There is a big difference between Dragon and Orion, just as there was a big difference between Apollo and Soyuz. Apollo had over ten times the delta-V and the ability to return to Earth at over 24,000 MPH. Soyuz is purely an orbital vehicle that can enter the atmosphere at 17,500 MPH. That said, a plan to send a Soyuz to the moon simply means adding a second propulsive stage and a second heat shield. Dragon launches on a Falcon 9. Space-X is also developing a Falcon 9 Heavy, which is far larger. A Falcon 9 Heavy launching a “Dragon 2″ could easily match Ares I/Orion, although the capsule itself would probably be redesigned from scratch. All that said, I still support Ares V. The economies of scale of super-heavy-lift boosters is vital to lunar base construction and interplanetary exploration.
