NASA has begun to outline some of the specifics of its plan to put a human presence on Mars. The proposed mission vehicle is going to weigh in at a hefty 400,000kg (880,000lb) and is intended to put a "minimal" crew on the surface in 2031. Three or four of NASA's new Ares V rockets will be needed to loft the ship into space, which will require assembling in orbit. An advanced cryogenic fuel propulsion system would propel the mission to Mars on a six to seven month voyage. A cargo lander and surface habitat would be dispatched ahead of the crew vehicle and astronauts will be expected to grow their own fruit and vegetables during their trip. The mission will require an unparalleled degree of expertise from the astronauts, who will be required to respond to any likely situation or emergency far from any possible help. The plan as outlined is still extremely tentative and very likely subject to change, but with other countries eyeing the red planet, the coming decades are shaping up to be very exciting.