Fortunately, Celine had a practical task to occupy her mind. She had been told to search the derelict for a dozen of a particular type of bonding clamp, needed in the orbiters, and she had located a whole cabinet of them in the central supply room of ISS-2. Now she was heading back through the desolate corridors. The previous two days had not hardened her to the sight of the frozen corpses, but she knew where they were and she had learned not to look at them.
At the open airlock she paused. In front of her, framed against the backdrop of a sunlit Earth, hung the Schiaparelli. It had been home for so long, the very idea of leaving it was frightening. To leave it in one of those - she glanced to her right, at the tiny, vulnerable orbiters — was doubly daunting. The interiors, even with the padded seats pulled out, were impossibly small. They were definitely one-person ships.
If everything went well, Lewis and Clark — Reza Armani’s off-the-cuff names for the twin orbiters had stuck — would return to a torn and battered planet, whose peculiar cloud patterns and high dust clouds were evidence of the physical trauma that the world had suffered. What would the crew find when they landed? The radio signals remained sparse and weak, with some countries and continents totally silent. The Schiaparelli had sent calls for help and information on all frequencies. It had received not a word or a beep in reply.
Celine floated her way across to Clark, the nearer orbiter. She confirmed that the clamps were the right size and style to attach the hammocks to the walls, and performed the simple installation. The hammocks were tough, made of Mars tent materials that by good fortune had neither been landed on Mars nor discarded before the return trip. Without seats, hammocks would be the crew’s only cushion against the high accelerations of reentry.
Celine tested that the bonds would hold for body loads up to thirty gees. Beyond that, humans would not survive even if the clamps could. She moved across to Lewis and performed the same task of installation. Then she headed to the home ship — home, at least, for another few hours — and passed through the Schiaparelli’s airlock. She removed her suit, rubbed her itching eyes, and floated on to the main cabin.
The other crew members were already there. Zoe gave Celine an inquiring glance, and she nodded.
“I found them. They fit.”
“Good. Jenny?”
Jenny Kopal was crouched over a diagnostic pad. She shrugged. “I can only debug to a point using simulated inputs. According to every test routine that I have, the chips we put into the orbiters from this ship will perform identically to the dead ones they replaced. I loaded them all from the general program library for single-stage orbiters. But you know what they say. No matter how much testing you do, every program always has one bug left in it.”
“Let’s hope it’s a bug we don’t encounter before we’re down on Earth.” Zoe leaned back. “Alta?”
“I don’t know.” Alta paused and thought for thirty seconds. “I guess the orbiters are as ready as they’ll ever be. I’m still worried about center-of-mass changes because of the unusual loading. But I think any one of us could fly one.”
“Coming from a pessimist like you, I take that as a rave report. All right.” Zoe leaned back. “It’s showtime again, folks. And here is the plan. Lewis will perform reentry first. As you know, it can only hold three people. Those three are going to be Zoe Nash, Ludwig Holter, and Alta Mclntosh-Mohammad. I will pilot Lewis. Then, unless someone wants to stay up here and wait for the next shuttle up from Earth” — Zoe smiled at her joke, but no one else did — “Clark will take Reza Armani, Jenny Kopal, Celine Tanaka, and Wilmer Oldfield. Reza will pilot Clark.
“Lewis will send telemetry back here all the time during reentry, except when it goes through the period of radio blackout. I believe the increased mass load on the second reentry will be more than compensated for by the opportunity to fine-tune Clark’s control parameters using the data from Lewis. Any questions so far?”
There was silence. It was obvious to Celine, as it must be to all of the others, that Zoe had included factors other than mass balance in deciding the complement of the two crews. She had placed the people pairs, Jenny/Reza, Alta/Ludwig, and Celine/Wilmer, on the same orbiter as each other. To some, that might suggest sentiment on Zoe’s part. To a worrywart like Celine, it said that the reentry dangers were more than Zoe was willing to admit. She was offering them a chance to die as the couples that they had become.
“Now there is the question of where,” Zoe went on. “Where should we aim to land? I think we can make one decision very easily: we avoid the Southern Hemisphere. We’ve picked up hardly a radio signal from there. Also, if we are off in our final along-track position, the Southern Hemisphere offers a higher chance of landing in water. The orbiters are not designed for an ocean splashdown, and even if they were I don’t feel like a thousand-mile swim.
“The majority of the radio signals we have received come from North America, with considerably more from the northern states than the southern, and more from the east than the west. So north is good, and east is good. We are in a low inclination orbit, so a very high latitude touchdown is not possible. I think we can reach forty degrees north, and I propose that we try to do so. I will aim to make Lewis’s landing close to the fortieth parallel, near the eastern seaboard but at least a hundred miles from the Atlantic Ocean. Normally the orbiters can land on a dime, but we need a margin of error. I will not try to specify a final landing location now, because we have not been able to obtain a clear picture of surface conditions. We’ll see what we have available when we get there. An airport would be nice, but any decent highway will do at a pinch. Naturally, once Lewis is down we’ll send a message telling Clark what to aim for or what to avoid. We’ve been over all this before, in smaller groups. But does anybody have a question or a comment?”
She waited a few moments, and went on: “Then the only remaining question is, when?
“We will do one final start-to-finish checkout of everything, which ought to take no more than a few hours. After that, Lewis will take the next available reentry window. The main requirements are that we have a daytime landing — it’s currently night in North America — and that Lewis has line-of-sight communications with those of you who are still here on the Schiaparelli. That means there has to be some orbit matching, but Jenny already did those calculations. Once Lewis is down, we can decide the schedule for Clark based on our experience. Any other questions?”
“I have been thinking.”
To Celine’s surprise, the speaker was Wilmer. He almost never contributed to group meetings. Quite often, he didn’t seem to be listening. But he was. He would go away, brood over what he had heard, and return to offer crucial suggestions or devastating criticisms.
Celine decided that Wilmer understood, better than she had, the nature of this particular meeting. There would be no chance for later discussions. This was it, the final meeting of the Mars expedition until they were all once more on Earth.
“All right, Wilmer,” Zoe said. “What’s your worry?”
He put his hand up to scratch the top of his bald head — a habit that looked ludicrous and that Celine had not been able to change. It gave him a permanent and ugly red patch. “This is a suggestion, not a worry. You speak of a line-of-sight requirement for communications, and I assume that you mean radio signals. But I think we should also track the descent of the Lewis visually, using the biggest scope on the Schiaparelli.”