Geoffrey Landis - Mars Crossing

“You said it,” Tana replied.

During the training exercises, Ryan had tagged the bubble habitat the “hobbit habit,” since it was so small that ordinary humans had to hunch over when standing inside. “Damn thing is built for hobbits, not humans,” he’d said. From the outside, the bubble habitat looked like three golden brown biscuits baked together into a single mass, with a smaller biscuit, an airlock, stuck to one side. The yellow was the natural color of Kapton, a puncture-resistant polyimide, reinforced with invisible strands of high-strength carbon superfiber. The walls were just translucent enough that, from the outside, the hobbit habit shone with a deep, almost incandescent glow.

All five of them were inside now. Tana had seated Ryan on one of the supply cases and had strapped an oxygen mask on him. She drew a sample of his blood to analyze later. “Who’s president?” She hit him on one knee and watched his reflexes critically.

“Yamaguchi.” From under the oxygen mask, it sounded something like “Yohmoosh.” “Unless he’s been impeached. Or better yet, hanged.”

“Dream on.” Yamaguchi was not well liked among the Mars crew. As a senator, he had sponsored the legislation that killed the NASA Mars program after the Agamemnon disaster; as president, he had tried—unsuccessfully—to stop the Quijote expedition by demanding a billion-dollar payment as usage fee for the government equipment.

She tapped his other knee and watched the reflex. “What’s your mother’s maiden name?”

“Sagan, just like the astronomer. No relation.”

“Stick your hand out straight and hold it steady.” She watched it critically, looking for tremors. “Good. Touch your nose with your index finger, please. Good, now again with your left index finger. Excellent. Tell me, where are we right now?”

“Inside a teeny little hobbit room that smells like plastic and”—he sniffed—“something else, maybe peroxide.”

“And where is that?”

He grinned. “On Mars.”

“Good,” Tana said. She peeled one eyelid up and shone a flashlight in his eye, watching the pupil contract, then did the same in the other. “I’d say that you’re oriented times three. You had a bad case of anoxia there, and I’m not real happy about it, but it looks like there’s no permanent damage. You can take the oxygen mask off now if you want. Do you have a headache?”

Ryan pulled the mask off. “I’m okay.”

“Roll it up neatly and put it away. Any idea what happened?”

Ryan shook his head, wincing slightly as he did so. Tana thought that he probably did have a headache. She would have liked to do a full PET scan workup to make sure she hadn’t missed anything, but without equipment, that was obviously impossible. “I’d say that something went wrong with the zirconia cell, but I don’t know what,” he said. “It wasn’t feeding me oxygen. I’ll take it apart tomorrow.”

“Do it tonight. None of us are going anywhere until we know what’s happened and can be sure it won’t happen again.”

Ryan winced slightly again, but nodded his head. “You’re right. Okay, tonight.”

Tana called through the opening, “I’m done here. Come on in.”

Commander Radkowski came into the bubble-segment, then Trevor, and finally Estrela, Estrela managing to be graceful even when she was hunched over like a caveman. With five in the segment, it was extremely crowded.

Now Ryan was the center of attention, and he fidgeted.

“Something you said,” Tana remarked casually. “Right at the end. Do you remember it?”

“It’s kind of hazy,” Ryan said, but when Tana gave him a sharp glance, he added, “Yes, I think so.”

Tana looked over to Commander Radkowski, hoping he would help, but he didn’t seem ready to take over the questioning. “Only three of us can fit on the ship, was that what you said?”

Ryan nodded, and when everybody was silent, looking at him, he cleared his throat. “Well, it’s a small ship.” Nobody said anything. “I did tell the commander.”

Tana turned and looked at Commander Radkowski. “You knew this, and you kept it from us?”

“I—well, it seemed a good idea at the time.”

“You’re saying, if we do make it all the way to the pole, only three of us can go home? And you didn’t tell us?” She turned to Estrela. “And you?”

Estrela looked away. “It is our ship. I know the specifications.”

Tana looked at Trevor. He shook his head mutely. “So, the only ones who didn’t know that two of us have to die were the nigger and the kid, is that right?”

She’d used the word hoping for some shock value, and it seemed to work. Radkowski spread his hands out, and turned them palms up. “It’s not like that—”

“Really.” She crossed her arms. “Okay, explain it to me.”

“All I was thinking was, we get to the ship, anything can happen. We need to work as a team. We can’t have everybody worrying. And, besides, who knows? It’s a tough trek anyway, I can’t be sure everybody is going to make it. If two of us die—”

Tana widened her eyes dramatically. “You’re saying that you were actually planning for two of us to die on the road?”

“No! Not that at all! I just meant—” Radkowski lowered his head. “I just thought that if we went, at least three of us could be saved.”

“Or maybe we could fix the ship so it could launch four,” Ryan added. “I don’t know for sure that it can’t.”

“Okay,” Tana said, and looked back at Commander Radkowski. “Now, tell me another thing. What were you and Estrela doing in the rockhopper an hour ago?”

Tana didn’t think that Radkowski could blush, but he did. He looked down at his feet. “Nothing.”

“Nothing?” She looked at Estrela as she said it. Estrela looked back imperturbably, her head cocked slightly to the side. “You must have been doing something.”

“She wanted to talk to me.”

“Really? In private? About what?” She was still looking at Estrela, and Estrela’s slight hint of a smile told her more than she wanted to know.

Radkowski said, almost mumbling, “I should have realized she would know how big the ship was.” He looked up at her. “Nothing happened. She just wanted to talk to me.”

When Trevor’s broadcast had gone out, it had taken almost ten minutes for Radkowski to get to Ryan. It shouldn’t have taken him two.

They must have been doing something. Tana had a very good guess as to what.

The mood the next morning was subdued. Commander Radkowski told Trevor Whitman that it was time for him to practice driving the dirt-rovers, and sent Estrela to supervise him. Apparently Trevor’s reaction to the episode of anoxia had met some threshold of the commander’s approval. Or perhaps Ryan’s encounter with anoxia had impressed the commander with the fact that a crew member could be incapacitated at any time, and he might need the help of any of the crew, even Trevor.

Ryan, meanwhile, had finished analyzing the failure of the zirconia electrolysis unit in his suit. It was a replication, in miniature, of the same problem that had attacked the Dulcinea . The oxygen partial-pressure sensors had been suffused by sulfur radicals, and both the primary and backup sensor gave a false reading of oxygen overpressure. As a result, the feedback mechanism in the suit had turned down the oxygen production rate, until the gas mixture that Ryan had been breathing was nearly depleted of oxygen.

An overnight thermal bake-out of each of the sensors should be sufficient to clear away the accumulation before it reached a dangerous threshold. It would be best to do it every night. To be safe, Ryan changed the parameters in the oxygen control software so that if an apparent excess of oxygen occurred, the suit’s computer would keep oxygen production going, rather than cut it to zero. Finally, he suggested that when they were on the surface, everybody should run a manual oxygen level check on their suits twice a day—the manual system used a different sensor that should be immune from the problem—and they should swap out sensor elements if they saw any sign of trouble.