First Man

by James R. Hansen

  CHAPTER 23

  Wingless on Luna

  Armstrong had begun to study the problem of how to land a flying machine on the Moon some seven and a half years before he became the commander of Apollo 11. “We knew that the lunar gravity was substantially different [roughly one-sixth that of Earth’s],” Armstrong recalls of the engineering work begun at Edwards following President Kennedy’s commitment in May 1961. “We knew that all our aerodynamic knowledge was not applicable in a vacuum. We knew that the flying characteristics of such a vehicle were going to be substantially different from anything we were accustomed to.”

  The notion of attacking the unique stability and control problems of a machine flying in the absence of an atmosphere, through an entirely different gravity field, “That was a natural thing for us, because in-flight simulation was our thing at Edwards,” Armstrong relates. “We did lots and lots of in-flight simulations, trying to duplicate other vehicles, or duplicate trajectories, making something fly like something else.”

  The assistant director of research at the Flight Research Center, Hubert M. “Jake” Drake, got the small group organized. Back in the early 1950s, Drake had played a similar catalytic role in conceptualizing ways to attain speeds of Mach 3 and altitudes over 100,000 feet in a research airplane, an initiative that led to the hypersonic X-15 program. Attacking the problem of a lunar landing research vehicle along with Drake were research engineers and frequent collaborators Gene Matranga, Donald Bellman, and Armstrong, the only test pilot involved.

  The first idea that the Drake group considered was some form of helicopter, because of the helicopter’s abilities to hover and to take off and land vertically. Unfortunately, according to Neil, helicopters “could neither replicate the consequences of lunar gravity nor the handling characteristics of reaction system machines.”

  Another idea that the Drake group entertained was to suspend a small lunar landing research vehicle beneath some sort of giant gantry and “fly” the vehicle tethered. Independently, a pair of researchers at NASA Langley in Virginia, Hewitt Phillips and Donald Hewes, later developed this idea into a useful simulator called the Lunar Landing Research Facility (LLRF). The mockup could not actually fly. Tethered to an overhead trestle, it moved in limited ways and was not the realistic flying machine that the FRC group sought. An even safer option was to go the route of an electronic, fixed-based simulator. Ultimately, NASA used all three methods—helicopters, Langley’s LLRF, and different electronic fixed-base simulators—to study the problems of lunar landing and to train Apollo astronauts.

  Seeking to simulate as exactly as possible what Armstrong would later call flying “wingless on Luna,” Drake’s group opted for a bolder, more innovative scheme, one based on VTOL technology. VTOL referred to “vertical takeoff and landing.” It was a new and potentially revolutionary technology in which an aircraft equipped with translatable engines (like the Harrier jet that the British eventually built) flew with some helicopter-like traits.

  “There were dozens of experimental VTOL machines during the late fifties and early sixties,” Armstrong relates, “and each of them had a unique attitude control system.” The person who was building the best-known VTOL test rigs at the time was British engineer A. A. Griffith. As Armstrong began his last semester at Purdue in 1954, stories appeared in the aviation and popular press about Griffith’s pioneering vertical takeoff and landing device. It was hard not to pay attention to the weird-looking machine. Its pilot sat in a control station atop an entirely open-air framework of tubing, a calliope of “puff pipes” for attitude control arranged all around him. The bizarre contraption earned the nickname the “Flying Bedstead.” Others called it the “Pipe Rack.”

  “We were aware of that work, certainly to the extent that it was covered in Aviation Week,” Armstrong states. “However, since lunar gravity simulation was the foundation of our concept, and the British Flying Bedstead had no such system, the most value to us of such a craft was its reaction control system. An Earth-based VTOL had to be able to handle the winds, wind shears, and gusts of our atmosphere. A lunar landing machine had no such need. Of course, an Earth-based flying simulator would have some of those problems. That was our challenge—to build something simulating lunar conditions that could fly that way here on Earth.”

