GEMINI MANNED FLIGHT PROGRAM to DATE by LT

Home , Gemini 2, Gemini 3, Gemini 4, Gemini 5, Gemini 7

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 critical 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 discrepancy 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 anticipated. 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 rounded 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 operating at fu!l thrust or not, ii secondary guidance light and an attitude overrate light. These are the instruments that we monitor during launch and the reaction time that you have to the ve;y ION altitude abort situations that ! mentioned are very short. As we go higher and higher and higher we can relax these almost , instantaneous requirements but we have a number of different kinds of abort , rules and different modes that we go through. As you're all well aware the Gemini ha; ejection seats and Jrom 0 to 50 seconds, which is somewhere in the order of I2 to 15 thousand feet we use the ejection seat mode if we have to get off the booster. Above 50 seconds and up until we reach the velocity of 21,000 feet per second which is on the order of 5 minutes flying time, we salvo I fire the retro rockets to come off the booster. We shut the booster down and Gemini Manned Fliaht Proaram to Date I37

salvo fire the retro rocksts. Above 21,000 feet per second, from about 5 minutes and 10 seconds till about 5 minutes and 30 seconds, we just separate from +he booster. We shut the booster down, separate in a standard manner, turn around, do a normal retro fire and re-entry. There is a point at which we can actually insert ourselves into orbit if the booster shuts down from a fuel depletion situation. We can actually separate from the booster and thrust on into orbit. The amount of capability that we have on board spacecraft varies with the particular configuration we're flying. I'd like to talk just a bit about the sensations that we have during the power phase. At lift-off, although there is a lot of vibration and noise and no real high acce!eration it is very obvious when you lift-off, there is a change in frequency and amplitude of the vibrations, not great, but just enough to really clue you that you've lifted off. Also our clock right there starts counting. These vibrations build up in intensity until we've reached maximum Q, then drop off abruptly as we go supersonic which is just shortly thereafter. It is a very quiet flight from there on. The pogo on our flight was hardly noticeable although we reached a level of about ,229. I just barely noticed it and Ed never even knew that we had it. Staging has been a very smooth and uninteresting type kind of thing as far as the vibrations and motions go. Engine shutdown is another very smooth thing. When the engine shuts off and when you're in orbit the booster and the spacecraft are very stable. I'd like to show you a movie of what the gauges actually look like. This particular movie was taken in Gemini 2, our unmanned launch and it shows some rather interesting things, but before we start I want to explain one thing. You'll be looking at the all-attitude indicator and it will look like the spacecraft is going over in yaw. The situation here is that the spacecraft is not mounted in the same axis system that the booster is. We'vs had to position the spacecraft on the booster in such a manner that there would be a clear ejection path and we wouldn't 5ave to worry about the towers and we wouldn't have to worry about ejecting in the wrong direction. So we had the spacecraft mounted on top of the booster such that during launch it looks iike the spacecraft is yawing over but it's booster pitch and it's kind of a confusing item there. I'd like to show the movie now. This wili be a little faster than normal time. There's ignition! You can see the first-stage tank pressures coming down. We've got the roll program where the booster is aligning us up with the flight path. Now we've started the pitch program. These are rate needles here. You can see the fuel pressure coming down, the stage two pressures are nice and stable here. We're going through or approaching maximum Q region here and you can see the slight oscillations that we have. One thing that is quite interesting is right after staging. We I have a period of about ten seconds before we actually get guidance initiate. This is a pre-program thing and we're coming up on staging. It should occur

around 2:23. And you'll see these needles rise to the top indicating that . , . there they go, we've staged, now you can see the pressure is coming down. We should have guidance initiate here and you'll see the thing pitch over rather , abruptly - there it goes. That's when the guidance actually starts. It's all open ' loop up until that time and that was radio guidance coming in. I don't know if you can notice it back there but these two needles are independent of each

~ other and if one fails they fail up indicating that the pressure has not .:allen and we have two completely independent power sources for these. That is an I38 THE SOCIETY OF EXPERIMENTAL TEST PILOTS

