Another widely circulated, and denied, report was contained in "Living in Space" by G. Harry Stine, a former NASA consultant. Stine, who died in 1997 as the book was being published, claimed that sexual experiments had taken place in the neutral buoyancy tank at Marshall Space Flight Center in Huntsville, Ala.
NASA is not alone in fending off questions about sexual rendezvous in space. For years, similar rumors have circulated about the Russian space program.
"It hasn't happened, although there have always been rumors," cosmonaut Talgat Musabayev told the Russian daily Rosiskaya Gazeta in June.
If NASA hasn't experimented with sex in space, is it possible, as Noonan suggests, that astronaut couples might have slipped off for an unsanctioned rendezvous?
Asked what astronauts do in their limited spare time in space, NASA insists that their off-hour pastimes have been limited to resting, eating, reading, exercising, sending e-mails to their earthbound loved ones, watching television and looking out the window.
If two astronauts were romantically inclined, space shuttles have sleeping bays that accommodate two, and the space station has a recreation area and other small rooms that afford privacy.
"People in space for long periods of time will find a way," Noonan said. "NASA should be studying this now. Sex will more than likely have a beneficial effect on morale and performance in the enclosed, confining and hazardous environment of space. It certainly does on Earth."
J. Scott Orr wrote this article for Newhouse News Service.