As we move further and further from our planet and begin exploring space, we need to know that we can survive and function during these long trips in zero-g. Astronauts would need to live outside Earth’s gravity for three years on a trip to Mars — three to six months each way, plus two years waiting for the planets to align favorably once again. Mars has some gravity, but it’s approximately 1/3 that of the Earth’s. We need to understand how living in that kind of environment for an extended period of time will affect astronauts, and how they can mitigate any effects on their bodies and neural function.

Are we really an interstellar species? Can we even survive a Mars trip, let alone staying there a while longer?

Source: Living in space has drastic, negative effects on the brain