Two More Trial Flights - Apollo 5 and 6

With the success of Apollo 4, NASA had recovered much of the ground lost the previous January. An ambitious schedule was set up for the new year. The last of the Surveyors, the unmanned spacecraft that were photographing the lunar surface and analyzing the lunar soil, would go up 7 January 1968 from Cape Kennedy. The same month the unmanned Apollo 5 would be launched from LC-37 on a Saturn IB to test the lunar module. Two months later NASA would launch the second unmanned Saturn V, Apollo 6, on what was intended to be its final qualification flight. If both missions proved successful Gen. Samuel C. Phillips, Apollo Program Director, planned to advance the manned Apollo 7, a Saturn IB mission, to July or August. Assuming Saturn V was man-rated by then, Apollo 8 in October would have astronauts on the giant rocket for the first time. Should either Apollo 5 or 6 fail to meet its objectives, alternate plans provided for an additional lunar module test on a Saturn IB or a third unmanned Saturn V mission.¹

The lunar module stood center stage on the Apollo 5 mission. The flight would verify operation of the subsystems of the lunar module, conduct the first firings in space of the ascent and descent stages, and test the capability of the ascent stage to fire while still attached to the descent stage, a procedure that would eventually be used on the lunar surface. Test engineers would monitor the lunar module’s performance for six hours in near-earth orbit.

General Phillips’s office originally planned to launch the first lunar module aboard Apollo-Saturn 206 in April 1967. Anticipating six months of checkout on the lunar module, Debus had requested a delivery date of September 1966. Development took longer than expected, however, and delivery slipped from month to month. The lunar module’s arrival was still uncertain in January 1967 when KSC erected AS-206 on pad 37. In March AS-206 was taken down and replaced with AS-204, the launch vehicle from the ill-fated Apollo 1 mission.² Lunar module 1 finally arrived on 23 June 1967. In the meantime NASA and Grumman engineers had built a plywood mockup on LC-37 to be used for facilities verification. For a simulation of the cable hookup, they bought hundreds of feet of garden hose at a hardware store and routed the garden hose “cables” down from the complex interfaces through the spacecraft lunar adapter. Since the first model did not carry all the extensive electrical systems of later lunar modules, checkout mainly concerned the propulsion system.³

The summer and fall were filled with problems. Both the lunar module and its ground support equipment required extensive modifications. The week of 13 August was typical: engineers replaced helium regulators and the water glycol accumulators on the ascent stage, corrected four deficiencies in the spacecraft acceptance checkout system, contended with leaks in the support equipment, and located the source of contamination in the gaseous nitrogen facility. On the 18th, the test office reported a “significant misalignment” at the juncture of the fuel inlet elbows and the spacecraft’s propellant line. The elbows, built to the specifications of the original engine, did not fit the new engine, which had a slightly different configuration. Grumman fabricated new elbows and had them at KSC within three days.

The lunar module was mated to the launch vehicle on 19 November 1967. Without the command-service module, the vehicle stood 52 meters high. A protective covering that would detach in orbit shielded the 14,400-kilogram lunar module and its adapter. The flight readiness test on 22 December came off satisfactorily. Preparations for the countdown demonstration test started on 15 January 1968. Following simulated liftoff on the 19th, the launch team began the actual countdown.⁴

Early in the month, Petrone had announced that Apollo 5 would be launched no earlier than 18 January. The indefinite date allowed for unforeseen problems with the lunar module, which lived up to expectations: problems in loading the hypergolic propellants delayed the terminal countdown until the 22nd. At T - 2.5 hours, Test Supervisor Donald Phillips called a hold because of failures in the power supply and ground computer systems. These were corrected in time to launch the vehicle before dark. The S-IVB engine shut down ten minutes into flight and Apollo 5 went into orbit ten seconds later. The Saturn had performed entirely according to plan. The lunar module did likewise until a few seconds after the first ignition of the descent propulsion engine. The engine started as planned, but when the velocity did not build up at the predicted rate, the guidance system automatically shut down the engine. Experts analyzed the problem and recommended an alternate mission plan. The flight operations team carried this out successfully. As a result, Apollo 5 accomplished all its primary objectives.⁵

Apollo 6 - A “Less Than Perfect” Mission

Besides its primary function as a flight-test vehicle, Apollo 6 (AS-502) served as a milestone in the site activation of LC-39. The Site Activation Board’s second flow required that high bay 3, mobile launcher 2, and firing room 2 be in operation for the second Saturn V launch. Delays in the arrival of flight hardware and setbacks to the Apollo 4 schedule helped the board meet its schedule in time for Apollo 6. In April 1967, Boeing officials estimated that modifications on the swing arms, hold-down arms, and the tail service masts would require another 12,000 manhours. The mid-July date for the completion of this work was seven weeks behind schedule and threatened to delay a mid-August rollout. As events would eventually unfold, Apollo 6 did not reach pad A until February 1968, several months after the swing arm work was completed.⁶

The S-IC first stage arrived at KSC on 13 March 1967, and erection of the booster on mobile launcher 2 came four days later. Since the delivery of the S-II stage was another two months off, the Boeing crew substituted the S-II spacer again. The S-IVB stage and the instrument unit followed on the same day. The launch vehicle team quickly discovered that the high bay’s environmental control system could not support the checkout. Portable high capacity air conditioners, used originally to protect Pegasus spacecraft on LC-37, were pressed into service. Even so, the humidity approached the maximum allowable for certain pieces of ground support equipment.⁷

During the month of April, a number of tests on Apollo 6 were postponed because of Apollo 4 support requirements, illuminating one of the limitations of the mobile concept in its early days. Although the facilities could physically accommodate two vehicles at the same time, their checkout could not proceed without the removal of men and equipment from one vehicle for temporary use on the other.

