MSC-07631 03. Powered flight

Cernan

The S-IC ignition - The lights started going out at 7 seconds, and somewhere around 3 seconds they were completely out. You could feel the ignition. You could feel the engines come up to speed. Just prior to lift-off and during the first few seconds of lift- off when we were near the pad, both the CMP and I could see the reflection of the engine ignition out the left-hand window and the hatch window in the BPC. We could not see the fire but could see a red glow through the windows reflecting apparently off the surface. Ignition was like a big old freight train sort of starting to rumble and shake and rattle and as she lifted off. We got a good tower clear. As you go through max-q, as in the past, it gets very rough and much noisier, but I don't think we ever had any trouble hearing each other in the spacecraft. I had my intercom very high and all my S-bands and tweaked everything up prior to lift-off. We went through max-q and the only unusual thing going through max-q, considering wind components that we had was that I saw 25 percent on the ALPHA going through max-q. The yaw needle was right on, but the pitch needle had dropped to a degree and a half at the most. I guess I didn't really expect it because of the predicted wind components. After we got through max-q, you could still certainly tell the bird was burning as we pressed on toward staging, but it got much quieter and it was very evident that you were through max-q when that time came. We had center engine shutdown on time. We had staging on time.

I don't think it's ever been recorded on a daylight launch before, but as soon as the S-IC shut down during the time involved in recycling and getting the staging sequence going and the S-II lit off, apparently the trailing flame of the S-IC overtook the spacecraft when we immediately went into that zero-g condition. And, for just a second, as the S-II lit off, we went through the flame. It was very obvious. We could see it out of both windows. I particularly could see it out of the left-hand rendezvous window of the BPC. It was not a smoke; it was not an orange fireball; it was just a bright yellow fire of the trailing flame of the S-IC; and it happened for just a split second. Then we got off on the S-II and things got very quiet and very smooth and was a very long, quiet, smooth ride.

Evans

I really wasn't watching the lights because I guess I didn't expect the thing to shake quite as much as it did. To me, I felt like I was really vibrating. I wanted to find out what was making me vibrate. I wasn't expecting that much vibration when the S-IC lit off. At lift-off, again, once it got vibrating, I didn't feel the yaw. I was watching the needle on the thing but didn't feel the yaw, though. The shaking increased a little bit up to max-q and then there was a different type of shaking. It was more of a vibration, I think, going through max-q. And there was more noise associated with going through max-q. Of course, with the shutdown of the S-IC, I think that was about 4-1/2g.

Cernan

We pushed 4g.

Schmitt

Just pushing 4g on the thing and it quits just like that. I was prepared for it because Gene had said, "Hey, brace yourselves because it is going to happen," and it happened all right. It just flat quit when we went from 4g to 0.

Cernan

The great train wreck.

Schmitt

I think in all those booster cutoffs, it's hard to see how rapidly the g-level decreases. I guess the only other comment I have is that I think that it is good to do a lot of simulation about malfunctions during launch, but up through max-q it is a little bit unrealistic to think that you are going to analyze a malfunction in the spacecraft.

Cernan

To sum up the S-IC, I personally didn't think it was any different than my previous ride on the S-IC and up through this point being a night launch really didn't make any difference at all. The only thing I did different that I hadn't really though a lot about until I sat on the pad and began to think about staging was, just prior to staging, I took my hand off the abort handle and held the support arm rather than the translation control handle until after staging. I did this just a couple of seconds prior to staging. I had talked about it with John Young a little bit prior to the flight and it turns out that's what he did, also. Probably a good thing.

The S-II ignition was very smooth. We got skirt sep right on time. I could feel skirt sep going. We had tower jett, which was really sort of spectacular at night. I think the LMP is going to add something to it, but from the left-hand rendezvous window, I could not only see the flame, but the inside of the BPC seemed to be lit up. Of course, it doesn't stay there very long; it's gone in just a split second. But it was a very spectacular sight at night to see that tower go against the blackness of space out there. We could see guidance come in very definitely. It was not as big a pulsation as I've seen on the simulator but I did see the needle and the spacecraft did change its attitude slightly. You could see the mixture ratio shift. It was just a long, smooth, quiet ride. Inboard cutoff was right on time. You could feel it, a definite physiological feeling. Of course, the g-meter saw it also. The S-IC cutoff, as Jack said, is again very sharp, almost instantaneous, from almost 4g to 0. But on the S-II , although it's sharp and a very hard hit, you don't unload the entire stack like you do when you're on the S-IC. The staging was very smooth. It did not seem like an exceptionally long time before we separated and the S-IVB lit off.

