Tithonium Chasma, Mars
Sol 5637: 1330 hours MMT
It was, Garroway thought, one of the oddest-looking marches in the annals of military history…the Mars cat, a bug-faced, tracked monstrosity piled high with stores and armored Marines, grinding along at the pace of a man’s walk and dragging behind it in a swirling cloud of dust a flat sled similarly loaded down with men and supplies.
The sled was the brainchild of Gunnery Sergeant Knox and Staff Sergeant Ostrowsky, who’d suggested the idea as a way of beating some unpleasant facts of life. The Mars cat was designed to carry six to eight people comfortably, but experiment demonstrated that sixteen could be jammed in with considerable crowding, a crowding made worse by the fact that none of the people aboard would remove their armor during the trek. Six or eight more at a time could ride on top of the crawler, clinging to plastic straps rigged from cargo-handling grips.
That left at least four more who would have to walk…and anyone moving on foot would drastically slow the cat from its usual fifteen to thirty kilometers per hour down to the two to three kph that could be expected of a human in full armor trudging along through the sand. At one point, during the planning before they’d left Heinlein Station, Garroway had been convinced that he was going to have to leave at least four of the Marines behind, simply because they couldn’t afford to crawl all the way to Candor at the speed a man could walk.
His two senior NCOs had suggested an alternative, however. A number of carbaluminum pipes—sections for the microwave relay mast that was to have been built at Heinlein Station in the near future—were stored outside the hab. The interior walls of the hab were made of foamboard, a lightweight composite-material used extensively in the cyclers and other MST-derived habs and spacecraft for interior fittings. By wiring sheets of foamboard cut from the hab partitions to an X-framed rectangle of carbaluminum piping, a team of Marines had managed to jury-rig a sled four meters long and three wide and attach it to the Mars cat by its rear tow cable.
“Now, in the old Marine Corps,” Knox had wisecracked, “we could go weeks at a time without food. Just thinking about those old MREs was enough to keep us going on spit and cusswords. But a tow-sled’ll let us carry enough food and water to see us through a couple of weeks, anyway, and it means the people outside can ride instead of walk.” The sled would also carry some of their bulkier equipment—fuel-cell-powered heaters, a rolled-up plastic pressure tent, and spare tanks of liquid oxygen and nitrogen.
The whole assembly looked bizarrely improbable once it was loaded and yoked to the cat’s winch. It was a compromise and, like all such, was not perfect. The drag sled slowed the cat considerably. Both because of the strain put on the Mars cat’s electric drive and for safety reasons, the cat would not be able to make much better than eight kilometers per hour, at the very best…and in rough terrain, the Marines outside would have to actually carry the sled like a huge canoe, portaging their way across the steepest or roughest stretches.
Nor could they travel a full twenty-four and a half hours a day. The period of the Martian night between midnight and dawn was far too cold for Marines to remain outside for more than two or three hours at a time, nor could the cat’s engines take the sustained punishment of round-the-clock travel with that kind of load. They were going to have to stop and camp for at least six hours each night while the cat’s fuel-cells recharged, and the people riding outside would all have to be cycled through the cat’s interior every couple of hours in order to get warm and to recharge their suits’ batteries.
They’d made only fifteen kilometers that first day, traveling southeast to pick up the opening in the encircling chasma walls that would give entrance to an extremely narrow and steep-sided canyon. According to maps found aboard the Mars cat, this was where the wider portion of Tithonium was squeezed down to a slender rille—actually a chain of deep fault-collapse craters puncturing the surface in a straight line all the way to the broad expanses of Candor Chasma, some 450 kilometers to the east.
They’d not set off, however, until a scant two hours before sunset, and moving at a slow and painful crawl, they’d managed about ten kilometers before the sun set. The Martian night swept down the valley with astonishing swiftness, the sky fading from pink to orange to deepest, star-strewn black within the space of a couple of minutes. The outside temperature began plummeting as well, from minus five centigrade to minus forty-five in the first three hours after sunset.
With nightfall, they kept going…but their speed was reduced even further. Garroway didn’t want the cat to show lights, not with the very real possibility of a UN air search by lobber, and the two tiny moons shed almost no illumination on the dark desert floor. Marines took turns walking ahead of the Mars cat, scouting out obstacles like craters or boulders and slowly guiding the vehicle through the night practically step by step.
And they were still on the flat and sandy floor of the chasma; their progress would be slower still once they entered the rougher terrain of the canyon proper.
At some point around local midnight, Garroway had called a halt, set the watches, and let the party hunker down for a restless night. At the very best, at this rate of travel, Garroway estimated that they could make the passage from Heinlein Station to Mars Prime in four to five days…if they could average ninety miles per day—almost 150 kilometers—across almost four hundred miles.
He knew better than to expect that kind of average, however. Given the fact that they faced unpredictably rough terrain and the likelihood of things breaking down or simply taking longer than expected, he figured they would be lucky if they managed something on the order of ten to twelve days instead, and a much longer time was distinctly possible. Water was going to be a headache, with food and air nearly as bad. They were carrying as much extra water as could be held in a pair of large, pressurized drums, plus enough readymeal packets to last twenty-eight people for twenty days. The air re-circulators both in the cat’s cabin and in their suit PLSS backpacks would extend their breathing time, but they would need occasional recharges of liquid oxygen and nitrogen to make up for the unavoidable loss each time an airlock was opened or a helmet was removed. Garroway’s best back-of-the-envelope calculation said…twenty to twenty-five days, depending on their exertion. If they didn’t make it in that time…well, he could always call for help. That meant surrender, however, an option he was not willing to consider.
Not yet.
During the drive out from Heinlein Station, Garroway, King, and Knox had worked out a rotation schedule for the twelve people outside. Each night after they stopped, every person in the party would spend a two-hour security watch outside, the ones outside exchanging with the ones inside. It looked like no one was going to be getting much sleep on this trek, not with everyone taking a turn freezing in the desert each night.
Garroway had insisted that both he and King take their turns outside with the rest, and he volunteered for the first watch. Alexander had volunteered himself and the other two scientists too, but Garroway had turned him down. Marine Corps armor was designed to stand up to the horrors of the NBC battlefield and, with adequate power, could handle life support for literally days on end. The three scientists were wearing lightweight EVA suits with much weaker heaters and power units, and he didn’t want to risk losing the civilians in his charge.
The Marine armor should be able to take the cold, though he had plenty of reason to question that the first night, as he stomped around outside, trying to stay warm in the pitch-black of the frigid Martian night. Class-One armor was rated at sixty below for four hours, but as far as he knew, no one had tested it yet at lower temperatures. He would have his people stick with two-hour watches, at least for now.
Garroway had a lot of time to think, he found, walking around on the desert with the other outside Marines, trying to keep his feet warm as his suit’s heaters battled the frigid cold. No one spoke. They were officially on radio silence, though everyone had cables and jacks that would let them hard-wire into one another’s intercoms if they wanted to chat. There didn’t seem to be much to talk about, however.
When his watch had ended at last, he’d limped inside, found a place to wedge in between two other Marines, and fallen into an exhausted and fitful sleep.