McDIVITT: There is more than just maneuvering around in space. We thought the problem of what it is like to be flying formation essentially in space would be rather interesting to investigate especially since we're going $0 have to do that on Gemini 6 and on all of our rendezvous missions so we incorporated a little station keeping or formation flying on Gemini 4. Since the only object we had was our booster we tried to utilize it to the best advantage. The other modification we made to the booster was the installation of a pair of flashing lights that were diametrically opposed and mounted about the middle of the stage. The overall flight plan called for us to come off the booster, turn around, thrust back towards the booster and get in formation with it and stay in formation with it around the few minutes of daylight that we had, then the darkness of about 45 minutes, and take some pictures of it in the next dayside pass of about 45 minutes then prepare for EVA, then do EVA the next thing. This was a little crowded but I think it might have been done. As the booster shut down, instead of separating at the normal time of 20 seconds after engine shut down we decided we'd delay until 30 seconds so that we could damp any booster spacecraft rates that we might have. When the booster shut down though it was very stable. We had combination rates of less than .2 of a degree per second as read off the instrument station. However, I did try to damp these rates even more by using a translation thruster rather than the attitude thrusters which for this particular mass combination went right through the CG and really didn't affect the attitude. So we did attitude control with our translation thrusters. We separated the spacecraft and started turning around. At separation, for some reason or other we feel that we got a larger relative velocity change between the two vehicles than we had anticipated and this could be due to two different effects. One is the pop gun effect of firing the aft-firing thrusters down onto the dome of the second stage, building up a pressure between the two vehicles so that when they came apart they were sort of pushed apart or a very like thing of thruster impingement on the second stage as we actually fired away from it. Whatever the case, the postflight investigation showed that we probably separated with three or four feet per second more than we'd anticipated. We felt that we came off the booster a little sideways. However, the instrumentation didn't subsrantiate this postflight but it felt like we came off pitching and yawing all at the same time. Not a great amount but a little indication of an abort or at1 abort requirement - if both needles fall past ser- tain limits. Now you can see that we're sort of in a steady state condition here with very few oscillations and it is a nice quiet ride. Still interesting but quiet. Right about this time is where we would change to a different kind of abort or we would just shut the booster down and turn around and do a normal retro fire. There's SECO, which is a second stage cut-off. On this particular flight the spacecraft was rolled around, turned around, retro fired and re-entered. I think that gives you a little insight into our launch problems and the techniques that we use. ARMSTRONG: An important Gemini objective is the demonstration of precise orbital maneuvers. In addition to the obvious requirements of rendezvous and docking, maneuvers are frequently performed to change orbit size. Gemini 3 was the first to demonstrate the feasibility. Both Gemini 4 and 5 maneuvered to raise the perigee to provide increased orbital lifetime. Both Gemini 3 and 4 lowered the perigee to 45 N.M. just prior to retrofire to provide an early orbit decay in case the retros failed to fire. Gemini Manned Flight Program to Date I39 bit. We turned around and as we started the turn-around it was just like being in a snow storm. We used pyrotechnics to separate the spacecraft and the booster and we had little bits and pieces of metal and flakes and I don't know what all out there. We separated the nose fairing and the fairing for the IR sensors at the same time and we had bits and pieces of that all over. It was quite interesting. Through all the debris I finally found the booster. It wasn't quite that bad. We were slightly out of plane at the time, which surprised me, but here again it could have been due to two things. The thrust that we applied to change the attitude actually has a translation component with it and it could have thrusted us off in the direction perpendicular to our orbit or it could have been due to this kind of catawampus separation that we thought we had. As soon as we turned around, I was quite surprised to find that the booster was tumbling at a relatively higher rate of about 8 to IO degrees a second and we really didn't anticipate this until maybe an orbit or two later since the booster had no stabilization whatsoever. At the end of an orbit though this rate had actually increased to about 40 degrees a second and it was really ripping around. The flashing lights were visible as soon as we got around even though the sun was shining on it and it was very brightly lighted. We thrusted back towards the booster and I thought we had killed off our relative velocity, +he indications that we had from on-board instrumentation showed that we had applied somewhat more velocity than we had separated with and we should be closing with it. So I went ahead and started aligning my inertial platform which takes about ten or fifteen minutes to get an accurate alignment and since this was only the second flight we wanted to make sure we would be in shape to retrofire at the end of the first orbit if we had to. During this period of time the booster dropped below the spacecraft and out of the view of the window but it didn't seem to be moving particularly fast the last lime I saw it. After about five or six minutes of alignment I pitched down to find it and it had moved a lot farther away than I'd expected so I pitched back up to alignment attitude and put the platform to orbit rate or a mode that keeps it aligned with the local vertical and then pitched back down and started chasing the booster. Because of the flight plan we really didn't have the time available to us to perform a rendezvous where we would retrofire essentially and drop down below the booster, and then because of the orbit change essentially catch up below it and then come back up and catch it and since we didn't have any sensors either onboard rate or on ground tracking that was available to us i? would have been a little bit difficult to start a rendezvous from unknown initial conditions. So we elected to use sort of a brute force technique where instead of assuming that we were in orbit, we just assumed that we were flying across the earth like in an airplane which is sort of a rectilinear approach. I feel that this would have worked out if we had had the proper kind of lighting on the booster but unfortunately we lost it. Let me talk a little bit about the lighting here. The lights could be seen flashing if we were close to the booster in the daytime but when the booste- was up against the lighted earth background and it was some distance away these lights, although very intense, were not visible. At booster-sunset, which wasn't necessarily sunset on the ground, the shape and size of the booster dis- appear almost instantly and the lights appear at the same time. It's a very quick thing. These two lights that we had which were diametrically opposed were excellent for iudging range when you could see both lights because the distance I40 THE SOCIETY OF EXPERIMENTAL TEST PILOTS between them could never be fore-shortened by particular attitude positions but because of this they weren't always visible. A single flashing light at night just didn't provide the kind of range and range-rate information that I needed. So during the nightside we tried to close with the booster and we did. A post flight analysis based on our attitudes and the thrust and the trajectory of the booster showed that we closed this to a minimunr distance of around 400 feet and probably a maximum distance of around 2,000 feet. At that time, the booster had been tumbling and I could see the double lights and had an idea of where we were but shortly thereafter I didn't see the second light for quite some time. I had no idea where we were and the next time we saw the lights it was readily apparent that the booster had drifted a considerable distance from us. Shortly thereafter we came out into the daylight and the lights disappeared instantane- ously. We could see the size and shape of the booster and it was between a mile and two miles away and it was rapidly disappearing. We followed it through the daylight side up until the United States portion of the pass and at ,hat time we had elected to not pursue the booster anymore. We had a fuel budget that was limited for this phase of the mission prior to flight and we stopped short of the alloted amount of fuel we had set aside for this but we had a number of things that we were going to do and it depended entirely on how ;he mission went which of these we selected to do. It didn't look like we :ould close with the booster unless we took all the fuel that could have been used for OAMS retrofire and we elected no+ to do this at the time. ! think that the problems we faced were primarily the lighting, secondarily the tumbling booster which wasn't exactly what we'd anticipated. The fuel budget and the flight plan considerations sort of limited the number of approaches we could use and we happened to lose one of our aft firing translation thrusters during the portion of this phase of the mission which meant instead of thrusting 200 pounds in one direction we were thrusting 100 pounds in that direction and 50 pounds in another direction. I do feel that this is a phase that can be done in exactly the same configuration that we flew with in a spacecraft with no radar, although the radar would be nice, and I feel that we do need a little better lighting on the booster and we need a slightly different arrangement on the fuel allotment so that we can spend a lot of fuel early in the mission to get close to the booster before we get into the darkness. ARMSTRONG: Rendezvous is, of course, one of our major obijectives. (Slide 4.) The technique to be used on our initial rendezvous flights is relativelv straight forward. The spacecraft achieves an orbit parallel to and below the target. Its lower orkit requires a higher velocity and therefore it is catching the target. As a predetermined elevation is reached, a velocity increment is added along the line of sight. To begin a transfer trajectory toward the target, several mid-course corrections are added prior to the rendezvous reaching its terminal phase. The maneuvers are normally computed on the spacecraft computer, using data obtained from the spacecraft's radar and inertial platform. Gemini 5 was the first spacecraft to carry the radar set and the rendezvous calculations in its computer. In order to give them their first flight test, this rendezvous evaluation pod was carried in the spacecraft. [Slide 5.) It weighed 77 Ibs. and carried flashing strobe lights and a radar transponder. The plan was to eject the pod from the spacecraft, then perform a series of maneuvers to put the spacecraft in the position shown in the slide with the rendezvous evaluation pod as the target. Radar measurements would be taken, computations and Gemini Manned Flight Program to Date 141

