 And I guess I was thinking, because I was reading some articles about how frequently astronauts, it's almost become commonplace. Now we have all of these launches, and they go up to the Space Center, and they exchange, and somebody else has been up there for six months, comes back to Earth. And so one of the things with regard to us taking this in stride, Ken, a question about what happens to an astronaut's immune system during spaceflight, because they're weightless, they're moving around, and