Chapter 11

Pillars of Confidence

Although the revised Gemini flight plan of April 1963 remained the basic framework of program operations through 1965 and 1966, it proved to be, at least in some respects, still too optimistic. Lagging fuel-cell development forced the Gemini Program Office in August 1964 to settle for four days, rather than seven, as the goal for Gemini IV* and also to delete the practice rendezvous with the evaluation pod from that mission. Gemini V had been slated as the first in which would rendezvous with Agena target, but that goal, too, had to be deferred.

If some aims had to be postponed, however, they were balanced by some worthwhile gains. Extravehicular activity (EVA) emerged as a new feature of Gemini IV, and Gemini V expanded to an eight-day mission that included practice with the rendezvous evaluation pod. The new Mission Control Center in Houston assumed flight control duties for Gemini IV,¹ taking over that job from the former control center at Cape Kennedy. Only two months were to elapse between Gemini IV and V, a sign of the progress that NASA was making toward putting space flight on something like a routine basis. Perhaps most important, these two missions set Project Gemini firmly on the path to reaching its major objectives, sweeping aside fears that astronauts might not be able to survive long periods of weightlessness in space and holding out the promise that rendezvous could soon be achieved.

NASA announced the crews for Gemini IV on 27 July 1964, and two days later James A. McDivitt and Edward H. White II, along with their backups, Frank Borman and James A. Lovell, Jr., talked with reporters in Houston. McDivitt and White, aged 35 and 34, had known each other since college and had been in the same class at the Air Force test pilot school. Borman and Lovell, both 36, first met when they were undergoing testing by NASA. Borman was an Air Force officer and Lovell was in the Navy. All four men were second generation astronauts, part of the group selected by NASA in September 1962.²

Their first task after the announcement was to review the status of the spacecraft and booster assigned to their mission. Spacecraft 4 was still being built in St. Louis, with some problems caused by a shortage of parts.³ In Baltimore, GLV-4 was also in the process of being assembled.⁴ After that quick look, the crewmen spent the next five weeks cleaning up work left over from their former assignments. Mission training had to wait until the end of November, when Gemini Simulator 2 became operational in Houston.⁵

Meanwhile, McDivitt and his crewmates, knowing that EVA might be included in Gemini IV, seized every chance to press the case for making it part of their mission. This persistence won NASA management’s consent to provide the special space suits that EVA required. The astronauts were not merely chauffeurs; their role in the program went far beyond that of the normal test pilot in determining what was to be done and when. Without the strong pressure from the Gemini IV crewmen, the G4C suit might have been too far down the line to have permitted NASA’s late decision to include EVA in the fourth mission.⁶ That decision was not, however, quite so late as it appeared.

When Cosmonaut Aleksey A. Leonov walked in space on 18 March 1965, during the Voskhod II mission, he revived press complaints that America lagged in the space race and raised fears that a year might pass before a Gemini astronaut matched the Russian’s feat. When, a little more than two months later, NASA announced that White would step into space on the next Gemini flight and use a “zip gun” to propel himself, most space watchers merely assumed that NASA was still trying to keep up with its Soviet rival.⁷ This may have been true as far as timing was concerned; but EVA had been a part of Gemini thinking almost from the beginning, and studies had begun as early as 1962.⁸ The road from study to a place in the flight plan, however, was a rocky one.

Even the public linking of EVA with Gemini IV preceded Voskhod II by nearly eight months. At the same press conference in July 1964 where the Gemini IV crewmen took their bow, Gemini Deputy Manager Kenneth Kleinknecht had said one of the crew might open the hatch and stick his head outside during the mission. McDivitt was surprised at how little notice newsmen took of Kleinknecht’s statement.⁹ At that point, it was still far from certain that even a simple hatch opening would be permitted in Gemini IV. The key questions involved equipment and training.

Gemini IV first appeared as the program’s lead-off EVA mission in a “Program Plan for Gemini Extravehicular Operation,” during January 1964. Management response was cool, largely because equipment development was only beginning.¹⁰ During the next few months, however, matters improved. The AiResearch Manufacturing Company was awarded a contract for the extravehicular chestpack, the David Clark Company was sent specifications for the extravehicular suit, and McDonnell was authorized to begin an EVA design that was eventually applied to Spacecraft 6.¹¹

After Kleinknecht’s largely ignored statement in July on standup EVA plans for Gemini IV, the issue continued to be debated within NASA. MSC’s Engineering and Development Directorate, and its Crew Systems Division, in particular, opposed any EVA in Gemini missions until crews faced some realistic simulations on the ground.¹² The scheduled altitude chamber tests of Spacecraft 3 in November 1964 offered a good chance to meet that demand. Gus Grissom and John Young wanted to depressurize the cabin during their training for Gemini III and open the hatch at a simulated altitude of 46,000 meters. Selling this idea to McDonnell was not easy. McDonnell, as Young later remarked, “certainly didn’t want to take the chance of bagging a couple of astronauts in the altitude chamber,” and NASA was none too happy about “putting guys in vacuums with nothing between them but that little old lady from Worcester, Massachusetts [the seamstress at the David Clark Company], and her glue pot and that suit.”¹³

Kleinknecht argued that “if we can’t do it in the altitude chamber, then we haven’t any business doing it 100 miles [160 kilometers] in space.” GPO told McDonnell to “include at least one complete depressurization, hatch opening and closing, and repressurization cycle at 40,000 feet [12,000 meters] altitude conditions in each spacecraft manned altitude chamber test commencing with spacecraft 3.” The first try at EVA practice left something to be desired, Young recalled, when “we opened the hatch and [then] we couldn’t close it.” But the three-orbit Gemini III mission was really too short for EVA anyway, and GPO focused its efforts on Gemini IV.¹⁴

Plans were firmer by the start of 1965, and the Gemini IV crews began training for EVA.¹⁵ Nevertheless, the decision of whether to include EVA in the mission was far from settled, either at MSC or NASA Headquarters. MSC Director Gilruth did approve altitude chamber tests for the crew, but only on 12 March 1965, less than a week before Leonov’s space walk.¹⁶ That feat spurred new efforts to get extravehicular activity into an early Gemini mission. With the flight of Gemini III just a week away, that meant Gemini IV. During that week between Voskhod II and Gemini III, Gilruth and Deputy Director George Low had their first look at a “hand held maneuvering unit,” which had been designed and built without fanfare in MSC’s Crew Systems Division. That device, along with a display of the progress with other EVA equipment, brought the Center’s top management solidly behind trying for EVA in its second manned mission.¹⁷

