Ponca City, We Love You writes "Nasa has released details of its strategy for sending a human crew to Mars within the next few decades. The US space agency envisages dispatching a "minimal" crew on a 30-month round trip to Mars in a 400,000 kg spacecraft. The mission's journey from Earth to Mars would take six to seven months in a spacecraft powered by an advanced cryogenic fuel propulsion system assembled in low-Earth orbit using three to four Ares V rockets. The spacecraft itself would be equipped with "closed-loop" life support systems, in which air and water would be recycled and plants would be grown onboard to feed the crew and contribute to the "psychological health" of the astronauts. The original presentation shows that astronauts could spend 500 days on the Martian surface (pdf, page 6). Nasa still needs to come up with solutions for effectively protecting the astronauts from high levels of cosmic radiation and astronauts will also need medical equipment for the diagnosis and treatment of illnesses or injuries. The Mars Design Reference Architecture also envisions using the Moon as a proving ground to demonstrate supportability concepts for long duration missions and component performance in dusty environments."