Gravity. Tess Gerritsen

scientists outside NASA.

      This message was from SeaScience in La Jolla, California.

      To: Dr William Haning, ISS Bioscience

      Sender: Helen Koenig, Principal Investigator

      Re: Experiment CCU#23 (Archaeon Cell Culture)

      Message: Our most recent downlinked data indicates rapid and unexpected increase in cell culture mass. Please confirm with your onboard micro mass measurement device.

      Another jiggle-the-handle request, he thought wearily. Many of the orbital experiments were controlled by commands from scientists on the ground. Data was recorded within the various lab racks, using video or automatic sampling devices, and the results downlinked directly to researchers on earth. With all the sophisticated equipment aboard ISS, there were bound to be occasional glitches. That’s the real reason humans were needed up here—to troubleshoot the temperamental electronics.

      He called up the file for CCU#23 on the payloads computer and reviewed the protocol. The cells in the culture were Archaeons, bacterialike marine organisms collected from deep-sea thermal vents. They were harmless to humans.

      He floated across the lab to the cell culture unit and slipped his stockinged feet into the holding stirrups to maintain his position. The unit was a box-shaped device with its own fluid-handling and delivery system to continuously perfuse two dozen cell cultures and tissue specimens. Most of the experiments were completely self-contained and without need of human intervention. In his four weeks aboard ISS, Bill had only once laid eyes on the tube #23.

      He pulled open the cell specimen chamber tray. Inside were twenty-four culture tubes arrayed around the periphery of the unit. He identified #23 and removed it from the tray.

      At once he was alarmed. The cap appeared to be bulging out, as though under pressure. Instead of a slightly turbid liquid, which was what he’d expected to see, the contents was a vivid blue-green. He tipped the tube upside down, and the culture did not shift. It was no longer liquid, but thickly viscous.

      He calibrated the micro mass measurement device and slipped the tube into the specimen slot. A moment later, the data appeared on the screen.

      Something is very wrong, he thought. There has been some sort of contamination. Either the original sample of cells was not pure, or another organism has found its way into the tube and has destroyed the primary culture.

      He typed out his response to Dr Koenig:

      …Your downlinked data confirmed. Culture appears drastically altered. It is no longer liquid, but seems to be a gelatinous mass, bright, almost neon blue-green. Must consider the possibility of contamination…

      He paused. There was another possibility: the effect of microgravity. On earth, tissue cultures tended to grow in flat sheets, expanding in only two dimensions across the surface of their containers. In the weightlessness of space, freed from the effects of gravity, those same cultures behaved differently. They grew in three dimensions, taking on shapes they never could on earth.

      What if #23 was not contaminated? What if this was simply how Archaeons behaved without gravity to keep them in check?

      Almost immediately he discarded that notion. These changes were too drastic. Weightlessness alone could not have turned a single-celled organism into this startling green mass.

      He typed:

      …Will return a sample of culture #23 to you on next shuttle flight. Please advise if you have further instructions—

      The sudden clang of a drawer startled him. He turned and saw Kenichi Hirai working at his own research rack. How long had he been there? The man had drifted so quietly into the lab Bill had not even known he’d entered. In a world where there is no up or down, where the sound of footsteps is never heard, a verbal greeting is sometimes the only way to alert others to your presence.

      Noticing Bill’s glance, Kenichi merely nodded in greeting and continued with his work. The man’s silence irritated Bill. Kenichi was like the station’s resident ghost, creeping around without a word, startling everyone. Bill knew it was because Kenichi was insecure about his English and, to avoid humiliation, chose to converse little if at all. Still, the man could at least call out a ‘hello’ when he entered a module to avoid rattling the nerves of his five colleagues.

      Bill turned his attention back to tube #23. What would this gelatinous mass look like under the microscope?

      He slid tube #23 into the Plexiglas glove box, closed the hatch, and inserted his hands in the attached gloves. If there was any spillage, it would be confined to the box. Loose fluids floating around in microgravity could wreak havoc on the station’s electrical wiring. Gently he loosened the tube seal. He knew the contents were under pressure; he could see the cap was bulging. Even so, he was shocked when the top suddenly exploded off like a champagne cork.

      He jerked back as a blue-green glob splatted against the inside of the glove box. It clung there for a moment, quivering as though alive. It was alive; a mass of microorganisms, joined in a gelatinous matrix.

      ‘Bill, we need to talk.’

      The voice startled him. Quickly he recapped the culture tube and turned to face Michael Griggs, who had just entered the module. Floating right behind Griggs was Diana. The beautiful people, Bill thought. Both of them looked sleek and athletic in their navy blue NASA shirts and cobalt shorts.

      ‘Diana tells me you’re having problems,’ said Griggs. ‘We just spoke to Houston, and they think it might help if you considered some medication. Just to get you through the next few days.’

      ‘You’ve got Houston worried now, have you?’

      ‘They’re concerned about you. We all are.’

      ‘Look, my crack about the CRV was purely sarcastic.’

      ‘But it makes us all nervous.’

      ‘I don’t need any Valium. Just leave me alone.’ He removed the tube from the glove box and returned it to its slot in the cell culture unit. He was too angry to work on it now.

      ‘We have to be able to trust you, Bill. We have to depend on each other up here.’

      In fury, Bill turned to face him. ‘Do you see a raving lunatic in front of you? Is that it?’

      ‘Your wife is on your mind now. I understand that. And—’

      ‘You wouldn’t understand. I doubt you give your wife much thought these days.’ He shot a knowing glance at Diana, then launched himself down the length of the module and into the connecting node. He started to enter the hab module, but stopped when he saw Luther was there, setting up the midday meal.

       There’s nowhere to hide. Nowhere to be alone.

      Suddenly in tears, he backed out of the hatchway and retreated into the cupola.

      Turning his back to the others, he stared through the windows at the earth. Already, the Pacific coast was rotating into view. Another sunrise, another sunset.

      Another eternity of waiting.

      Kenichi watched Griggs and Diana float out of the lab module, each propelled by a well-gauged push-off. They moved with such grace, like fairhaired gods. He often studied them when they weren’t watching; in particular, he enjoyed looking at Diana Estes, a woman so blond and pale she seemed translucent.

      Their departure left him alone in the lab, and he was able to relax. So much conflict on this station. It unsettled his nerves and affected his concentration. He was tranquil by nature, a man content to work in solitude. Though he could understand English well enough, it was an effort for him to speak it, and he found conversation exhausting. He was far more comfortable working alone, and in silence, with only the lab animals as company.

      He peered through the viewing window at the mice in the animal habitat, and he smiled. On one side of the screened divider were twelve males; on the other were twelve females. As a boy growing up in Japan,