Astronauts are serious when it comes to playing make believe. In fact, it’s their job. Before going to real space they have to visit pretend space in full dress up. Depending on what they need to learn, astronauts may have to suit up for a mission in the Arizona desert, a ride on the vomit comet, or a couple hours dangling over a giant air hockey table. But to experience full immersion in a three-dimensional environment, astronauts turn to the deep blue.
NASA has been dunking its astronauts since the mid sixties, when Buzz Aldrin pioneered underwater training in preparation for his Gemini spacewalk. In recent years, the underwater experience has become immersive through the NASA Extreme Environment Mission Operations (NEEMO), which places astronauts in a cramped underwater habitat for weeks at a time. The most recent mission, NEEMO 15 in October, had the “aquanauts” preparing for asteroid exploration in the Florida Keys, before hurricane Rita interrupted the mission.
Of course, the ocean is an imperfect simulation of space. But as a liquid environment, it holds a few advantages over other mock-ups. We consulted the experts, Jason Poffenberger, a NASA engineer who helped plan this year’s NEEMO mission, and Taber MacCallum, the co-founder of aerospace engineering company Paragon, about what astronauts learn underwater.
Whether a mission involves fixing the Hubble telescope or anchoring to a near-Earth asteroid to collect samples, every detail gets mapped out beforehand. Improvisation is only a back-up plan. When astronauts head off to space they bring along one refined strategy. Underwater tests help them to select the best one.
The DeepWorker submarine. Courtesy NASA
During their six-day stay, NEEMO 15 aquanauts tested different ways to collect asteroid samples. They also practiced using tethers and booms and tested whether it was more efficient to traverse an asteroid terrain with a rover or a jet pack.
“NEEMO is frequently the best fit for these sorts of tests we want to do because you get the benefit of being able to experiment with microgravity environments,” explains Jason Poffenberger.
Teamwork and stamina
Although NASA has many ways to feel out the psychological fortitude of its astronauts, saturation diving gives them a unique opportunity to immerse themselves in another world. The Aquarius Habitat, where the NEEMO missions take place, anchors down about 70 feet below water. At this depth and pressure, tissues in the astronauts bodies absorb dissolved nitrogen that can form bubbles in the blood if they resurface too quickly. The NEEMO crew requires about 16 hours to decompress, meaning they have no immediate escape hatch. Just like in space.
“It certainly gives people an environment that they can’t leave from readily. That aspect is a good thing to have experienced already,” MacCallum says.
Locked in, as they are, NEEMO crewmembers also get a good sense of how well they collaborate. “You never really know someone that you’re working with until you’re in stress,” says MacCallum.
Making a mental map is one of the great challenges of floating weightless in space, as human beings are accustomed to building maps on a two dimensional plane. Weightlessness forces astronauts to orient themselves in three dimensions.
Commander Shannon Walker and fellow aquanaut David Saint-Jacques. Courtesy NASA/Mark Widick
“We sort of calibrate ourselves to the world we’re in and you have to recalibrate yourself to space,” says MacCallum. But it’s not easy to teach an astronaut how to do this, because each has an individual approach, “Some people orient themselves in the space around them and other people have themselves as the center,” says MacCallum. Spending consecutive days suspended in microgravity can help astronauts figure out which approach is best for them.
Space gives back
Quite often, these sessions of make believe lead to breakthroughs in marine engineering. After all, while pretending to survive in space, astronauts must really survive underwater. Some of the tools to do so were developed during NASA training.
“In 1969, NASA was getting ready for SKYLAB and learning to work underwater and be in those kinds of environments and it really was the very first of its kind. And it developed a lot of the protocol for saturation diving as well,” says MacCallum.
Divers and marine engineers especially took inspiration from NASA’s Gemini and Mercury missions during the lead up to the moon landing. Those were the first missions for which astronauts were placed underwater on an umbilical cord with a closed life support system. Until then, explains MacCallum, divers wore systems that exhaled directly into the water. NASA’s technology inspired engineers to experiment with diving equipment that collected exhaled gas in a contained system.
At Paragon, MacCallum has advanced this concept and designed an umbilical life support for the Navy that divers could use while swimming in contaminated waters. The gear attempts to recreate a “space-suit like environment.”
Putting it all together
Although underwater sites like Aquarius have become powerful tool for astronauts in training, no single simulation can recreate an unfathomably foreign experience that runs contrary to all human instinct. “We can simulate various aspects of space flight on the ground, but ultimately the astronaut has to sew all these things together,” says MacCallum.
Top image: The Aquarius Habitat. Courtesy NASA.
Morgen E. Peck is a contributor to IEEE Spectrum, Innovation News Daily and other publications. Her last article for Txchnologist looked at a system that generates power from slow river currents.
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