The S-II stage arrived on 24 May. It was mated with the interstage and moved to a low bay the next day. Further delays in the launch vehicle tests forced a postponement of several procedures including the launch vehicle overall test 1 (plugs in). Although propellant dispersion and power transfer tests were completed by the end of the month, the plugs-in test did not get under way until 13 June. The restacking of Apollo 4 in mid-June delayed the movement of the S-II to a horizontal position in the transfer aisle, and threatened the latter’s erection date of 7 July. By the end of June, a new schedule for Apollo 6 was in hand, based upon the arrival of the command and service modules on 29 September.⁸

Apollo 6 operations in July and August continued to be marked by frequent delays. Several postponements were caused by hardware problems such as a request from Marshall that the launch team x-ray all liquid-hydrogen lines on the S-II stage. Vehicle tests were interrupted by the Apollo 4’s plugs-in test on 1 August and again by ordnance installation on AS-501 during the week of the 14th. By September rescheduling had become a way of life for the checkout team.⁹

Another revised schedule in mid-September placed Apollo 6’s countdown demonstration test in late January. Within a week the validation of swing arm 1 was four days behind schedule. Work on the service arms halted altogether on 26 September when most of the Apollo 6 crew was detailed to work on problems on mobile launcher 1. Support for Apollo 4 continued on an “as required” basis. Although the tests of the service arms for mobile launcher 2 fell three weeks behind schedule, this was not critical, because the delivery of the spacecraft was also postponed - this time by two months.¹⁰

With Apollo 4 launched and the spacecraft for Apollo 6 on hand, operations picked up. The swing arm tests were finally completed on 11 December, a day after the command and service modules joined the Saturn stack. During the remainder of the month, the launch team contended with a variety of problems: late flight control computers and flight program tapes, faulty memory in the RCA 110A interface unit, and glycol spilled on the outer surface of the spacecraft and S-IVB stage. The troubles of another plugs-in test on 21 December were typical: failure of a printed-circuit board in a digital events evaluator, a false fire alarm in the assembly building, failure of the emergency detection system test program, and a faulty battery that put an early end to the test.¹¹

Problems with flight hardware continued to consume much time. During the plugs-out test on 28 December, the launch team had a premature cutoff of engine 5 in the S-II stage. An investigation indicated that the culprit was the engine control actuator. On 5 January 1968, North American began a three-day operation to replace the actuator. Just as this was being completed, a crack was discovered in the weld of a 2.5-centimeter LOX fill and drain purge line that paralleled a similar line inside the second stage. By the time the replacement line was cleaned and installed, the S-II crew had lost another three days. Unfortunately, the problems of the S-II stage on Apollo 6 were not limited to the checkout; they were precursors of malfunctions that would occur in flight.¹²

The space vehicle electrical mate, emergency detection system check, and overall test 1 were run during two days in mid-January, and the space vehicle swing arm overall test was completed on 29 January. As the launch crew reextended the swing arms after the test, the retract latch mechanism on arm 1 failed and the first stage took a blow. A gimbal joint in the support system was damaged, but the dent in the launch vehicle proved superficial.

Apollo 6 was transferred to the pad on 6 February. Under cloudy skies the crawler with its load paused briefly just outside the assembly building for the erection of the communications antenna and lightning rods on the mobile launcher. Winds and rain hit the area, and the crawler stopped when the storm disrupted communications with the launch control center. After two hours, with contact restored, the control center gave orders to proceed. The four double-track trucks moved ahead in the driving rain. A rainbow formed above the glistening height of Apollo 6 shortly before the crawler reached the foot of the pad. Two diesel engines began leveling the platform as the transporter negotiated the incline to the top of the pad. The sun had sunk behind a low bank of clouds, and the rocket inched up the pad in semidarkness. By the time the crawler reached the top of the pad shortly after 7:00 p.m., the clouds had scudded away, the winds had died down, and the stars glistened in a rain-washed sky. The mobile service structure could not be moved to the pad for two days because of high winds.¹³

The flight readiness test for Apollo 6 was completed early on the morning of 8 March. Three days later the flight readiness review was held at KSC. The meeting included representatives of all the major supporting elements for the mission. Apollo 6 was cleared for flight subject to the satisfactory completion of space vehicle testing and the closeout of action items identified by the review. The launch was set for 28 March. The next week the hypergolic loading team ran into some minor problems, and the stabilized platform in the instrument unit was replaced. The latter meant an extra 18 hours to reestablish the guidance system’s integrity. The launch was changed twice again, first to 1 April, then 3 April.¹⁴

Preparations for the countdown demonstration test ended 23 March, and the precount began on schedule at 1:00 p.m. on the following day. The test was completed within a week. The launch countdown was picked up on 3 April at 1:00 a.m., the T-8 hour mark. There were no unscheduled holds. At the mission director’s informal review held at KSC on 3 April, Apollo 6 received a “go” for launch the next day. Launch day dawned warm and humid with scattered clouds. The prelaunch countdown and liftoff, in the words of Rocco Petrone, “followed the script”; but the script included one cliff-hanger, again in the S-II stage. During the countdown demonstration test, four propellant pump discharge temperatures had been a few degrees above redline values at the engine inlets. This threatened to convert the liquid hydrogen and oxygen into gases before reaching the injector. If this happened, Petrone told a prelaunch press conference, the pumps could malfunction and upset the ratio of fuel to oxidizer. After the test, steps had been taken to improve the insulation, and the LOX redline was raised two degrees to 98 kelvins (-175 degrees C). Whether these changes would correct the condition would not be known until the countdown went into automatic sequence a little more than three minutes before liftoff. If the temperatures exceeded the new redline, the sequencer would be halted at T-22 seconds. As it developed, the launch readings were within the new tolerances.¹⁵

Two Engines Out but Still Running

After liftoff Apollo 6 ran into a sea of troubles. In the closing seconds of the first stage burn, the vehicle went through 30 seconds of severe longitudinal oscillation - the pogo effect, it was called, because the space vehicle vibrated up and down like a child’s pogo stick. As George Mueller later explained in a congressional hearing:

Pogo arises fundamentally because you have thrust fluctuations in the engines. Those are normal characteristics of engines. All engines have what you might call noise in their output because the combustion is not quite uniform, so you have this fluctuation in thrust of the first stage as a normal characteristic of all engine burning.

Now, in turn, the engine is fed through a pipe that takes the fuel out of the tanks and feeds it into the engine. That pipe’s length is something like an organ pipe so it has a certain resonant frequency of its own and it really turns out that it will oscillate just like an organ pipe does.

