Here is a fascinating article about space travel. Apparently, a trip to Mars will take about 6 months. A team at NASA has shown that putting astronauts in a form of hibernation can significantly reduce the cost of a trip, as much less food will need to be brought if the crew is hibernating.
The way it works is that the crew members will be cooled down to 89°F – 93°F by fluid pumped through their noses! The crew will be fed intravenously while they hibernate. The article does not mention how urination is dealt with - catheter maybe? When the crew arrives at Mars, they will be warmed up again and woken up. The article mentions that during hibernation, the crew will be in a "spinning habitat...to offset bone and muscle loss." Sounds like something out of a science fiction movie, only apparently it's very possible to do this now.