, but he pulled it out of her reach. Her fingers curled, longing to claw his fleshy cheeks.
His phlegmy laugh made her skin crawl. “Relax, Itty Bit,” he said. “Just checking to see if they’re as small as the rest of you. I would say—” he grinned wider, showing his big yellow teeth. “I would say the design is consistent!”
“I’ve told you to keep your hands off me,” she said. “I’ve filed a complaint with Command, so you better watch yourself.”
“Yeah, I heard about that. You did it twice, in fact. Waste of time, wasn’t it? You need to understand command priorities.” He stopped grinning, and shook a finger at her. “You ring techs are lucky to have work. One day they’ll invent their way out of the problem with the monitors, and leave you and the rest of them on Earth where you belong. That’ll save a lot of air and food out here.”
“If they could, they would, Tie Dye.” Isabet spun away from him, and kicked off down the corridor toward the mess.
He called after her, “Get used to it, Itty Bit! It’s the way we do things here.”
Over her shoulder she snapped, “Get used to it? This is my third voyage.”
“You should know, then,” he said. “Like I said, you’re one of the lucky ones!”
It was true enough. Isabet and Skunk and Happy and the others were fortunate to have their jobs. Skunk, whose Icelandic name none of them could pronounce, had fled his home as his village disappeared under the cold waves of the North Atlantic. He’d been living on Government rations since he was six, and it showed in his short stature and wispy hair.
Happy Feet had been a dancer Earthside; when he got too old for that, he applied to be a ring tech, and was accepted because of his small size and agility. He joked that he was only here so he could eat. He said, with his high-pitched laugh, “I’d rather soak up G-rays than eat G-rations!”
Ginger almost didn’t fit the profile of a ring tech. She hadn’t starved. She was just naturally small. She had once had a business, something to do with books, Isabet thought, but the Global Depression had wiped out her business and scattered her family. Bony and worn down by sorrow, she was grateful to be aboard the North America. Too gra
teful, in Isabet’s view. She took Tie Dye’s abuse without the slightest resistance.
Isabet knew she was the luckiest of all. She was also the youngest and the smallest. Abandoned as an infant—a doorstep baby—she had been kicked out of the orphanage at the age of sixteen to find her own way. The orphanage called it graduation, but all it meant to her was being turned out on the street with few resources. In one of the shelters, she saw a poster about the positronic reactor ships and for the first time, learned that there was an advantage to having been starved as a baby. There was work for a person of small physique if that person had the guts to go into space, crawl through the narrow maintenance tubes every day, and risk gamma ray poisoning as well as all the other dangers of space travel.
Isabet had guts. She didn’t have much else to work with, but her courage and native intelligence won her the job, and she liked it. The voyages to Ganymede were a lot more comfortable for her than the required months of gravity Earthside between trips. It wasn’t just that her pay ran out before it was time to return to the ship. On the North America she didn’t have to fight for a bed in a shelter and then sleep with one eye open and a knife in her hand against the threat of rape or theft or worse.
She scowled as she told Ginger and Happy and Skunk what Tie Dye’d done. “The worst part is,” she concluded, “he’s right. I complained to Command, and they never even answered me.”
“Probably never reached ’em,” Skunk said glumly.
“I think it did. I think they just don’t want to hear it. He’s good—a containment expert, in fact. They need him more than they do me. I’m dispensable.”
“That’s not fair,” Skunk said.
“It’s not right, either.” Isabet wriggled impatiently against the straps that held her on the stool. “Our contracts provide for redress of grievances.”
Ginger sighed. “You’re the only one of us who ever reads those,” she said.
Happy Feet spread his hands. “I, of course, don’t actually read,” he said slyly.
“Oh, you do, too,” Skunk said. “I mean, you can.”
Happy waggled his eyebrows and did a little freefall dance, feet and hands flashing so that he rose against the restraining straps like a puppy pulling at his leash. “Waste of effort,” he said blithely. “I just dance!”
“In the maintenance tubes?” Skunk said sourly.
Happy chuckled. “If you could only see me.”
Skunk shook his head. “I don’t know how you stay so cheerful. We’re trapped here. No better than slaves.”
“We’re not slaves,” Ginger said.
Isabet said sharply, “That’s right. We get paid, we have opportunities, and responsibilities. We should be treated with respect.”
“I don’t think Tie Dye agrees,” Happy said.
“You better be careful with him,” Ginger warned. “If he catches you alone someplace—”
“Yeah, I know. I can take care of myself.” Isabet paused, tilting her head, listening. “Notice that?”
“What?” Skunk said.
“The ship. We’re getting ready to brake.”
“How can you tell?”
“The vibration changes. You can’t feel it?”
The other three shook their heads. Happy said, “I can’t believe you can tell.”
“You just have to be sensitive to it. Three days now, and we’ll be there.”
“I don’t know how you know that,” Happy Feet said.
Isabet patted his thin cheek. “Reading, Hap. Reading. That thing you say you don’t do.”
