If you’ve ever napped during a road trip, you know how good it can feel to wake up in a city you didn’t fall asleep in. (Important safety tip: This only works if you’re not the one driving.) One NASA-funded area of research looks at the possibility of using medical "suspended animation" technology to make the six-month trip to Mars easier, cheaper, and more comfortable, but it’s important to note that we’re not talking about real suspended animation—we’re talking about a torpor state (essentially therapeutic hypothermia), which means sedating someone by lowering their body temperature by 10°F.
In addition to dramatically reducing the mass, weight (from 400 tons to a mere 220), and complexity of any Mars-bound craft, this would also allow NASA to provide better radiation shielding (since the astronauts would be restricted to a single small space) and disregard comfort (since the astronauts wouldn’t be conscious enough to know or care whether they’re comfortable or not). For example, astronauts can avoid the tissue degeneration normally associated with long-term space travel—but not comfortably:
"One possible solution is to induce artificial gravity by spinning the spacecraft, [SpaceWorks’ John] Bradford said — a strategy that could be made even more effective by the astronauts' unresponsive state. 'Typically, you have to have these very slow rotation rates, because spinning too fast makes people sick,' he said. (Rotation rate dictates the magnitude of the induced gravitational force.) 'Because they're not conscious, they obviously won't be susceptible to disorientation, and we think we can actually put them on a much faster rotation.’"
Most of us wouldn’t want to lower our bodies to room temperature and rocket them out in a rapidly-spinning 220-ton vehicle through 34 million miles of radioactive deep space, but think of it from an astronaut’s perspective: instead of being conscious for a dangerous six-month voyage and coming home with potentially terminal health issues, they have the option of literally going to sleep on Earth and waking up safe on Mars. What’s not to love?
Of course, this is assuming torpor is safe. So far, the longest anyone has been kept in medical hypothermia is 10 days; while many other mammals can safely hibernate for six months, we don’t know for certain that humans can yet. It may be another decade or two before we can definitively find out. But for now, this presents us with the intriguing possibility of sending astronauts safely to Mars and beyond—without sentencing them to an early death. That’s a possibility worth exploring.