schwit1 writes: Check out this detailed and informative look at the unspoken competiton between NASA's SLS rocket and SpaceX's planned heavy lift rocket. It's being designed to be even more powerful than the Falcon Heavy. Key quote: "It is clear SpaceX envisions a rocket far more powerful than even the fully evolved Block 2 SLS – a NASA rocket that isn't set to be launched until the 2030s." The SpaceX rocket hinges on whether the company can successfully build its new Raptor engine. If they do, they will have their heavy lift rocket in the air and functioning far sooner than NASA, and for far less money.