The structure of the vehicle is much like a tuning fork, so if you strike it right, it will oscillate up and down longitudinally. In a gross sense it is the interaction between the various frequencies that causes the vehicle to oscillate.¹⁶

The pogo effect had not been significant on Apollo 4. On Apollo 6 it started about 30 seconds after maximum dynamic pressure or “Max Q” - between 110 and 140 seconds after liftoff - and produced unacceptable g loads in the spacecraft.

Simultaneously, the spacecraft lunar module adapter was experiencing trouble. Made of bonded aluminum honeycomb, the adapter not only housed the lunar module but connected the command-service module to the Saturn launch vehicle. At T + 133 seconds, sizable pieces of the outer surface, more than 3 square meters, flaked off. Telemetry data and airborne cameras verified the damage. Nevertheless, the adapter performed its function without impairment of the overall mission.¹⁷

More was to come. Despite the pogo effect, the first stage completed its task and the S-II took over. At T + 206 and T + 319 seconds, the performance of engine 2 fluctuated. At T + 412 seconds, the engine shut down. Engine 3 cut off about two seconds later. The control system kept the vehicle stable for the remainder of the burn, 427 seconds or about 58 seconds longer than normal. This resulted in a deviation from the S-II flight pattern, and the third stage had to burn 29 seconds longer.¹⁸

In a postlaunch press statement, Phillips acknowledged, “there’s no question that it’s less than a perfect mission.” However, he took comfort in a “major unplanned accomplishment” - the ability of the second stage to lose two engines and still consume its propellants through the remaining engines.¹⁹ At the launch site Mueller described the mission as “a good job all around, an excellent launch, and, in balance, a successful mission... and we have learned a great deal... with the Apollo 6 mission.”²⁰ The flight had tested altitude control, the navigation and guidance systems in conjunction with the service module engine, and the command module’s heat shield. In spite of all difficulties, Apollo 6 had gone into orbit. Nonetheless, Mueller admitted later that Apollo 6 “will have to be defined as a failure.”²¹ The Apollo team set out to find what had gone wrong and why.

A week after the launch, Marshall issued an initial report. In relation to the malfunction of the J-2 engines, there was some speculation that the wires that carried cutoff commands to them had been interchanged. Although the basic source of the difficulties in the second stage had not yet been determined, this at least appeared to explain the premature cutoff. Later the trouble was identified as ruptures in small-diameter fuel lines that fed the engine igniters. The lines were redesigned to eliminate the flexible bellows section where the break occurred; the fix was then verified by tests at the Arnold Engineering Development Center.²²

Coordinated plans for the resolution of the Apollo 6 anomalies, presented to the Apollo Program Director in a teleconference 2 May, included the fixes related to pogo. Prior to the launch of the first Saturn V, the longitudinal stability of the vehicle had been analyzed extensively. The results indicated that any pogo effect could be suppressed by detuning the natural frequencies of the propellant feed system and the vehicle structure. NASA had ruled that any modifications to existing hardware must be minimized. Now, from a screening process in which many solutions were considered, the corrective action emerged - it involved filling a series of cavities with helium gas. This required little change in hardware, but effectively changed the Saturn’s resonant frequency. On 15 May a review of the oscillation problem determined that the fixes could be verified in an acceptance firing about mid-July. A final decision would be made at a planned August delta design certification review^* for AS-503 (Apollo 8). All aspects of the problem were reviewed in June during a day-long teleconference among the Apollo Program Director and his staff, Marshall, Houston, KSC, and contractors. Tests and analyses had demonstrated that the modifications to 503 and subsequent vehicles had dampened the oscillations. The second of the major mechanical obstacles to man-rating had been successfully overcome.²³

At the Manned Spacecraft Center, work on the spacecraft lunar module adapter’s structural failure was concentrated in two areas: launch vehicle oscillation and spacecraft structures. No provision had been made to vent the honeycomb cells between the inner and outer surfaces of the adapter during launch. Pressures induced by aerodynamic heating of trapped air and free water in the cells could have ripped loose some of the adapter surface during the flight of the first stage. During the summer, North American engineers in Tulsa studied the effects of pressure on unbonded sections of the honeycomb panels. Dynamic tests at Houston verified a mathematical model of the spacecraft. At KSC the adapters for the Apollo 7 and 8 missions were inspected. Minor areas of unbonding were found and corrected. To equalize internal and external pressures during boost, holes were drilled through the adapter surface; and to reduce thermally induced stresses, a layer of thin cork was applied to all areas that had not been previously covered. The additional inspection at KSC and these two modifications were approved for subsequent missions, and as of late September no further changes were anticipated. It was generally agreed that the failure of the adapter had not been directly related to the pogo effect.²⁴

NASA’s efforts to resolve the Apollo 6 problems satisfied the Senate Committee on Aeronautical and Space Sciences, which in late April reported that NASA had analyzed the abnormalities of the flight, identified them with dispatch, and undertaken corrective action.

Apollo Astronauts at KSC

Before the end of February 1968, 18 Apollo astronauts had gone through exercises in the flight crew training building at Kennedy Space Center. This included both prime and backup crews for the first two manned Apollo missions. They used the mission simulators and the emergency egress trainer and were schooled on functional and operational aspects of the spacecraft.²⁵

The saga of the astronaut as a superman had begun and ended with the first seven astronauts, not from their doing, but because the public demanded a space legend. With the Apollo program, it became clear that the astronauts were exceptional men, but human. Even though selection policies tended to produce a type, the crews included diverse personalities. Some were informal and convivial, some serious and tending toward the scientific in outlook, some difficult to deal with, others easy of access. Some astronauts were extremely courteous to the ground crew, totally cooperative; others were not. Some challenged the test teams to softball games or went fishing with them, while others remained aloof. But while the men on the pad knew this, the nation as a whole and the world at large saw a different picture - a group of all-Americans who, if not supermen, had “nary a failing among ’em.”