The four of them gathered in the aft observation area as Ganymede began to swell against the blackness of space, with the great disc of Jupiter a vague, immense shadow beyond it. As the ship adjusted attitude, they sank to the deck, briefly weighted, then rose again. It was like being aboard an ocean-going vessel, and Isabet saw Ginger swallow and press her hand to her lips. “It’ll pass in a little while,” she said, touching Ginger’s shoulder. “We’ll be in electrogravity soon. It’s magnetic, so we’ll pick it up from the habitat.”
Skunk said, “Wow, Isabet. I don’t know how you know all that.”
“My third voyage.”
“Yeah, but—electro-what?”
“Electrogravity. There’s a great video about the habitat, Skunk. You should see it.”
Ginger nodded, but she still looked a little green. Happy moved close to her other side, and steadied her with his arm. Isabet turned back to gaze with pleasure at the lavender-tinted disc of Ganymede. The poles of the moon glistened faintly, and the pockmarks of craters layered the surface. Isabet pressed her palms together, entranced. This was her reward for putting up with the indignities of the North America, with the insults of Tie Dye and the rest of the crew. She never tired of it. She only wished—
“That’s it?” Ginger said, pointing to the disc.
“That’s it,” Isabet said happily. It was somehow massive and delicate at the same time, and it seemed immune from the ugliness that had overtaken Earth, the crowding, the fouled air, the threatening seas. She sighed with pleasure. “That’s Ganymede.”
“It’s so dim,” Ginger said. “I thought it would be brighter.”
“We’re a long way from the sun,” Isabet said. She felt a faint disappointment that Ginger didn’t share her admiration for the magnificence of the alien world. “Wait till you see Starhold,” she said. “You won’t think that’s dim.” She yearned to see the inside of the habitat, but she didn’t say so. There wasn’t much chance of that happening, and the others wouldn’t understand.
A half hour passed, with Ginger gulping nausea, and even Skunk groaning once or twice. Isabet felt the acceleration as the ship changed its trajectory, but her stomach didn’t react. She clung to the bar beneath the window, and waited with gleeful anticipation for her first glimpse of Starhold One.
“There it is!” She pressed as close to the icy plexiglass as she could, peering out into the layered darkness. It was tiny at first, a star among stars, only discernible because she knew it had to be there. The North America rolled as it aligned with the docking ports. Isabet fastened her gaze on the habitat’s yellow and amber lights. She could pick out the lighted column of the vacuum elevator, revealed in fragments by the myriad windows. The habitat, silver and ovoid, shone dully against the backdrop of space. Layers of fuel cells spiraled around it, making it look like a gigantic seashell.
“Is that it?” Ginger asked. “That egg-shaped thing?”
“Yes,” Isabet said. “That’s it. Starhold One.”
“Why One?”
“Because there will be others, as we go further out,” Isabet said. “Space Service already has plans for two more. They’re mining Ganymede, and building an antimatter plant.”
“Why?” Ginger asked.
Isabet, startled, glanced across at her friend. Ginger stared vaguely at the habitat, but without real interest. “Why what?”
“Why build others? What good are they?”
“What good?” Isabet’s voice squeaked with surprise. “We need them if we’re going to explore space, get out into the universe!”
Ginger shrugged as if the whole idea were of no interest.
“Ginger!” Isabet said. Suddenly it seemed vital that her friend understand the immensity of the achievement. “We’re building an interstellar ship, you know. It’s going to be five times the size of North America, and carry a crew outside the solar system! It’s the most amazing thing human beings have ever done, the biggest ship ever built—and to power it, we need lots of antimatter.”
“Geez,” Happy said. “That’s gotta be one really big containment ring.”
“Enormous,” Isabet said with satisfaction. “Imagine working on that ship, Happy! Going out into real space, instead of just between Ganymede and Earth.”
“Naw,” he said. “They’ll fix the monitor design by then. They won’t take us.”
“I’m going to find a way to go,” Isabet insisted.
�
��I don’t know.” Ginger sighed, leaning against the frame of the window. “We have enough problems at home, don’t you think?”
“Don’t worry about it, Ginger,” Skunk said. “We’ll never live to see it, anyway.”
“Come on, Skunk!” Happy cried. “Why so dour?”
“Because it’ll take decades, and ring techs don’t live that long.”
“We’re tested all the time,” Isabet said absently. “We’re fine.”
“Tested!” Skunk said bitterly. “You realize the norms for us are twice what they are for the rest of the crew?”
“Are they?” Ginger said, pulling back from the window as if it were the source of the poisonous rays.
“Skunk’s exaggerating,” Happy said.
Isabet turned her head to her friends. “No, Skunk’s right. They say, though, that when we’re Earthside our readings return to normal levels.”
“Do you believe them?” Ginger said, her voice rising.
Isabet shrugged. “I guess.”
“Believe if you want to,” Skunk said. “But don’t have babies.”
“None of us are having babies.” Isabet turned back to the window to watch Starhold grow. It was both massive and graceful, with a halo of light that faded the stars. She had studied the diagrams of its construction, pored over the blueprints of its hydroponic level and command deck with its crown of communication and power arrays. She had seen the cubbies and the gallery level in the video, and the men and women smiling into the camera. They looked friendly and smart. Starhold, to Isabet, looked like a home, the home she had never had. She thought she would willingly take a blast of G-rays if she could go in and see it for herself.
