Apollo 11 had moved out of the VAB building on May 20, almost two months before, through doors advertised to be large enough to receive the UN Building, doors which left an opening forty-five stories high in the fifty-two-story-high wall of the VAB. Through that exit, inching along at about the speed a turtle can trundle down the road, had emerged Apollo-Saturn, attached next to a movable structure larger than itself, the Mobile Launcher, declared to be “the heaviest portable structure known to the Free World.” The launcher was four hundred forty-five feet tall, it weighed twelve million pounds. Its base, on which Apollo-Saturn sat, was two stories high and covered half an acre. Its vertical structure rose for forty-four stories, an open pillar of battleship-gray girders and platforms which resembled a skyscraper in early construction. Apollo-Saturn was tall, it was 363 feet high, thirty-six stories long, and it stood straight up, but the Mobile Launcher was larger, it towered above the rocket like a basketball player seven feet tall reaching over a player who is five and a half feet tall—there was even room for a twenty-five-ton-load overhead hammerhead crane to extend comfortably from the top of the Mobile Launcher over the needle-sharp nose of the Launch Escape Tower on the very top of the rocket. Below, nine retractable steel bridges, some sixty feet long, reached out like arms, umbilical cords and phalluses from the Launcher to Apollo-Saturn, offering access back and forth from the space vehicle to seventeen work platforms, some movable, some fixed in the four-hundred-plus feet of rise of the Mobile Launcher, the work platforms providing a base for loading propellant, charging pneumatic systems, checking out the instruments, and overseeing the electrical networks.
Now this huge piece of sculpture composed of shining Apollo-Saturn and the intricate girder-work of the Mobile Launcher, each embracing the other over nine bridges of steel, came crawling out of the doors of the VAB at the pace of a tortoise, or the pace of a caterpillar. The last velocity is not ill-chosen. Apollo-Saturn and its mate were installed on a giant crawler, a six million pound behemoth of a moving fundament with four tracks ten feet high and forty feet long, each track at the corner of a two-story steel structure 131 feet in length and 114 feet wide, an area larger than a baseball diamond. This tractor, the size of three long barges strapped together broadside, had a weight in combination with its vertical cargo, forty-five-odd stories high, of over eighteen million pounds, so this caterpillar tractor had individual treads on each crawler track which measured over seven feet in width and weighed a ton. This tank which, in relation to ordinary Army tanks, made the men clustered at the feet of its tracks look like Lilliputians, this mechanical monster and marvel with its modest two diesel engines each but a fraction under three thousand horsepower, had an overall top land speed when loaded of one mile an hour, but generally it took six or eight hours to travel the three and a half miles from the VAB to Pad A on Launch Complex 39, for although the Crawlerway was a special fine highway as broad as an eight-lane turnpike with median divider, and had six feet of various kinds of hydraulic fill, crushed rock, asphalt prime coats, and small river rock for topping to support these ambulatory eighteen million pounds, the road had nonetheless a couple of demanding turns to be negotiated, and a five-degree incline to be ascended at the finish in order to reach the launch base of the pad itself, that last some forty-eight feet above sea level. Before one even begins to conceive of the terror of Apollo-Saturn and the Mobile Launcher keening their forty-five stories over some five degrees (as if to reduce the Tower of Pisa to a tortured sapling!) rest in the comfort that the crawler had a hydraulic leveling system powered by two one-thousand horsepower diesels (1,065 h.p. to be precise) which could adjust the base hydraulically within an inch, no, two inches of the horizontal while climbing the last five percent of the incline up the concrete launch hill. That was done with the aid of a sort of carpenter’s level one hundred and thirty feet long from end to end—doubtless the longest carpenter’s level in the world—so the top of the space vehicle was kept vertical within ten minutes of arc, not bad, a deviation not much larger than the diameter of a volleyball.