The hardware still needed to be qualified. Gilruth gave the job to Crew Systems with a warning to keep the work as quiet as possible, perhaps to avoid any appearance of too-hasty reflex to Russian accomplishments. A model spacecraft was quickly installed in MSC’s 6-meter vacuum chamber, and preliminary testing was begun.¹⁸ By the end of April, the vacuum chamber was ready for full-scale EVA simulation, and Flight Operations people had come into the picture to begin working out techniques for handling EVA as a flight control matter.¹⁹

But NASA Headquarters had yet to be won over. Manned space flight chief George Mueller learned about the MSC plans when he visited Houston on 3 April; his response was lukewarm, perhaps because of the still unqualified status of the hardware. Although he offered no encouragement, Mueller was not inclined to order a halt, and MSC went ahead with its plans. On 14 May, when Gilruth arranged an EVA demonstration for Associate Administrator Robert Seamans, he won a high-ranking ally. Seamans promised to discuss MSC’s new venture with Administrator James Webb and his deputy, Hugh Dryden.²⁰

The next day, Mathews and three of his men were in Washington for another attempt to convince Mueller that EVA belonged on Gemini IV. Mueller’s crucial question was how EVA, not officially scheduled until Gemini VI, could be moved up two flights; the answer was simply that everything was ready: all EVA gear was qualified, or nearly so, and the crew was trained. After he got back to Houston, Mathews called Mueller on 19 May to report that the last piece of EVA equipment was now flight ready.²¹

Seamans, as he had promised, did describe the EVA plan for Gemini IV to Webb and Dryden. Webb liked it, but Dryden objected strongly; he thought it smacked too much of a reaction to what the Russians had done. At Webb’s request, Seamans drew up a brief stating the reasons for putting EVA on the current Gemini mission, which concluded: “The hardware for extravehicular activity is flight qualified and the astronauts are trained for this operation. Since extravehicular activity is a primary goal for the Gemini program, it is recommended that this activity should be included in Gemini IV.” Webb gave the paper to Dryden. On 25 May, Dryden called Seamans to his office and, without saying a word, handed him a document. It was the case Seamans had made for EVA; scribbled on one corner was “appendix-roved, after discussing w. Dryden [signed], J. E. Webb, 5-25-65.”²²

There was still a question about how and when to make public the plans for EVA. MSC opinion was divided. Some favored breaking the news after the fact, some while EVA was in progress, and others at the premission press conference 24 hours before launch. In April, MSC decided to announce it at the press briefing, if it were approved. Seamans, however, rejected that scheme as incompatible with NASA’s historic policy of openness on plans for manned launches and ordered EVA material to be included in the press kit for Gemini IV. When the kit appeared on 21 May it contained a one-page discussion of “Possible Extravehicular Activity.” On 25 May, the same day EVA was approved, the press was informed that White would leave his spacecraft and walk in space.²³

One reason for Mueller’s resistance to EVA was a plan to combine it with rendezvous. Gemini IV was scheduled to rendezvous with the second stage of its booster in orbit, and White could then use his zip gun to propel himself over near the floating stage. This idea was also a latecomer to Gemini. The rendezvous evaluation pod scheduled for the fourth mission had been forced out in January 1964, when problems with the radar design made it unlikely that that crucial equipment would be available in time.²⁴ A bit of joking by Gordon Cooper over the communications link to Grissom in Gemini III on 23 March 1965, suggested another kind of practice rendezvous.

Cooper: I have a time for when you’ll be nearest the booster [second stage]. Would you like to have that so that you can look for it?

Grissom: Roger.

Cooper: Roger. 02 plus zero eight plus five two will be dead ahead at an elevation of plus eight zero degrees at one niner miles. This will be just prior to darkness. It should be very bright. Proceed to see if you can rendezvous.²⁵

Gilruth and Low overheard the exchange and thought it sounded like a pretty good idea. Low checked with GPO and Crew Systems and got an enthusiastic response. With Gilruth’s wholehearted support, in May 1965 stationkeeping joined EVA as part of the Gemini IV flight plan. The spacecraft would match velocities with the orbiting second stage a relatively short distance away in the same orbital plane and maintain that position for a time. Grissom had maneuvered “Molly Brown,” but he had no target. Closing in on a specific object (or point) in space was much more ambitious, especially since McDivitt and White would have to depend on their eyes to track the target, since the rendezvous radar was still unavailable. Martin did install flashing lights on the GLV-4 second stage to help the crew find it.²⁶ McDivitt and White had still another handicap. There was simply no way for them to train on the ground for stationkeeping - neither the Cape nor the Houston simulator was designed for this task. McDonnell came through by rigging equipment to provide a simulated view of the target against a star background. McDivitt and Borman spent half a day in St. Louis practicing optical rendezvous, but it was makeshift at best.²⁷

One other major problem confronted Gemini IV planners, the physiological consequences of a prolonged stay in orbit and of EVA. Charles A. Berry, medical director of the Gemini program, was troubled by the leap of faith implied by the Gemini flight schedule of April 1963, which followed the three-orbit Gemini III with the seven-day Gemini IV. He wanted the length of the mission reduced by half, and trouble with fuel-cell development might come to his aid. If batteries had to be used, the mission could not last more than four days. In August 1964, Mathews reported to NASA Headquarters that Gemini IV would be a four-day mission, not only for medical reasons but also because the fuel cell would have to be replaced by batteries.²⁸

Berry was not happy even with a four-day mission. Cardiovascular problems had cropped up in the last two Mercury missions, and every physiologist he met made the same comment about Gemini IV, or so it later seemed:"[Don’t you] really know that these guys [are] going to stand up and pass out and might, indeed, die from this flight?"²⁹ The astronauts would be subjected to much the same kind of physiological strain as that imposed by prolonged bedrest followed by vigorous activity. After their bodies had been deconditioned by days of weightless flight, they had to face high reentry g forces, which might well cause them to faint. If an astronaut fainted during or after landing, he would be held upright by his harness, forcing a perhaps already overtaxed heart to work even harder pumping blood to his head. But astronauts were not bed patients; besides using their muscles for flight tasks they would have been exercising with a bungee cord, a device adapted from the nylon strap and handle of a spear gun that required a force of 300 newtons (70 pounds) to extend it 30 centimeters (12 inches).³⁰

EVA added still another medical concern, the disorientation and motion sickness that might overtake a floating astronaut unable to distinguish “up” from “down.” Leonov, according to Russian reports early in May 1965, had trouble with his vision and orientation “when he didn’t see the spacecraft.” Berry, McDivitt, and White studied a filmed interview, with scenes of the space walk, which clearly showed Leonov using numerous reference points - the Sun, the spacecraft, Earth - to maintain orientation. That seemed to be the best answer, the astronaut making sure he knew where he was at all times in relation to the spacecraft.³¹

