In Orion from the very first day of course, we knew that fall out was a major consideration. What we proposed to do was to take the thing off from the ground under nuclear power, so we'd be exploding bombs in the atmosphere all the way up, and we'd be plastering the ground with fallout, of course, and radioactivity would be spread far and wide. And you might say, 'Isn't that totally crazy? Isn't that totally unacceptable?' Well by present day standards, of course, it's completely unacceptable and it's absolutely clear we wouldn't want to do it. In those days it was different because it's a question of compared with what, and we were comparing this with a nuclear war, which in those times was, we felt to be a very real possibility. We were thinking of a nuclear war in which hundreds of megatons would be exploded on the ground, would be plastering the earth with fallout on a vastly larger scale, killing billions of people. But what we proposed to do was a few kilotons per shot, so as you go up through the atmosphere, maybe a few hundred kilotons total, and getting rid of the bombs, so we wouldn't have a nuclear war. I mean that was the idea. So our mindset was: You compare this with what the bombs could do if they were really used in anger. And in that case of course, what we were doing was tiny by comparison. In addition, in those times, there were bomb tests in the atmosphere going on all the time. There was a heavy testing programme, but what was actually being put into the atmosphere every year during that time was much larger than what we proposed in the total programme.