Astronauts should have little trouble adapting to Mars after a long flight in zero gravity, said departing residents of the international space station in a live interview with CNN. Taking their final laps around the planet, the three took part in a long distance conference call with CNN Space Correspondent Miles O’Brien on Tuesday. Noting that the duration of their flight was similar to the time necessary to send a manned mission to Mars, O’Brien wondered if humans arriving at the red planet would “be able to do any useful work” or “stand up in the one-third gravity of Mars?” Certainly, if the crew worked out with specialized exercise equipment, like that onboard space station Alpha, said Jim Voss, who spent 5 1/2 months on the orbiting outpost, along with fellow NASA astronaut Susan Helms and Russian Cosmonaut Yury Usachev.