From a medical viewpoint, then, some degree of tension marked the approach of the Gemini IV mission. This was, after all, the first four-day flight by Americans, and the Russians were airing their fears of disorientation and physiological dangers at numerous medical conferences. But the crew was trained, and everything that could be foreseen had been considered. There was nothing to do now but wait to see what happened.³²

Four Days and a “Walk"

About 12 hours before Gemini IV’s* scheduled liftoff on 3 June 1965, the Martin crew started fueling the booster and calibrating its propellant loads. Borman and Lovell, the backup crew, flipped spacecraft switches, tested communications circuits, and handled other chores to relieve the prime crew. McDivitt and White had gone to bed at 8:30 the night before. Awakened at 4:10 a.m., they were given a brief physical examination. The astronauts left their Merritt Island quarters after breakfast and boarded a van for the ride to the pad 16 suit-up area, where they were helped into their suits while breathing pure oxygen to get the nitrogen out of their systems and thus prevent aeroembolism, or the bends.³³

McDivitt and White arrived at pad 19 at 7:07 a.m., rode up in the elevator, and climbed into their spacecraft at T-100 minutes. Getting in was relatively easy, but even so White’s faceplate fogged. He started his suit fan and cleared up the moisture.³⁴

Thirty-five minutes before the scheduled launch, while the erector was being lowered, it stuck at a 12-degree angle from the booster. Raised to its full height, then lowered again, the erector still stuck. After more than an hour, technicians found a connector incorrectly installed in a junction box, replaced it properly, and gave the signal to lower the erector. This time it worked. Space travel was becoming operational. This hold, lasting 1 hour 16 minutes was the only delay for Gemini IV. On Mercury-Redstone 4, the second manned launch in that program, Grissom’s Liberty Bell 7 was scrubbed twice and was plagued by six holds that totaled 4 hours 1 minute.³⁵

At 10:16 a.m., Thursday, 3 June 1965, millions of people throughout the world looked and listened while Gemini IV lunged spaceward. Television coverage of the launch for the first time had an international audience, as the scene was broadcast to 12 European nations via Early Bird satellite.³⁶ Heightened by the prospect of EVA and the first use of the new Mission Control Center in Houston, interest in Gemini IV reached levels never again matched in the program. The Manned Spacecraft Center faced a major challenge in the number of reporters who wanted to cover the story from Houston. Although MSC’s Building 1 auditorium had been “designed to house all large events covered by the news and television services,” its 800 seats fell short of the space that would be needed to accommodate the 1,100 requests for accreditation NASA had received. To meet the demand, MSC leased one of the new buildings springing up across the highway from the Center for local offices of aerospace companies - and that move came under fire from the local press when its cost was revealed: besides the $96,165 year rent, MSC spent $166,000 for modifications, $8,000 for television monitors, and $6,600 for 610 chairs.³⁷ But “Building 6,” housing the NASA Gemini News Center, served its purpose well as the base for 1068 newspaper, magazine, radio, and television representatives, as well as 60 public relations people from industry.³⁸ It opened on 25 May, somewhat earlier than the “launch minus five days” that had been customary for news centers during Mercury.

In the spacecraft, McDivitt and White had no doubts about liftoff, as they felt their vehicle pick up speed. There was very little noise. The hush was broken only when the launch vehicle bounced like a pogo stick for a few seconds. Then everything smoothed into near silence again. Pyrotechnic shattered the illusion of quiet at stage 1 and, later, at stage 2 separation. The spacecraft entered an elliptical orbit of 163 kilometers at the low point (perigee) and 282 kilometers at the high point (apogee).³⁹

As Gemini IV separated from its booster, McDivitt turned the spacecraft around to look for the trailing vehicle. White saw the rocket venting, with propellant streaming from its nozzle. How far was it, and where was it going? McDivitt estimated the distance as 120 meters; White guessed it was closer to 75 meters.

McDivitt braked the spacecraft, aimed it, and thrusted toward the target. After two bursts from his thrusters, the booster seemed to move away and downward. A few minutes later, McDivitt pitched the spacecraft nose down and the crew again saw the rocket, which seemed to be traveling on a different track. He thrusted toward it - no success - and stopped. McDivitt repeated this sequence several times with the same luck.⁴⁰

As night approached McDivitt spotted the booster’s flashing lights. He estimated that the distance to the target had stretched to perhaps 600 meters. He knew he had to catch the booster quickly if they were going to stationkeep and do extravehicular activity as planned. For a while, Gemini IV seemed to hold its own and even to close with the other vehicle. McDivitt thought they got to within 60 meters, but White estimated it at 260 to 300 meters. The target’s running lights soon grew dim in the gray streaks of dawn and vanished with the sunrise. When the target hove into view about three to five kilometers away, McDivitt again tried to close the distance. Additional thrusting did not seem to bring it any closer. Well aware that he was a pioneer in orbital rendezvous and that choosing the right maneuvers might not be as easy as it seemed, McDivitt had previously asked Mission Director Kraft which was more important, rendezvous or EVA. The space walk, said Kraft. McDivitt knew he had to stop spending fuel chasing the elusive target by the “eyeball” method.

[Page 247 consisted of photos from Gemini IV, 3 June 1966]

As GPO engineer André Meyer later remarked, “There is a good explanation [for] what went wrong with rendezvous.” The crew, like everyone else at MSC, “just didn’t understand or reason out the orbital mechanics involved. As a result, we all got a whole lot smarter and really perfected rendezvous maneuvers, which Apollo now uses.” Catching a target in orbit is a game played in a different ball park than chasing something down on Earth’s essentially two-dimensional surface. Speed and motion in orbit do not conform to Earth-based habit, except at very close ranges. To catch something on the ground, one simply moves as quickly as possible in a straight line to the place where the object will be at the right time. As Gemini IV showed, that will not work in orbit. Adding speed also raises altitude, moving the spacecraft into a higher orbit than its target. The paradoxical result is that the faster moving spacecraft has actually slowed relative to the target, since its orbital period, which is a direct function of its distance from the center of gravity, has also increased. As the Gemini IV crew observed, the target seemed to gradually pull in front of and away from the spacecraft. The proper technique is for the spacecraft to reduce its speed, dropping to a lower and thus shorter orbit, which will allow it to gain on the target. At the correct moment, a burst of speed lifts the spacecraft to the target’s orbit close enough to the target to eliminate virtually all relative motion between them. Now on station, the paradoxical effects vanish, and the spacecraft can approach the target directly. Gemini IV’s problem was compounded by its limited fuel supply; the Spacecraft 4 tanks were only half the size of later models, and the fuel had to be conserved for the fail-safe maneuvers. When McDivitt and White broke off their futile chase, they had exhausted nearly half their load of propellants.⁴¹

White had been too busy helping his partner to give much thought to getting ready for EVA. Now that the rendezvous attempt was over, White put the zip gun together, while McDivitt read off a list of things for him to do. White pulled out the umbilical package and mounted suit connectors for the tether and the emergency oxygen chestpack. With 20 minutes still to go before cabin depressurization, the commander noticed that his copilot already looked tired and hot. McDivitt told the Kano tracking station that EVA would be postponed until the third revolution - he wanted White to rest.