One could assume that the possible presence of high winds, slow turns, and upgrades would be the reason the crawler travels at less than its full speed, travels rather at turtle speed, half a mile an hour, but since the sight of the open skyscraper and the rocket in nine-armed embrace clanking along the Cape Kennedy moors at a rate somewhat less than one foot a second is a sight no man has ever seen before he has seen it, it is indeed a moment in the symbolic pageantry of legend perhaps not unequal to that hour when Birnam Wood came to Dunsinane: perhaps the exquisite sense of caution in Rocco Petrone which is reflected in the speed of half a mile an hour, instead of the possible rush through at twice that rate, is due to some secret pleasure taken in the magnified luxury of treating all the workers at the Space Center to the pleasure of watching their mighty moonship edge along the horizon from morning to dusk, or even more spectacularly at night, with lanterns in the rigging, like a ghost galleon of the Caribbean! The beginning of the trip to the moon was as slow as the fall of the fullest flake of snow.
The trip had been made on May 20, just two days after Apollo 10 had taken off—Apollo 11 was in fact on the pad before Apollo 10 had made the first of its thirty-one orbits about the moon. There Apollo 11 was to remain for the next fifty-seven days while finishing touches were put to its works, and a Mobile Service Structure even stouter than the Mobile Launcher, if not quite so high, was brought in from its parking station a mile and a half off to approach the rocket from the other side. Now two giants of gridwork, one forty-five, one forty stories tall flanked the rocket, their mutual arms encircling it from all directions, the new Service Structure employing five adjustable platforms which could move up and down, and open and close each floor like adjustable jaws. Swathed and swaddled in open air, technicians with access to her at every hatch and every port, the space vehicle was given its Flight Readiness Test. If the components had all been tested before in vacuum chambers and simulators, if, in fact, the assembled rocket had recently been checked in the VAB via a Plugs-In Test, a full mission simulation of every moving part expected to function in flight, every switch, valve, gimbal and sensor having been activated, now again, outside, on the ground of Launch Pad A Complex 39, the Flight Readiness Test was given, the complete vehicle was counted down, the Command Module was put through an imaginary mission to the moon, all connections hydraulic and electric tested between the ground support equipment, the technicians at the base, the technicians in the firing room, and the computers buried in their insulators and shock-proof containers at the base of the Mobile Launcher, all to be coordinated finally in that Firing Room of the Launch Control Center built on a wing of the VAB, three and a half miles away. All this had been done in the intervening weeks, and then there was a last Countdown Demonstration Test, a rehearsal in full of the real countdown. This exercise required loading liquid oxygen and liquid hydrogen aboard the stages, then draining the fuels after the simulated time for ignition had been reached. Yes, Apollo 11 had been filled and unloaded in order to strain every connection and joint, probe every hose and every seam for leak, and since the huge rocket was as sensitive to change as a harp taken from the cellar to the sun room, the pipes and valves shifted their accommodations subtly: launch engineers having learned to live with some sympathetic equivalent of a sense of pitch, the rocket was in effect retuned after the simulation. As the pad leader, Guenter Wendt, would put it, “The whole thing moves and groans. It has its own noises you haven’t heard before.”
It was a Promethean preparation for a Herculean task, and by its end the last week had been reached, the last ninety-three hours of countdown had begun, this count to be spread over five days, with pauses or holds designed to give time to solve unglimpsed problems or relieve crew fatigue; on they pushed now into the final tuning and tightening of preparations on the rocket, every gauge and every dial, every display and every computer on the space vehicle now monitored in the Firing Room at Launch Control Center, the nerve
s of hundreds of engineers (with the experience of previous launchings to fine those nerves) were now alert for the subtlest signs of any malfunction which might first be revealed by some hesitation of a valve, some fluctuation in pressure, some recalcitrance in an electrical sensor—for five long days the count proceeded, and then with nine hours to go, over six hours before the astronauts would even approach the hatch to the Command Module, the most critical operation began, the loading of the four and a half million pounds of liquid oxygen and liquid hydrogen into the tanks of the three stages.
