 The thing about a Mars mission that really is important is dealing with the difference in gravity, and you're not going to get that on Earth. And getting to Mars, and you're not going to get that by walking into a pseudo-containing vehicle. They talk a lot about, you know, the psychology of people having to live together for long periods of time, but I also have also thought for many years that that's pseudo-silliness, because, you know, for...