maneuvers performed, and the rendezvous completed. providing a good check of the entire rendezvous system. This photo, taken by Pete Conrad (Slide 6.), shows the pod was ejected, but, as you know, the entire effort was abandoned shortly after, when a cryo- genic oxygen heater failed requiring the computer, radar, and platform to be shut down to minimize electrical load. However, 23 minutes of REP radar data were recorded. An identical transponder was located at Cape Kennedy and tracked successfully. Lock-ons were achieved at ranges of over 400 miles. Mini- mum range read in the cockpit was 166.72 N.M. comparing with closest approach computed by 2 ground methods as 165 and 171 N.M. Azimuth and elevation data appear to be good. This kind of information indicates that on-board orbital navigation can be a practical reality, using a few well placed beacons around the world. A rendezvous with an imaginary target was successfully performed on Gemini 5 using a series of four maneuvers based on ground computations and ground based radar coverage. It was a closed loop problem with any maneuver error on one burn requiring a correction to the next. Maneuvers are performed to less than I fps accuracy with .I fps being the objective. McDIVITT: As you know, we also looked into the field of extra vehicular activity for the first time during this past year. I'd like to talk about that for just a few moments here. To accomplish this, you realize that we had to develop a little extra equipment. This wasn't the standard kind of equipment that we flew in the spacecraft. So we developed a, or modified really, a pressure suit. We developed an extra vehicular life support system and a maneuvering unit. May I have the first slide please. (Slide 7.) The pressure suit which you see here is the same type of pressure sult flown on Gemini 3 but with some modifications. It was called the G4C suit and was developed specificallv for extra vehicular activity. The single zipper closure was changed to a double zipper. We installed auto locking with quick discon- nects so that in case one of the hoses wds pulled out the disconnect would auto- matically close and the suit pressure wouldn't dump. It had a thermal micro- meteoroid outer garment that was installed over the normal legnet and bladder that we had. It had a tripie visor. The first one was an extra thick plexiglass as a pressure sealer. The middle one was a Lexan - impact visor. We had broken a few visors in training so we thought we ought to try to protect that - it'; sort of a sickening sound to hear it go psssss, and it does, and then the outer visor was a gold coated sun visor. You can see the reflections in the gold co3t right there - it turned out to be a pretty good mirror. The extra vehicular life support system consisted of three major units, umbilical -this gold coated umbilical, the chest pack right across here and Y I connection, which you cannot see. The umbilical provided oxygen from the jpace- craft to the suit. The suit-regulation unit was within the EVA pack there. It had electrical hard lines in the tether to provide communications to the spacecraft I and carried the biomedical instrumentation, It also acted as a safety tether. The chest pack, as I indicated here, provided The pressure regulation and it also provided a supply of emergency oxygen. Emergency oxygen was provided to +he 1 suit through this very small tube that ran up and into the helmet through ihe normal feeding port. The emergency oxygen was manually turned on with a lever right down in this area. So, if the suit pressure started dumping for jome reeson, for a break in the umbilical or from the umbilical hose actually :ailing off, we could go ahead and turn on the emergency supply and hopefully get back I42 THE SOCIETY OF EXPERIMENTAL TEST PILOTS

in the spacecraft and seal the hatch within the eight minutes that we had available. The Y connections were really a normal suit connection modified so that it had two inlets and they were down in here and are very difficult to see. We provided this Y connection so that in case we got back into the spacecraft and we couldn't get the spacecraft pressurized we could at least change back to the spacecraft suit loop without depressurizing the suit, which would have mads it senseless to bother changing back. We practiced this a number of jimes and although difficult it could be done. Ed with his long arms was quite adept at getting at all these little handles. The maneuvering unit which you see right here is a very simple device. (Slide 8.) It has three nozzles on it, one right here which you use to go to +he rear, that particular nozzle puts out two pounds of thrust and has two nozzles on the end which put out a pound of thrust each so that we really had two pounds of thrust in each direction. The total impulse was 40 pound seconds and it could change your velocity by about 6 feet per second. It carried about two- thirds of a pound of oxygen and 4,000 psi. Now the particular techniques that we used in flight were developed using the zero g KC-135 at Wright-Patterson and a mock-up of the spacecraft and our own air bearing table at the Manned Spacecraft Center. In general, the technique for maneuvering is to keep the thrust line through the CG for no attitude rate changes: at the ship thrust line away from the CG to achieve a combined change in rate of translation and rate of attitude. This is the typical position that the unit was used in. It is held in the right hand, a camera is mounted on the top, the oxygen supply is here, it's playing back through the C.G. and :his would be typical of a translation without any attitude changes. In actual flight we experienced no surprises. The training had been adequate. In the maneuvering, we found that if we do it slowly, we do it best. I think that the main fhing we brought back is that EVA is practical, and if you do it slowly it's very safe. I'd like to show you some of the films that we actually took on board. May I have the movie please. (MOVIE) I guess the main thing you get out of that is that Ed needed more air and I guess if we'd used some of the air that we used up talking and put it in a bottle we would have been all right. Neil, would you like to carry on here. ARMSI'RONG: Orbital activities include experiments in four categories - engineering, scientific, medical, and Department of Defense. ( I ) Engineering experiments and operational checks are generally speci- fied by the Manned Spacecraft Center. One example is determining suitable landmarks for the ADOIIO navigation system. Such landmarks, necessary for taking sextant sightings for fixina the smcecraft's oosi- tion, should be easily identifiable, have high contrast, and have generally clear weather. Slide 9 Sultanate of Muscat & Oman Slide IO Arilin & Crooked Islands Slide I I Florida Keys Slide I2 Gibraltar Slide 13 Baja California Other typical operational experiments include such things as UHF and HF communication checks, antenna checks, measurement of the electrostatic charge buildup on the spacecraft, and photographs of the earth's limb. Gemini Manned Flight Program to Date I43

