Marc bristled. “This vent thing is making me rethink—”
“Geology, we have plenty,” Viktor rumbled on. “A cold, dry desert with red rocks and ancient water erosion. Not much better than the Viking pictures.”
Raoul said reasonably, “Julia, this is an old argument. Of course the Viking landing spots were purposely picked to be flat and boring and dry. Not the best places to look for life, but the safest to land. Now we know Viking could never, anywhere on Mars, have found microbes that retreated below ground when the seas and lakes dried up.”
“Over a billion years ago, I estimate,” Marc put in. “Maybe two.”
“We don’t know that those fossils are the whole story,” she said. “Stromatolites on Earth were the beginning, not the end, of evolution.”
Viktor called, “Ah, your new version of the old Sagan argument. While Viking was licking dust into the biology experiments, an undetected Martian giraffe walked by on the other side of the lander.”
Julia bristled but did not show it. Sometimes she wondered if Viktor had to occasionally show that he was not an automatic ally just because he was her husband. “You know I’m not really expecting Earth-type animals, but I’m keeping an open mind about other possibilities.”
Marc blinked. “You really think we’ll find something alive in that vent?”
“I certainly think we should look. We’re probably never going to be here again, any of us.” She looked around at them. “Right?”
This they had never discussed. In some ways the surface mission was the safest part of the expedition. Their coming launch was risky, and the aerobraking into Earth’s atmosphere would be more tricky than their rattling deceleration in the comparatively soft Martian atmosphere. Still, the sheer wearing-down of laboring in the harsh, cold dryness of Mars had sobered them all somewhat. When they returned home—or if—they would be wealthy, famous. Would they do this again?
“I might come back,” Marc said.
“I, too,” Raoul said, though without the conviction he had before.
“I am honest enough to say that I will not.” Viktor grinned at them. “I will have a wealthy wife, remember.”
They all laughed, maybe more than the joke deserved. Warm chuckles, after a filling meal, served to remind them that they were a team, closer than any contracts could bring them. This was a highly public, commercial enterprise, of course, but none of it would work without a high degree of cooperation and intuitive synchronization.
Julia looked at the others, their clothes emblazoned with the logos of mission sponsors, all quite soiled. Through the Consortium’s endless marketing they had endorsed a staggering array of products. But this grand adventure was not itself a product. They were destined to be a team forever, no matter what happened in the future.
Marc said, “The metals, that’s why I’m here. They’ll be more important than fossil life, in the long run.”
“Not so,” said Viktor. “Asteroid belt is where we will go for metals. Mars is where we build base to mine the asteroids. Going to be much cheaper to boost from here than anyplace else.”
Raoul emerged from the pint-sized galley toting his coffee. It was in a large mug, incongruously solid ceramic, in sharp contrast to the rest of their lightweight plastic dishes. Katherine had hand painted it with flowers for him early in their courtship, and he had toted it with him as part of his personal mass allowance. Only he ever used it, of course. He sipped and scowled. “So we’ve just wasted our time looking for metals on Mars? Suits me. If we jettisoned all of the damned ore samples there’d even be room to breathe on the return.”
Julia said, “We shouldn’t be limited by what we think we know. Or what we think we’re going to find. A biologist named Lovelock pointed out, well before the Viking landings, that there was probably no life because the atmosphere was in chemical equilibrium with the surface. Spectroscopy from Earth showed plainly that there was nothing in it but boring CO2 and nitrogen.”
“Good argument, you have to admit,” Marc said.
“But it assumed life would use the atmosphere as its buffering chemical medium. Unlikely, because it’s so thin…so, what about life that has long abandoned the atmosphere?”
“How could it do that?” Marc looked puzzled.
“Life may be holding on deep underground. Using emissions of, say, hydrogen sulfide, as an energy source. That’s just a guess, of course, but we’ll never know if we don’t look. And we can’t do that except through the vents.”
“Good theory, but until we get the ERV fixed, there’s no use talking about what else we could be doing.” Raoul had his set look, jaw solid and eyes narrowed, announcing his position.
