GEMINI MANNED FLIGHT PROGRAM TO DATE bY LT. COL. JAMES A. McDIVITT, USAF (M) Astronaut - NASA/MSC NEIL A. ARMSTRONG Astronaut - NASA/MSC SHEPARD: We'd like to talk during this part of the presentation aboui the Gemini program and tu give you a current status report on the last three flights which we have completed this year. A few days ago, a Marine colleague of mine and I were having a discussion in the control center at Houston. This Marine colleague is now a soft drink salesman but he happened to be there for the occasion of the receni eight-day mission which we completed. We were discussing a flight which occurred in May of 1961. The flight plan indicated so many seconds of control and rate command, SO many seconds of control in manual, so many seconds to look out the window, so many seconds for this, so many seconds for that, a completely chalked full flight plan. In the meantime on the control center floor discussion was going on between the ground and the pilots and they were saying "well if we don't get this thing done Tuesday we can do it Thursday." We have two gentlemen here to present the last part of this session for you. I could spend a great deal of time introducing both of them. They both have wide experience, varied backgrounds, with emphasis of course in the aero- space and aeronautical professions. They both I think are fairly well known to you so I won't take too much time in enumerating the many accomplishments which they have achieved to date. However, I will say that the first of these gentlemen, Jim McDivitt, is an Air Force pilot, test pilot trained, has combat time in KO- rea for which he has been decor- ated. He is currently serving with the NASA in Houston, was the command pilot of the four- day GT-4 mission. The second gentleman, Mr. Neil Armstrong, McDlVlTT is Navy trained, combat time in i Korea for which he has been de- corated, served as test pilot with the NACA/NASA including X-15 time and is ' currently with the NASA ;n Houston - Neil Armstrong. Jim and Neil will you come up please? 1 ARMSTRONG: Good morning gentlemen. We are pleased to again be at The Society of Experimental Test Pilots' Symposium and give our second status ' report on the Gemini program. Gemini Manned Flight Program to Date I35 The Gemini program objectives are simply stated - to extend the useful duration of man and spacecraft . in space: to develop the equipment and techniques required to perform useful tasks - specifically the rendezvous. Since our status report last year, 4 Geminis have flown - Gemini 2--Unmanned, first all systems flight. Gemini 3-First manned flight, first orbital maneuvering. Gemini 44day duration. First extra-vehicular activity. Gemini 5-8 day flight. We will discuss mission phases with reference to the individual flights - starting with the launch. McDIVITT: I'd like to start right off where we normally start space +lights and that's at the launch. Since we have to launch someplace I'd just like to show you one of the typical Dhotographs that was taken on one of our flights and this is the launch complex down at the cape and I'm sure most of you are familiar with it but I might point out some of the significant features. [Slide I.) You can see right in here the Saturn BAB and the Saturn pads, Titan Ill and its pads and we started right about there. It is quite easy to see where these things start and we want to show you how they continue. Now you know in our launches we didn't have any major problems. Each and every flight got into orbit ihe way it was supposed to. We did have a few minor problems though and they are worth mentioning because I think they sort of demonstrate our capability to handle off nominal occurrences without any catastrophic effects. As you know, Gemini 2 had one attempt that I guess we wouldn't say was completely successful but it certainly did show that we had the capability built into our booster to shut the thing down if we had any malfunctions during that very criti- cal time between engine ignition and lift off. I'm not sure you're all aware of it but there are three seconds where we are held down on the pad with bolts and during this short period of time we sense for malfunctions and our malfunc- tioning sensing system detected a hydraulic failure and shut the booster down. There were some pretty long faces but they could have been a lot longer if that thing had fallen over. Gemini 2 and Gemini 3 also had a slight discrepancy, the same kind of dis- crepancy on both flights, they had somewhat lofted trajectories which meant that the booster wasn't necessarily flying its optimum path into orbit. The reason for this was that we were flying with somewhat hotter engines than we had anti- cipated. Our thrust levels were a little higher. We reprogrammed the pitch pro- ~ f gram to take advactage of this higher thrust and on Gemini 4 and up we have , a slightly different pitch program that seems to be working just right. I On Gemini 4 you are probably well aware that the erector didn't lower which really didn't affect the flight of Gemini 4 but could be a serious problem on a rendezvous mission because you already have the Agena launched and you just don't have a teal long window to launch the Gemini in. We also had an umbilical hang-up that broke loose just after lift-off. Gemini 5, of course, we had an attempt, that after a few problems with filling the hydrogen system for the fuel cells, a TM drop-out, a power glitch, a I36 THE SOCIETY OF EXPERIMENTAL TEST PILOTS thunderstorm, and a few other things, it became apparent that that wasn't the day to try it and late in the afternoon we all decided to qo home. But the next time we tried we had a real on-time launch. As a matter of fact I don't know if you're all aware of it but we launched, I think it was .38 seconds, ahead of time and we do things in flight in elapsed time but since the elapsed ,time round- ed off the way the computers round it cff was in the 59 minutes and 59 seconds we were going to have to carry that odd second for 8 days we arbitrarily said we were 38 hundredths of a second later and rounded it off to an even number and flew with it. This time is very important. The one anomaly that we had during Gemini 5 that was of some iignificance was the pogo. Now this pogo was discussed at last year's symposium and I'm sure you all remember exactly what we raid but it's really a longitudinal oscilla- tion that is due to a first stage mechanical hydraulic-dynamic feed back and has been taken care of through a fix which put a couple of things on the booster we call horns and they are tuned so that they have the proper amount of air pressure. There was a slight procedural error in the tuning of these horns bor the second attempt at Gemini 5 so we got a slightly larger than normal pogo. May we have the next slide please. (Slide 2.) This is a slide of the comparative pogos on all the flights. You can see right here that Gemini 5 at about 130 seconds had a pogo that was about .38g peak amplitude. It didn't incapacitate the pilots by any sense of the word but of course those of you who heard them talking obviously noticed the up and down frequency of Gordo's voke. I'm not sure it was all pogo. You can see that on Gemini 4 we had one that was about .22 maximum and the other flights were considerably lower. I might add that the spec value was 259 at peak. During the launch we have B lot of things that the pilots do. First I'd like to show you what we see on the outside, what the people on the ground look at. May I have the movie please. Fortunately the booster doesn't jump around like that. Now that's a pretty view from the outside but unfortunately we don t enjoy that view from the inside because there isn't any automatic abort system on the Gemini, this is a manual function. We have certain key displays that we monitor during flight and because a lot of these things are very time critical, especially those close to the ground, we are kept pretty busy and I'd like to illustrate the kind of things that we look at during flight. (Slide 3.) First of all we have the three axes attitude ball, we have rate needles, one here for ro!I. and a pitch and yaw needle. We have tank pressure gauges that monitor the first and second stage fuel and oxidizer tanks. We have a timer that starts at lift-off. not ignition, but lift-off. We have engine lights, two stage one engine lights and one stage two engine light that indicate whether the engines are oper- ating at fu!l thrust or not, ii secondary guidance light and an attitude overrate light.