Two words: size and cost.
Trips to other worlds aren't short, and packing enough food and supplies to keep astronauts alive for months at a time is a major challenge. One proposed solution? Deep sleep, or, more accurately, an induced state of hypothermia resulting in torpor, a kind of hibernation. You know, like bears do.
Except in this case, NASA-funded researchers plan on inducing torpor with RhinoChill, a device that uses invasive tubes to shoot cooling liquid up the nose and into the base of the brain.
When it comes to space travel, "anytime you introduce humans, it gets an order of magnitude or two more challenging," says Bobby Braun, NASA's former chief technologist. This is especially true when it comes to eventually shipping people to Mars.
Flying people to another planet poses a ton of technical and logistical challenges, which NASA is addressing with innovations like the Z-2 space suit. One of the largest hurdles is figuring out how to fit a crew on a spaceship with enough food, entertainment, and amenities to last for the estimated 180-day journey to Mars without going over budget.
NASA is bankrolling research into the technology necessary to put people to sleep for months at a time via SpaceWorks, an Atlanta-based company that presented their work at last week's International Astronomical Congress in Toronto.
According to the company, inducing torpor in a crew of astronauts would eliminate the need for space-wasting accommodations like food galleys, exercise equipment, and large living quarters. Robots that electrically stimulate key muscle groups and intravenously-delivered sustenance will take care of all that.
By eliminating the extra room required for people to live and move around in, ships could be smaller, and more safety features like better shielding could be added. According to SpaceWorks' mockups, the size of astronaut crew living quarters for a Mars mission could be reduced from their currently proposed size of 8.2x9 metres to just 4.3x7.5. That drastic reduction in size means huge savings on build materials and lift costs for the cash-strapped agency.
Current projections for Mars-ready habitats put their weight at roughly 31 tons for a 4-person crew. With a torpor statis habitat, according to SpaceWorks, the same crew could be housed at a comparatively feathery 15 tons. Thus, the crew size of a Mars mission could be theoretically doubled without increasing the weight of the craft. A lightweight spaceship means less powerful rockets are needed to launch it, which further reduces fuel weight and cost.
Of course, SpaceWorks mentions the psychological benefits of being asleep for 180 days instead of slowly descending into space madness. However, the chief advantage of deep sleep during space travel is likely cost and resource savings.
As you might expect, there's a ton of research that still needs to be done before astronauts can be made to hibernate for months at a time. RhinoChill has so far only been used in therapeutic scenarios—and most importantly, only here on Earth. It remains to be seen whether the technique can be used in orbit, but the potential savings on a flight to Mars could just be motivation enough for NASA to try it out.