NASA has scheduled the first SpaceX flight with a Dragon crew capsule on board. It is a test. There will be no astronauts aboard. The space agency is taking progress step by step, leaving little to chance. When there are humans involved, there is little room for experiment. NASA learned that lesson the hard way after losing crews in its early days and during its time with the shuttle. It is a matter of credibility. SpaceX has to prove that its capsule can do the job of ferrying astronauts to and from the international space station. If it does, NASA need no longer to rely on Russia for transport. Russia for its part lost a bit of credibility when its most recent rocket failed with a space crew on board. They landed safely, but it was scary.