McDIVITT: As you can well imagine, the scientific community has an obvious interest in the Gemini program as a base for specific experiments and for general observations. The specific experiments have covered the broad fields of astronomy, weather, and geology. A single astronomical experiment and investigation of (?????) light has been performed to date. Weather experiments using both cameras and spectrometers have been completed. These have covered the range from broad photographic coverage to measurements of individual clouds. These results have been compared with ground and aircraft measurements and unmanned weather satellite TV transmissions, such as the TIROS. I'd like to show you three slides of weather phenomena that I sort of .reel are classic and the weather people sort of agree with me. I think you might .find them interesting. May I have the first one please. (Slide 14.) This one was also in LIFE magazine. It's a storm off the coast of Morocco and it's about the classic type of a circulation that you find in a storm center. It's a real beauty. The next one please. (Slide 15.) Any wind tunnel experts here certainly see the vortices that are formed behind this particular Isle. This is an island off the coast of Baja, California. The low level air flow is in this direction. It's Brming a vortice that comes around in this direction, around and out this direction, around and out this direction, and then sort of poops out out there. These are phenomena that weather men have felt occurred but have never really had photographic proof that they are really there. They have their theories and they say that these are things +hat should occur but they just can't get far enough away from the darn things to take good pictures of them to substantiate their theories. We've, I guess, helped prove and disprove some theories. I'd like to show one other that's sort of a classic. (Slide 16.) That is the entire state of Florida there in the summer time. The typical southeastern United States summertime weather with the puffy Cu all over tha land mass. The water has no clouds over it to speak of. Lake Okeechobee, another water mass, does not have the problem of the rising air, unstable air that you might find, the sinking air over the water, the rising air over the land, +he nice cumulus clouds outlining the whole thing. You can actually see up the coast to probably North Carolina, I'd guess, and then you can see the coastline is really outlined by this particular type of cloud with a lot of thunderstorms in the background right across the edge. Slide off please. The geological experiments have been completely photographic in nature. They've included targets of opportunity that have been selected by the crew in-flight based on their previous training in geology, and broad coverage of areas that were selected prefiight and programmed in such a manner as to provide stereo-pairs for photographic interpretation. I'd like to show two slides to indicate the typical target of opportunity. May I have the first slide please. (Slide 17.) This is the Richaet crater in Africa. The crater itself is right here and there should be another small crater either right here or right here. I'm too close to see. Oh here it is right here. There have been aerial photographs taken of this area, obviously, because of its interest to geologists, but they have never really had the thing taken on such a large scale where you can actually photograph the Richaet crater and the other smaller crate1 next to it and although they've been land mapped and aerial photographed they've never really had them all on the same picture and, of course, they find them quite interesting. I44 THE SOCIETY OF EXPERIMENTAL TEST PILOTS

The next slide please. (Slide 18.) These are Seif dunes in Arabia. These particular sand dunes are a couple of hundred miles across. It's roughly 75 miles from one edge to .the other edge of these photos if they are taken straight down. This is sort of an oblique shot so we can probabiy see on the order of 125 to 175 miles across .there. Those sand dunes vary from a mile wide to more than that and they are probably 400 to 800 feet high. It's pretty obvious why all the caravan trails run the same direction over there because you just can't get over these things. All the traffic is this way whether you wan1 to go that way or not. These are .formed by wind and it sort of gives the geologists a little ipsight into the origin of .the countries that they can find that have this type of rock formation rather than a sand For- mation. Ncw our experiepce has shown that obtaining good photos of a preselected object is really a two-step process. First is the acqu get, which I think is the most difficult. The second is the photograph itself. We found that a high contrast landmark, just like the one that Neil was showing you before, near the target is essential to early acquisition. Now you don't necessarily have to have the target as high contrast but you need .this high contrast object near it. Topographical features such as mountain ranges without any

contrast are practically no help. You can see a mountain range but the small heights that these things have with respect to your own altitude, make +he altitude changes on the ground almost insignificant, while the water-land inter- faces, which sometimes have no altitude change, because of their high contrast are excellent. Techniques for taking a photograph vary really with the type oi camera mounting. The hand held cameras of course require only that the spacecraft be pointed in the general directicn of the target. On the other hand, a vehicle mounted camera requires a very accurate pointing and tracking with the spacecraft to obtain both high resolution and non-smear photographs. Normally you would expect a high magnification comera to be mounted to the spacecraft and if you just let the thing pass through the target, you're going to get smear. Even though you're a long ways away and the rates are small it stiil smears when you try to reproduce them. They are a very high fidelity photograph. I'd like to show two sets of photographs now. They both have high contrast objects near them. Just to iliustrate the kind of things that you see as you approach a target that you want to take a picture of, whether it be a city, a salt mine, an air field, a road, a boat or anything, this is the kind of view that you get. Now the first three slides were taken with the hand held camera. They show the approach into the El Centro area. We could select any object in the picture and say that that's what we want to take the picture of. This is sort of what the pilot sees as he comes in. May I have the first slide. (Slide 19.) You can see this is the Pacific Ocean, California along here, Santa Cata- lina and San Clemente Islands down there, the Salton Sea out here and +he El Centro area right down in here and you can see that you are way. way out there and you can see how well you can see that area just because of the contrast oi the water-land interface. While we were over in here it would be really difficult to pick out a target in that area, even when you get close. Sort of keep this view in mind. and we'll run through the next two slides. Next one please. [Slide 20.) Here we have the Salton Sea again and the El Centro area and the Canal. Next slide please. [Slide 21.) Here we are just about over it, looking down on an oblique shot. You can pick out the El Centro airfield down +here, all the cultivated fields and the town of El Centro is down here. You can see Gemini Manned Fliaht Proaram to Date I45 how the contrast helps you out. Now I'd like to have the next slide please. (Slide 22.) This is a slide of the Middle East. This is the Nile Delta right in here with Cairo over there, the Red Sea back here, the Suez Canal through here, the Gulf of Suez there, a little canal that runs into the Nile Delta here, Israel is up here, I think this is Egypt and Iran back here and Saudia Arabia down there. It's practically the seed of civilization as we know it. In the Nile Delta right there there are something in the order of 23 million people living and if you've got keen eyes you can see the pyramids right there. That's an eye test. Everybody that doesn't pass can't fly. Now keeping this in mind, I'd like to show you a movie that we made trying to take a, not trying, we actually accomplished this, taking a picture of an airfield near a little town in Egypt. We had preselected this target and we said this is what we're going to take a picture of. We had a little letdown chart kind of thing to show what the airfield looked like. We had a little World Aeronautical Chart to show us the surrounding area and we'd been over this area before so we knew what the contrast was. Obviously this cultivated area with all the trees on and the high contrast didn't show like that on the map. The map was almost useless. The first time I saw it I thought it was a big lava flow that flowed out into the Mediterranean. We'd been over it and we knew what the contrast was and we'd tried to find a field before. We knew about where it was. It's right in there. Now, we'll start out with the movie and it'll show us looking around over here and you can see part of the Suez Canal, the Nile River, and some of the Gulf of Suez. Why don't we start the movie now. This is a part of the Gulf there and we're getting over towards the Canal. Here's the Nile River right in here and we're looking for a place right down in here. There's the Canal. This is three power by the way, it isn't one power. We'll sort of track down this way now. All I'm using is a typical fixed gun sight in the spacecraft. I'm wandering a little bit. This is without any attitude reference inside the spacecraft, no pointing commands. We're lobking for a target that is right down here. It's not visible yet. You'll get a zoom effect as we approach this thing. We're hundreds of miles out, obviously, and these things get larger. Now the target is down here someplace and I'm afraid I can't see it. It moves down into the corner here and it's pretty obvious when we pass right over it. That's it right there. It's an airfield and it'll get larger as we come closer. It's right in this area. OK, I've seen it and we're bringing it right up to the middfe of the picture and I've put the gun sight on it and now we'll try to track right on it. These tracking tasks have shown that we can probably track to within about a half of a degree. I don't know if you can see the runways coming out back there or not. This is step printed - it's in real time. It was taken at 6 frames per second. It's step printed so that we were seeing it in real time. The jumping or pulsing that you see is due to the fact that the step printing gives it that effect. Now it's past the nadir and we're starting out now and the range is going to start increasing and the target will get smaller. Remember, now that this isn't like an airplane, it doesn't matter which way you point you always go in the same direction so we're starting to go backwards now. We approached it going frontwards right side up and we're now departing upside down and backwards. We spent so much time upside down backwards that it didn't make any difference. And it just fades silently into the sunset.