In an article in the Columbia Journalism Review a few years later, Robert Sherrod attributed this stereotype to an unfortunate contract that Life magazine had made to tell portions of the astronauts’ stories.²⁶ Sherrod told of a visit with a team of astronauts. He found them freely available. One cooked steaks for the Life crew. Another told of his Lincoln-like rise from obscurity. A third made flapjacks for his son’s Cub Scout pack. “These three astronauts. . . . went sailing together,” Sherrod wrote, “though they didn’t really like each other very much. . . . It took some time for the truth to sink in: these famous young men were doing handsprings for Life because they were being paid for it. . . . My story never came off, except as a picture story; the astronauts came out, as usual, deodorized, plasticized, and homogenized, without anybody quite intending it that way.”²⁷

In actuality they were distinct and interesting human beings, and, at times, major problems for the men who had to deal with them.²⁸ One of the heroic astronauts, for instance, was extremely rough in his language with the men on the ground - so much so that one of his most respected colleagues called a meeting of the ground crew to apologize for the man’s conduct. One member of the launch team thought the tantrums deliberately contrived for two purposes: to get maximum efficiency out of the ground crew and to release personal tension. He said: “I would trust that astronaut to function perfectly in any tense situation. There is nothing I feel he couldn’t do.” The majority, however, agreed with their pad partner who remarked after listening to a recording of one outburst: “I hope they burn that tape.”

The veteran astronauts were able to get one of their favorite pad men of Mercury and Gemini days, Gunter Wendt, transferred to Apollo. Gunter, a former Luftwaffe flight engineer, had emigrated to Missouri, where his father lived, after World War II. He had worked as a mechanic until he gained his citizenship papers and then joined McDonnell Aircraft Corporation. Sent to Florida, he had served on every spacecraft close-out crew from the launch of the monkey “Ham.”²⁹ Wendt had a commanding way, a heavy accent, and a wiry frame - all of which brought him the nickname among the astronauts of “Der Fuehrer of the Pad.”³⁰ The entire country was to hear his name in a few weeks. When Gunter looked in the window to make his final check of the Apollo 7 spacecraft, Wally Schirra quipped: “The next face you will see on your television screen is that of Gunter Wendt.” Gunter retorted: “The next face you fellows better see is that of a frogman - or you’re in trouble.” Shortly after liftoff, Schirra asked Eisele what he saw out the window of the spacecraft. Eisele recalled the incident on the pad. As he looked out the window at endless space, he imitated Gunter’s accent with words that went out to the television and radio audience: “I vunder vere Gunter vendt.” This was to become the title of a chapter in a book of reminiscences by astronauts and their wives a few years later.³¹

Long before he “vundered vere Gunter vendt,” Donn Eisele and his fellow crewmen of Apollo 7, Walter Schirra and Walter Cunningham, had gone through almost endless practice flights in the Apollo command module and lunar module simulators in the flight crew training building. Houston provided the management and operational personnel and KSC the facility support. After a series of lectures, the astronauts entered the simulators to practice all types of docking and rendezvous maneuvers, mission plans, malfunctions, and other situations that the pre-programmed computers threw at them. Gradually simulator work took precedence over briefings, and the astronauts concentrated on specific procedures for rendezvous and reentry.³²

Each simulator consisted of an instructor’s station, crew station, computer complex, and projectors to simulate stages of a flight. Engineers served as instructors, instruments keeping them informed at all times of what the pilot was doing. Through the windows, infinity optics equipment duplicated the scenery of space. The main components of a typical visual display for each window of the simulator included a 71-centimeter fiber-plastic celestial sphere embedded with 966 ball bearings of various sizes to represent the stars from the first through the fifth magnitudes, a mission-effects projector to provide earth and lunar scenes, and a rendezvous and docking projector which functioned as a realistic target during maneuvers.³³

Two years later, when simulated moon landings had become commonplace for the astronauts and the simulator crews, they invited important guests to participate. Surprises were occasionally arranged for special guests. When French President Georges Pompidou moved the module toward the moon, he found the Eiffel Tower in the Sea of Tranquility. Another time, Chancellor Willy Brandt of the Federal Republic of West Germany landed the simulator on a Volkswagen symbol.³⁴

While the astronauts continued their repetitious exercises in the simulators, crews prepared two altitude chambers in the manned spacecraft operations building, adjacent to the flight crew training building, to test the Apollo spacecraft before its first manned flight. One chamber would serve the command and service modules, the other the lunar module. The program called for manned sea-level tests of the command-service module with astronauts on board, an unmanned altitude test, and two manned altitude tests, one with Schirra’s prime crew and one with the backup crew of Thomas Stafford, John Young, and Eugene Cernan. These tests were principally designed to prove the machines at very low pressures. Mercury and Gemini flights had already demonstrated man’s capabilities.

During the final 90 days prior to their flight, the astronauts lived on a relatively permanent basis in crew headquarters on the fourth floor of the manned spacecraft operations building. From here, they could “big brother” their flight hardware as each system went through its tests. The quarters consisted of three 3-man apartments, a small gymnasium, a lounge, and a kitchen, as well as a small but fully equipped medical clinic.

Apollo 7 Operations

Apollo 7, the first manned mission, was also the last Saturn IB flight in the Apollo program. Originally scheduled for late 1966, the launch had been delayed about 20 months by the fire and its repercussions. In mid-1967 while NASA was scrambling to recover from the disaster, the mission was tentatively set for March 1968. On the eve of AS-501, the Apollo Program Office scheduled the mission for October 1968. If the lunar module test on Apollo 5 went well, Phillips planned to proceed to the first manned flight in July 1968. Apollo 5 had accomplished its objectives, but because of extensive modifications, the command and service modules for Apollo 7 arrived at KSC more than two months late - on 30 May, three weeks after the launch vehicle had been erected on LC-34. In his operations schedule of 3 June, Petrone planned to stack the spacecraft on 19 July and launch in mid-September.³⁵

Despite the best intentions, North American could not meet Petrone’s schedule. The new block II command module was substantially different from the earlier model; there had been nearly 1,800 changes to systems and procedures since the fire. The unmanned altitude run, scheduled for 1 July, was not completed until the 23rd. The following week the astronauts made the manned altitude runs. The prime crew of Schirra, Eisele, and Cunningham spent more than nine hours in the spacecraft on 26 July, most of the time at a simulated altitude of 68,900 meters. They performed many assigned tasks to test their ability to work in their pressurized spacesuits. Technicians first purged the cabin, using a mixture of 65% oxygen and 35% nitrogen. Then the test team “dumped” the cabin’s atmosphere, the astronauts relying on their spacesuits as the pressure dropped to nearly zero. After about an hour’s work in near-vacuum conditions, the cabin was repressurized to 0.4 kilograms/square centimeter (5 psi) of pure oxygen - the normal atmosphere used in orbit. Three days later, the backup crew of Stafford, Young, and Cernan spent eight hours in the spacecraft at a simulated 61,000 meters altitude.³⁶

