NASA engineers work on alternative moon rocket

This artist rendering shows NASA's next-generation of moon rockets being developed at the Marshall Space Flight Center (MSFC) in Huntsville, Ala. Ares I, left, is the crew launch vehicle that will carry astronauts to space. Ares V is the cargo launch vehicle that will deliver the lunar lander and other large hardware to space. By day, the engineers in Huntsville, work on NASA's new Ares moon rockets. By night, some go undercover, working on a competing design. These dissenters and their backers say their alternative rocket would be safer, cheaper and easier to build than the two Ares spacecraft, which have already cost NASA $7 billion. (AP Photo/NASA, Marshall Space Flight Center)