Now the control mode that we used in this particular exercise was one that we call pulse. It's really ai acceleration control - it has no rate damping or attitude holding feature. It just puts out a very short pulse, I8 milliseconds. I46 THE SOCIETY OF EXPERIMENTAL TEST PILOTS

We're using attitude thrusters, two of them, 25 pound-thrusters. We get approximately 1/10 of a degree per second change in attitude rate and eYen though this particular exercise here was a three-axes exercise we're changing rates and pitch roll and yaw all at the same time. You can see it really wasn't too difficult to track the spacecraft right on the target. I think that these techniques will find many applications in space flight and I'm sure that you're all aware of it too. The general observations that we made that the scientific community finds to be not only interesting but practical, and it sort of leads them into new experiments, is the fact that all of the southetn and northern lights appear below you in the spacecraft and not necessarily above you. You can look down and see these things. The shooting stars are all below you. That's kind of obvious when you think of it, that's where all the air is and these things light up because they're re-entering. We found that the light of a real severe thunderstorm can actually light up objects in the spacecraft. We took a map and held it up to the window, turned all the lights off, and let the thunderstorm flash actually light up the maps so that we could see the lettering on it. We've investigated air glow and taken some pictures of it, or tried to, and we've looked at a number of sunrises. Sunsets are the most beautiful things you've ever seen. Scien- tists have been interested in finding out why the astronauts keep saying $hat the light appears to be banded. The light blue area just above the limb of the earth appears to be banded. We were fortunate enough to be able to obtain a movie of a sunrise. It really shows that you see light and dark blue bands. May I have the movie please. The nice part of this is you get to see a sunrise or a sunset every 15 minutes. It's pretty obvious, the light and dark blue banding and the orange band.. ing. Actually there's about 7 or 8 different colors that appear - actual stripes. There is the bright spot of our presentation. ARMSTRONG: No medical information has been recorded which has had any influence on our plans or schedules. Some data have been received which is not fully understood, however, and medical experiments are included in each flight in an attempt to clarify these areas. Defense department experiments have included navigation, photography, and radiometry. Sextant measurements of angles between celestial bodies and angles between celestial bodies and surface landmarks have been performed for space navigation. Photographs using long focal length lenses have shown the practicality of using spacecraft as a photograph;c platform for celestial and ground subjects. Infrared measurements were performed on Gemini 5 using radiometers and spectrometers. Basic background measurements of earth, ocean, and sky were recorded as well as infrared signatures of active targets, such as a rocket sled run at Holloman Air Force Ease and Minuteman launches from 1 Vandenberg. McDIVITT: I'd like to speak a little bit about housekeeping and just plain 1 living in space. It doesn't sound like the kind of thing you really would be inter- 1 ested in but on the other hand it takes so much of your time .that it becomes very important. We found that stowage, eating, sleeping, plain old comfort, and disposal of body waste are really not insignificant items at all. In Gemini 3 we tested all of the equipment but we really didn't have time to investigate all I of the procedures thoroughly and we just didn't have much of a basis to go 0'1 for Gemini 4. We worked out a few details on Gemini 4 and we found +hat Gemini Manned Flight Program to Date I47

