Space Sex: It’s a Mystery : Unknown Effects on Reproductive System: ‘It’s a Fertile Field for Research’
They may know a lot about the birds and the bees on Earth, but when it comes to sex in space, some scientists admit profound ignorance, and cannot rule out the possibility that space travel could cause reproductive damage in crew members.
Biologists outside NASA say ignorance about sex is symptomatic of a space program bias against research in the life sciences. They say they can provide few answers to vital questions about having sex and children during or after extended space travel, or raising food in the absence of gravity.
But NASA scientists discount the biologists’ fears as professional carping, and say years of human space flight have given sufficient proof that reproductive effects are minimal and other health effects preventable.
They believe the animal studies in space that some scientists have called for are difficult and uninformative, and charge that biologists are trying to grab precious cargo space and NASA funds to answer questions that will not be important for decades--until people contemplate living for extended periods in space.
A recent keystone to this debate is a report published last year by the National Research Council, part of the National Academy of Sciences, a congressionally chartered group that advises the government on scientific issues.
“The bottom line is that we really don’t know anything about space and sex. Zip,” said Lynn Wiley, one of the authors of the report.
The panel wrote in the report, “Studies on the effects of space travel and the physiological adaptation to zero gravity have not yet addressed alterations in the reproductive system in either men or women.”
A table in the report listed potential effects of spaceflight on the human reproductive system: damage or loss of sperm, birth defects, hormonal disruptions, impotence, altered menstrual cycles, endometriosis--a painful condition in which uterine tissue can grow outside the uterus--abnormal pregnancy and accelerated bone loss.
Wiley, an associate professor of obstetrics and gynecology at UC Davis, said in a recent telephone interview that the committee did not even know if a chicken could lay an egg in space, or whether male and female rats would be able to remain physically coupled for insemination without mechanical assistance.
The lowly rat is the foundation of scientific research. The animals are pressed into service for studies of all sorts, some of which later advance to other animals and even humans.
But the problem of how to design space experiments using rats or other animals had committee members bemused. Some proposed special mating tubes or little Velcro vests to assist mating rodents, Wiley said.
But in a more serious vein, Wiley said, “Out of something like 4,500 rat hours in space, there has never been a successful complete cycle from copulation, to conception and birth.” She pointed out that most of the rat experiments had been done by the Soviet Union, which, unlike the United States, has a part of its space program and some space flights dedicated just to biological research.
Another author of the report downplayed reproductive and other human health risks: “I would not emphasize the medical hazard,” said L. Dennis Smith, dean of the School of Biologicial Sciences at the University of California, Irvine. “But the opportunity to study basic biological processes, from development to senescence, is unique.”
“It’s a fertile field for research--no pun intended,” Smith said.
Biological research has often seemed to be the poor stepchild of the space program, although, Smith said, “Research on the life sciences is as important as research on astronomy, astrophysics, solar or planetary exploration and other traditional space sciences.”
But scientists at the National Aeronautics and Space Administration dispute the notion that biology has gotten short shrift and insisted that enough is known about the effects of space travel on humans to assure astronauts that even a 6-month stay in space will not harm them if they exercise and eat right.
“I would love to go on a 180-day mission,” said 59-year-old astronaut-physician Dr. William Thornton, veteran of two space missions and overseer of medical and biological experiments aboard the 1985 Spacelab mission. “For them to say we have not studied man in space . . . is naive in the extreme.”
“It may not be the kinds of studies the scientists want to see. It may not be good science. It may not involve cutting up animals or invasive studies, but nevertheless we have the kind of study needed to advance to long-term stays in space,” Thornton said.
Surrounding him in his office, Thornton said, were thousands of feet of film, 25 stuffed file drawers, shelves of books and, nearby, two rooms crammed with data about the health in space.
Thornton agreed that basic studies in space biology might be lagging behind other space research, but insisted this was primarily the fault of biologists themselves. He said few had come forward with sound proposals for research, and those that did were only interested if NASA agreed to pay for the studies.
Thornton also faulted NASA for making the paper work, rules and procedures for doing even the simplest experiments too complicated.
Carolyn Huntoon, director of space and life sciences at NASA’s Johnson Space Center, said she did not think biological research was the poor stepchild of space research.
“Any scientist is going to say there has not been enough work in their area,” Huntoon said. “We’ve been given a pretty good shot at it.”
