Young: Ground communications and countdown were nominal; launch preparation was nominal; systems preparation was nominal. Crew Station Controls and Displays: I think thereÂ’s a couple of things we can say here. One is that we knew that the H2 Tank 1 pressure read-out was oscillating, didnÂ’t we?
Mattingly: Yes. They told us that. We had a caution and warning on it.
Young: They told us that. But the other thing that we didnÂ’t know was that the SPS pressure - the fuel pressure was what - 7 psi low? Due to a transducer.
Mattingly: IÂ’ve got all those numbers written down. Apparently the problem with the SPS pressure was something that they had known about and it was not something that we ever discussed. The problem that Charlie saw was that the Delta-P on the pad was greater than 20.
Duke: ThatÂ’s right.
Young: When we were sitting there, we were sitting with an abort condition for LOI. We had a greater-than-20 Delta-P laying there on the pad.
Mattingly: And they came back and said thatÂ’s the way it is because there is a shift in there.
Young: And then some other thing had failed and nobody told us anything about that. Some ground reference thing had failed and I guess it could have been our fault and they asked us if we wanted a final briefing on the actual systems, how they were operating, and I asked Dave Ballard if there was anything we ought to know about and he said not that he knew of. So I said, letÂ’s not do it then because weÂ’re kind of busy and I donÂ’t want to unnecessarily fill squares.
Mattingly: We talked to Don Arabian about it and he was sending us all the preflight problem tracking lists and I read every one of those reports.
Young: It wasnÂ’t in there.
Mattingly: There was a transducer shift, I remember, and it was a telemetry transducer shift. That was the way it was described, and it was something that the MOCR had calibrated and that was all taken care of and whether this was the same problem or whether it was an additional problem, I donÂ’t know.
Young: The point being, I think we could have had that problem all worked out before we ever left the ground with the mission rules and every-thing for LOI instead of going through a couple of days of LOI mission rules and coming up to LOI with an SPS light and that kind of thing. The bad feature about an SPS light, is - thatÂ’s not the only thing you can get an SPS warning light for.
Mattingly: ThatÂ’s right. It negates the value of the SPS pressure light because youÂ’ve masked it by having it on all the time.
Young: For future design, we ought to be able to reset lights if thereÂ’s more than one variable going to them. For example, when you get a fuel cell light, thereÂ’s five things going into a fuel cell.
Duke: Concerning the SPS fuel and oxidizer Delta-P; I couldnÂ’t believe it when I looked up there and it was out of limits. It was 7 psi low.
Young: Was that what it was?
Duke: Yes. It was about 165 or 163, and it normally runs around 175, because IÂ’ve always seen it right in the green band.
Young: How about the oxidizer?
Duke: The oxidizer was in limits. At that time, it was okay. It looked like it was riding a little high, but it was still in the green band.
Mattingly: DidnÂ’t you have a greater-than-20 Delta-P?
Duke: Yes. Right then, we had a greater-than-20 Delta-P which - the rules say you donÂ’t burn. So we asked them about it and that was the first we heard that we had a bias shift on the fuel side.
Young: ItÂ’s one of those communications problems, IÂ’m sure, but we ought to solve it.
Duke: But they apparently knew about it.
Mattingly: I donÂ’t think the ground, the MOCR guys, knew about it.
Duke: No, they didnÂ’t.
Mattingly: They were caught by surprise. They were doing a lot of scurrying there also just like we were.
Young: Apparently so.
Young: Okay. Distinction of Sounds in Launch Vehicle Sequence, Countdown to Lift-off. I didnÂ’t hear any sounds, did you?
Mattingly: I was surprised at how quiet everything was.
Duke: I didntt hear any valves or any valves opening or anything like that.
Young: No, I think itÂ’s nominal. I didnÂ’t hear any on Apollo 10, either.
Mattingly: Not a thing; I was really surprised.