Chapter 1

Between Mercury and Apollo

In Houston, Texas, December temperatures in the low sixties seem cool.¹ And so it must have seemed to Robert R. Gilruth when he landed in the city on 7 December 1961, especially in contrast to the muggy end-of-summer heat that had greeted him on his first visit two and a half months before. Gilruth’s September visit had followed close on the heels of the announcement that the Space Task Group (STG) he headed was moving to Houston. With several of his colleagues, he had come to look over the new site for his fast-growing branch of the National Aeronautics and Space Administration (NASA). Now he was back in Houston to tell the city’s business community something about his group and its work - putting American astronauts into space and eventually landing them on the Moon. The occasion was what the Houston Chamber of Commerce billed, with a bit of Texas hyperbole, as its 121st annual meeting. True, a chamber of commerce had been formed in 1840, but it soon vanished without a trace. Seventy years later, the 15-year-old Houston Business League voted to rename itself the “Chamber of Commerce.”² Whether the 1961 session was the 121st, the 66th, or the 51st, it was still a big event. Houston “was a businessman’s town.”³

And it was a booming town, sprawling over more than 480 square kilometers (300 square miles) of Texas Gulf Coast “like a bucket of spilled water.”⁴ In the same month that Gilruth first visited Houston, the city’s population had passed the million mark. And that, according to the president of the Chamber of Commerce, was one of the “most significant milestones of Houston’s progress in 1961.”⁵ Houston and its people blended, not always smoothly, the South and the West. Chicanos joined blacks as part of the “problem” that sometimes troubled the ruling Anglos, who were “conservative, cautious, and business-oriented . . . because they reflect community attitudes.”⁶ September 1961 was also the month when the first black pupils, twelve of them, entered Houston’s white school system.⁷

But Houston’s leaders, in a pattern that has marked American development at least since the 19th century, coupled social conservatism with economic opportunism. Founded as a lucky real-estate venture, the city had grown by exploiting the resources of a vast hinterland. Freewheeling promotion was, and remained, the order of the day, and nowhere more so than in the multibillion-dollar oil industry that Houston headquartered.⁸ The hotel to which Gilruth repaired was a perfect symbol of the city and a fitting site for the “121st” annual meeting of the Chamber of Commerce. Brainchild of Glenn McCarthy - oil millionaire, land speculator, and all-round promoter - the Shamrock Hotel had taken five years to build and cost $21 million. It opened grandly on St. Patrick’s Day 1949, with 50,000 people gathered to eat $42-a-plate dinners. Six shades of green garnished its outer walls, a prospect otherwise so dull that Frank Lloyd Wright refused to comment on it, though glimpsing the interior did move him to muse, “I always wondered what the inside of a juke box looked like.” McCarthy lost the hotel when his oil empire collapsed five years later, and it ended up in the hands of another Texas entrepreneur, Conrad Hilton. So it was the Shamrock Hilton, with Hilton’s portrait gracing the lobby instead of McCarthy’s, when Gilruth arrived.⁹

Gilruth himself symbolized another of the “milestones of Houston’s progress in 1961.” On 19 September, just a day after the city officially topped a million, NASA had announced its choice for the site of a new multimillion-dollar manned space flight laboratory.¹⁰ It was to be near Clear Lake, some 32 kilometers southeast of the city on a tract of land donated by the Humble Oil and Refining Company. This, too, fit the pattern of Houston’s growth, at least since World War I, as federal funds had begun to flow into the city like the oil that much of that money financed. The president of the Chamber of Commerce welcomed NASA’s new move as “one of the Houston’s most meaningful developments since the opening of the Ship Channel for deep sea shipping in 1915.” Gilruth directed the new facility, the Manned Spacecraft Center (MSC), which came officially into being on 1 November l96l.¹¹

The Center was, in fact, merely the renamed Space Task Group (STG), created in 1958 to put Americans in space via Project Mercury. So far, STG had managed to loop two astronauts over the fringes of the atmosphere on Redstone boosters and to orbit with an Atlas rocket a chimpanzee named Enos. But the much-delayed attempt to orbit a man still receded. On the same day that Gilruth spoke to the Houston Chamber of Commerce, he announced that the scheduled 19 December launch of Mercury-Atlas 6, with John H. Glenn, Jr., aboard, was now postponed until 1962. The United States was not going to match, at least in the same year, the Soviet Union’s feat of sending a man into orbit. Nonetheless, optimism prevailed. The causes of the delay were minor, and success seemed just around the corner.¹²