  The Drake group’s only known contender for attitude control of a lunar flyer was a reaction system using small rockets. At the High-Speed Flight Station in the late 1950s, as mentioned in a previous chapter, researchers had devised a test rig known as the Iron Cross. The rig investigated the basic handling qualities and control needs of a reaction control system for use in the X-15. Unlike the Flying Bedstead, the Iron Cross did not actually fly, but it did employ nitrogen gas jets, which provided control moments for testing in simulated near-vacuum maneuvers.

  The basic concept for a lunar landing research vehicle that the Drake group arrived at in mid-1961 was to mount a jet engine in a gimbal placed underneath the test vehicle so that the thrust produced by the jet always pointed upward. The jet would lift the test vehicle to the desired test altitude, whereupon the pilot would throttle back the engine to support five-sixths of the vehicle’s weight, simulating the Moon’s one-sixth gravity. The vehicle’s rate of descent and horizontal movement would be handled by firing two throttle-able hydrogen peroxide lift rockets. An array of smaller hydrogen peroxide thrusters would give the pilot attitude control in pitch, yaw, and roll. If the primary jet engine failed, auxiliary thrust rockets could take over the lift function, temporarily stabilizing the machine. What was so radical about the concept was that aerodynamics—the science on which all flying on Earth was done—played absolutely no part. In this sense, the lunar landing test vehicle that Armstrong helped to conceptualize in 1961 was the first flying machine ever designed for operation in the realm of another heavenly body, yet one that could also fly right here on Earth.

  “Our first idea,” according to Armstrong, “was to have the mockup of the lander carried on another, larger vehicle and make that larger vehicle something that created the conditions that duplicated the lunar gravity and the lunar vacuum. Our thought was, when the actual vehicle got built—and at that point no one knew what the Apollo configuration would be—we could put something like it on top of this carrier and pilot-astronauts could fly it just like they would over the Moon. They could do it at Edwards or wherever, and learn how such a machine flew. Then we decided it was going to be a pretty complicated project, and that what we should do first was build a little one-man device that just investigated the qualities and requirements of flying in a lunar environment. With that, a database would grow from which we could build the bigger vehicle carrying the mockup of the real spacecraft.”

  Through the summer and fall of 1961, the Drake team devised such a craft. According to Neil, “It looked like a big Campbell Soup can sitting on top of legs, with a gimbaled engine underneath it.”

  Unknown to the Drake group, another team of engineers was also busy in late 1961 exploring the design of a free-flight lunar landing simulator. The news that this team worked at Bell Aerosystems in Buffalo, New York, came as no surprise. The descendant of the company that had built the X-1 and so many of the other early X-series aircraft, Bell Aerosystems was the only American aircraft manufacturer with any significant experience in the design and construction of VTOL aircraft using jet lift for takeoff and landing. Jake Drake heard about the Bell initiative from a NASA Headquarters official in the fall of 1961. “We’ve just had a proposal from some people at Bell for a machine to do what you’re talking about doing,” the official told Drake. “You ought to go talk to them.” According to Gene Matranga, “We talked to them, and they had not only thought about, they were much further down the road to a practical solution to the problem.”

  Immediately Drake invited Kenneth L. Levin and John Ryken, two of the principal Bell engineers at work on the concept (a third was John G. Allen Jr.), to Edwards for consultation. Subsequently, Bellman and Mat
ranga traveled to Bell, where they rode the company’s Model 47 helicopters on simulated lunar descents. Armstrong did not make the trip, because he had heavy responsibilities at the time in the X-15 and Dyna-Soar programs. It was also shortly before his daughter died. What the FRC engineers saw at Bell confirmed their strong suspicion that helicopters just could not fly the descent trajectories and sink rates that came close to what was expected for a lunar lander. Helicopters could approximate a variety of final descent trajectories, but to do that often required their flying for substantial periods inside the so-called Dead Man’s Curve, the terminal phase of a descent trajectory where it would be impossible to abort safely without crashing into the surface.