While they relaxed, the crewmen talked with Grissom, the Houston CapCom, about the synoptic view of the Gulf of Mexico and all of Florida, including the Cape and its launch complexes. After a 15-minute break, McDivitt picked up the list and White began checking suit hose locks and suit integrity. The flight planners had certainly not foreseen how much time getting ready for EVA would take, McDivitt thought.⁴²

Over the Indian Ocean, White was ready for EVA at last - hoses hooked up, umbilical ready, gun in hand, and chestpack in place - and they again rested and chatted. Nearing Carnarvon, Australia, they began to depressurize the cabin. Then a mechanical problem arose - the door would not unlatch because a spring had failed to compress. After much yanking and poking around the hatch ratchet, the door suddenly cracked open. White found the hatch as hard to push up in zero g as it had been on the ground.⁴³

Once he had it opened, White rose slowly through the hatch and installed a camera to record his movements as he swam in space, with the zip gun, tethered to his right arm, floating freely by his side. White triggered a burst from the gun, rose above the hatch, and, without imparting any motion to the spacecraft, propelled himself away. Experimenting with the double-barreled device, he traveled about 5 meters but found himself higher above the spacecraft than he intended. He wanted to go over to McDivitt’s window. Short bursts of the gun worked well; in fact, it responded throughout much as it had in ground training on an air-bearing table, at least in pitch and yaw. White was less sure about roll, which he thought would be harder to control without using too much fuel. Floating freely, he felt a tendency to pitch, roll, and yaw, all at once. He knew the gun could correct this, but he was concerned about the fuel it would take. Instead, he tugged on the tether and pulled himself aft and high atop the spacecraft adapter. White saw the thrusters firing, expelling plumes of flaming gas, as McDivitt steadied the spacecraft. White propelled himself away from the danger - across the top of the spacecraft and out beyond its nose. He used the gun for two pitchovers and two body turns, each time stopping easily. Then the compressed oxygen fuel bottle was empty - how he wished it had been bigger!⁴⁴

There was the usual brief loss of communications between Hawaii and Guaymas, Mexico. While White was using the zip gun over the Pacific, Mission Control was unaware of how he was making out. After the voice circuit was restored, radio listeners had a chance to hear an American human satellite broadcast his views of the spectacle of Earth. White told McDivitt and the world how beautiful it all was, of the pictures he was taking, and how well he was feeling - no vertigo or disorientation whatever. And when McDivitt had to tell him it was time to come back inside, Mission Control and the whole world heard him sigh, “It’s the saddest moment of my life.”

While he was floating freely, White had paid no attention to the time; and, since they were on the internal spacecraft communications link, Flight Control could not break in on them. Finally, after 15 minutes 40 seconds, McDivitt broke off to ask the ground if they wanted anything. “Yes,” Kraft chuckled, “Tell him to get back in.” After he passed this on to White, McDivitt heard boots thumping atop the spacecraft. White came back to the hatch as Gemini IV was passing over the Atlantic, dismounted the camera and removed electrical connections, and handed all these items to McDivitt along with the gun. McDivitt then helped White get settled, pulling on his legs and guiding his feet into the footwells.⁴⁵

White closed the hatch and reached for the handle to lock it. When it failed to catch, he knew it was going to be as hard to close as it had been to open. Pushing on the handle lifted White out of his seat, so McDivitt pulled on him to give him some leverage. Finally White felt a little torque in the handle and yelled for McDivitt to yank harder. The door was latched.

White sat back, physically exhausted, sweat streaming into his eyes and fogging his faceplate. McDivitt also felt tired, so they rested before extending a radio antenna to find a ground-based voice and tell Earth all was well. Carnarvon answered them. The crew of Gemini IV had almost circled the globe in an unpressurized spacecraft.⁴⁶

While White relaxed, McDivitt began powering down some of the spacecraft systems to save electrical power and control fuel, intending to drift for the next two and a half days. Seven and a half hours after liftoff, White went to sleep. He and McDivitt had intended to sleep alternate periods of four hours each, but this was hard to do. The constant crackle of radioed information and orders and the occasional automatic thruster firings kept them awake. Whoever was on duty frequently bumped the sleeper in this uncommonly small bedroom.⁴⁷

Gemini IV was the first of the program’s longer missions, and it imposed a set of new demands on ground control, which moved for the first time into a three-shift operation. Kraft acted as both Mission Director for the entire flight and Flight Director for the first shift. Eugene F. Kranz directed the second shift and John Hodge the third. Kraft’s shift focused its efforts on helping McDivitt and White carry out the flight plan. The second shift concerned itself mainly with keeping track of systems performance and the use of such consumable stores as oxygen and fuel. Realtime flight planning was the special province of Hodge’s shift. The basic framework of the flight plan was set before launch; but on the basis of what had already been achieved, how systems were working, and what stocks of fuel and other consumables remained, the third shift was ready by morning with specific instructions for the crew on tasks to be done or eliminated during the day ahead.⁴⁸

Backing up the flight control teams were a number of systems experts who stood by in the staff support rooms of the new Mission Control Center. They included not only NASA specialists but also contractor people, some of whom were assigned full-time to Houston while missions were in progress. At their home plants, other teams maintained systems under simulated flight conditions to provide quick answers to flight problems. Technical monitors and principal investigators were also on hand in the Mission Control Center for the Gemini experiment program, now more methodically handled by a new Experiments Program Office under Robert Piland in the Engineering and Development Directorate. Gemini IV’s 11 experiments made it the first American mission to bear some resemblance to the manned space laboratory that had long been a staple of space flight thought.

Gemini IV was also the first mission to employ systematic methods to gather, evaluate, and publish information quickly, another demand imposed by longer flights and shorter intervals between missions. Willis Mitchell and Scott Simpkinson of GPO headed the 150-person Mission Evaluation Team that began work at liftoff and kept working through postflight inspection and mission evaluation.⁴⁹ Gemini IV served as training ground for pilots, flight controllers, and evaluators alike, setting the style for later Gemini missions, as well as for future Apollo flights.