VIII
For the first and largest stage, a kerosene called RP-1 would be ignited with liquid oxygen. That fuel would fire the F-1 engines. There were five of them, each capable of delivering better than one and a half million pounds of thrust, the largest rocket engines ever designed—any one of the five motors was in itself ten times as powerful as the rocket in the Mercury-Atlas which first carried John Glenn into orbit, and all of this force fifty times greater than Mercury-Atlas, was grouped at the base of Apollo-Saturn, one engine at the center, the other four at the corners of a square, each motor eighteen feet high and with a thrust chamber or bell near to twelve feet in diameter at the bottom, thus a huge bell comparable for example to the great bell at Moscow raised by the Emperor Nicholas in 1836, or the bell at Notre Dame, or at St. Paul’s in London—the bell of the thrust chamber in these rocket motors was in fact larger by far than Big Ben or the Liberty Bell, and flames hundreds of feet long would fire from it when the oxygen and kerosene were ignited. Indeed much more than two thousand gallons would be consumed each second. That was one good reason to use the kerosene called RP-1. Since it was stored at normal temperature, that fuel was relatively easy to handle. In fact, it was even loaded into the first stage before the ninety-three hour countdown had begun. The problems of storing it in the RP-1 tank of the first stage were no greater relatively than holding fuel oil in the heater tank of a house basement for a few weeks. While kerosene was about half as efficient by weight as liquid hydrogen (which was used with liquid oxygen in the second and third stages) the ease with which it could be stored encouraged the designers of the F-1 engine to employ it. There is a tendency in engineering design to take only one large gamble at a time; if you are planning a new machine, sound procedure suggests taking on no more untested techniques than are necessary. So, while kerosene for the first five engines would weigh almost a million and a half pounds, and the use of liquid hydrogen would save three-quarters of a million pounds in weight, still no one had ever tried to transfer that much liquid hydrogen through pipes at a temperature of 423 degrees Fahrenheit below zero. (As Marx’s Engels had been the first to point out: Quantity changes quality.) Besides, liquid hydrogen was so light in relation to kerosene that it took up more volume; it would have needed a tank five times as large, which would have taken back some of the saving in load. So the engineers designed the huge F-1 engine to use oxygen and kerosene. The additional weight would not prove so crucial at the base because one could always increase—at least up to a point—the amount of fuel, and therefore the duration, of the first stage and so lift the extra heft of the kerosene. It was in the upper stages, and in the Apollo spaceship itself, that one had no choice but to conserve on weight, for those fuels would be dead load for all of that period the first stage was burning. It was one thing for kerosene to be obliged to lift its own relatively heavy mass, quite another to have to raise kerosene which would be doing no work until later. So RP-1 was employed for the first stage, and was pumped into its tank one hundred and twenty-six hours before lift-off. (The tank, incidentally, held 212,846 gallons.)
The liquid oxygen and the liquid hydrogen, the Lox and the LH2, were a different matter. They were gases converted to liquid and therefore highly unstable. The physics was basic. In the same way boiling water becomes steam, so every liquid will convert to a gas if it is given enough heat; in turn, every gas will concentrate itself into a liquid if the pressure upon it is high enough, or the temperature sufficiently low. As rocket fuels, oxygen and hydrogen were used in liquid rather than natural form because more oxygen and hydrogen could be kept in the same space once the gas had been compressed to become liquid. But what problems to contain it! What higher powers of hydrodynamics were now demanded to pump it! For it had to go from its storage tanks through a quarter-mile of pipe all the way to the bowels and belly of the rocket, and that at a rate which must be so high at times as ten thousand gallons a minute, more than a hundred-sixty gallons a second of a liquid down 423 degrees below zero had to pass by any given point—what an icy rush of sludge! Yes, hydrodynamics, that sturdy engineering science of plumbing, pipes, valves and pumps, had taken its own leap to create Saturn V—the world of technology had been shifted in its natural evolution by the development of the moonship, whose inbuilt emphasis on hydrodynamics and electronics had altered the balance of technological achievement as much as our conception of man might be staggered by a new species whose capacity to think and pass food through his system had raced far ahead of his ability to walk, run, play, work, or do anything else. The pipes which carried the liquid hydrogen were vacuum-jacketed tubes of stainless steel, pipes fifteen hundred feet long, ten inches in diameter and pushed from storage tank to rocket tank by a pressure so great as sixty pounds per square inch, which once one recognizes how light is liquid hydrogen—hardly more than half a pound a gallon, half a pound a gallon!