As Titan’s long night drew to a close, Benacerraf and Rosenberg prepared for their expedition to El Dorado, the crater on Cronos, in search of kerogen.
Working in the scuffed-up gumbo around the orbiter, they prepared to load their sleds. The sleds — six feet long, two wide — were improvised from Command Module hull sections, and had a covering of parachute canvas. Right now the sleds were configured to slide across gumbo; later, on Cronos, Rosenberg expected them to face a surface of raw ice, so they were carrying runners made from steel struts.
The equipment pile was dauntingly high.
Benacerraf bent and started to haul gear up onto her sled, the heaviest stuff at the bottom. The bulky items responded oddly in the low gravity; she had to haul to get them moving, but then inertia took over and she had to guide them, rather than lower them, into the right place on her sled. She checked each item off on the ring-bound checklist she had strapped to her wrist.
The first item was the S-band radio they would use to navigate, triangulating off Cassini. Next came a light, high-density power cell, cannibalized from the skimmer, and bottles of oxygen and hydrogen to feed it. Every time they stopped and made camp they would have to recharge the batteries in their EMUs; and the power cells would have to keep them warm during the “nights.” There were spare lith canisters for scrubbing carbon dioxide from their suits’ circulation: precious, irreplaceable. Benacerraf packed a tent, the flimsy hemispherical affair taken from the skimmer.
There were skis, improvised from pieces of Jitterbug’s frame. A length of rope. A small bag of tools. Spare parts for the gadgets that would have to keep them alive, Clancy clamps and silver bell wires. Their snow shovels. A medical kit, assembled by Rosenberg: cream for their hands and Benacerraf’s lips, powder and gel and antiseptic cream for skin afflictions and wounds, plasters for blisters, cuts and rubbed raw patches of skin, drugs and painkillers, Lomotil for diarrhea. They had pethidine and morphine — opium derivatives — and various forceps, scalpels, hypodermics and stitching needles.
The rations were based heavily on what was left of the dehydrated stock they’d brought from Earth. Benacerraf hated to exhaust these final supplies, making them almost totally dependent on the CELSS farm thereafter, but Rosenberg insisted. Their diet; he said, was crucial. He had calculated they would each need five thousand calories per day. He showed her how the diet he planned would be high in fats — nearly sixty percent — whereas their normal diet was more than half carbohydrates.
When the load was assembled, Benacerraf had trouble closing her canvas over the top of it. She had to repack a couple of times, trying to balance the mass of the load and to give it all an even shape.
At last she had it tied up with rope. The sled, bound together, was the size and shape of a coffin. Benacerraf hoped that wasn’t an omen. When she was done, she felt exhausted already: she was hot, her breath pumping, her limbs aching from fighting the suit’s stiffness.
Rosenberg estimated that each of their sleds, on Earth, would weigh more than five hundred pounds: the best part of half a ton. Here, gravity reduced that to seventy pounds.
Five stone, to be hauled across a hundred and twenty miles, in full EVA suits.
She pulled her harness around her torso.
The sled harness was improvised from Apollo seat restraints and Shuttle orbiter foot loops. There was a bandolier set of straps she lifted over her shoulders and chest, and a belt around her waist. There was a buckle at the front of her chest, relatively easy for suited fingers to reach and manipulate, and adjustable straps on the shoulders. The most difficult thing about designing the harnesses had been ensuring they would not foul any of her suit’s essential equipment, like the control panel on her chest, and the umbilicals carrying oxygen and water from her PLSS.
She leaned forward, and let the straps take her weight. She adjusted the shoulder straps until they felt comfortable through the layers of her suit.
She thought it was ominous that her sled didn’t move at all in response to her body weight.
Benacerraf looked back, one last time, at Tartarus Base.
Discovery looked like a DC-10 that had come down in the ice. But her white upper surfaces were uniformly coated with tholin, obscuring what was left of the colorful Stars-and-Stripes and NASA logos. The big windows on the flight deck, streaked by tholin, showed no lights; the interior of the orbiter was black. All the non-essential systems in the orbiter had been shut down, so they could save every last erg from the Topaz reactors while they were away. And that meant almost everything, save the heating and the nutrient, lighting and air supply for the CELSS farm. She played her helmet lamp over the orbiter’s flanks, which glistened with gumbo; it looked as if Titan was drawing Discovery gradually into its icy belly.
She stood beside Rosenberg.
“You remember to cancel the newspapers?”
“Yes,” he said gently.
“Let’s get out of here.”
She turned her face resolutely away from the orbiter. Her helmet lamp cast a ghostly ellipse of white light on an anonymous patch of gumbo. The greater darkness beyond, which they must penetrate, was concealed.
She leaned into her traces, with her full body weight. Her snow-shoes pawed at the gumbo. The harness rubbed at her shoulders and hips.
The sled, stuck to the gumbo, wouldn’t move.
She straightened up and looked back. There was a hummock in the gumbo, just in front of her sled, to its right. She was catching on that.
She turned again, and leaned into the harness with her left shoulder. She jerked at the harness, throwing her weight into it, trying to keep her footing in the tholin.
She felt something give. She almost stumbled over.
She looked again. The sled had moved forward, a couple of feet.
Rosenberg whooped. “Way to go, Paula.”
“Sure,” she said. She’d covered two feet, out of a hundred miles.
She leaned into the harness again, and jerked. The sled moved forward, coming free of the sticky gumbo with a slurping noise.
She pawed at the slush, trying to keep a steady rhythm. It got easier once she’d started, as long as she maintained the momentum of the sled. Whenever she stopped, she could feel the sled sink back into the welcoming mud. Still, her movement was jerky and uneven, stop-start.
Soon it felt as if the canvas band around her stomach was crushing her insides against her backbone.
It would be a comfort to think the sleds would get lighter as they proceeded, as the two of them ate up the food. But Rosenberg was insisting that they retrieve every piece of waste they produced — every drop of piss, every dump — and haul it back to feed the hungry CELSS farm. It made sense. But the thought of hauling bags of her own shit for a hundred miles across the surface of Titan did not chime with her romantic dreams of what exploring, an alien planet should be like.
A wind blew up. It came straight in her face, heavy and dense, and the gumbo rippled sluggishly before her. Her suit temperature dropped as a wind chill set in; she could feel the hot diamonds of her heaters trying to restore the balance.
Rosenberg called, “We have to expect a lot of this. That wind is a katabatic. A gravity-fed wind, blowing downhill, out of the heart of Cronos—”
“Shut up, Rosenberg.”
She bent her head and pushed at the gumbo, the harness digging at her shoulders and hips, Rosenberg’s katabatic wind shoving against her chest, driving onwards.
The light level rose slowly. A burnt orange glow seeped uniformly into the sky.