Meanwhile, McDivitt and White drifted through space, watching systems, making observations, and doing experiments. A rigid constraint on fuel usage hampered most of these activities, although several of Gemini IV’s 11 experiments were largely unaffected.**

Five dosimeters checked radiation in the spacecraft (experiment D-8), especially while Gemini IV was passing through the South Atlantic Anomaly (an intense pocket of the ionosphere), where radiation levels were considerably higher than in all other regions. In the Simple Navigation experiment (D-9), the pilots used a handheld sextant in an attempt to get celestial navigation readings, to judge sextant operation and navigational accuracy. McDivitt and White agreed that the sextant might be useful for Apollo.⁵⁰

McDivitt and White had good fortune in the Synoptic Terrain (5-5) and Synoptic Weather (5-6) photography. The 70-millimeter Hasselblad camera worked well and, tourist-like, they tried to capture the view. They were especially smitten with the Nile River area - one saw Cairo, the other Alexandria - and White remarked that a landmark near a body of water was easier to spot. On one occasion, they snapped pictures from the Pacific Coast to Texas, showing good geological detail. They performed like professionals in getting pictures of weather phenomena. Unmanned Tiros weather satellites provide coverage from 640 kilometers, but Gemini IV gave the meteorologists a closer look, without a mosaic patchwork, at cellular cloud patterns, cloud layers in tropical disturbances, lines of cumulus clouds over the ocean, and thunderstorm areas.⁵¹

The crew used the bungee exerciser (M-3) more than had been planned, but White later said that his desire to do strenuous work dwindled during the flight; although, as McDivitt suggested, this might have been caused by lack of sleep. Both agreed that a systematic exercise program would be needed for long missions. Sensors attached to the pilots’ bodies, in the Inflight Phonocardiogram experiment (M-4), gathered data on heartbeat rates, especially during liftoff, EVA, and reentry. As might be expected, their heartbeats were essentially normal except during these periods. The bone demineralization experiment (M-6) did show a greater mass loss in the small finger and heel than that experienced by Earthbound, bedrested patients.⁵²

One engineering experiment - Electrostatic Charge (MSC-1) - gave higher readings than expected. Investigation later determined that thruster and water boiler operation produced some moisture, resulting in a high electrical charge, which dissipated very quickly. Concerns that docking in space might generate a harmful jolt were laid to rest. The Proton-Electron Spectrometer (MSC-2) and Tri-Axis Magnetometer (MSC-3), complementary radiation studies, provided useful data about Earth’s radiation environment and the magnitude and direction of local geomagnetic fields. Photographing the red-blue Earth limb was the final engineering experiment (MSC-10), designed to help train Apollo astronauts in making navigational fixes.⁵³

After 48 revolutions, covering 75 hours of flight, the spacecraft computer was updated during a stateside pass. Told to turn the computer off, McDivitt flipped the switch and discovered that he could not. On the ground, efforts to solve the problem began at once. For the next few revolutions, the crew received instructions for trying different switch positions, but the computer finally quit entirely. Now they would have to resort to a rolling Mercury-type reentry, rather than the lifting bank angle the computer was supposed to help them achieve.⁵⁴

In revolution 62, at 97 hours 28 minutes, they fired their maneuvering thrusters in the proper retroattitude for 2 minutes 41 seconds. Afterward they jettisoned the equipment adapter. Bang! bang! bang! bang! went the retrorockets. White watched the brown, dusty Texas plains pass in review and then released the retroadapter. Gemini IV was returning to Earth.⁵⁵

At 120,000 meters, McDivitt started the rolling reentry. As the spacecraft rotated, the crew saw the adapter, trailing them, turn into an orange mushroom as it burned. Without the computer, McDivitt and White suspected, they would land short of the planned Atlantic landing point. The spacecraft was getting some lift, but they were sure it would not be enough. McDivitt and White welcomed the increasing g-rates. White noticed no dimming of vision and no shortness of breath. They talked, watched their instruments, and enjoyed the scenery.⁵⁶

At 27,000 meters, McDivitt slowed the roll rate and stopped it completely at 12,000 meters. Shortly, he punched out the drogue parachute. When it deployed, the spacecraft gyrated instead of stabilizing. At 3,230 meters, the main parachute deployed and unfurled with a comforting shock, and then they braced themselves for the 1,500-meter, two-point suspension mark. When the spacecraft assumed its new position, the crew lurched forward, then backward, but neither knocked their helmets against anything. The splashdown - at 97 hours 56 minutes 12 seconds after launch - was rough, slamming them against the water. But they were down and safe, so far.⁵⁷

Gemini IV missed its mark by 80 kilometers; but several of the recovery ships had begun moving toward its landing site, and one helicopter crew watched the spacecraft descend to the ocean. Within a few minutes, swimmers jumped into the water and attached a flotation collar. Then the pilots were hoisted into the helicopter. Fifty-seven minutes after touchdown, the crew stepped onto a triumphal red carpet on the deck of the aircraft carrier Wasp to be greeted by the ship’s crew.⁵⁸

During the helicopter ride, an MSC physician reported that the crew seemed to be in good shape. Nevertheless, everyone wondered about their physical condition after being weightless so long. A NASA information specialist, who had seen Cooper stagger after his Mercury flight, was surprised to see White do a jig-step. A colleague commented, “The air of tension [immediately] dissipated.” Berry and his medical team met the crew aboard the Wasp. Medical examinations over the next 66 hours revealed no major problems. In fact, on the day after the landing, on his way to the ship’s medical ward, White noticed some Marines and midshipmen having a tug-of-war. He joined the midshipmen for 15 minutes. Although his team lost, White certainly appeared strong and healthy. Later McDivitt and White inscribed a picture of themselves walking across the red carpet, “The day the straw men fell down.” Berry agreed, as he found his patients fatigued but showing no sign of faintness. Although the loss of bone mass in the heel and little finger was not surprising, physicians were startled to find a loss in the volume of plasma - circulating blood. Both lost weight, as have all American astronauts - McDivitt, two kilograms (four and a half pounds); White four kilograms (eight and a half pounds). But they paved the way for an even longer mission.⁵⁹

Gemini IV roused great excitement, with all its daily activities heralded in newspapers around the world. Its deeds shunted aside dark clouds that loomed on 7 June (the day that McDivitt and White returned from space), when the U.S. Military Command in South Vietnam announced that its troops would fight alongside Vietnamese forces. President Johnson came to Houston to congratulate them; a million Chicagoans showered them with ticker tape; and Administrator Webb sent them, at the request of the President, to the Paris International Air Show, where they met Cosmonaut Yuri Gagarin, the first space traveler.⁶⁰

Prelude to Gemini V

Although Gemini IV chalked up a success, rendezvous remained a question mark. Seamans asked Langley Research Center to study orbital mechanics, especially the complex decisions on attitude and velocity changes and probable fuel usage both with and without computers. Langley engineers reviewed the Gemini IV mission results and concluded that the fuel allotted seemed ample for stationkeeping but that the crew had simply not been adequately trained for the job. As Paul Purser later remarked, “no one was ‘adequately trained’ in that the differences between motions on earth and motions in orbit were not intuitively realized or ’second-nature’ to anyone.”⁶¹

Another postflight concern was the computer failure. IBM, the subcontractor, was unable to duplicate the failure on a test computer, and the Gemini IV computer itself worked perfectly through 500 tests in St. Louis. Since the trouble remained a mystery, IBM modified the Gemini V computer with a manual switch that allowed areas that might have caused the problem to be bypassed.⁶²

A number of other questions also had to be answered for Gemini V. Should a fail-safe reentry be flown? Should there be an EVA? What type of suits should the crew wear? Could the crew be trained soon enough to shorten the launch intervals from three to two months? Could the scientists get their experiments ready in time for them to be integrated into crew training?