STG, like Houston, had boomed in 1961. Two largely successful manned suborbital flights, followed by Mercury-Atlas 4 with its “mechanical man” and the ape-bearing Mercury-Atlas 5, had eased the worries caused by Mercury’s technical problems during 1960. In the meantime, STG had added the manned lunar landing program, Project Apollo, to its responsibilities. It had outgrown its makeshift facilities at Langley Research Center in Virginia and its old name as well. After a painstaking search, NASA settled on Houston for STG’s new location and soon furnished the group with a new name to match its larger role.¹³

For Houston, it was love at first sight, but the 750 NASA workers faced with moving 2,400 kilometers from Tidewater Virginia to Gulf Coast Texas in the midst of Project Mercury were less enthusiastic. Gilruth himself had qualms after his first view of the new site in September, shortly after it had been swept by Hurricane Carla.¹⁴ The decision had been made, however, and the space fever that promptly seized Houston helped smooth the changeover. A crowd of some 900 greeted Gilruth with a standing ovation when he stepped to the dais at the Shamrock Hilton to begin his remarks.¹⁵

What Gilruth had to say turned out to be headline news and earned him another standing ovation when he finished. NASA, he revealed, planned to launch a third manned space flight program to fill the gap between Mercury and Apollo. He outlined a half-billion dollar project to orbit a two-man Mercury capsule via the Air Force’s new Titan II booster. The key goal was to develop orbital rendezvous, a novel technique NASA planned to use in the Apollo mission to the Moon. Once in orbit, the crewmen would steer their rocket-powered craft to a meeting with an unmanned Agena spacecraft, boosted into orbit separately by an Atlas.¹⁶ Gilruth had learned only that day of NASA Headquarters’ approval of the new project.¹⁷

Still something of a puzzle was what to call it. In making it public, Gilruth labeled it a “two-man Mercury.” Inside NASA, at one time or another, it had gone by the name of Advanced Mercury, Mercury Mark II (the one-man capsule being Mark I), or simply Mark II. Within three months, however, an ad hoc “program-naming” committee in NASA Headquarters decided on “Gemini” for the new project. Recognition for having picked that name, along with a bottle of scotch as prize, went to Alex P. Nagy in NASA Headquarters. Gemini, “The Twins,” was one of the 12 constellations of the zodiac. Nagy thought that “‘the Twins’ seems to carry out the thought nicely, of a two-man crew, a rendezvous mission, and its relation to Mercury. Even the astronomical symbol (II) fits the former Mark II designation.”¹⁸

By an unlikely coincidence, since Nagy disclaims any knowledge of astrology, Gemini as a sign of the zodiac is controlled by Mercury. Its spheres of influence include adaptability and mobility - two features the spacecraft designers had explicitly pursued - and, through its link with the third house of the zodiac, all means of communication and transportation as well. Astrologically, at least, Gemini was a remarkably apt name, the more so since the United States is said to be very much under its influence.¹⁹ To those with no more than a passing knowledge of astrology, however, Gemini must have seemed a most obscure choice. To this day, its proper pronunciation has not been settled in NASA. Although an informal survey of astronomical opinion came down on the side of a terminal “ee” sound, many still opt for “eye.”²⁰ The new program publicly became Project Gemini on 3 January 1962.²¹

The Background of Rendezvous

The project that Gilruth announced on 7 December 1961 had not just then sprung into being. A year of planning, work, and advocacy had gone before, and more than three years of intense effort lay ahead before Gemini carried men into space. Even so, Gemini was something of an afterthought in the American manned space flight program. Gemini did fly after Mercury had achieved its major goal of putting an American into orbit and bringing him back safely and before Apollo first bore men aloft on the path that led eventually to the surface of the Moon. But that is misleading. One of the reasons for Gemini, in fact, was to keep Americans in space during the time when Mercury had run its course but Apollo had yet to be launched.

Gemini took shape after Apollo had begun, in part to answer a crucial question for Apollo: Was rendezvous and docking in orbit a feasible basis for a manned lunar landing mission? When NASA officials appeared before Congress early in 1962 to justify the new program, the heart of the case they argued was the need to develop and prove the techniques of orbital rendezvous.²² Project Gemini was intended to show that a piloted spacecraft could meet an unmanned target in space - the orbit of the spacecraft matching that of the target so that there was no significant difference in speed and no significant distance between the two, in much the same way that two aircraft might fly in formation.

Many aspects of modern space flight were first suggested in the sometimes fanciful but often profound space-travel writings of the early 20th century. One was the value of rendezvous in orbit. It first emerged as part of the space-station concept, which can be traced through the works of the Russian pioneers of astronautics - K. E. Tsiolkovskii, Yu. V. Kondratyuk, and F. A. Tsander - and in the writings of their Central European counterparts - Hermann Oberth, Walter Hohmann, Guido von Pirquet, and “Hermann Noordung.” Their goal was flight to the Moon and planets, but their calculations suggested that chemically propelled rockets might lack the power to launch such journeys directly from Earth’s surface. If a journey were carried out in stages, however, the problem might be surmounted.