While launch team and astronauts tested the command-service module, other KSC engineers tried out a slidewire that would serve as an alternate route of escape from the 65-meter level of LC-34’s service structure. The 360-meter wire, designed by Chrysler, increased the options open to the astronauts and launch crew. If the hazard were a fire at the base of the service structure or any immediate threat, the slidewire offered a better means of escape than the high-speed elevators. Inside the spacecraft, of course, the astronauts could employ the launch escape system. On 16 August after a successful dummy run, the engineer in charge strapped his harness to the slide mechanism and rode safely to the ground. The next test, a mass exit of dummies, revealed some problems. With a strong wind behind them, the 89-kilogram dummies sailed down the wire faster than expected; two overshot the embankment. The mass exit was tried again two weeks later, using a different brake setting on the slide mechanism. Five dummies and then five men rode the slidewire safely to the ground. The system was ready for Apollo 7.³⁷ Petrone revised the Apollo 7 schedule on 1 August, laying out the remaining milestones at an Apollo Launch Operations meeting:

• Space vehicle erection 10 August
• Space vehicle electrical mate 28 August
• Plugs-in test 30 August
• Countdown demonstration test 11 September
• Flight readiness test 24 September
• Final countdown 7 October

There were no serious delays during the last ten weeks of the operations. The flight crew’s presence gave the mission extra meaning for many members of the launch vehicle team who had not launched an astronaut since the Mercury-Redstone days. The countdown began at 2:34 p.m. on 10 October 1968 with the launch scheduled for 11:00 the following morning. After a smooth countdown, with only one brief unscheduled hold, the Saturn IB lifted off.³⁸

Apollo 7 went into a circular orbit about 242 kilometers in altitude. The spacecraft, consisting of command and service modules, but no lunar module, separated from the Saturn’s second stage nearly three hours after liftoff. The crew practiced docking maneuvers by bringing their spacecraft to within a few feet of a target circle painted on the S-IVB stage. In 11 days the crew demonstrated that three men could live and operate in the Apollo spacecraft for the period of time needed to get to the moon and back. The astronauts appeared to millions around the world via seven live television transmissions from “The Lovely Apollo Room High Atop Everything.”

Splashdown was close to home. At 7:11a.m. on 22 October, less than 30 seconds off the scheduled time, the astronauts hit the squally Atlantic south of Bermuda. The command module tipped over after the splashdown, but inflation devices soon righted it. Helicopters from the prime recovery carrier Essex brought the bearded trio onboard for medical assessment. They returned to Kennedy Space Center for further debriefing.³⁹

“The Apollo 7,” von Braun stated flatly, “performed... as nearly perfect as one can rightfully expect a development flight to be.”⁴⁰ The Director of NASA’s Apollo Program Office, General Phillips, agreed. “Apollo 7 goes in my book as a perfect mission,” he stated. “Our official count is that we have accomplished 101 per cent of our intended objectives.”⁴¹

Apollo 7 evoked more lines from budding poets than most previous launches from the Cape, as well as three memorable letters from youngsters. One small boy volunteered to “ride on a space ship to Mars,” and listed three outstanding qualifications he had: he weighed only 27 kilograms, he was very observant, and he would not marry any of the women up there because he was “not fond of girls of any kind or shape.” Another asked if he could train for interplanetary space travel, stating: “I have a very high eye cue and am smart.” A 14-year old commented, “I would like to congratulate you on your progress. As I see it, you have only two problems remaining to conquer space - how to get there and how to get back.”⁴² No one at KSC disagreed!

Apollo 8 Launch Operations - Early Uncertainties

When AS-503 - the third Saturn V - was erected on 20 December 1967, it had been scheduled for the unmanned launch of a boilerplate Apollo in May 1968. By late January the launch team had stacked the remaining stages on mobile launcher 1. Despite the success of Apollo 4, the flight hardware still carried considerable research instrumentation. As the Apollo 6 mission neared, KSC hastened to complete the integrated testing of AS-503 in the assembly building. Admiral B. O. Middleton, KSC’s Apollo Program Manager, had informed Phillips that, if Apollo 6 failed and another unmanned Saturn V were needed, AS-503 could roll out to the pad within ten days. Final preparations for the move were held pending analysis of the Apollo 6 flight test data and the decision whether AS-503 would be manned or not. KSC’s chance to demonstrate the relative speed and economy of the mobile concept disappeared in the ripples created by pogo.⁴³

Despite the disappointment of the Apollo 6 flight, NASA was reasonably confident in its analysis of the Saturn V problems. On 23 April, Mueller recommended a revised Apollo schedule to Administrator Webb, including provisions to man Apollo 8. The next day in a press briefing at NASA Headquarters, Phillips stated that, in spite of the problems, Apollo 6 had been a safe mission. He supported Mueller’s recommendation by advocating that NASA prepare for a manned flight late in 1968 on the third Saturn V with the option to revert to an unmanned mission if corrections did not meet the requirements felt necessary to ensure crew safety.⁴⁴

The revised schedule was approved by the Administrator on 26 April in a note endorsing the planning, design, fabrication, development, and proof-testing necessary for a manned AS-503. The Administrator did not, however, authorize such a mission at that time. The decision would come later and would be subject to several restrictions. Specifically, manning the mission was contingent upon the resolution of the Apollo 6 problems and the results of the Apollo 7 (AS-205) flight.⁴⁵