Fail-safe orbits had been planned for all manned Gemini flights. Missions not slated for rendezvous would use spacecraft thrusters to bring the vehicle into the atmosphere. Other flights would depend on the Agena to push the spacecraft into the atmospheric fringes. NASA Headquarters had imposed this precaution on Gemini III, whose crew later had little to say about it. But Gemini IV’s McDivitt and White lambasted it; saving fuel for the fail-safe reentry had forced them to limit both operations and experiments. With Gemini V slated for 8 days and 17 experiments, Houston wanted to scrub the maneuver. Since the retrorockets had fired as advertised, even after soaking four days in space, Mueller agreed.⁶³

White’s successful EVA was going to be a hard act to follow. There was little to be gained from merely repeating it, but the environmental system was not ready for anything more advanced. And there were other reasons for skipping EVA in the next several missions. McDivitt and White had trouble stowing even reentry; the 8- and 14-day missions coming up would produce even more garbage. As for Gemini VI, that crew wanted to stress only rendezvous and docking.Then, too, the Gemini V pilots had been campaigning vigorously for more comfort in orbit - wearing their helmets, goggles, and oxygen masks but not their suits. They lost that battle and later wore the G4C extravehicular suits that had been bought for them before the decision to fly EVA on Gemini IV. With no reason for repeating the standup EVA, Mueller and William Schneider decided there would be no EVA on the next three missions.⁶⁴

Shortening the intervals between missions was part of the problem in getting the crew ready to fly. In September 1964, when plans for speeding up the flight schedule were first being studied, flight operations and crew training had emerged as the most likely stumbling blocks. When the study was completed and accepted in January 1965, Gemini V still did not have a crew and training time was getting short. Cooper and Conrad were finally named on 8 February, with Neil A. Armstrong and Elliot M. See, Jr., as backups.⁶⁵ Now there were 12 men (crews for missions 3, 4, and 5) lining up for the trainers and simulators. By the end of June, the Gemini V training program was in trouble. That was eased somewhat when the Houston simulator, which had been used chiefly to familiarize new crews with Gemini systems in general, was refitted more specifically for Gemini V.⁶⁶

One of Gemini V’s chief objectives, the practice rendezvous with the evaluation pod, became more urgent after the doubts raised in Gemini IV. Cooper and Conrad devoted a large part of their training time to preparing for this exercise, which now seemed a crucial prelude to Gemini VI. It was being planned to simulate, as closely as possible, the terminal phase of a rendezvous with an Agena.

Another requirement for the first rendezvous flight that Cooper and Conrad rehearsed was a simultaneous launch countdown, which involved their Titan II and spacecraft on pad 19 and an Atlas-Agena on pad 14, to give the launch crew and flight controllers some experience in launching two vehicles at precise times. On 22 July, the Gemini V crew went through the motions of a double launch, including five holds - for propellant tanking, a faulty command panel switch, spacecraft problems, erratic range sequencer performance, and spurious pulses received at Lockheed’s ground stations. The demonstration lasted 867 minutes instead of the scheduled 505 minutes, but it did give the needed practice. When the test ended, the lowered erector could not be raised. The crew had to be rescued with the “cherry picker,” a cabin on the tip of a crane that had been used in Mercury and that Cooper had insisted be included in the Gemini program. Riding it down gave him a sense of vindication.⁶⁷

Although Cooper and Conrad were putting in some very long days, the scheduled launch of 9 August was simply too soon. Astronaut Chief Donald K. Slayton flew to Washington to try to argue Mueller into delaying the date. On 21 July, Mueller reluctantly agreed to postpone the launch until 19 August.⁶⁸

The usual reviews started on 29 July with the spacecraft readiness review, followed by launch vehicle readiness, 16 August; mission, 17 August; and flight safety, 18 August. On 19 August, Everett E. Christensen of NASA Headquarters assumed the role of mission director.⁶⁹

Although thunderstorms threatened that morning, the operations crew decided to push on and launch, if possible. But the predicted storm welled over the pad area, and - shades of Gemini 2! - a lightning strike near the power facilities caused the spacecraft computer to waver. Finally, the erector was raised and the crew was helped out of the craft. Propellants were drained, pyrotechnics removed or defused, and a 48-hour recycle begun.⁷⁰

The Covered Wagon

Although NASA Headquarters refused to allow nicknames for Gemini spacecraft, Cooper was not so easily put off. Conrad’s father-in-law had whittled a model covered wagon, which inspired Cooper with the idea of a patch using that motif and the motto: “Eight days or bust.” A personal appeal to NASA Administrator Webb led, after much discussion, to approval of the “Cooper patch.” But Webb heartily disliked the motto - if the mission did not go the full eight days, for whatever reason, many would say it had “busted” - and turned it down.⁷¹

On Saturday, 21 August, Guenter F. Wendt, the McDonnell pad leader, hustled Cooper and Conrad into their couches. Precisely at 9:00 a.m., they felt the modified Titan II start them on a far longer journey than any made by a bygone, continent-crossing covered wagon. The start was smooth enough but then came the bumps of Pogo.* A few seconds before staging, the bouncing stopped. Gemini V cut loose from the booster’s second stage at 163 kilometers altitude, with an orbital apogee of 349 kilometers.⁷²

Because of the mission’s length, the supply of oxygen and hydrogen for the fuel cell was a concern. Cooper intended to operate the cells at the lowest possible pressure. But Conrad suddenly noticed that the pressure had upped too low. Flight Control told him to switch on the oxygen heater to raise the pressure. To his surprise, the needle continued to drop. At 2 hours 13 minutes, Cooper yawed the spacecraft 90 degrees and ejected the rendezvous pod.⁷³

Cooper turned the spacecraft to the rear, flipped on the radar, and got an immediate signal. The radar scale showed the pod moving off at a relative speed of two meters per second. Conrad had expected it to drift away and trail behind the spacecraft, but to his astonishment it went out to the side. Finally it started to follow them as they thought it should.

