In preparation for a possible manned mission to Mars, NASA is researching ways to utilize human hibernation to circumvent problems associated with prolonged deep space exploration. Working in tandem with Atlanta based aerospace company SpaceWorks, NASA’s preliminary plan was revealed at the 2014 International Astronomical Congress in Toronto. “Sending astronauts that far into space would be too challenging, costly and grueling without it,” said SpaceWorks engineer John Bradford.
The obstacles involved in sending a team of scientists into deep space are many, not the least of which is cost. For starters, such missions will require ample supplies of food, air, and water. Other issues include adequate living quarters, extensive radiation shielding, and the availability of exercise equipment to prevent bone loss and muscle atrophy. In addition, all of these necessary accommodations add considerable weight, and the more a spacecraft weighs the more fuel is required for flight. In fact, room for storing fuel is the single largest component of any craft, and since rocket fuel is an expensive commodity, the correlation between the mass of a ship and the cost of the mission is directly proportional. Finding ways to minimize the mass of a space-going vessel is an important part of making the cost of space travel fit the restricted budgets of space programs today.
The psychological effects of long term space flight on astronauts pose additional challenges. Crew members can suffer from a variety of adverse psychological effects ranging from insomnia and anxiety to depression and cabin fever. All of these can threaten not only the health and well being of the afflicted astronaut confined to the duration of the mission, but also the safety and psychological health of the other astronauts.
The solution proposed by SpaceWorks is a medically induced hypothermic condition known as torpor, which is a form of hibernation. Torpor, which has been used in hospitals since 2003, is induced by lowering the body’s core body temperature to between 89-93 degrees Fahrenheit, unlike popular sci-fi movies where the characters’ metabolisms are brought down to zero. The intranasal system proposed by NASA and SpaceWorks, known as RhinoChill, cools the body with a proprietary gas that is breathed in, lowering the body’s core temperature by one degree per hour. The entire process takes about six hours to reach a state of hibernation. As uncomfortable and disturbing as it sounds, this method is meant to minimize medical issues such as tissue damage and shivering if cold gel packs alone were used. When the RhinoChill system is shut off, the body temperature automatically starts to rise with complete revival occurring in about 8 hours. In case of an emergency, the revival process can be sped up with heating elements located in the stasis pods.
The crew participating in a long term space mission would be put in stasis at the beginning of their journey. Robots would administer the torpor inducing gas, intravenously administer nutrition, and electro-stimulate major muscle groups to prevent atrophy. An alternative to electric stimulation of muscles would be to rotate the stasis chamber at a rate that simulates Earth gravity (if astronauts were awake during this process they would most likely experience motion sickness). As they near their destination, the hibernating crew would be revived and ready to accomplish their mission objectives.
SpacwWorks and NASA are hoping that with this technology many of the major obstacles to manned deep space missions would be a thing of the past. The weight and cost of the craft would be significantly reduced given that less quantities of air, food, water, and fuel would be required as a result of the use of torpor.The living quarters alone could be reduced from a proposed 8.2 x 9 meters and 31 tons to 4.3 x 7.5 meters and 15 tons. Cosmic radiation, another potentially life threatening aspect of space travel could be addressed more economically as well; the stasis pods could be heavily shielded at a fraction of the cost of shielding the entire living quarters of the ship.
Although many of the problems associated with deep space travel are being addressed, several technological and medical challenges remain when considering missions involving astronauts. The estimated duration for a mission to Mars is 180 days, one way. Since the current record for a sustained state of torpor is just one week, more medical research has to be done to verify the plausibility of a journey lasting up to six months. “It may take some time to get it to the state of effectiveness we want it to go to,” Bradford says. Also, the potential side effects of an intravenous diet are numerous. In addition to the possibility of an infection at the IV site, the astronauts in stasis could suffer from hypoglycemia and hyperglycemia, among other serious medical conditions. One potential solution to the IV problem is staggering the sleep-wake cycle of the astronauts: Astronauts can take turns staying awake to monitor the other hibernating crew members for a few days.
The dream of manned exploration of deep space is ingrained in our culture. Hopefully, when this technology matures it will make manned missions to Mars and beyond a safer and more cost-effective reality. In tandem with proposed nuclear fusion rockets, perhaps even the outer planets could be within our grasp sooner than we realize.