Apollo 11 astronaut Buzz Aldrin has a problem with NASA’s current manned space plan: Namely, the five-year gap between the shuttle’s scheduled retirement next year and the debut of the Ares I rocket and the Orion spacecraft, which will take us no further than the moon—a place we’ve already been. Aldrin thinks NASA can do better. His plan is to scrap Ares I, stretch out the remaining six shuttle flights and fast-track the Orion to fly on a Delta IV or Atlas V. Then, set our sites on colonizing Mars. Here, Buzz challenges NASA to take on his bolder mission.