Schmitt

On the tower jett, I wouldn't say a split second. As a matter of fact, I was surprised it lasted as long as it did. It was a few seconds.

Evans

I couldn't see the rocket go. All I could see was an orange glow out the center window.

Cernan

While we were on the S-II, we would see no indication of light from the engines. We were just thrusting out in the darkness of space. I tried to see stars for potential mode IV and, of course, at that time, mode II abort and turned the lights down on the left side once or twice. But even with the lights down on (we had the LEB lights relatively low), in my estimation, it would have required all the lights in the spacecraft to have been off and certainly more than a few seconds to become night adapted to be able to see through the windows and pick up stars that would have been able to help in an abort situation had you lost the computer and the SCS. We had looked, potentially planned to use those stars in an abort condition if we had to. We had excellent constellations to look at. They obviously were there, but I could not see through the low glow reflection on the window even with our lights, floodlights, turned almost all the way down. I even went to the extent of trying to shield my eyes on the S-II and looked out the window and I still could not pick up anything that I could have recognized for an abort. I also could not pick up any night horizons during that point in time which I thought I might be able to base on seeing where the stars cut off and where they do not.

Schmitt

We had another indication of that during entry when we were looking for a night horizon and finally saw it, but it was extremely hard to find.

Cernan

We got lit off on the S-IVB, and, unlike the flame we flew through on the S-II, we did not do that on the S-IVB. I don't know where the reflection came from, but I could see the reflection from somewhere out the forward window. Either it was the S-II trailing flame trying to overtake the vehicle but didn't quite make it, or it was S-IVB ignition reflecting off the S-II because there's no atmosphere up there at that point. But I did not see a flame, but a residual back light out that window just for a short period of time, either right at staging or just at S-IVB ignition. As I think back, my best guess would be that the same thing happened on the S-II, that the trailing flame, when you go from 4g to 0 instantaneously, tends to overtake the vehicle. But in the case of the S-II, it's not nearly as big a pattern and just didn't quite make it up the stack. I just saw some of the glow of it. That's my best guess. After the S-IVB ignited, we never saw anything except the APS firing throughout that burn.

You could see the mixture ratio shift.

Schmitt

But PU shift, both vehicles, was surprisingly noticeable.

Cernan

Communications throughout the booster phase were excellent. I never had any problem hearing either Stony or CAPCOM.

Controls and displays performed super.

Crew comfort through powered flight - I felt very comfortable throughout the entire flight in orbit.

As far as I'm concerned, there was no pogo on the burn.

Evans

No, none.

Cernan

Summing up the birds. If you want to put them in more layman terms, I think the S-IC acted and performed like some big, old, rugged, shaky, big monster. It has to be noisy, has lots of vibration, and smoothed out somewhat after max-q, but still was a rumbling bird. The S-II was a Cadillac: quiet, less than 1g flight most of the time until we built up our g-load prior to staging. It was quiet, smooth, had very little noise, or feeling of rumbling or anything else. The S-IVB: a light little chugger is probably the best way I can describe it, which is not different than I remember it in the past. It just sort of rumbled on, not anywhere near the extent of the S-IC, but just sort of continued to rumble on through the burn. After a while, especially during TLI, it got to be a very pleasant, warm feeling that she was burning like she should burn.

Evans

Chugging, I think, has two different connotations. I felt the S-IVB was more of a very light rumble in the background, something that is kind of rumbling as opposed to chugging. A chug to me is a bang-bang type thing, and to me it was more of a rumble.

Schmitt

I agree, it may be a sense of rumbling but the ride was smooth. I could sense some activity behind it, but I wouldn't have said that it was chugging.

Cernan

I'll modify chugging to say it was a hummocky chug, just a rolling type. Nothing different, and, as I say, the best recollection, similar to the S-IVB I had the opportunity to ride on before, but probably even more steady and continuous flow of light rumbling.

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Edits and errors by Eric Hartwell are licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 2.5 license. The original NASA material is copyright-free.