With current rocket technology, it takes between seven and nine months to reach Mars. That’s a long time to be cooped up inside a tiny spacecraft with, presumably, a small number of crewmates.
The potential psychological effects of such isolation are not fully known, although there are parallels here on Earth with long-duration submarine deployments and wintering expeditions in Antarctica.
|NASA announces world's biggest-ever rocket to take man to Mars and beyond|
And then there’s food. Who wants to spend seven months eating instant meals? Growing some edible plants during the journey sounds like a good idea, but it’s a bit of a risky proposition — what happens if your crops fail?