The heater had still not raised the pressure in the cells. Gemini V was out of communications range, so Cooper had to make a decision without help from the ground stations, as the pressure had fallen below 138 newtons per square centimeter (200 pounds per square inch). Never having seen a fuel cell working at a pressure that low, he was afraid it might stop entirely, and he reluctantly elected to power down. Without electrical power, rendezvous with the pod was out of the question. Gemini V’s crew now wondered if, as Administrator Webb had feared, the mission had “busted.” Would Mission Director Christensen continue the flight or have them come home?⁷⁴

Flight Director Kraft now had his first major problem at the new Mission Control Center. He knew the spacecraft had enough battery power for reentry even if the fuel cell failed completely, but he needed to know if there would be time enough to reach a good reentry zone, such as the mid-Pacific near Hawaii on the sixth revolution. While Kraft waited for an answer, the fuel cell pressure dropped to 83 newtons (120 pounds). McDonnell set up a test in St. Louis to find out the lowest working pressure for a fuel cell. During the fourth revolution, the oxygen pressure stabilized at 49 newtons (71 pounds). About this time, Kraft was assured that the batteries were good for 13 hours. Mission Control Center learned that the low-pressure tests in St. Louis were going well. With these facts in hand, Kraft decided Cooper and Conrad could fly for at least one day.⁷⁵

Kranz and his crew then came on duty. While he and his problem solvers wrestled with the heater, Edwin E. Aldrin worked with a Mission Planning and Analysis Division team to design maneuvers for some sort of practice rendezvous now that the pod was out of the picture - just in case the electrical supply should be salvaged. Kranz’s team thought it would be safe to go ahead and operate the cells. When Hodge arrived, the three Flight Directors agreed to tell Cooper to turn the electricity back on. They were relieved when the pressure remained stable as the stacks were brought back on the line. Hodge’s flight planners gave the crew some experiments and systems checks to perform, which required more and more power.⁷⁶

Thinking they might have to land early, the crew had begun to put things away. Now that they were back in business, the cabin was soon full of loose gear again. Then it was time for some rest.⁷⁷ It had been a long, cliff-hanging first day for Cooper and Conrad in their “Covered Wagon.”

While Gemini V drifted, the cabin got cold. The crew turned the airflow on low but continued to shiver. This was different from Mercury flights, where the capsule had tended to overheat. The suit coolant circuit seemed cold, too, so they took the hoses off and stopped the flow inside the suits. As the spacecraft tumbled through space, the sight of the stars spinning around outside the window bothered them until Cooper covered the windows and blocked out the view.⁷⁸

Cooper and Conrad had no better luck sleeping than McDivitt and White. At first they tried sleeping alternately, but the dozer was soon disturbed by the ground calling, “Gemini 5, Gemini 5, Gemini 5.” As long as one of them was awake, there would be radio transmissions, and they decided this sleep schedule would not work. So they tried, not altogether successfully, to sleep, eat, and work together.⁷⁹

Cooper and Conrad considered the third day the high point of the flight. They worked steadily on experiments and did a series of maneuvers for a “phantom rendezvous.” Setting up their calculations on the assumption that they were tracking an Agena in a different orbit than the spacecraft, the flight controllers would pass information to the crew, just as though the target vehicle really existed. Using both ground and spacecraft computations, Cooper would then maneuver Gemini V to a rendezvous with this moving point in space, giving him a chance to check out the complete maneuvering system. Such precise moves were new to manned space flight, but Cooper came through like a champion, bringing his spacecraft to the exact position Kraft had asked for. Doubts about being able to accomplish rendezvous faded, and the mission planners were confident and ready for Gemini VI.⁸⁰

The crew powered the electrical systems down again and resigned themselves to drifting in space, performing experiments when possible. Since the inertial guidance platform was not working, they had little success, although they did some experiments, performed radar tests, and made vision tests. They saw smoke at Laredo, Texas, for example, but did not see a checkerboard pattern that had been laid out for them on a field. In the evening, Cooper asked for some uninterrupted sleep and got it.

Cooper slept seven hours and Conrad five, so their work day began at a more normal time. It was to be the last busy shift. First, they saw a rocket sled test as they flew over Holloman Air Force Base, New Mexico. Over Vandenberg, on the next pass, they sighted the contrail of a chase plane just before they glimpsed the ignition of a Minuteman missile. In the Atlantic, they observed their prime recovery carrier, Lake Champlain, with a destroyer astern. But, down below in Mission Control Center, a new problem was causing fresh worries.

Since there was no way to dump the fuel cell’s product water overboard, its storage tank had been partitioned by a bladder wall; one side held drinking water, the other stored the acidic liquid. As the crew drank, more room for the fuel-cell discharge was provided. But the cells were producing 20 percent more fluid than had been foreseen. When an analysis by Kranz’ team disclosed that, even at the high rate of production, there would be some room left at the end of the mission, everyone sighed in relief. Then still another problem arose to plague the mission controllers.

Late in the fifth day, the orbital attitude and maneuvering system (OAMS) grew sluggish, and one thruster quit. Kraft canceled all experiments that required fuel, and the crew turned off the electrical system to help reduce the water buildup. Although several possible solutions to the thruster problem were worked out, none was successful. So Cooper and Conrad again drifted through their rest and sleep period, awakening only to find that the whole OAMS had become erratic. Two thrusters had now stopped. The spacecraft drifted for the rest of the mission, with Cooper only turning on the system occasionally to stop excessive tumbling. When things had been working right, the crew had been busy. Now Conrad mentally kicked himself for not bringing a book.⁸¹

Despite all the problems, the crew did a creditable job on the experiments. Only one of the 17 had to be scrubbed - D-2, Nearby Object Photography - since it depended on rendezvous with the pod. Two complementary Department of Defense experiments were successful. Experiment D-1, Basic Object Photography, proved that the crew could acquire, track, and photograph celestial bodies. Weather conditions somewhat hampered D-6, Surface Photography, but Cooper and Conrad did obtain photographs of Merritt Island, Florida; Tampico, Mexico; Rocas Island, Brazil; and Love Field, Dallas, Texas.