some of the conclusions that we came to were wrong and we tried to modify these for Gemini 5. We tried them on Gemini 5 and we find that we still have some problems but we're making headway and we're going to modify these Bor Gemini 6, 7 and all the rest. I think thai each flight is going to teach us a little more about this. Of course that's why we're flying them. Let me take stowage first. This doesn't seem too tough. You've got a spacecraft that has so much volume to stuff all the things in there and then you're all set to go. But it's really not quite so simple because you've got three separate, independent problems. First you've got to get it all packed in there bor launch. Then you've got to get it all out and use it in orbit. Then you've got to pack it all back in for re-entry. Unfortunately, the bulk that you have for re- entry is a little bit greater than the bulk you had for launch because all +he things that we pack in there are really stuffed in and we +ound that vacuum packing can make a very small package but unfortunately when you undo it you've got wrappers, and you've got water in the bags now. It ends up that you're actually coming in with more bulk than you took off with so we've now got to look at a stowage problem not only .for launch, which was the way we looked at it initially, but we've got to look at it for re-entry too. They're two sort of independent problems. Also the re-entry problems include the heating effect on some of the equipment such that you can't carry it back the same way you carried it out and you went to put it in an area within the spacecraft that has a little better environment. On Gemini 4 we even ran into a specia! problem because we took so many things with us in the spacecraft +hat we sorta anticipated opening up the hatch the second time and throwing them out so that we wmld have a little room to move around in. When we didn't open the hatch for the second time we had a little stowage problem and it .turned out that Ed re-entered carrying a lot of the stuff in his lap. I guess it was better than floating around. We rart of worked out a procedure right then and +here as to what we'd do and how we'd eject and the techniques ,that we'd use i.0 take care of our extra equipment. Eating - I like to, and we have a general bite-size and rehydratable i'ood. It's quite high calorie, low bulk and it's quite good. The only thing is they just don't seem to give us enough. It provides all the energy you need but it just doesn't fill up your stomach. We do get between about 2500 and 3000 calories a day and an average of something on the order of 6 to 8 pounds of water. Sleeping has been a problem and this is one'of those that we don't have ironed out yet. We've had crew members sleep individually. We've used two different sleep cycles. During Gemini 4 we used two four-hour sleep cycles per day per man. On Gemini 5 we used a six-hour sleep period and a two-hour , sleep period. Then an 8-hour period where both crew members were up. This didn't work out satidactorily either. We found that when one crew member was up and the other crew member was asleep, his actions, the communications, +he 1 thruster firing and all the cockpit activity kept the other man awake. Beside5 we are all nosey and when the other guy is doing something we want to find out what it is. This really isn't funny because although I had the greatest confidence in Ed and I know Ed had the greatest confidence in me and I know Pete and ~ Gordo had the greatest confidence in each other, when the other guy is doing something you want to find out what it is, how it's going to effect it, what'; going right, what's going wrong, what you are going to do next. So I quer: we're kinda nosey human beings and we really haven't - this technique prob- I48 THE SOCIETY OF EXPERIMENTAL TEST PILOTS ably isn't going to work. So I think what we may do in .future flights is have both crew members sleep together for a longer period of time, like maybe for eight hours. We're looking into this sort of a technique. The best thing I can say is that what we've used 50 far is not adequate. On Gemini 4 the crew members slept with their helmets on and their visors down and covered. That didn't seem to work out so well. Ed kept getting hot with his visor down and he wanted to open it up and then tos he didn't look good with the cover over his face, so on Gemini 5 Pete and Gordo worked out a snazzy helmet. Could I have the next slide please. (Slide 23.) It's a little blurry, I think this is when Gordo was cold and he was shivering so bad he couldn't hold the camera still. There's a picture of Pete sleeping. It looks like he's about to play football but what he's got on is a sort of eye shades, and something over his ears to keep $ha sound out in trying to sleep. It didn't work out. You could probably guess that by looking at it. In the crew comfort area we've found that our pressure suits are acceptable although not necessarily desirable for the mission duration that we've experienced to date. The cabin and suit temperature in general have been acceptable. How- ever, during some high workload periods in Gemini 4 and some low workload power-down periods in Gemini 5 the temperatures reached undesirable levels. We feel by carefully planning workload and by some manipulation of the environmental control systems we should be able to avoid operating in these regions for unacceptably long periods of time. We did have some minor eye irritations duricg Gemini 4 which was cleared up for Gemini 5 and they didn't experience it. We l.ave been pleasantly surprised by the low humidity that was experienced in Gemini. You kncw Mercury was practically under water the whole flight but the humidity in Gemini would run around 70% and it's a lot better than it is in Houston. We are continuing work on better pressure suits. You know we just can't ever be satisfied with those suits, there's always room for improvement and we're leaning on the contractors to help us out because as we get longer and longer missions these things are going to have to be improved. We found that in the area of body waste disposals that our defecation bags have been adequate. The urine collection system on Gemini 4 was somewhat inadequate and we tried to improve it on Gemini 5 and we did make some strides forward but it still needs a little more improvement. I might add here that the urine dump system failed on Gemini 4 but like all good engineers we had engineered a redundant dump system and I'm glad we did. I would have hated to drown up there. ARMSTRONG: In the area of spacecraft systems, some significant new concepts have been demonstrated during the past year. The small rocket engines or thrusters, used in varying sizes +or both translation and attitude control have performed very well. Using storable hypergolic propellants of nitrogen tetroxide and hydrazine, the units can be operated con- 1 tinuously or in pulses of approximately 20 millisec. The thrusters with their abla- tive throats have significantly extended their lifetime. I In addition to the development of life support systems for extra-vehicular I I activity, the Gemini environmental system uses supercritically stored oxygen - oxygen stored at a pressure temperature combination that provides the density of a liquid but has the properties of a gas. Supercritical storage is also used for the hydrogen and oxygen propellants for .the fuel cells. The vacuum in Dewar Gemini Manned Flight Program to Date I49

storage bottles and its resulting high quality insulation has been admittedly difficult to maintain. We still don't understand heat transfer characteristics and asso- ciated venting of these storage containers very well. The fuel cells themselves were first flown on Gemini 5 and were a resound- ing success. As you know, the fuel cell works on a principle which is the reverse of electrolysis - combining hydrogen and oxygen to produce water and elec- tricity while providing a weight advantage over batteries of about 2 to I.

