Eric Flint: Threshold

But the ESDC's engineers hadn't really had any choice, if they were to keep the hidden design a secret. But inthis case, the problem of poor maneuverability was irrelevant, since Hohenheim couldn't possibly keep the ship intact anyway. The general initiated a search for the triggering systems. With his command overrides, it wasn't hard to find. He couldn't reach many of the hab-section controls, but for his purposes it didn't matter. He was going to use the extreme variant.

First things first. He checked his chronometer. Munin must long since have left for its rendezvous with destiny, and hopefully survival. It was possible that there were one or two other survivors on boardOdin, but Hohenheim had managed no contact. At this point, he had to assume that only the dead remained with him. And he had to hurry. Every passing hour brought him closer to Io and made any desperate attempt to evade that hellish globe that much less likely to succeed. The lateral thrusters… Some still operative. Enough, he hoped. He modeled the current movement of the ship on the main console, thanking whatever gods there were that modern interfaces did not require him to do the calculations. Then he ordered a precisely timed sequence of thrusts. Slowly, slowly, he began to feel a sense of turning that was separate from the ship's earlier axial spin. Odin was now spinning, more and more quickly, about her lengthwise center of mass as well as the axial. He could feel a faint pressure toward the wall in that direction, as theOdin now tumbled like a thrown bolo instead of a rifled bullet. It was an end-over-end spin that would normally signify disaster. But theOdin was doomed anyway, and there was a purpose for this tumbling. The tumbling sent Io spinning smoothly around the cameras' field of view. Once more he input the model, then incorporated the vectors of their approach to the moon. Taking a deep breath, waiting for the designated conditions… Hohenheim ordered,

"Separate." The concussion of separation would have knocked Hohenheim off his feet if he had not strapped in; as it was, his head slammed painfully into the back of his helmet. There were other distant sounds and vibrations that did not bode well for even the section ofOdin he had kept with him. But he did not care about that; what was important was whether his desperate maneuver had worked. Spinning on approach, when the two pieces separated they retained the same total momentum.

Their center of mass would remain in the same place, barring some form of acceleration placed on one component separate from the other. But the center of mass was merely a geometrical and physical construct, one that now occupied empty space. The shattered hab ring and most of the main body hurtled off in one direction, while the engine and drive section spun off in the opposite direction-away from the meeting with Io. By itself, that would not be enough; Hohenheim had known that before he started. But he needed all the help he could get; at least it started him edging away from direct central impact with the deadly moon, and drastically reduced the mass ofhis part of the ship.

Now… First the spin had to be brought back under control. The laterals left on this section would be driven past normal design limits, but-again-he didn't need to worry about long-term endurance.

No, his main worry was something else entirely, the major remaining question mark in this enterprise, one that might render everything he was doing futile. But it was better to die trying than not to try at all. Finally, Odin -what remained of her, rather-was no longer tumbling or spinning. She sat with her mass-drives pointed almost directly away from Io, the blunt-nosed engineering section almost facing toward the pockmarked moon. Almost, but not quite. And now, the moment of truth. For there really was no other choice. Mangled though the nozzle was, the NERVA-based drive was still operative. It might work for a second, or ten seconds, or longer. It might, possibly, have some failure mode that would blow the control room into shrapnel. But if it worked-even for just a few moments-it just might give him enough thrust to send them plunging around Io instead of into it, hurtling out into the Jupiter system, probably to never encounter another solid object again for years or even centuries. He would not get home. But the maneuver might give him the time he needed to report home, and to make his peace with family and friends left behind, before he died. He would die onhis terms. He checked the vectors one last time. The nozzle control systems were… shot. He would have to hope that the imbalance from the missing section of number four driver rib would not be too significant for the time the main drive fired. He offered a silent prayer. Let me not have entirely wasted my last few hours in this world. Then he activated the drive. For its last time, Odin came fully alive, the thunder of the NERVA rocket delivering a million pounds of thrust, shoving the now greatly lightened vessel forward.

Amber telltales lit, then shifted to red, and he could see the drive nozzle starting to come apart. He overrode automated shutdowns. Run until you can run no more, or until you reach the limit of reaction mass I have allotted. The power of the rocket vibrated through Hohenheim's bones, a defiant cry of the wounded ship against the approaching destroyer, and he brought his head up proudly. The great ship, the largest ever built by the human race, had done well. One last effort, one final task, andOdin could rest. The ship had been done a great disservice, but it would still give its best to save the last living human being aboard. And then, with a doomsday roar that echoed throughout the wrecked vessel, the main engine's nozzle blew entirely off.

Chapter 43 "The best hope we have is that someone figures out a way to come get us. And is willing to spend the hundreds of millions to do it," Joe said gloomily. "That bad?" Helen asked. "It's not good, that's for sure. We were cramped for equipment space, you know that.

Our lander has a little reactor on it, but nothing like what we'd need to run the drive. Jackie and I think we can rig it to provide us with power to live on, but that's about it. I can do some slow maneuvering if we have to with the few ion jets we've got, but those do use reaction mass and power, so we sure ain't going home on them. We can't deploy the sail, and we can't refuel the engine, and even if we could refill the reaction mass tanks, without the reactor we couldn'tuse it." "It's ironic," Helen said after a few silent moments on the bridge ofNebula Storm. "How so?" asked A.J. "Well, usually in the lost-in-space kind of stories, the real problem is either not knowing where you are, or running out of air or food or water. But we've got close to two years of all of that, if we manage to keep power going at all. And we know exactly where we are and where we want to go."

Jackie, Helen noticed, was still silent. She'd been waiting quietly at the console ever since Horst had been cut off by a burst of static that A.J. had localized to somewhere onboardOdin -a deliberate jamming transmission. That implied that Fitzgerald had caught up with them. No one knew what to say to Jackie. Knowing that Madeline Fathom saw Fitzgerald as someone dangerous, and knowing what Maddie was capable of, no one wanted to raise false hopes. The screen suddenly lit up with a transmission. "Nebula Storm, Nebula Storm, this isMunin.

Please answer." Jackie, of course, answered first. "Horst!

Is… are you all right?" The German's voice was solemn. "I am all right, and so is Anthony. We have six other members ofOdin 's crew on board. The general asked me to pass on his apologies to you all."

"General Hohenheim is alive?" "He was when we left. At his orders."

A.J. closed his eyes. "Oh, Jesus." "What about Fitzgerald?" Madeline asked. "The general stayed to deal with him, Madeline. There is no other way off the ship." Maddie nodded slowly. "I see. I hope… that you have considerable supplies on board?" "We have better than that." Anthony LaPointe's face was actually smiling, a startling contrast from the last few conversations. "I think that I have a way for us to all go home." "What?" Everyone, even Horst, seemed surprised. "Why did you not tell me, if that is true?" he asked. "Because until we were able to see whether our friends were still alive, there would have been no point. We will need both of our ships and talents." "All right," Larry said. "What's your idea?" "Our orbits, they are not terribly different. We can match with you, I think you will agree, by doing an Oberth around Io at the right time."