let's bring our guests in now. rick, and mike are the astronauts. we've got john zarrella, with us, also mike massimino, who joins us to talk us through what's happening. i want to start with you, john. tell us what's happening now. we're just a few minutes in to this. >> yeah, that's it. right now the astronauts have just exited the air lock there and they are going through some preps and check outs. mike massimino knows all about this from the space walks that he's done, and ultimately what's going to happen is on the end of the robotic arm, one of the astronauts, for much of this day. this first day out there while they're working, what they're going to be doing is preparing to change out that whole cooling pump box and put the new one in, but today is just disconnecting wiring and hoses and pumps and electrical connectors so that they can, then, get to that box,