—is certainly at sixty pounds a square inch, one mighty push on such froth. Each pipe proved to be a pipe within a pipe, a vacuum installed between to maintain the insulation of the extreme cold, and indeed the speed of the pumping was doubtless to reduce the risk of the leak, for vacuum or no, that kind of cold fuel, that intensely low cryogenic liquid energy, was bound to warm if it tarried in the pipes. It would then expand, leaks would spring. “We can live wiz some leak,” Kurt Debus, the Director of the Space Center, had said in his fine Junker accent, leaks in such high pressure pipes were the order of procedure, indeed every pipe and valve in the whole plumbing combine of Apollo-Saturn, the Launch Pad and the storage tanks was redundant, which is to say that for every pipe there was another unused pipe equal to it and ready to be used if the leaks in the first could not be found and controlled, leak they could live with—if it were modest—but everything in their technology looked to remove the likelihood of such conditions, and so they rushed the fuel through the pipes, through the ingeniously fitted double pipes and valves jacketed to keep the vacuum intact, past the jacketed couplings, through the insulated umbilicals, up into the insulated tanks of the rocket stages, there to sit, and boil, and boil off, a small percentage of this million gallons of varied fuels stirring in their icy containers, turning to gas, and then being vented into the air to form the clouds which clung to Apollo-Saturn through the early morning and on into the dawn of the day of its launching. As the fraction boiled off, they topped it with new fuel, kept up the topping, kept it up indeed until the last of the countdown minutes was ticking.
Now, nine hours earlier, they had cleared the launch area for the loading of propellants, all of that blast area which could go up in conflagration if the rocket blew. But it was beyond the imagination to conceive of a million gallons of fuel suddenly ignited. Such an explosion would bear comparison to the early atom bomb. So no one was in the area while the fuel was transferred, no need, the loading was done by automation, Saturn V sitting silently, ship of space on her pad. The Service Structure having been drawn down the road by the crawler at lift-off minus 10 hours, Apollo-Saturn was alone again with her Mobile Launcher. For four hours and thirty-seven minutes, from lift-off minus 8 hours and 15 minutes to lift-off minus 3 hours and 38 minutes, first the liquid oxygen and then the liquid hydrogen and associated cryogenics (or low-temperature fuels like liquid helium, liquid nitrogen) were loaded into the stages of Saturn V, and into the fuel cells and thrusters of the Service Module, the Command Module and the Lem, floodlights playing on the white skin of the spaceship, hints of the dawn beginning to breat
he over the ocean. Back at MSOB, eight miles away, they awakened the astronauts at four-fifteen in the morning and gave them a last quick medical examination before they proceeded to breakfast on orange juice, toast, steak and eggs. Then silver chloride electrodes called biomedical sensors were pasted in place, taped to the skin—at least four had to be worn by each astronaut in order to monitor his heartbeat and respiration, the wires running into a bio-instrumentation harness, a belt each astronaut wore which had little radio transmitters called signal conditioners, each the size of cigarette packages. Equipped with a built-in power converter, the bio-instrumentation harness sent constant signals to an electrocardiograph and an impedance pneumograph in the spaceship. Therefore, the astronauts did not have to be plugged into any socket for a medical record to be kept. Plugged in they would be in other ways, by hoses from their space suit to oxygen supply, by electric cable with a twenty-one-socket connector which ran from earphones and microphones (worn in a black and white helmet on their head) to their garment. But then they even wore film packs on their legs and dosimeters on their arms to measure the belts of radiation through which the spaceship would pass, yes, space suits donned, and thus installed with detectors on every flank, they picked up their life-support systems, which fed oxygen to their helmets, and life now passing into them through the umbilical hose attached to their suit, passed, helmets on, through the aisle of reporters and photographers waiting for a glimpse of them and rode in the crew transfer van to the Launch Complex, where they arrived a little after six-thirty, rose up in the elevator to the 320-foot station, entered the Command Module over the highest of the nine swing-arms, a view below thus vertiginous that they might as well have been walking along the cable of a bridge, and settled in, Armstrong in the left seat, Aldrin in the center, Collins at the right for the last two hours and forty minutes.