Meanwhile he was getting used to microgravity. When he put his hands out he found he could make himself spin in the air, like a sycamore seed.

The feeling was wonderful. He felt like laughing.

Rolf Donnelly was at the center of a web of information, argument, and extrapolation, a web that swept across the country: from the Marshall people in Alabama, to Rockwell at Downey, with its intimate understanding of Apollo-N, to Boeing, which was doing some hard analysis of the telemetry data from its balky S-IC first stage, to a dozen or more groups in the MOCR, and the back rooms, and in Building 45. He imagined phone lines singing as the ground controllers and the crew worked through comprehensive checklists covering the propulsion systems, gimbal systems, gyros, computers, life support, spreading their findings out across the country.

Slowly the answers were coming in, filtered and assembled by Indigo Team.

The S-IC pogo was, it seemed, due to an unexpected resonance mode of the Saturn VN, the new Saturn/NERVA stack. It should have been anticipated by somebody, long before the stack was assembled for launch.

What the hell happened to quality control on this program? Donnelly understood how everyone involved was under great time pressure. But still: It won’t fail because of me. It sounded like some assholes at Boeing or Marshall had kind of forgotten that motto; and there couldn’t have been a worse mission to forget it on.

Anyhow, what to do?

The logical thing to do was just to abort, to bring the crew home. After all, the spacecraft hadn’t been designed for the treatment it had received during launch.

But Donnelly had started out as a physicist, and he remained, at heart, a scientist. Never mind the mission rules, or the politics: what does the data tell you?

The failure had been Saturn’s, not NERVA’s. And Saturn had been discarded, and the Booster people were assuring him that everything was fine, that the pogoing hadn’t hurt the S-NB nearly as badly as it might have. Besides, the S-NB had already worked — and well, given the situation it had found itself in when it had tried to find its flight path. Meanwhile, the other subsystem teams were continuing to click off the items in their checklists as sweet as honey.

Behind him, in Management Row and the Viewing Room, there were more little clusters of senior management, worrying themselves to death. There was Bert Seger, with the directors of Flight Operations and Crew Operations; and behind Seger, beyond the Viewing Room glass, Donnelly recognized Tim Josephson.

The strategic importance of the flight was obvious to everyone: NERVA’s nuclear technology had to succeed — it had to be demonstrably safe — because if public hostility wasn’t assuaged, and if the nuclear program was cut back or even terminated altogether, well, hell, you could kiss good-bye to Mars.