KSC work schedules reflected the ambivalence of the Apollo 8 mission. If the vehicle was to have the unmanned boilerplate aboard with a lunar module test vehicle, the launch date would be 10 July. Allowances for a slippage to 15 October were built in for testing the fixes. If 503 was to be manned, it would fly CSM-103 and LM-3 no earlier than 20 November. As the manned alternative took precedence, KSC moved quickly to meet its demands. One requirement was an additional cryogenic proof pressure test for the S-II stage at the Mississippi Test Facility. By 30 April the launch team had taken the Saturn V apart and put the S-II aboard a barge. At Mississippi Test Facility the second stage, in addition to cryogenic testing, underwent modifications to the spark igniters. The J-2 engine of the third stage received the same modifications at KSC. Phillips hoped to increase the chances of meeting a manned launch in November by spreading out the necessary modifications among the various centers.⁴⁶

In early May a problem in the first stage added to KSC’s hardware difficulties. On 7 May, during a leak check on the turbopump of an engine on the first stage of AS-503, about 0.6 liter leaked from the main fuel seal in a period of 10 minutes. After evaluation, a decision to change the engine was made. The new engine was shipped on 20 May and arrived at KSC the following day. It took the remainder of the month to install and check out the replacement.⁴⁷

By the middle of June, all approved modifications to the stages and the ground support equipment at KSC were in work. Several expected modifications, however, had not yet been approved or received. Consequently, KSC officials had some doubts that the planning schedule could be maintained. One anticipated change was the modification to suppress pogo in the first stage. Although KSC had not received approval for the modification, the work had to be done and it would probably delay the internal power tests on the stage. On 13 June the RCA computers in firing room 1 and in mobile launcher 1 malfunctioned. They, too, were undergoing modifications. The troubles were isolated to two printed-circuit cards and an open circuit in the mobile launcher’s computer.⁴⁸

After two Saturn V missions, operations at LC-39 were still not what might have been hoped. As one participant later observed about the period after Apollo 6: “Few working here on a daily basis really thought we were going to be able to make it by 1969. Everything took too long." This observation was directed largely at the Apollo spacecraft.⁴⁹

The same mood was evident at a closed meeting held at Grumman Aircraft and Engineering Corporation in July 1968. At that time, Phillips noted that “the lunar landing next year is within our grasp, but we don’t have a hold of it because of the [contractors’ disregard of planned delivery dates].” Mueller noted that “the rate of changes in the [lunar module] was three times that of the Apollo command module, whose rate of changes, in turn, was four times that of the Saturn V rocket. . . . The changes placed added burden on [KSC] technicians who should be concentrating on launching operations, not on vehicle modifications."⁵⁰

By the summer of 1968, problems at Apollo factories were stretching KSC’s workload beyond its capabilities. Furthermore, the preparation of lunar module 3 for the Apollo 8 mission was only the second mission for the Grumman team, and its inexperience showed. Charles Mathews, former Gemini program director, expressed concern about launch operations after a two-day visit to KSC. “The amount of rework [on LM-3] necessary at KSC was more than should be required in Florida.” While acknowledging the overload, Mathews criticized Grumman engineers for reacting too slowly. They in turn complained about a lack of support from Bethpage. Mathews believed that neither North American nor Grumman had sufficient knowledge of manufacturing requirements. He recommended that both contractors appoint spacecraft managers to direct operations from factory to launch - “someone with as much authority within the Cape organization as he has at the factory."⁵¹

In mid-July Debus addressed the problem of KSC’s handling three Apollo-Saturn V missions concurrently. A letter to Mueller noted an apparent misunderstanding between headquarters staff members and KSC. Debus pointed out that, prior to the issuance of Apollo Program Directive 4H in November 1967, no schedule had shown more than two Saturn V vehicles at KSC simultaneously. Since then, he continued, discussions with Phillips had indicated that KSC should be able to process three vehicles concurrently. Funding constraints, however, had hampered efforts to enlarge the stage contractors’ operations team.⁵²

In a reply to Debus the following month, Phillips stated that the schedule was not, in fact, being met by KSC. To carry out the flights that were programed for the next year, KSC had to be able to process three vehicles concurrently. Phillips emphasized the efficient use of available resources and authorized KSC to provide crews for some phases of work on three vehicles simultaneously.⁵³

Lunar Module Problems and Another Change of Mission

The uncertainty about the Apollo 8 mission, temporarily relieved by the progress on Apollo 6’s deficiencies, reappeared in June when KSC began testing lunar module 3. Although it was to have arrived in flight-ready condition, KSC soon found out otherwise. The ascent and descent stages were delivered separately during the early part of June. Several leaks appeared during early tests of the ascent stage; one of them required a redesign and valve change. Early in July, a damaged flight connector in the rendezvous radar of the spacecraft caused a delay in its final installation. A week after this, there was a meeting at KSC of Houston, Grumman, and KSC officials to resolve the modification requirements. KSC estimated that it would take four days to complete the approved modifications prior to altitude chamber operations. An additional three to four days might be required if other pending modifications were approved. While work proceeded around the clock, engineers began a combined systems test for the spacecraft on 17 July. Problems with the radar, guidance, and communications systems delayed completion of the test for three days.⁵⁴

During July, KSC was also investigating an electromagnetic interference problem in which the rendezvous radar locked onto the telemetry signal. Filters sent from the Grumman plant did not correct the problem. Attempts to tune the coaxial connection between the radar dish and the electronics package lessened the interference with the telemetry system, but resulted in a new interference with the abort guidance system. On 2 August when the spacecraft internal systems were activated, electromagnetic interference increased and further investigation began. As George M. Low later recalled, it was about this time that a circumlunar mission without a lunar module first appeared as a real possibility. Difficulties encountered at KSC were having their impact on decision-making at headquarters.⁵⁵

The S-II second stage had gone immediately to the low-bay transfer aisle after its return on 27 June. Between 1 and 11 July, the augmented spark igniters in the five engines were changed. When the second stage was erected on 24 July, the third stage was still undergoing modification. Forecasts that the instrument unit’s flight control computer would not arrive on time threatened the schedule. Between delays in the delivery of launch vehicle hardware and difficulties with the lunar module rendezvous radar, the period of late July and early August was critical. Without a firm decision from headquarters, KSC could not move effectively, and difficulties at KSC tended to preclude firm decisions.⁵⁶

At a Management Council Review in Houston, 6-7 August, Low presented the details of the lunar module problems and asked the Houston mission director, Christopher C. Kraft, to look into the feasibility of a lunar orbit mission without a lunar module. Low noted that the KSC work schedule was currently headed for a January 1969 launch and that insistence upon the use of lunar module 3 could result in a delay of up to two months. At a second meeting on 9 August, Kraft reported that the lunar orbit mission was feasible. Debus indicated that KSC could support such a launch as early as 1 December. Only two items remained open: the location of a suitable substitute for the lunar module and the approval of the Administrator, who was overseas at the time. Within three days after the meeting, the command and service modules for Apollo 8 had arrived at KSC.