Defense experiments D-4/D-7, Celestial Radiometry and Space Object Photography, were combined to make irradiance measurements on celestial and terrestrial backgrounds and on rocket plumes. The final defense experiment - S-8/D-13, Visual Acuity/Astronaut Visibility - combined use of an inflight vision tester and the observation of rectangular marks in fields near Laredo, Texas, and Carnarvon, Australia. Weather and operational problems made ground observations difficult - they never were able to see the Carnarvon field, but the Laredo pattern was partially read in the 48th revolution. The tester showed that the crew’s vision did not change during the eight-day flight.⁸²

Gemini V carried the same medical experiments as Gemini IV, plus M-1, Cardiovascular Conditioning, and M-9, Human Otolith Function, to see if the ability to perceive the horizontal deteriorated during flight. Postflight responses were not significantly different from those reported before the mission. Conrad wore inflatable leg cuffs for M-1. When activated, the cuffs pressurized automatically for two minutes out of six. They could be run continuously throughout the flight or be turned off. Conrad had some problems with the equipment but he felt the cuffs might be useful for extremely long missions. His pulse rate returned to normal faster than Cooper’s after the flight, and he lost four percent less plasma volume. But this could not be conclusively traced to the use of the cuffs, since individual responses differ. Principal investigator Pauline Beery Mack found that both had lost more calcium than the Gemini IV crew, but she was unwilling to predict a trend since “a form of physiological adaptation may occur in longer space flight.”⁸³

Cooper obtained the first photographs of the light of the moonless sky (zodiacal light and the gegenschein), experiment S-1. He made a series of stepped exposures and took two pictures of the gegenschein, a faint nebulous light opposite the Sun. Like their predecessors, Cooper and Conrad took synoptic terrain and weather photographs. Pictures of the Zagros Mountains showed more detail than the official Geologic Map of Iran. The crew also provided pictorial cloud studies, including tropical storm Doreen. S-7, Cloud-Top Spectrometer, the other science experiment, proved the feasibility of making cloud altitude measurements from spacecraft.⁸⁴

During the mission, Hurricane Betsy moved relentlessly toward the planned landing area. The landing area sea-state constraints for Gemini were considerably relaxed from those of Mercury. For Mercury, the limits were winds no more than 34 kilometers per hour (18 knots), waves no more than one and a half meters (five feet); for Gemini, winds up to 47 kilometers (25 knots) and waves up to two and a half meters (eight feet) were acceptable. Weather for Mercury in all of the recovery areas - primary secondary, or contingency - had to be good. No such restraints were ever placed against Gemini - but it certainly could not be expected to touch down in a hurricane area. The Weather Bureau recommended that Gemini V be brought down early to avoid landing too near the storm. Kranz agreed in plenty of time for the Lake Champlain to reach the new recovery zone.⁸⁵

Because of the erratic, and sometimes inoperable, OAMS, Kraft allowed the crew to use one of the two rings of the reentry control system to position the spacecraft properly more than one revolution before coming back to Earth. During the 120th pass, Cooper told McDivitt (CapCom in Houston for reentry) that Gemini V was ready for retrofire.⁸⁶

In the darkness near Hawaii, on the morning of 29 August, at 190 hours 27 minutes 43 seconds, the first retrorocket went off followed by the second and third. After what seemed like an eternity, the fourth fired. Cooper peeked out the window and felt as if he were sitting “in the middle of a fire.” With the control system thrusters spewing flame in front and the retrorockets firing behind, a nighttime reentry had to rely strictly on instruments, Cooper discovered. There was absolutely no way of seeing the horizon or a landmark. He and Conrad stayed on instruments until they had passed over the Mississippi in the morning light.⁸⁷

[Page 261 consisted of photographs from Gemini V, 21 August 1965]

Cooper held the spacecraft at full lift until it reached the 120,000-meter altitude and then tilled it to a planned bank angle of 53 degrees. The reentry gauge con indicated that they were high; there might be an overshoot the landing point. Cooper, responding to the instrument, slewed to 90 degrees left instead of 53 to create more drag and reduce the landing error. The g-loads quickly shot from 2 1/2 to 7 1/2.⁸⁸

At 20,000 meters, Cooper punched the drogue parachute button. Gemini V, unlike Gemini 1 did not oscillate - it was completely stable on the drogue. Cooper then cut in the second control ring thrusters to discard the fuel as the spacecraft came straight down. He and Conrad watched the main parachute as it unfurled and felt the expected jolt at two-point suspension. In contrast to the McDivitt-White landing, impact was very, very soft.

Gemini V landed 190 hours 55 minutes 14 seconds after launch, 130 kilometers short of the planned landing point. The computer had worked as it should in this case - the error had been human. Earth’s rotation rate is 360.98 degrees per day. But, in programming the computer, someone had left off the two decimal-place numbers and fed the machine just the 360 degrees. Cooper’s efforts to compensate for what he recognized as an erroneous reading had brought them down closer to the ship than they would otherwise have been.

The short landing caused no problems for the U.S. Navy recovery forces. A helicopter soon arrived over the spacecraft and three swimmers dropped into the water. Cooper and Conrad were very comfortable. With a calm sea, Cooper wanted to stay with the spacecraft on this pleasant summer morning (about 8:30, Cape time) until he learned that the carrier was still 120 kilometers away. Then he and Conrad rode the helicopter to the Lake Champlain.⁸⁹

The admiral welcomed them aboard ship. Asked what they had been thinking about when it looked as though the fuel cell heater problem might cause the mission to end early, Conrad pointed out a picture he had drawn between the spacecraft seats of a covered wagon halfway over a cliff.⁹⁰

Although the crew’s worries were over, Berry’s were not. His postflight concern was the trend in plasma volume and calcium losses, which were increasing on these longer missions. He was aware that the crew had been forced to drift through space the last three days, with little to do; but they should have exercised more. Two days later, to Berry’s relief, both were physiologically almost back to normal.⁹¹

A safe landing and healthy crew after an eight-day space voyage increased NASA’s confidence in achieving its lunar-landing goal during the sixties. In a span of only three months in 1965 and after just two long-duration flights, medical fears of weightlessness began to subside. Hugh Dryden reflected this optimism in his report for the President:

The primary objective of the Gemini V mission to demonstrate man’s ability to function in the space environment for 8 days and to qualify the spacecraft systems under these conditions was met. This milestone duplicated the period required for the manned lunar exploration mission.

Gemini V also demonstrated the capability of man to withstand prolonged periods of weightlessness. The adaptability of the human body was indicated by the performance of the astronauts. For example, their heartbeat rates gradually dropped to a level significantly lower than their preflight normal rates, but by the fourth day, adapted to the weightless condition and leveled off. Upon return to Earth, the heartbeat rates were slightly higher than normal, as expected, but returned to normal rate during the second day. This has assured us of man’s capability to travel to the Moon and return.⁹²

Postflight activities for Cooper and Conrad included a six-nation goodwill tour assigned to them by President Johnson. During the trip, they attended the International Astronautical Federation Congress in Athens, where they talked with the crew of Voskhod II, Russian Cosmonauts Aleksey Leonov and Pavel Belyayev.⁹³

NASA now turned to plans for the rendezvous and docking mission and for the final long-duration flight, both scheduled before the end of the year. The goal of five manned flights in a single year seemed phenomenal, compared with the experience of Project Mercury. But Gemini IV and Gemini V had indeed proved to be pillars of confidence, a solid base from which to build.