“You’re all under a lot of pressure,” she said. “I know a lot of questions are being asked about the ability of NASA to deliver NERVA 2.”

“By who?”

She shrugged. “The press. Congress.”

“Yeah,” he said evenly, showing no resentment. “Well, hell, maybe there are questions to ask. You know, the program’s led by the Germans, from Huntsville. And they didn’t pick the design goal — which is two hundred thousand pounds of thrust for thirty minutes — because they knew they could build it; they chose the goal because that’s what we need for the Mars mission profile. They didn’t go through a lot of analysis to try to figure it out; they just started building toward it. It’s the way they’ve always worked. And it’s kind of hard to argue against their kind of record. But…”

“But you’re not so sure.”

He hesitated. “The truth is, the development schedule we’re working to was modeled on experience of chemical technology. Nuke stuff is different. I think they’re only just figuring out how different. And that’s even after we’ve eliminated a lot of nice-to-haves, like a deep throttling capability… I think maybe we’ve underestimated the schedule, here. We’re pushing too hard.”

Now a crew, in white protective gear, was moving into the cordoned-off zone, converging on the NERVA. York wondered vaguely if one of them was Mike. There was no way of knowing.

She stared at the inert NERVA 2, resentful. Thanks to that broken-down thing, I’m not going to see a trace of Mike for weeks now.

Bleeker had to leave her, to get on with his own work.

She watched the slow, painstaking demolition job for a few minutes, then she went back to the car and managed to fall asleep in the passenger seat.

When she awoke, the sun was well above the horizon, and the car was stuffy and hot. There was no sign of Mike. She found a bathroom, and left a note for Mike.

She drove herself back to L.A. Mission Elapsed Time [Day/Hr:Min:Sec] Plus 004/21:38:11

Daily execute packages were uploaded from Mission Control overnight as twenty feet of teleprinter output. The packages contained suggested time lines, and a few personal messages. York split up her portion of the list and put it into her ring binder, throwing away yesterday’s draft, and began to figure out how to follow the day through.

She looked down the list, searching first for time-critical items. Then she looked for stuff that would need advance setup and preparation, and items that weren’t solo, where she’d have to work with the others.

The execute package wasn’t so much a detailed time line, as the first generations of astronauts had had to follow, but a “shopping list” of objectives. Mission planning was a lot more laid-back, compared to the days when moonwalks had been choreographed down to the minute. The shopping list approach had evolved during the long-duration Skylab flights of the 1970s. York was relieved; she was a senior professional, after all — they all were — and she didn’t need her activities handheld by some remote roomful of experts down in Houston.

In her pocket, to help her with the timing, she carried a small personal alarm clock, a cute clockwork thing she’d picked up from a five-and-dime in a mall in Nassau Bay. Its crudity and lack of accuracy appealed to her, in the midst of all that high technology.

Her main objective for the day was going to be powering up the Ares Transfer-Orbit Science Platform. She drifted upward, along the cylindrical length of the Mission Module.

The Mission Module was based on the design of the Skylabs, which had been in use for more than a decade. Such was the lifting capacity of the Saturn VB that the Mission Module had been delivered to Earth orbit “dry” — carrying no fuel — and with interior partitions and equipment already fitted. The crew occupied what had been the hydrogen tank, all forty-eight feet of it, with its domed ceiling and floor. Hidden under the floor was the lox tank, much smaller, a cramped, squashed sphere. The lox tank was used to hold stores, and with its thicker walls it would serve as the crew’s storm shelter — shielding them from solar flares, if any blew up in the course of the mission.

The hydrogen tank was split into three levels by partitions of triangular metal mesh. York was wearing Dutch shoes, with V-flanges in the sole, to enable her to cling to either side of the floors. There was a fireman’s pole running down the middle of the workshop, and there were straps and guide ropes and harnesses everywhere.

The tank’s bottom level was “home” — the wardroom, sleep and waste compartments. The middle belt doubled as a command and control area, covering all of the spacecraft’s subsystems, environmental processes, and flight operations, and as an experiment and exercise area, with a running strip around the tank’s circular wall. The exercise machines, still in their launch configuration, were strapped against the pressure hull. And the top level, closest to the prow of the Ares cluster, was the Science Platform.

The whole module was something like a big engine room, York thought, with clunky tanks and storage boxes stuck to the curved walls, and cables and pipes running everywhere, under smooth covers of yellow plastic.

When she floated up into the science platform, it was like entering an octagonal cave. Bulky equipment racks and storage bays were fixed all around the curved hull. One side of the octagon served as a ceiling, broken by a couple of high-quality viewing ports — disks of darkness — and by small science-experiment airlocks, sturdy wheeled hatches like the doors of little safes. Everything was still in its place, stowed neatly away, still in the wrapper.

She pulled herself to the right-hand wall and locked her feet into a couple of stirrups. It was the display and control console: a long rack of switches, cathode-ray displays, and numeric and qwerty keypads. She closed switches and began booting up the science platform’s computers, then started to power up and check out the rest of the equipment.

As it started to come to life, the cramped little science station reminded her of some bespectacled kid’s bedroom laboratory; it was compact, miniature, kind of sweet.

Some of the experiments carried by Ares were part of long-term microgravity research programs. There were experiments in protein crystal growth, and the diffusion of bacteria in microgravity conditions, and a chunky arrangement called the heat pipe performance experiment, a dry engineering test of the diffusion of heat from hot spots on pipes and ducts in microgravity.

But Ares offered some special opportunities. There was a scheme to observe major solar events like spots and flares from the two widely separate vantage points of Ares and Earth, and so there was a whole bunch of instruments which would be directed at the sun: a coronagraph, a spectroheliograph, a spectrographic telescope. Since in flight the Ares cluster would keep itself aligned to point at the sun, to save boiloff, all the equipment was mounted in a pallet, which would be unfolded and held out from the body of the Mission Module, like a rearview mirror.

The setting up took longer than she expected. The computers, Hewlett-Packard minis, were slow. The models Ares was carrying were out-of-date: the design of the platform, already nearly a decade old, had become frozen around those customized, low-weight, low-power machines years before. Hewlett-Packard and the other computer suppliers had made a commitment to keep supporting NASA’s in-flight equipment as long as was necessary. But it was ironic that York was — in deep space, en route to Mars — having to make do and mend with technology which no self-respecting middle-sized savings and loan in Gary, Indiana, would put up with anymore.

And besides, microgravity was turning out to be a pain in the butt to work in. Anything that wasn’t tied down just floated away. It was easy enough to remember that for major pieces of equipment, but it also applied to her notebook, pens, pencils, handkerchief, and she wasted a lot of time chasing down elusive items of equipment. And she had to make a conscious effort to anchor herself — with foot stirrups, or by holding on to a rack surface, or by wrapping her legs around a strut — before she tried to move anything. Otherwise, every time she turned a switch on the control panel, the switch would just turn her back.