Sperm: The Final Frontier

This meant also thinking back to his undergraduate days at Northwestern. There, a scientist named Erwin Goldberg had theorized that there might be a unique enzyme in sperm, an enzyme critical to sperm's ability to move. Goldberg's idea was that you could inject an antibody that would stop this enzyme from helping sperm move. One reality stood in the way: A biological firewall protects all the cells in the testes, and antibodies can't break through.

"I was able to make discoveries and gain insights into how things work," Tash says. But the purely academic pursuit of knowledge wasn't enough. Tash wanted to find something people could use.

By then, other scientists were beginning to look for the same thing.

The Population Council, an international organization based in New York, has been working on male contraceptives for 20 years. It has tested inconvenient-sounding combinations of hormones and testosterone replacements and in recent years has trademarked an implanted contraceptive, but it's only 85 percent effective — not good enough.

In his Houston lab, Tash was growing frustrated. Research money was hard to get — it was the '80s, and the National Institutes of Health was suffering the Reagan administration's budget cuts. He began to think about doing his work at another institution.

At the end of the decade, Tash heard about a faculty opening in the physiology department at the University of Kansas Medical Center. Impressed by Kansas City and the people he met at the medical center, he took the job.

"We packed up an 18-wheeler and a half worth of lab equipment," he says. The family settled into a house surrounded by big trees in the older section of Leawood.

He continued the work he'd started in Houston, but he still hadn't found a practical male contraceptive. And he still had trouble getting his grants renewed.

Tash was reluctant to admit that what he'd been doing wasn't the best approach. Maybe, he thought, everything his critics were saying was right.

That's when NASA called. It was 1996, and the space agency wanted to study reproductive systems in space.

Tash had submitted a proposal. He was on a faculty retreat when he got a message to call NASA. On a pay phone in the hallway, a flight manager for a series of experiments wanted to know whether he could be in Washington, D.C., within a week, all expenses paid.

Tash met with representatives from NASA, the European Space Agency and the Russian Space Agency.

He hoped to do an experiment that might answer two simple questions: Does sperm swim differently in a weightless environment than it does on Earth? If so, why? But when he told NASA that the tests were impossible without hauling a microscope aboard the space shuttle Atlantis, the agency rejected his idea.

He was crushed. But he learned a lesson: He needed to be flexible.

Soon, NASA solicited proposals for the shuttle's next two flights. Tash created a different experiment, one that would work with equipment he knew would fly. NASA approved his experiment — for two flights just six months apart.

In 1997, Tash went to the Kennedy Space Center in Florida. His team re-created his med center lab in a set of offices next to Hangar L, a tall bay on Cape Canaveral that was set up with a mini mission-control area.

When the shuttle launched at night, Tash watched from a parking lot. The rockets lit up the place as if it were day. Huge, bright smoke billowed from the launch pad, and sound waves rippled across the water before slamming through his body. He could still see the light of the rocket when it was almost over Africa.

More than 127 miles above the Earth, astronauts on Atlantis performed Tash's experiments by turning screws on a hand-sized cassette with tiny wells containing sea-urchin sperm. When seawater rushed in, the sea-urchin sperm began swimming. The astronauts measured distances after 30 seconds and after a minute.

Tash's ground team had all of the same equipment. They watched what the astronauts were doing on a video feed delayed by two hours — that gave the ground team time to adjust for any unexpected temperature changes or other anomalies in space. It was critical that the experiments on the ground matched the space experiments precisely.

On the second flight, Atlantis approached an area over Australia where the shuttle would temporarily lose radio contact. Thirty seconds before losing the signal, Houston's controller called Tash to see what he wanted to do: Tash needed to tell astronaut Edward Lu whether to keep going with the precisely timed experiment, but Tash was too focused on his own work. Atlantis headed toward the dead zone.

The voice from Houston began counting down — 10, nine. Tash froze. He was worried that, without audio and video feeds, his team wouldn't be able to replicate Lu's work two hours later.

"Wait," he told Houston's controller. But it was too late. He heard only crackling. Eight minutes passed, then 10. Then Tash heard Lu's voice: "Atlantis."

Lu had waited. The experiment was still on track. And it occurred to Tash that he'd just experienced something that happens to few men: NASA had asked him what an astronaut should do.