They proposed using a space station, a stopover point in orbit. Once such a station was built, any number of rockets might be launched to meet it, each bearing its cargo of fuel or supplies to be transferred to the station. When enough had been gathered, fuel and supplies might then be loaded aboard an interplanetary vessel, perhaps itself constructed in orbit, and the real journey to the planets could begin. In effect, the trip would be launched from orbit, the greater part of the velocity needed to escape Earth’s gravitational field having been already attained. This concept had been widely accepted in space-travel circles by 1929.²³

While rendezvous was clearly a key technique in this scheme, it failed to receive any special emphasis. That changed after 1949, when two members of the British Interplanetary Society pointed out that orbital staging need not depend on first building a space station. The new concept was called “orbital technique” or “orbital operations.” The pieces of an interplanetary vessel might simply be assembled in Earth orbit without troubling to construct a space station, or several rockets might meet in orbit and transfer their fuel to one of their number, which would then embark on the final mission.²⁴ As Wernher von Braun, later one of NASA’s leading advocates of orbital operations, remarked, the space station really amounted to no more than a “space rigger’s hotel.”²⁵

The rapid spread of this idea brought rendezvous into sharp focus. Unlike the space-station concept, to which rendezvous was a sometimes neglected adjunct, orbital operations moved rendezvous to center stage. The first paper specifically addressed to the problem of “Establishing Contact Between Orbiting Vehicles” appeared in 1951.²⁶ One result was a renewed attention to orbital mechanics, a topic that had languished since the path-breaking work of Walter Hohmann in 1925. By the end of the 1950s, a theoretical framework for rendezvous techniques had been largely erected.²⁷

When NASA planners began to grapple with the problem of picking long-range goals for the American space program, however, they tended to overlook the part rendezvous might play except as it related to space stations. This may have reflected, as much as anything else, the imprint on NASA of the National Advisory Committee for Aeronautics (NACA). When NASA began its career on 1 October 1958, its core was the 43-year-old NACA, to which had been added several military and quasi-military space projects. NASA was designed to be, and in time became, something larger, wealthier, and more adventurous than NACA had been. But for a time much remained unchanged or changed only slowly. The habits of mind, the viewpoints, the styles, the biases fostered by the old setting did not vanish overnight with the old name. The same NACA engineers, scientists, managers, and technicians who left work on 30 September 1958 were back on the job for NASA the next morning. Time would bring new faces and fresh view-points, thin the ranks of the old NACA hands, and weaken the grip of old habits; but NACA left an enduring mark on NASA and its programs.²⁸

NACA had existed to serve - to solve problems for military and industrial aircraft programs. Its field, in which it was very good, was applied research - solving general engineering and technical problems in aeronautics. NACA laboratories had produced many of the technological innovations that transformed the post-World War I airplane, a slow and inefficient machine of small military and no commercial importance, into the major weapon and economic giant of mid-century. Langley Memorial Laboratory was the first and, until the eve of World War II, the only NACA laboratory; Langley research pioneered many prewar innovations in aeronautical design. Lewis Flight Propulsion Laboratory and Ames Aeronautical Laboratory went into operation early in the Second World War, the Pilotless Aircraft Station in 1945, and the High Speed Flight Station in 1947. In 1940, NACA had 650 employees and a budget of $4.37 million; five years later it employed 6,800 and spent $40.5 million. But NACA still focused its research in those areas where lack of knowledge hindered aviation progress, spending little effort on basic research - expanding scientific knowledge - and steering clear of development, which meant seeing a specific project through design, building, and testing.²⁹

During the 1950s, some of the most pressing problems in aeronautics arose from the little studied and poorly understood effects of high temperatures on very fast-moving aircraft and rockets. This made the focus of NACA research in that decade transonic and hypersonic flight, with special stress on aerodynamic heating phenomena.³⁰ When Sputnik I on 4 October 1957 transformed space from a region of scientific curiosity to an arena for national rivalry and spurred planning for manned space flight, this background stood NACA in good stead.

A small group of engineers at Langley began working informally on a manned orbital satellite. At the start of October 1958, in one of his opening moves as NASA’s first Administrator, T. Keith Glennan approved the project. He formed the Space Task Group to run it and announced its name as Mercury two months later. STG started with 45 people led by Robert Gilruth and they had only one job: the most direct and speedy achievement of manned orbital flights.³¹ It was a complex but straightforward engineering task. Project Mercury “did not require and does not require any major technological breakthroughs.”³² What it did need was just what a NACA background provided, the skills of applied research and aeronautical engineering and particularly experience in the aerodynamics of hypersonic flight.

