Space & Innovation

NASA Eyes Crew Deep Sleep Option for Mars Mission

A NASA-backed study explores an innovative way to dramatically cut the cost of a human expedition to Mars -- put the crew in stasis.

A NASA-backed study explores an innovative way to dramatically cut the cost of a human expedition to Mars -- put the crew in stasis.

The deep sleep, called torpor, would reduce astronauts' metabolic functions with existing medical procedures. Torpor also can occur naturally in cases of hypothermia.

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"Therapeutic torpor has been around in theory since the 1980s and really since 2003 has been a staple for critical care trauma patients in hospitals," aerospace engineer Mark Schaffer, with SpaceWorks Enterprises in Atlanta, said at the International Astronomical Congress in Toronto this week. "Protocols exist in most major medical centers for inducing therapeutic hypothermia on patients to essentially keep them alive until they can get the kind of treatment that they need."

Coupled with intravenous feeding, a crew could be put in hibernation for the transit time to Mars, which under the best-case scenario would take 180 days one-way.

So far, the duration of a patient's time in torpor state has been limited to about one week.

"We haven't had the need to keep someone in (therapeutic torpor) for longer than seven days," Schaffer said. "For human Mars missions, we need to push that to 90 days, 180 days. Those are the types of mission flight times we're talking about."

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Economically, the payoff looks impressive. Crews can live inside smaller ships with fewer amenities like galleys, exercise gear and of course water, food and clothing. One design includes a spinning habitat to provide a low-gravity environment to help offset bone and muscle loss.

SpaceWorks' study, which was funded by NASA, shows a five-fold reduction in the amount of pressurized volume need for a hibernating crew and a three-fold reduction in the total amount of mass required, including consumables like food and water.

Overall, putting a crew in stasis cuts the baseline mission requirements from about 400 tons to about 220 tons.

"That's more than one heavy-lift launch vehicle," Schaffer said.

Mars, the Red Planet, in a view from NASA's Hubble Space Telescope in 2003. To get there, it could take a crew 180 days to travel the interplanetary expanse, so NASA is looking at putting a crew into a deep sleep, or torpor, state. | NASA

The study looked at a two-part system for putting Mars-bound astronauts in stasis and bringing them out. The cooling would be done through an internasal system, which Schaffer admits is "not very comfortable," but inhaling a coolant has several advantages over reducing body temperatures with external cooling pads. Cooled from the outside, the body is more susceptible to shivering and possible tissue damage, Schaffer notes.

The so-called RhinoChill System lowers body temperature about 1 degree Fahrenheit per hour. Reaching torpor state -- between 89 degrees and 93 degrees Fahrenheit -- takes about six hours.

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Simply stopping the flow of coolant will bring a person out of stasis, though the SpaceWorks study included rewarming pads as a backup and to speed up the waking process in case of an emergency.

An alternative to having the whole crew in stasis is to have one person awake for two to three days, then hibernate for 14 days. By staggering the shifts, no one person would be in stasis for more than 14 days at a time and one crewmember would be awake to monitor the ship, conduct science experiments and handle maintenance chores.

Schaffer also points to a potential psychological advantage to stasis.

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"Rather than being stuck in a can for 180 days, you go to sleep, you wake up and you're there," he said.

More research is needed to assure prolonged stasis is safe, but initial results are promising, Schaffer added.

"We have not seen any show-stoppers on the medical side or on the engineering side," he said.

During interplanetary transit, the crew would receive low-level electrical impulses to key muscle groups to prevent muscular atrophy.

Nothing says “astronaut” quite like a spacesuit. Whether it’s the shiny aluminized nylon flight suits worn by the original Mercury Seven astronauts or the pressurized bright orange “pumpkin suits” worn by space shuttle crews, the clothes do make the man or the woman. It’s much more than a look; the suits could be the only thing that separates an astronaut from life or death in case of an emergency. Here’s a look at some spacesuits in NASA’s storerooms.

With the end of the space shuttle program, NASA began working on a spacesuit that astronauts could wear for forays into deep space, beyond where the space station flies. Last month, the agency awarded an 18-month, $4.4-million contract to ILC Dover to design, manufacture and test a new type of spacesuit called the Z-2. Pictured here is a predecessor prototype, the Z-1, which resembles something Buzz Lightyear might have in his closet. The design is intended to be more comfortable and more flexible for spacewalkers than the Extravehicular Mobility Units, or EMU, that spacewalkers wear today.

NASA looked to the U.S. Navy when it came time to design a spacesuit for its first group of astronauts, the Mercury Seven, pictured here, who were selected in 1959. The agency modified a version of high altitude jet aircraft pressure suit. Beneath the shiny layer of aluminized nylon is an inner layer of Neoprene-coated nylon.

It wasn’t enough to simply land on the moon. The Apollo astronauts were tasked to get out of their spaceship and walk around. Three crews even got to drive around in lunar rovers. Their spacesuits were the first to include a liquid-cooled inner garment and an outer layer to protect against micrometeoroid impacts. Pictured here is the iconic shot of Apollo 11 astronaut Buzz Aldrin taken by his crew mate and commander, Neil Armstrong.

NASA dropped pressurized flight suits for space shuttle crews after four test flights. When Vance Brand, Bob Overmyer, Joe Allen and Bill Lenoir blasted off aboard Columbia on Nov. 11, 1982, for the fifth shuttle mission they wore just blue flights suits with oxygen helmets.

After the 1986 shuttle Challenger accident, NASA beefed-up safety requirements, which included a redesign flight suit for astronauts to wear during launch and landing. The so-called “pumpkin suits” evolved into the Advanced Crew Escape Suit, pictured here. The full-pressure suit is based on U.S. Air Force high-altitude pressure suits worn by SR-71 Blackbird and U-2 spy plane pilots. It includes a parachute pack and harness, life raft, life preserver, gloves, oxygen manifolds and valves, boots and survival gear.

To protect astronauts working outside the shuttle or the space station, NASA developed the Extravehicular Mobility Unit, or EMU. It’s more like a self-contained satellite than a spacesuit, offering spacewalkers environmental protection, life support and communications. The two-piece semi-rigid suit, which weighs about 300 pounds, is one of two kinds used on the space station today. The other is one-piece semi-rigid Russian Orlan suit. Astronaut Steve Robinson, attached to the Canadarm2 during STS-114 in 2005, is pictured here.

NASA has studied dozens of spacesuit designs over the years, including the AX-5, pictured here, which was developed at the Ames Research Center in California. The high-pressure suit uses hard metal and a composite rigid exoskeleton design.

Many old spacesuits end up in museums. But this decommissioned Russian Orlan suit took on a new life as a low-cost satellite. Dubbed SuitSat, the discarded spacesuit was filled with old clothes, outfitted with a radio transmitter and released into Earth orbit on Feb. 3, 2006. It was eventually pulled back into the atmosphere by the planet’s gravity and burned up.