  NASA contracted with Bell to draw up blueprints for a small, relatively inexpensive lunar landing test vehicle whose design would be independent of the actual Apollo configuration, which it had to be, since the Apollo configuration had not yet been decided upon. Bell’s job was to lay out a machine with which NASA could investigate the inherent problems of lunar descent from altitudes up to 2,000 feet with vertical velocities of up to 200 feet per second. Results from the $2.5-million study, NASA felt, could significantly help in the design of the Apollo spacecraft, a much larger contract that North American Aviation, Inc., had been awarded the previous autumn.

  Not until July 1962 did NASA settle on how to go to the Moon. When JFK boldly called for the Moon landing, a great many qualified engineers and scientists envisioned getting there and back in one brute rocket ship. That was how Jules Verne and most other visionaries had seen it happening. A gargantuan rocket roughly the size—and no doubt the weight—of the Empire State Building would take off from Earth, fly to the Moon, back down rear end first to a landing, and blast off for home. It was a mission mode that advocates called Direct Ascent. A new rocket with twelve million pounds of thrust, by far the most powerful booster ever built, would take astronauts directly from the Earth to the Moon, with no stops in between. The name of the proposed monster was the Nova.

  A second major option for the lunar landing—and one that many spaceflight experts, including NASA’s rocketmeister Dr. Wernher von Braun, came to favor—was Earth Orbit Rendezvous, or EOR. According to this plan, a number of the smaller Saturn-class boosters being designed by the von Braun team at Marshall Space Flight Center in Alabama would launch components of the to-be-lunar-bound spacecraft into Earth orbit, where those parts would be assembled and fueled for a trip to the Moon and back. The main advantage of EOR was that it required far less complicated booster rockets, ones already nearing the end of their development. Just two or three of von Braun’s early Saturns would do the job. Another benefit of EOR was long-term: in the process of going to the Moon, the U.S. space program would build a platform in Earth orbit that could easily be converted into a space station.

  To the surprise of many experts, NASA selected neither Direct Ascent nor Earth Orbit Rendezvous. On July 11, 1962, officials announced that a concept known as Lunar Orbit Rendezvous would be America’s way to the Moon. Lunar Orbit Rendezvous, or LOR, was the only mission mode under consideration that called for a customized lunar excursion module to make the landing.

  The LOR decision was made over the strenuous objections of President Kennedy’s science adviser, Dr. Jerome Wiesner. Like other skeptics, Wiesner felt that LOR was too risky to try. If rendezvous had to be part of the lunar mission, he felt that it should be attempted only in Earth orbit. If rendezvous failed there, the threatened astronauts could be brought home simply by allowing the orbit of their spacecraft to decay. If a rendezvous around the Moon failed, the astronauts would be too far away to be saved. Nothing could be done. The specter of dead astronauts sailing around the Moon haunted those who were responsible for the Apollo program and made objective evaluation of its merits unusually difficult.

  In the end, NASA’s mission planners determined that LOR was no more dangerous than the other two schemes, likely even less dangerous, and that it enjoyed several critical advantages. It required less fuel, only half the payload, and somewhat less new technology. It did not require the monstrous Nova, and it called for only one launch from Earth, whereas the once-favored EOR required at least two. Trying to bring down a behemoth like the upper stage of a Nova onto the cratered lunar surface would be next to impossible, as every analysis came to show. Even if a landing with Nova could somehow be managed, there would still be the problem of the astronauts getting down to the lunar surface from atop such a giant structure, for, even after all of its rocket staging, the spacecraft that landed would still be about the size of the Washington Monument. Engineers had even looked into the design of a transport elevator for the spacecraft for that purpose. A Moon landing via EOR looked only marginally easier. The ship leaving for the Moon after Earth orbit rendezvous would be smaller than the battleship-sized Nova, but it would still be a very ponderous stack of machinery to eyeball down to a pinpoint landing. After months of study, with absolutely no satisfactory answers to the landing dilemmas of Direct Ascent or EOR appearing, there was no choice but to go with LOR.