At a meeting in Washington on 14 August, NASA substituted a test article for the lunar module. Since the circumlunar mission depended on KSC’s ability to support a 6 December launch, Debus was asked to assess the launch team’s chances. The KSC director replied that he had no technical reservations. Although Mueller expressed a reluctance to decide before Apollo 7 results were evaluated, he conceded the necessity of doing so. The overall review of the circumlunar mission plan resulted in an informal “go.” KSC’s response was immediate and positive: the following day, the spacecraft facility verification vehicle was erected on the instrument unit.

Administrator Webb agreed on 17 August to man Apollo 8 for an earth-orbital mission, but postponed the decision on a circumlunar mission until after the Apollo 7 flight. The launch of Apollo 8 was set for 6 December. On 19 August, General Phillips announced the earth-orbit mission to the press in Washington. He ascribed the change to the problems with the lunar module, then six weeks behind schedule.⁵⁷ To expedite prelaunch operations for Apollo 8, Phillips relieved KSC of much of the burden for hardware modification. The appropriate development centers were given the responsibility with the understanding that only changes necessary for crew safety would be accomplished.⁵⁸

In mid-September KSC completed the first ten parts of the launch vehicle malfunction test satisfactorily; part 11 was scrubbed because of a failure in the RCA 110A computer. A modification of the computer in the launch control center delayed the plugs-out test until 18 September. At this point the spacecraft was approximately 5 days behind the 10 September schedule.⁵⁹

NASA conducted a delta design certification review on 19 September by means of a teleconference. Since Boeing had not yet completed the testing and analytical work associated with pogo, Phillips asked MSFC to recommend a date in November for the final review of the Saturn V. Two days after the spacecraft was added to the launch vehicle stack, Apollo 8 rolled out to the pad on 9 October.⁶⁰ During the remainder of the month, the launch team conducted a series of space vehicle tests. The flight crew participated in several, such as verifying the performance of the command, control, video, and optical systems in support of the abort advisory system. They were also active in emergency egress training. Unlike earlier programs in America’s manned space effort, the crew did not spend a great amount of time with the actual flight vehicle.⁶¹

The Apollo 7 mission ended with splashdown on 22 October. Six days later, NASA outlined the steps that would lead to a final decision on the next manned Apollo during the week of 11 November. Dr. Thomas O. Paine, acting Administrator, said: “The final decision on whether to send Apollo 8 around the moon will be made after a thorough assessment of the total risks involved and the total gains to be realized in this next step toward a manned lunar landing. We will fly the most advanced mission for which we are fully prepared that does not unduly risk the safety of the crew.”⁶² On 12 November NASA made its decision public - Apollo 8 would fly a lunar-orbital mission beginning 21 December.⁶³

Launch Countdown for Men on Saturn V

Problems with the Sanders display unit [see chapter 15-8] in the firing room forced a postponement of the flight readiness test on 15 November. The second attempt on the 19th proved successful. The presence of a crew led to some alterations in the launch procedures. The commander could call a “hold” if he felt it necessary, or he could initiate an inflight abort. Weather restrictions for the launch were supplemented to meet the danger of impacting on land after a pad abort. The presence of a thunderstorm cell within 20 miles of the pad could force crew egress, and under no circumstances could a launch take place during or through a thunderstorm. These contingencies were the province of the flight director (who took control of the flight once the vehicle had cleared the tower of the mobile launcher), the launch operations manager, and the test supervisor.⁶⁴

The countdown demonstration test for AS-503 began early on 5 December. The spacecraft slipped approximately 14 hours behind schedule because of problems in the astronaut communications and cryogenic systems. On 8 December the wet test progressed to T-9 hours when a problem in a data transmission system caused several hours delay. Later in the day an error in the memory of a digital events evaluator and a malfunction in a helium regulator terminated operations. The launch team resumed the following morning after the problems were resolved. A defective heat exchanger in the third stage’s ground support equipment halted operations at T-2.5 hours. Once again the test conductor recycled the test clock to begin at T-9 hours the morning of the 10th. After completing the test by mid-afternoon, the launch team concluded the demonstration test with a dry run the following day. Problems with the astronaut communication system and ground support equipment were grim reminders of the 204 disaster.⁶⁵

The launch countdown for Apollo 8 began at 7:00 p.m. on 15 December and headed for a launch on the 21st. The following day, a three-hour physical examination found the crew in good health. Both the men and the machine appeared ready.⁶⁶

Apollo 8 - A Christmas Gift

Activation of the fuel cells and the loading of cryogenics heralded the final count on the night of 19-20 December. The added tension of a manned launch began to show. Debus expressed the general mood on the afternoon of the 19th: “To go to the moon is symbolic of man’s leaving earth, the opening of a vast new frontier. If we hadn’t gained confidence in what we’re doing, it would be an unendurable stress.”⁶⁷ According to Paul C. Donnelly of the Test Operations Office, the astronauts “do not make it more difficult. They make it easier, because people respond better; everyone does a little better than he did when they were unmanned.”⁶⁸ When night came, huge searchlights made Apollo 8 visible for miles. Poised on its pad, ready for man’s first trip to the moon, it was a Christmas scene of rare beauty. Before dawn of the 21st, the sightseers already clogged the roads. The air was chilly, the dark sky filled with stars. Buses brought newsmen through the gates, and helicopters carried VIPs above the traffic. The distant Atlantic was the pale blue of predawn. With the morning light, Apollo 8 held everyone’s gaze. People stopped their nervous prelaunch chatter, and stood in front of their cars. Radios announced “T - 30 minutes and counting.” Astronauts Frank Borman, James Lovell, and William Anders had long before taken their cramped, temporarily supine positions. On ignition, a jet of steam shot from the pad below the Saturn. The crowd gasped. Then great flames spurted. Clouds of smoke billowed up on either side of the giant, completely hiding its base. From the midst of this fiery mass, Apollo 8 rose, slowly at first, as if unsure it could really lift free.

