Safer way to reenter. you can only do that because of the computer technologies, our ability to control spacecraft in ways that were just impossible the first time. >> this is unmanned, but a test drive of what possibly come later. so what is nasa hoping to learn from whether this kind of rock skipping technique works? >> well, it's to see whether or not this process of shedding some of that velocity actually is going to be useful for the astronauts, allows you to land much closer. the old way, you have to splash down somewhere way out in the ocean, which required a lot of infrastructure, was ...