Before shuttle astronauts David Wolf and Piers Sellers could begin their space station construction jobs on Thursday, they spent hours swapping out spacesuit parts, reassembling the garments and checking them thoroughly for flaws.
The upper torso of one spacesuit became a spare for Wolf, who wears an extra large. A large-sized torso unit from the station's wardrobe was substituted in its place for Sellers. Flight engineer Sandy Magnus was dumped as the backup spacewalker because she would need a medium-sized suit and smaller gloves, creating additional logistics complications.
Spacesuit manufacturer ILC Dover of Frederica, Del., is quietly pitching another route: a light-weight soft suit with flexible sizing, universal parts and the option for astronauts to wear the same garment for spacewalks, launch and entry, as well as for future exploration missions on the moon or Mars.
The prototype, which ILC Dover calls the I-Suit, has won rave reviews from NASA astronauts involved in its design and testing. NASA has suspended development of its own small-sized spacesuit in part because the I-Suit proved so much more attractive.
NASA's existing spacesuits, called the Extravehicular Mobility Units or EMUs, which the astronauts use for spacewalks, are made in medium, large and extra-large sizes. They fit 90 percent of the male astronauts but only 60 percent of the females. The I-Suit incorporates some design and construction elements originally developed for the now-canceled small EMU project.
"What we found in developing the small EMU was that it became so popular -- larger crewmembers loved the design too," said Nancy Currie, a veteran shuttle astronaut whose small stature so far has kept her from spacewalk assignments.
"We want to accommodate as many sizes as possible, but we don't want to box ourselves into the corner where we have a unique design and the components are no longer compatible," added William Readdy, NASA's associate administrator for spaceflight. "Clearly what we want to do is step up to a better suit for everybody."
The upper torso of the new suit is made of cloth, not fiberglass as in the existing EMU, which greatly increases sizing options as well as comfort and flexibility for the astronauts. The arms, developed for the small EMU, offer an increased range of motion and the helmet, greater visibility. Boots are part of the leg coverings and have tread suitable for walking on rocky bodies. The current spacesuits are designed only for use in zero-gravity.
In addition, because the I-Suit's pressure can be varied, the garment can be worn in the shuttle environment for launch and landing, as well as in the vacuum of space.
The new suit weighs just 85 pounds, less than one-third of NASA's current spacesuit, and its parts are easily interchangeable, cutting down the number of spare components that need to be transported or stored on orbit.
The space agency spent between $6 million and $7 million on small suit design before canceling the program earlier this year. The suit would have fit 95 percent of NASA's female astronauts, as well as some of the men. Allen Flynt, head of the Extravehicular Activity office at the Johnson Space Center in Houston, estimates another $9 million would have been needed to complete development.
"The development money that went into the small suit was not forfeited," said Readdy.
He explained although ILC Dover is funding development of the I-suit on its own, it is receiving support from NASA's engineering staff and astronaut office, as well as access to some NASA facilities and laboratories. The prototype is scheduled to be sent to Johnson Space Center later this month for additional testing and development. A flight test could come in three or four years. "We're looking at where we're going to be able to further the development of this project in the next year or two," he said.
"Our existing suit is really about at the end of its evolution," Readdy said. "It fulfills our immediate requirements for assembly and maintenance of the space station, but clearly we need to commit to a new suit for the future, especially if we're going to continue to operate the space station and the shuttle for many more years to come."