McDIVITT: Because of so many variables we have found that we have a tremendous need for real time flight planning. The days of saying all right this is what we're going to do on this mission - we're going to take off at such and such a time and we're going to do this and that and something else and we're going to land thirty minutes later was fine. But we've found that the long duration rendezvous flights have created a new need for this real time flight planning. I guess we've always been able to take care of little things that come up on airplanes and change things and on our early space flights we changed them slightly too but it has almost come to the point now that if you looked at the launch and re-entry procedures you know you're going to do those things and you're going to do them in a certain order but you don't have any idea in the world what you're going to do in the middle. You've got a format that you'd likc to follow but you know that the chances of it are practically impossible and insurmountable. First of all let's look at what we've got to take care of. We've got the consumables. We've got propellant quantity, electrical power, oxygen, food and water. These things don't really sound like much. You should be able to preflight program these so that you don't have any problem at all. On our flight we had just finished the EVA and I was kind of thirsty so I reached over and got the drinking water thing and stuck it in my mouth and pulled the trigger and I didn't get any water out and I remember turning around to Ed and saying "Ed, this is going to be the shortest four-day flight you've ever seen." He asked me why and I told him about the water and he put it in his mouth and got a drink and said, "Well, I guess it looks like it's only going fo be you that is going to have to come down." He could drink! It turned out that the way the hose was mounted, it worked fine when you twisted it one way but it didn't work at all when you twisted it the other way. So I learned how to twist it the other way. But those are significant things. There wasn't any water gauging system at all on Gemini 4 and it became apparent as soon as we got up there that we needed it. And weather, we have not only the weather in the landing areas highly demonstrated on Gemini 5, the need to be able to react to typhoons and hurri- canes, but we also have experiment area weather. Let's say we're doing a geological experiment. There's no sense in taking pictures of clouds and not +he ground if that's the kind of experiment you are doing. So maybe we have to switch to a different experiment where we are looking at the clouds. We get I out the other type of equipment and forge on that way. We've got to look at the system status, the crew condition, whether they've had any sleep or not, experiments we've done to date, how many tests we've accomplished, and if , we're going to do a rendezvous we've got to consider the launch time of +he spacecraft with respect to the launch time of the booster or of the target. The funny part of real time flight planning is that you just don't go there and start. The only thing that makes real time flight planning work is a lot of preflight preparatioo. That sounds sort of inconsistent but it's really not. You've got to I50 THE SOCIETY OF EXPERIMENTAL TEST PILOTS go out and look at the weather data early. You've got to have sunrise, sunset, moonrise and moonset information for the spacecraft and since launch times make all these things vary you've got to have some kind of a computer program that can read this out to you in real time during the flight. You've got to know the time and position of closest approach to targets. Let's look at the rocket sled run that we did at Holloman. The crew members had to know that at a certain time they should have the spacecraft pointing in a certain direction and at that instant that sled was going to start off and that is the way we did it and it worked. It didn't happen just because we all went there and said well you ought to point to your left. We gave them attitudes to the nearest degree because we had gone ahead and done this preflight computer program. We also have to know the time of ground station pass and just a wealth of information has to be available to these people that are actually doing this in-flight real- time flight planning. When you consider that we're doing earth orbital missions now and the kind of problems we get into, just project this over to the lunar missions. I'm sure that Bob and Tom talked to you about that this morning but it's really something to think about. ARMSTRONG: I'd like to make a few comments on the Gemini entry trajectory. The thing called the footprint is the area that can be reached from a given retro fire. Footprint is based on the lift of the vehicle. It's a function of both the C.G. offset in the case of the Gemini and also the aerodynamic deriva- tives. The landing point within the footprint is determined by how the lift is used. We apply at a given trim angle and can't modulate the lift so we can maneuver only by rolling the lift vector by controlling the bank angle. Can we see the slide please. (Slide 24.) That is what a Gemini footprint looks life. The retro-fire point is several thousand miles back to the west here. If full lift is flown, that is the lift vector up all the way through the trajectory. it wil! land at this point here. If zero lift rolling trajectory or 90 degree bank angle either right or left is flown you'll land along this line. If you fly with your lift vector pointed to the north, you'll land at this point and to the south down at this point. The other places indicate intermediate bank angles. You could land further back by rolling the lift vector down but this would tend to make the g's intolerable. This line back here is a peak of about 8 g's in re-entry. This point up here is about 4 g's, here it's 6. and you rapidly get beyond 15 to 20 back in this position. The spacecraft is designed for 10 g normal trajectory and our guidance system is restricted to I I g's. I+ gets inaccurate results beyond that point. In general the spacecraft is very stable and very controllable during the re-entry. We have used pulse mode, direct mode, and rate command mode in the flights to date. Sound, vibration, and heating have not been a problem for the crew. Gemini 3 used the maneuvering rockets to lower the perigee +o 45 miles prior to firing the solid retro rockets. Since this was the first flight, there was little confidence, by ground personnel, in the on board re-entry navigation system. So ground computed bank angles were to be used and the navigation system would just be monitored, not followed. The actual lift to drag ratio was 1 ' approximately 30% less than the predicted value and the trajectory was short by 63 miles. The on-board navigation system worked properly and if it had been followed would have put the landing point right on target. Gemini 4 used the 45-mile perigee technique again and retro rockets but the computer had Tailed Gemini Manned Flight Program to Date 151

earlier in the flight and the on-board navigation system was not possible. Jim could not measure the velocity change of this perigee lowering maneuver due to this same failure problem so he did his maneuver on time. The time of the burn was 2 minutes and 40 seconds and Jim was off by half a second. The retro rockets fired one and a half seconds early. A rolling re-entry was used and the spacecraft landed 48 miles short. On Gemini 5 which was the first night retro fire and night re-entry, at least part way down the trajectory, they used retro rockets only; not having the fuel or desiring to use the 45-mile perigee maneuver. The spacecraft did have a computer and an on-board navigation system operative but it received an im- proper steering command due to an erroneous update from the ground computer system. It looked as though it was proper at the time guidance was initiated and Gordo followed it a little bit, dropping his trajectory. When the guidance didn't come in properly, he went back to the backup technique, or the alternate angles and he landed 90 miles short. We're not particularly impressed with our demonstrated ability to miss the landing point but we're hoping to give you an improved report next year. We're sure working on it. We'd like to show you a movie now. Would you turn the movie on. This film was taken from the Gemini 2 flight. It's taken through the cockpit window. Jim tells me it's very representa- tive of what you actually see through the window. (MOVIE) McDIVITT: Neil and I have tried to just give you a very broad brush treat- ment of the program the last year. There are a lot of people involved. There aren't just the people who fly it. There are thousands and thousands of people who make it go and we'd sort of like to extend our thanks to them at this time, too. We've sort of concluded that we've got a pretty good spacecraft here. You know it's just like an airplane. These spacecraft really aren't any differed than airplanes, but we try to make everybody think they are. It's like one of those airplanes that you get out and you say, "Man, I'd really like to fly that again," as opposed to the one you get out of and say. "Boy, that's a real dog." I think this is the one you want to really go out and fly again. As you know, we've got Gemini 6, Gemini 7, Gemini 8 coming up and a lot of other ones. Gemini 6 will be our first rendezvous. Gemini 7 will be a fourteen day duration mission. Gemini @ will be another rendezvous and EVA. I hope that next year we'll be able to come back and report on all the good things that happened on these flights and maybe even a bunch of other ones. I think that gives you an idea, at least I hope it goes you an idea of what we've done the last year and I'd like to thank you very much. But before we go I'd like to thank 1 our projectionist who really had a job. We've had to run some of this film backwards, some of it at sound speed, and some of it at silent speed and I fhink I, they deserve an academy award for getting it all up here right. Thank you very much. ! SHEPARD: I would personally like to thank Tom Armstrong and Bob Smyth, Neil Armstrong and Jim McDiviti for an excellent presentation. I think it's an outstcnding status report to you all of the space program to date. Bob and Tom, if you're here, will you come up for questions. While they're getting in place, 1'11 take the opportunity of having a captive audience to read a press re- lease which went out recently that some of you may not have seen. "The manned spacecraft center in Houston recently began another recruit- ing program to select additional pilot astronauts for future manned space flight I52 THE SOCIETY OF EXPERIMENTAL TEST PILOTS

