WHEN Shannon Lucid floats through the hatch and into Russia's Mir space station this weekend, she will become the first American woman to serve on the station's crew.
If all goes well, her 140-day stay will also set an endurance record for US astronauts - and perhaps more important, provide fresh insights on the human side of spaceflight, a field often dominated by discussions of physiology and hardware.
Dr. Lucid is one of six crew members scheduled to ride the shuttle Atlantis into space on Thursday. A biochemist who joined NASA in 1978 as one of its first female astronauts, she will stay in space to conduct research aboard Mir, while her shuttle colleagues return to Earth March 30.
Lucid's arrival begins 26 months of continuous US presence on Mir. It also inaugurates changes made in the program since American Norman Thagard returned last year from a 110-day stay on Mir.
His tour highlighted some of the challenges that long-duration crews face. Upon his return, Thagard said he had to grapple with a sense of "cultural isolation."
To ameliorate the problem, NASA will provide Lucid with audio news briefings three times a week, a weekly set of video news clips, and an indirect means of using e-mail to stay in touch with her husband and three children.
She will also have plenty of work to do. A problem with Thagard's assignment was that he didn't have much to do beyond his research tasks, which didn't fill his time, according to Yuri Glazkov, deputy director of Star City, the cosmonaut training center near Moscow.
"We have found that the more a person is working, the less psychological problems this person has on board an orbital station," he says. "Shannon Lucid will have to conduct a broader spectrum of operations" aboard Mir than Thagard did. This has become all the more important because some of Lucid's research equipment, which was to have been sent up from Russia and put in place before she arrived, will not reach Mir until well after she arrives.
Groundwork for the new space station
Lucid's stay is part of a nine-mission program to lay the foundation for US-Russian cooperation on the International Space Station. Construction on the new facility is scheduled to begin late next year.
With that milestone approaching, two other Atlantis crew members are scheduled to make a spacewalk that comes the closest yet to matching the kind of conditions that astronauts aboard the new space station will confront.
Hanging by a tether
Crew members Linda Godwin and Lt. Col. (Ret.) Richard Clifford will conduct the challenge spacewalk while Atlantis is docked with Mir. They will test tools and tethers that work on Mir as well as on the shuttle.
In addition, the astronauts will attach four experiment packages to the docking module attached to Mir. During the experiments, a variety of materials, paints, and coatings to be used for the international space station will be exposed to conditions that the station will experience once on orbit. In addition, the packages will capture natural and man-made space debris to help scientists and engineers evaluate the debris hazards that the new space station will encounter.
Dr. Godwin and Col. Clifford will have to leave the shuttle's cargo bay and work their way onto Mir's docking module, where they will attach the 55- to 60-pound packages. They will remain linked to the shuttle with 55-foot nylon tethers and will have emergency propulsion units on their backs if, for some reason, the tethers break and the astronauts float free of the station.
"In a spacewalk on the shuttle, most of the activity is confined to the payload bay," says Scott Bleisath, the mission's lead EVA officer. "So it's easy for the crew to see each other and where they are going. On space station, you have modules and trusses that crisscross. It's harder to tell how to get from one site to another."
He acknowledges the possibility that the tethers can get tangled, but adds that the two spacewalkers have spent time in NASA's training pool and with a new virtual-reality training tool to devise ways to avoid tangles.
Lucid, for her part, notes that her two Rus-sian colleagues aboard Mir, Yuri Onufrienko and Yuri Usachev, have bent over backward to make her feel like part of the crew. Her one regret is not having a better grasp of conversational Russian.
"My Russian is adequate," she notes. "But most of my focus has been on technical Rus-sian" in order to pass exams given all Russian astronauts. "I don't think that Yuri and Yuri are very much interested in sitting around and discussing ways of producing oxygen."