In orbit the entire assemblage of vehicles and human beings was effectively in zero gravity, weightless. Jamie felt his guts dropping away the instant the shuttle rocket engines cut off. His inner ears were telling him that he was falling, falling endlessly. Yet he could see that he was strapped firmly in his seat down in the crowded middeck compartment of the shuttle, jammed in with five technicians on their way to a week’s work. Their coveralls were stained and frayed from hard use; Jamie’s were so new there were still creases on his sleeves.

All the scientist-candidates had spent at least a few days in orbit during their years of training. Jamie had also flown three flights on the Vomit Comet, the big jet transport plane that simulated zero g by diving from high altitude, then pulling up into a long parabolic arc that produced about half a minute of gut-wrenching weightlessness. He knew what to expect and he did not panic. Still he could feel his stomach churning and his head going woozy.

Jamie felt all the classic symptoms of space adaptation syndrome as he followed the veteran technicians past the shuttle’s hatch, through the narrow metal chambers of the Mir, and into the more spacious receiving area of the huge shuttle tank. It was not like seasickness, not exactly. His head felt stuffy as his body fluids shifted within him, free of gravity’s pull. He felt slightly nauseous, disoriented, almost dizzy. As if he had come down with a heavy dose of flu.

Medical personnel took him in tow, literally, and after a perfunctory examination cheerfully pronounced him normal. They gave him a slow-release medication patch to stick behind his ear and told him that all the Mars scientists were assembling in the main briefing area. Jamie started to nod, found that the head motion made him feel as if he wanted to upchuck, and settled for asking directions to the main briefing area.

He knew enough to go slowly up the central passageway, pulling himself along easily on the ladder rungs that studded all four walls, like a swimmer working his way along the hull of a sunken ship. It was difficult to think of ceiling and floor when up and down had no objective meaning. Jamie began to think of the passageway as a deep well with metal walls that he was climbing, floating weightlessly as he made his way in dreamy slow motion toward the top.

"Ah, there you are! You made it."

Jamie turned at the sound of the voice behind him and instantly wished he hadn’t as his stomach lurched uneasily.

It was Tony Reed, smiling as if he had been born in zero gravity, gliding effortlessly along the passageway like a grinning dolphin.

Jamie tried to smile.

"Glad to see you here," Reed said, extending his hand as he rose to Jamie’s level, "even though you do look a bit green."

"I’ll adjust," Jamie said, hanging on to one ladder rung while his feet floated free.

"Of course you will. We’re all delighted that Brumado talked the powers that be into giving you the geology slot."

Reed started off along the passageway again and Jamie pushed against a rung to keep up with him. "I’m still kind of dazed… it all happened so fast."

With his slightly crooked smile Reed said, "You can thank Joanna for it. She led the revolt against Hoffman."

"Joanna did?"

"Yes. Got her father to support it, actually. She can be quite the little jaguar when she wants to be."

There were others gathering at the far end of the long passageway, Jamie saw. And more coming behind (below?) them.

Lowering his voice, Jamie asked, "You mean Joanna was the one who forced Hoffman out?"

"She was the ringleader. We all had something of a hand in it. Once it was clear that DiNardo was gone, we suddenly realized that we were facing two years locked up with that Austrian martinet."

"He wasn’t so bad," Jamie mumbled.

"Most of us thought he was, rather. And Joanna apparently wanted him off more than any of us." Reed’s expression turned canny. "Or perhaps she wanted you to be on with us. I feel rather jealous, you know."

Jamie bit back a reply. They were too close to the others now to continue the conversation. He wondered how much truth there was in Reed’s words and how much of what he said was joking exaggeration.

The scientists were not expected to do any work for the first few days in orbit; the mission planners had expected them to be suffering and useless for that long. But they could attend briefings. The psychologists even claimed that activities that required mental rather than physical exertion would take their minds off their queasiness.

Jamie followed Reed through a hatch set into the bulkhead that ended the long passageway. He found himself gliding weightlessly into a large open area, rising like a bubble into a cavernous chamber in the nose of the former propellant tank. The briefing center’s domelike interior had been painted with stripes of black and white that converged on the point of the nose cap. Jamie hovered in midair, blinked several times, and realized that the "wall" he had come through had become the "floor" of the briefing center.

The flat surface was studded with plastic foot loops, further defining it as the floor. The black and white stripes provided strong vertical orientation. With up and down clearly defined, Jamie felt somewhat better. He reached out a hand as he approached the curving wall and pushed himself lightly back toward the floor. Anyone can be an acrobat in zero gravity, Jamie realized. Or a ballet dancer.

Slowly sixteen queasy, faintly green scientists gathered on that floor, anchoring their boots in the foot loops, their bodies hunched forward slightly in what was called "the zero-g crouch," their arms floating weightlessly up around chest height. Like polyps attached to the sea bottom, Jamie thought, weaving back and forth in the currents.

Dr. Li, clad in sky-blue coveralls with a stiff collar, stood on a slightly elevated platform at one side of the circular area. Not that he needed a platform, with his height. In contrast, most of the astronauts and cosmonauts gathered around him were quite short, Jamie saw; American or Russian, most of the fliers had the sawed-off physiques of fighter pilots.

Li looked pretty green himself, Jamie thought. The expedition commander waited a few moments for the assembled scientists to quiet down. Then he began, in his thin, high-pitched voice, "Believe it or not, we are now going through the most difficult part of our mission."

"I believe it!" someone muttered loud enough for everyone to hear and laugh at.

"In a few days more we will become accustomed to microgravity. In a few weeks more we will transfer to Mars spacecraft, which will eventually be spun up to simulate terrestrial gravity — and then de-spun as we approach Mars to acclimate us to Martian level of gravity."

Li looked pallid, drawn. Yet his face was puffier than it had been on Earth, his eyes seemed narrower. It struck Jamie that if they maintained zero g all the way to Mars they could save tons of food; no one would have much of an appetite. But we’d be in no condition to work on the surface once we got there.

"In a moment I will introduce our astronauts and cosmonauts to you. Then we will break up into smaller groups to become better acquainted. However, first I wish to remind you of a very sensitive and very important point, a subject that you have all discussed individually with the physicians and psychologists. It is mentioned, but only briefly, in your mission regulations books."

Li took a deep breath. "I refer to the subject of sex."

Everyone took a breath, like a collective sigh wafting through the group. Jamie could not see the faces of the other scientists without turning his head — which would bring on a wave of nausea. But the astronauts and cosmonauts were facing the scientists, and Jamie saw a couple of grins and even a frown.