missions. During the next two months we hope to reach all of the potentially qualified people in the United States who are interested in participating in +his nationally significant program. We will accept applications from interested can- didates until the first of December of this year. The minimum standards for the current program are: be a citizen of the United States, no taller than 6 feet, and having been born on or after December I, 1929, have a Bachelors degree in engineering, physical science, or biological science, having acquired 1000 hours in jet pilot time or having graduated from an armed forces test pilot school, and if there are sny of you here who think you have a reasonable substi- tute for 1000 hours of jet time, we'd still like to hear from you. Lastly be able to pass a Class I flight physical exam which requires 20-20 uncorrected vision. All inquiries should be directed to Astronaut Selection, Box 2201, Houston I, Texas. We're just about on schedule. We'll take five minutes for any questions which you might have since we have none written. We have ladies here who, in case you do have written questions, will collect them or we'll take any questions you might have from the floor. Do we have any questions? MARSH BEEBE, Douglas Aircraft: When does the transition from zero liff to gravitation forces take place during the re-entry and what is the pilots' reaction and feel to this? SHEPARD: Jim, did you hear the question? McDIVITT: You mean from zero g to some g is that correct? BEEBE: Affirmative. McDIVITT: It takes place up around three hundred thousand feet and a lot depends on the trajectory that you're flying, where you were in the orbit, how you retrofired and many, many variables. Ed and I had a very peculiar experience on our flight because as we had been up there for four days we thought ' that we were still in pretty good shape and that we could take these g's but as we started on down, we knew it wds going to be an 8g re-entry, so we were flying along and I said to Ed, "Gee, it feels like we've got about a g, here it comes" and he said "Yeah, I feel it" and pretty soon he said, "Well, there's about two, there's about three" and about that time I looked at the g meter and it still said zero. So I said to Ed, "I think the g meter is broken." So I reached up and tapped it and reset it and it went back a little bit and I thought, "That's funny." Then we thought, "Well gee, something's wrong," so we ignored it and we knew that we were at three g's anyway. About that time the g meter started moving and it finally got to one. We did take the 8 g's with no problem though, it's a lot better than the centrifuge. BEEBE: Is it similar to g in an aircraft? McDIVITT: Well no, the g vector is this way. It eyeballs in instead of eyeballs down but aside from that it feels just the same. SHEPARD: I might add that in all of our Mercury experience and Gemini experience to date we've had no difficulty doing any of the re-entries that have 1 been performed. The pilots have lost no peripheral vision. Next question please. ANONYMOUS: Could Jim brief us just shortly on that hatch problem. 1 McDIVITT: We got the thing down and we needed to engage one gear with another gear. They didn't engage the first time we tried them and by manipulating around a little bit we were finally able to engage the gears. We just decided that since we finally had them engaged and the door locked, we Gemini Manned Flight Program to Date I53 wouldn't open it again. It was just a matter of engaging ,the teeth of one gear and another one. SHEPARD: I'd like to point out here this was purely mechanical problem and not as a result of cold-soak, hot-soak, or any of the space environment, so it is. we feel, an isolated case. Yes sir, right here, do you have a question? (Question inaudible on tape). SHEPARD: The question is directed primarily to the movie and the re- entry and generally on the control of the lift vector. If I may 1'11 just take that question briefly. If you offset the center of gravity from the longitudinal axis you have lift generated regardless of the re-entry angle. The lift is there and you must do something with it. Obviously, if you want to use it to extend your range in which case the lift vector is oriented away from the center of +he earth. To decrease your range to the landing point it's oriented toward :the earth. To adjust crossrange, you locate tire lift vector left or right. Now the rolling re-entry which you just witnessed was in an unmanned spacecraft. It gives you essentially a ballistic re-entry because with the continually rotating lift vector you essentially cancel dll of the lift which is generated in any specific direction. To further answer your question, zero lift can be obtained by adjust- ing a lift vector 90 degrees to the right or left, in which case you get also ad- justments in crossrange. There are several different combinations: re-entries as described this morning from Apollo and Gemini are essentially inertial platform and computer predicted but we also have a backup scheme for the re-entries which require only a bank-angle and a stopwatch. One more question please. ED WATSON, Douglas Aircraft: Was that re-entry real time? SHEPARD: The camera which we use is a 6 frame per second camera. It was projected at 18 frames per second so that was three times real Pime. The luncheon will start immediately. Thenk you very much. I54 THE SOCIETY OF EXPERIMENTAL TEST PILOTS

Slide 1 - CAPE KENNEDY Gemini Manned Flight Program to Date I55

Slide 2 - POGO I56 THE SOCIETY OF EXPERIMENTAL TEST PICOTS

Slide 3 - COCKPIT PANEL

Slide 4 - AGENA - GEMINI RENDEZVOUS Gemini Manned Flight Program to Date I57

Slide 5 - RENDEZVOUS EVALUATION POD

Slide 6 - REP PHOTOGRAPHED AFTER EJECTION I58 THE SOCIETY OF EXPERIMENTAL TEST PILOTS

Slide 7 - EXTRA VEHICULAR ACTIVITY

Slide 8 - EXTRA VEHICULAR ACTIVITY Gemini Manned Flight Program to Date I59

Slide 9 - SULTANATE OF MUSCAT AND OMAN

Slide 10 - ARKLfN AND CROOKED ISLAND IN BAHAMAS I60 THE SOCIETY OF EXPERIMENTAL TEST PILOTS

Slide 11 - FLORIDA KEYS

Slide 12 - GIBRALTER Gemini Manned Flight Program to Date 161

Slide 13 - BAJA CALIFORNIA

Slide 14 - STORM OFF MOROCCO I62 THE SOCIETY OF EXPERIMENTAL TEST PILOTS

Slide 15 - VORTICES OF CLOUDS OFF BAJA CALIFORNIA

Slide 16 - STATE OF FLORIDA (CLOUD PATTERN) Gemini Manned Flight Program to Date I63