Six aquanauts will rise from the deep today after nearly a week stationed on the ocean floor testing spacesuit concepts for future Moon and Mars missions.
A joint team of astronauts and divers, the NASA Extreme Environment Mission Operations (NEEMO) 10 crew is set to resurface just off Key Largo in the Florida Keys by 12:00 p.m. EDT (1600 GMT), leaving their undersea Aquarius habitat 67 feet (20 meters) beneath the ocean waves.
"It takes 17 hours for us to surface safely," shuttle flight veteran Koichi Wakata, NEEMO 10 commander and a Japanese Aerospace Exploration Agency (JAXA) astronaut, told SPACE.com in a sea-to-surface phone call. "In a sense, it is a very extreme environment."
The primary goal of NEEMO 10's six-day mission aimed at testing changes in spacesuit weight distribution that could affect an astronaut's performance during excursions on the Moon or Mars.
"This is outstanding," Wakata said during one "moonwalk" dive, while his helmet-mounted video camera - webcast live via the Aquarius website - relayed images of the undersea laboratory and its surrounding sea life.
Wakata and NASA astronauts Andrew Feustel and Karen Nyberg dived down to Aquarius on July 22 with professional divers Mark Hulsbeck and Dominic Landucci. They were joined by Karen Kohanowich, deputy director of the Undersea Research Program for the National Oceanic and Atmospheric Administration (NOAA), which owns Aquarius.
"The one thing that's so wonderful about Aquarius is that it's good for so many different things," Kohanowich told reporters during a teleconference this week. "[As] a NASA analogue, marine science and education, it's a very important aspect of what we do."
Aquarius is operated for NOAA by the University of North Carolina at Wilmington's (UNCW) National Undersea Research Center. The metal habitat contains about the same living area as NASA's Destiny laboratory berthed at the International Space Station (ISS).
Finding your center (of gravity)
NEEMO 10 aquanauts staged daily dives while wearing an adjustable rig that allowed them to simulate walking on the Moon (one-sixth Earth's gravity) or Mars (one-third Earth normal), as well as physically change the center of gravity on their mock spacesuits.
"Anybody that's backpacked knows that if you haven't packed your backpack just right, you end up top-heavy or feel like you're going to fall over," said Nyberg, who served as a spacesuit environmental control systems engineer for NASA before joining the Astronaut Corps in July 2000, in a telephone interview. "So the center of gravity is really important for how we pack the portable life support system, and how that weight is distributed on the suit itself."
Aquanauts went through the motions of walking, retrieving cargo from a simulated resupply container - an essential task for long-duration Moon or Mars missions - and fell over, then got back up, to evaluate how slight changes in a spacesuit's center of gravity alter an astronaut's mobility.
"We were so surprised how, depending on the location of the center of gravity, it really affects the efficiency and effectiveness of the spacewalk," Wakata said, adding that Aquarius moonwalks were a substantial change from the training runs he conducted in NASA's immense spacewalk training pool near Johnson Space Center (JSC). "It was a very strange feeling to be able to walk for a spacewalk, because [NASA's] spacewalks now are for zero gravity."
Feustel said the NEEMO 10 crew also conducted a series of communications and mapping demonstrations for moonwalk navigation. The aquanauts also worked with mission controllers at NASA's Exploration Planning and Operations Control (ExPOC) center at JSC to handoff control of a small ocean rover.
"What makes it special is that the decisions we make going out the door are life critical decisions, just like [those] you'd make in space," Feustel said.
While the NEEMO 10 crew's mission is ending, NASA plans at least one more expedition to Aquarius this year.
The agency's yet-to-be-announced NEEMO 11 crew is slated to begin training on Sept. 12 and dive down to Aquarius on Sept. 16 for a six-day mission, according to the undersea lab's schedule.
Despite their hectic daily timelines, some NEEMO aquanauts managed to take time out to ponder the sea life around their aquatic home.
"I did a dusk dive the other night and I saw a spotted moray eel I've never seen before, and I love moray eels," Nyberg said. "So I was pretty excited."
New fish aside, Aquarius is also home so some neighborly creatures that have earned a place in the hearts of NEEMO crews.
"This habitat has become home to so many fish, and there are a few that we've recognized," Nyberg said. "There's a huge grouper and a big barracuda named Bob."
- VIDEO: NEEMO 10 Commander Koichi Wakata on his STS-92 Shuttle Flight
- NASA's NEEMO 9: Remote Surgery and Mock Moonwalks on the Sea Floor
- NEEMO's Undersea Operations: Making Telemedicine a Long Distance Reality
- NEEMO 7: NASA'S Undersea Robotic Telemedicine Experiment