Suddenly the noise rolled across the three intervening miles, and vibrations struck the VIP and press bleachers. Flocks of ducks, herons, and small birds rose frantically from the marshes and filled the sky; and then came the most memorable noise of all, a triumphant cheer. A cloud blurred the view. Something fell out of the cloud, cartwheeling toward the blue ocean - the first stage had cut off. The giant second stage reappeared above the cloud, a bright star, diminishing second by second, until it faded from sight. People again turned their attention to their radios, listening attentively until the news came that Apollo 8 was in earth orbit.

Apollo 8 will be remembered for its demonstration of a great advance in space technology, for the incredible perfection that men and machines achieved throughout the mission, and for its television exploits. By television, people saw the earth from a distance of 313,800 kilometers. They saw the moon’s surface from a distance of 96.5 kilometers and watched the earth rise over the lunar horizon. The astronauts described the dark Sea of Tranquility - an area designated as a landing site for a later Apollo mission. The television cameras measured the long shadows of the sunrise on the moon.

Then followed on Christmas Eve one of mankind’s most memorable moments. “In the beginning God created the Heaven and the Earth.” The voice was that of Anders, the words were from Genesis.” And the Earth was without form and void and darkness was upon the face of the deep. And the spirit of God moved upon the face of the waters and God said, ‘Let there be light,’ and God saw the light and that it was good, and God divided the light from the darkness.”

Lovell continued, “And God called the light day, and the darkness he called night. And the evening and the morning were the first day. And God said, ‘Let there be a firmament in the midst of the waters. And let it divide the waters from the waters.’ And God made firmament, and divided the waters which were above the firmament. And it was so. And God called the firmament Heaven. And evening and morning were the second day.”

Borman read on, “And God said, ‘Let the waters under the Heavens be gathered together in one place. And the dry land appear.’ And it was so. And God called the dry land Earth. And the gathering together of the waters he called seas. And God saw that it was good.” Borman paused, and spoke more personally, “and from the crew of Apollo 8, we close with good night, good luck, a Merry Christmas and God bless all of you - all of you on the good Earth.”⁶⁹

On Christmas Day in the morning, Borman reignited the Apollo engine to break free of lunar gravity. Mission Control Center soon announced that Apollo 8 was on course, on time, at the correct speed. It landed in the Pacific shortly before midnight on 27 December.

The men of Apollo 8 had many firsts to their credit: they were the first to navigate the space between earth and moon, the first to experience the gravity of a body other than earth, the first to show live television transmission of the full earth disk, the first to exceed speeds of 38,625 kilometers per hour, the first to view the moon close-up with the naked eye, and they had set a distance-from-earth record for manned flight of approximately 359,000 kilometers. Somewhere in the list, but with a high priority at KSC and throughout the world of NASA and its contractors, they were the first men to ride the Saturn V.⁷⁰

During the outward flight and to a lesser extent on the return, Borman suffered some form of sickness that appeared to be related to sleeping pills and led to a feeling of nausea. As there had been a slight epidemic of influenza at Kennedy Space Center, there was some concern that the astronauts might be suffering from this illness, as had the Apollo 7 crew members. Fortunately this proved false, and the crew completed the mission in good physical shape.

The official objectives of the mission went beyond flying ten orbits around the moon and included navigating the command-service module, communicating with earth, making corrections in mid-course, determining food needs, and controlling temperatures inside the spacecraft. In addition, engineers had tested in detail the systems and procedures directly related to lunar landings and other operations in the vicinity of the moon.

NASA planned this mission, like all others, on a step-by-step “commit point” basis. This allowed Mission Control to decide whether to continue the mission, return the craft to earth, or change to an alternative mission before each major maneuver, depending upon the condition of the Apollo and its crew. Thus, Control could have returned the spacecraft to earth direct by way of an elongated, elliptical path in space, in effect still an earth orbit, instead of entering lunar orbit. The flight was a faultless demonstration of the command and service modules, particularly the restart capability of the main service module engine on which the return journey depended. Besides television, the crew carried cameras loaded with color film. These yielded dramatic pictures of the earth viewed from the vicinity of the moon and color photographs of the moon’s surface.

The Apollo 8 mission also highlighted KSC’s tremendous achievement in the managerial task of assembling the equipment, controlling the ground support facilities, and achieving a liftoff within 1/6 of a second of the time scheduled months before. In the technical debriefing of the Apollo 8 astronauts at the Manned Spacecraft Center in Houston on 2 January 1969, Borman, Lovell, and Anders had little to suggest for improvement of preflight procedures at KSC. Their only recommendation was for a later date for the emergency egress test at the pad.⁷¹ Other recommendations dealt with in-flight procedures of immediate concern to the experts at the Manned Spacecraft Center, not KSC. NASA granted awards to 12 key spaceport officials for their contribution to the Apollo 8 launch. Among those honored was George F. Page, Chief of the Spacecraft Operations Division. The recognition pleased the spacecraft team, several of whom spoke about Page as “one of the unsung heros, an outstanding intermediate management man. He applies the pressure that makes others perform.”⁷²

In briefing the Subcommittee on Manned Space Flight on 28 February, Debus said of the flight:

The impact of Apollo 8, in my opinion, is something that defies quantitative measurement. Following the launch of Apollo 8, the Kennedy Space Center received over 5,000 telegrams, phone calls, and letters from all over the world. This was by far the greatest volume of messages. . . . following a launch. A similar theme ran through all of these communications. For Americans, it was one of intense pride in their country and its achievements. From friends all over the world - and letters came from 28 countries - it was one of pride in the human race and a feeling of gratitude to America. These letters came from men, women, the elderly, the young, the black, the yellow, the Christian, the Jew, the Moslem, the Heads of State, the laborer, the engineer and the underprivileged. Apollo 8 had some specific significance for everyone. This reaction certainly must be evaluated in terms of world prestige, technological accomplishments, and power.⁷³