With today’s technology, it takes a spacecraft approximately seven months to reach Mars. That’s a long time for astronauts to be crammed together, especially if their Netflix access is choppy. It also means that astronauts have to eat, use the bathroom, exercise, and clean (at least a little bit) during the journey, which increases the amount of supplies they need, and thus, the cost of the mission. And something tells me that playing “I Spy” would get a little old. NASA is backing a study at SpaceWorks Enterprises in Atlanta to see if it’s feasible to put a crew into deep sleep for the journey.
The official term for the state is “torpor,” which involves slowing down metabolic functioning to the point where hypothermia is induced and people enter a state of hibernation. The technique has been used in medical facilities, particularly in trauma units, for keeping patients alive long enough to undergo surgeries or other procedures. For crews headed to Mars in the future, scientists consider six months to be an optimistic traveling time. So the idea of the idea is to see what it would take to keep humans in a state of torpor for 180 days. Thus far, the longest any human has been kept in this state is one week. Human suspended animation trials are currently being conducted on gravely injured ER patients, however, and may provide some insight into how the process can be adapted for longer-term scenarios.
SpaceWorks has concluded that the pressurized volume needed for a crew in a state of torpor is five times less than that of a conscious screw. The amount of mass on board a craft, particularly when it comes to food and water, would be roughly three times less. Overall, inducing hibernation could cut a mission mass from 400 tons to 220 tons.
The study is also trying to figure out how safely to induce torpor, as well as bring astronauts out of it. Right now, Spaceworks scientists believe that inhaling coolant through the nose is the best approach, even though it sounds godawful. Apparently, cooling a person from the inside is safer than cooling them from the outside, which can cause tissue damage. The RhinoChill Intranasal Cooling System actually already exists, and it decreases body temperature by 1 degree Fahrenheit per hour. It would take roughly six hours to achieve a state of torpor, which can occur anywhere from 89-93 degrees Fahrenheit. The system has to keep working for the entire trip, as stopping it will result in the raising of body temperature (though warming pads can be used if there’s a rush). This scenario leaves a lot up to the cooling system, and to the computer that regulates it.
SpaceWorks is also considering switching back and forth between torpor and consciousness, with a few days awake and then a couple weeks in hibernation, which would allow the astronauts to get some stuff done and to get some exercises between bouts. It would also provide a chance for them to make sure all their equipment is functioning properly—though if it weren’t, I guess they’d keep sleeping, which isn’t the worst outcome, all things considered.