They had been through all of this before, of course. In the course of two years you get to know each other’s views pretty damn well.
Life at Zubrin Base—their unofficial name, in honor of the hot-eyed founder of the Mars Society—settled into a dull routine of ERV repair, machine shop work, and normal maintenance. Through the long hours Julia dreamed of the vent, heard the clock ticking in her head, and seethed inwardly.
After a frustrating morning of hanging around doing trivial gofer tasks for the repair effort, she headed for the greenhouse. The task of trying to grow food on Mars was hers. A colony would need to produce much of its own calories to avoid the kinds of supply problems faced by Napoleon’s army in Russia.
One of the best-kept secrets of the space station age was that the astronauts had not been living in a closed system. Far from being self-sufficient, Mir, Skylab, and the International Space Station had been just end points of Earth’s delivery system. Oxygen, food, and water were ferried up, depleted tanks were returned to Earth, and garbage was just dumped, to eventually burn up on reentry into the atmosphere.
It fell to private, Earth-based experiments to start work on the problems of recycling within closed systems. The Biosphere II project in the Arizona desert had become a legendary cautionary tale by the time Julia joined the NASA astronaut corps. That two-year experiment in the 1990s had hardly been a success—everyone lost weight, medical emergencies led two people to be evacuated, and there was a mysterious loss of oxygen from the system.
Finally, fresh air had to be pumped inside to save lives. The culprit turned out to be the slow chemical curing of the tons of concrete in the buildings, binding oxygen within the walls of the structure. It was a complete surprise to the mission designers.
Closed life-support systems were still not practicable. Even on Mars, the crew used the local atmosphere to chemically fabricate their oxygen and water. That’s what the ERV’s chemical plant had been doing all this time, using hydrogen brought from Earth to produce methane and oxygen. When burned as Rover fuel, it produced waste carbon dioxide and precious water. What had been in most short supply was hydrogen. But since Marc’s discovery of the frozen pingos, future missions could use indigenous Mars hydrogen from water.
Food was still an unsolved problem. Julia was working on a series of trials proposed by NASA and contracted with Axelrod, following on years of research by earnest nutritionists.
They had long ago established that in the long term, the colonists’ diet would be vegetarian. It made sense to eat plant protein directly, rather than lose 90 percent of its energy by passing it through an animal first. So early on, the Consortium crew had set up an inflated plastic greenhouse next to the hab. They covered it with recycled parachute material, scavenged from their landing, for extra UV protection for the plastic.
In an inspired move, Raoul had hooked up the air-exhaust vent from the hab to the intake of the greenhouse. Warm air enriched with C02 for photosynthesis, but with enough oxygen for plant respiration, flowed into the greenhouse, displacing the arid CO2 of Mars. The heat helped to keep the plants from freezing overnight.
After about two months, Julia’s plants were growing strongly, and her tests showed that the oxygen content in the greenhouse was more than adequate for humans to breathe.
The hab’s air system provided clean, moisturized air at 1/3 Earth sea level pressure, like living on a mountaintop at 23,000 feet but with plenty of oxygen. So they didn’t feel altitude effects, and had lots of energy, but the air tasted flat.
When Raoul opened up the return path for the air, they clustered around the duct in the hab and waited. That first whiff of greenhouse air proved to be a great morale boost for the crew, their first non-canned air in over eight months. Greenhouse air was processed through plants, and it carried with it the fresh smell of Earth.
Never much of a gardener at home, Julia came to prize her time in the greenhouse. Inside she could work without helmet or gloves. With just a skin suit on, she could shuck her Marswear insulated outer garments.
What she enjoyed best was looking through the rows of plants, through the clear side walls to the dusty red landscape beyond. She could imagine then that Mars was a hospitable planet, and that humans would someday come here to stay.
She’d shared these feelings in a brief missive to the Mars Society, and had been inundated with e-mail from would-be colonists. The idea of growing food on Mars was immensely symbolic as well as practical.
