was talking with katie coleman who will be flying in a couple months to the space station for her six months, and she was in the buoyancy last week running through -- before they did the space walk, the procedures that they are doing up there now. to make sure that all that works before they actually do it in space, right? >> absolutely. so the coordination that you have here is, you know, years ago people had who say, well, what happens if the coolant pump fails, so let's carry some extra coolant pumps and get you familiar with what's going on. so the astronauts are up there as engineers, and e.v.a. crewmen and train for that. but then when something happens, you have to set up a new scenario, because it wasn't exactly like you thought it would be. it's not a standard, you know, change-out. >> john, let's he cexplain to o viewers why this is a bigger deal than it might seem. the issue here is they've got these replacements. if for some reason they couldn't fix this adequately, this is an issue. we've got six astronauts up