NASA's Constellation would be a leap forward from the space shuttle, but is it worth the price?

In Pictures: The Next Generation Of U.S. SpacecraftThe space shuttle is set to be retired at the end of 2010. Until its replacement, the Constellation system, is operational, NASA astronauts will have little choice but to hitch a ride on a Russian rocket to get to the International Space Station.With sufficient funding and political support, Constellation could get American