Sees ‘Turf Battle’
Wiley said the dearth of biological research reflected an ongoing “turf battle” in space research, with the basic turf in question--room aboard the few shuttle flights--severely reduced in the wake of the Challenger disaster and other setbacks to the space program, and further carved up by Department of Defense and commercial research payloads.
Huntoon said opportunities for biological research would increase substantially when the space station was deployed and staffed, probably in the mid- to late 1990s. Huntoon said work was already under way designing equipment for medical testing and treatment aboard the station.
Wiley said longer studies aboard the station, of reproduction in a variety of species--from plants to fish and chickens--would someday be essential for lengthy stays in space when the creatures would be grown as renewable food supplies and to recycle air and water. So far, however, there has never been a successful multi-generation experiment, raising a single plant from seed until it sets seed, or raising an animal from egg until it bears eggs.
Much Left to Learn
The space biologists on the National Research Council panel said that, beyond the studies on animals and plants, there is much to learn about what effects the stress, low or zero gravity and radiation of space travel will have on humans. Especially in the case of radiation, animal studies may not answer these questions because of differences in sensitivity from one species to another.
Sperm production is especially sensitive to radiation, which can cause chromosome damage and decreased production of male reproductive cells, possibly increasing the chances that a man would produce “a genetically defective offspring,” the report said.
Astronaut Thornton and panel member Smith said in the low orbits of the shuttle and the proposed space station, the radiation levels would not be of concern. But in deep space, on a mission to Mars, for example, the radiation would be more critical, Smith said.
Wiley said even in low orbits solar flares could cause severe radiation problems if an astronaut were outside the capsule. But more important, she said, was that the simplest tests had not been done.
“Not a single semen sample has been taken” by the astronauts, said Wiley, one of two women now serving on the panel. “Sex and semen are just not topics you talk about with those guys. They shut up like clams, so we have no data.”
Information Gathering Urged
To study the effects of space travel on human reproduction, the committee recommends collecting detailed information on astronauts’ reproductive history before and after space flight, including the menstrual cycles and the normal and abnormal pregnancies of female astronauts and wives of male astronauts.
To check for effects on sperm, the report recommends checking for chromosomal damage in semen samples collected before, during and after spaceflight. Depending on the results of these studies, male astronauts might want to leave behind frozen semen before they blast off to reduce the chance of defects in offspring fathered after they return from space.
Thornton was adamant that astronauts had always been fully cooperative in health studies. “For any legitimate question dealing with reproduction, I think you would find a little more interest than usual,” Thornton said. “You would not find the astronauts getting uptight, but it depends on the experiment.”
“They would contribute to any program that has value, but they do not take lightly to crackpot schemes,” Thornton said.
Huntoon pointed out that a number of astronauts had had healthy children born after they returned from space.
More Immediate Threat
The reduced gravity in space could pose an unavoidable and more immediate health threat than radiation, Wiley said, adding that this meant reproductive biology would probably take a back seat to studies on motion sickness, balance, coordination and damage to astronauts’ hearts, muscles and bones--systems more immediately affected by weightlessness than the reproductive system.
In the future, Thornton said, when people live for a long time in low or zero gravity, reproductive questions would arise. “What would happen if a baby is born in space?” he wondered. “How would it grow up?”
But, he said, these distant questions could be answered with further studies back home: “If we perfectly understood the physiology here on Earth, we could predict” what would happen in space.
Smith said he believes the physical problems would be of concern primarily when astronauts spent long periods in space, “not on a seven- to 10-day shuttle flight.”
“I would not want to volunteer for a mission to Mars and back, though, at least not knowing as little as we do now,” Smith said.
‘We Don’t Know Effects’
Wiley said she is not even prepared to say short flights are safe. “We don’t know if the effects are short- or long-term. I think we can say that so far there have not been noticeable deficiencies in reproduction” in astronauts after space flights.
Wiley predicted that before astronauts went on 90- or 180-day missions aboard the space station, they would be asking biologists about the effects of long space stints on their bodies.
“In all deference to the crews, they don’t know diddly-squat about the effects. They will be looking to us, but in truth, we don’t know diddly-squat either.”
“It would be desireable to have that information before we get them on the space station,” Wiley said, but added there was economic pressure on the space program “to send people first” and study the biological effects later.
“The bottom line is, we don’t know what to say. We don’t have any information.”