  The greatest technological advantage of LOR was that it turned the lander into a “module.” Only the small, lightweight lunar module (LM), not the entire Apollo spacecraft, would have to land on the Moon. Also, because the lander was to be discarded after use and would not be needed to return to Earth, NASA could customize the LM’s design for maneuvering flight in the lunar environment and for a soft, controlled lunar landing, and for nothing else. In fact, the beauty of LOR was that NASA could tailor all of the modules of the Apollo spacecraft independently—the command module (CM), service module (SM), and LM. The modularity extended to the LM itself. It would be a two-stage vehicle. The entire LM would descend to the surface using a throttle-able rocket engine. But the lower module, holding the landing legs, descent engine, and associated fuel tanks, would remain on the lunar surface and act as the launch platform for the upper or ascent stage, with its separate fixed-thrust engine, associated tank-age, attitude control rockets, and, of course, cockpit.

  Most important, LOR was the only mission mode by which the Moon landing could be achieved by Kennedy’s deadline of decade’s end. For NASA, that was the clincher. The phrase Armstrong remembers is that “LOR saves two years and two billion dollars.”

  The promise of the preliminary LLRV design played a very small but not inconsequential role in the LOR decision. The key people making the decision in favor of LOR at NASA were Associate Administrator Robert C. Seamans Jr.; Brainerd Holmes, the head of the Office of Manned Space Flight; George Low, Holmes’s director of spacecraft and flight missions; and Joseph F. Shea, head of the Office of Manned Space Flight Systems. They made the decision in personal consultation with Bob Gilruth, director of the Manned Spacecraft Center, and Wernher von Braun, director of the Marshall Space Flight Center.

  Von Braun’s preference for LOR had surprised his own staff. At the end of a daylong briefing given to Joe Shea at NASA Marshall on June 7, 1962, the immigrant German rocketeer had announced, “We at the Marshall Space Flight Center readily admit that when first exposed to the proposal of the Lunar Orbit Rendezvous Mode we were a bit skeptical—particularly of the aspect of having the astronauts execute a complicated rendezvous maneuver at a distance of 240,000 miles from the Earth where any rescue possibility appeared remote. In the meantime, however, we have spent a great deal of time and effort studying the [different modes], and we have come to the conclusion that this particular disadvantage is far outweighed by [its] advantages.”

  Overnight, a landing module became one of the most critical systems, if not the most critical system, in the entire Apollo program. The big Saturn V rocket could propel astronauts inside their snug command module into lunar orbit, but unless a special lander went along also, there would be no way for them to land. And Apollo was all about landing.

  Immediately, serious work on the LM began. In November 1962, the Grumman Corporation of Long Island, New York, won the contract. The evolutionary
path to a finished LM turned out to be torturous. The cabin volume was changed from spherical to cylindrical. The landing legs were reduced in number from five to four. The window area was substantially reduced. The seats were removed, meaning that the two-man crew of the LM would stand, like trolley conductors. Not only did the new standing arrangement move the pilots’ eyes closer to the “windshield,” improving visibility, it also reduced the weight of the overall structure, which was a crucial factor in everything related to the LM design. But it also meant that a cable restraint system had to be devised to keep the pilots in the proper position inside the cabin and hold them secure during the impact of touchdown.

  A long string of test failures—propulsion leaks, ascent-engine instabilities, stress corrosion of various aluminum alloy parts, electric battery problems—kept the Grumman team busy fixing and refining its extraordinary machine for nearly seven years. Not until March 1969 was even the first LM ready to test-fly. It took place in Earth orbit, as the primary task of Apollo 9. Throughout most of its developmental life, everyone called the vehicle the “LEM,” until May 1966 when a memo from the NASA Project Designation Committee officiously changed the name simply to “LM.” Apparently, the word “excursion” sounded too much like a vacation rather than a deeply serious enterprise for human space exploration. In the vernacular, people still pronounced the acronym, not as two individual letters, but as if the vowel were still there.