Manned space flight beyond Mercury, however, was another matter. The crucial role of boosters in setting the limits of what could be done in space prompted NASA to its first long-range planning venture, “A National Space Vehicle Program,” issued in January 1959.³³ This report surveyed existing boosters and proposed developing a series of new ones. It did no more than suggest a range of missions suited to each of them. What could be done, however, was one thing; what should or would be done was something else. Choosing among the possible goals now became NASA’s central planning concern.

This concern produced “The Ten Year Plan of the National Aeronautics and Space Administration” in December 1959. Ultimately spacecraft would carry explorers to the Moon and planets, but for the 1960s, NASA chose the more modest goal of circumlunar flight - a trip to the Moon, a few passes in orbit, and a return to Earth. “Manned exploration of the moon and the nearer planets must remain as major goals for the ensuing decade.”³⁴

NASA planners assumed that a trip to the Moon would be launched directly from Earth’s surface. That required the giant Nova booster, the largest of the four new vehicles proposed in January 1959. Nova was a concept built on an engine (the F-1) designed to produce 6.7 meganewtons (1.5 million pounds of thrust). Air Force contracts with Rocketdyne had begun F-1 development in mid-1958. This was one of the military projects turned over to NASA when it was formed. Four of these engines were planned for Nova’s first stage to provide 27 meganewtons (6 million pounds of thrust) at a time when the most powerful existing American booster required three engines to generate 1.6 meganewtons (360,000 pounds of thrust).³⁵ The belief expressed in the January report that, “with Nova, a manned lunar landing first becomes possible,”³⁶ pervaded NASA planning throughout 1959 and 1960. Even when refueling or assembly in orbit were discussed as alternatives worthy of study, they were discarded as a basis for planning, since “it is assumed that the Nova approach will be followed.”³⁷

The choice was by no means final, but NASA was leaning strongly toward direct ascent, perhaps more by default than by decision. To the extent that they had been compared at all, the merits of direct ascent and orbital operations had been merely asserted rather than studied. The question had been cited as a major one, and some of the problems involved in “the all-the-way approach versus the assembly-in-orbit approach” had been aired at meetings of the Research Steering Committee on Manned Space Flight, more commonly known as the Goett Committee after its chairman, Harry J. Goett of Ames, during 1959.* ³⁸ But, as NASA’s 10-year plan showed, the question had yet to exert much effect on NASA policy.

Notably absent from NASA’s budget request for fiscal year 1961 was money to study rendezvous, nor did NASA spokesmen mention rendezvous when they defended the budget before Congress early in 1960.³⁹ There was also little talk of space stations. That had not been true the year before, when NASA asked for funds to study both a small orbiting space laboratory and rendezvous techniques. These were closely related. NASA’s 1959 choice of lunar landing over a space station as its long-range goal caused rendezvous to fade into the background, since the agency had yet to conceive rendezvous for any purpose other than supporting a space station.⁴⁰

Challenge From the Field

Although rendezvous ceased to seem very important to NASA Headquarters, 1960 saw that viewpoint challenged in the field. Several NASA field centers had begun to look more closely at the possibilities, and two, in particular, began to urge strongly an open-minded reassessment of the merits of rendezvous. One was the George C. Marshall Space Flight Center, in Huntsville, Alabama; the other was Langley.

Marshall was unique in NASA for its background and outlook. It was the former Development Operations Division of the Army Ballistic Missile Agency, which joined NASA and received its new name in March 1960.⁴¹

Marshall’s Director, Wernher von Braun, and his chief lieutenants had been responsible for the German Army’s rocket development programs before and during World War II, coming to the United States after the Nazi regime collapsed in 1945.⁴² They had known the heady atmosphere of Weimar Germany’s dreams of space travel, and they had a long head start on their American colleagues in the hard, practical work of making these dreams real. They had studied space stations long before they joined NASA. Von Braun had moved on to the notion of orbital operations. As early as December 1958, he was urging NASA to base its lunar mission planning on rendezvous techniques. In a presentation to top-level NASA officials, von Braun dismissed direct flight as very difficult, then described four alternative rendezvous schemes, two requiring only Earth orbital operations and two calling for rendezvous in lunar orbit as well.⁴³

Von Braun and his colleagues had been working since 1957 on the concept of using a cluster of relatively small rocket engines to build a booster of 6.7 meganewtons (1.5 million pounds of thrust) as the basis for a space flight program leading to manned lunar landing.⁴⁴ The booster project was approved by the Advanced Research Projects Agency of the Department of Defense in August 1958.⁴⁵ Then known as Juno V, the vehicle became Saturn in February 1959 and studies began on suitable upper stages in a complete system for a military lunar mission.⁴⁶ Whether there was any military need for Saturn was the question of 1959, and the answer was no. The decision to shift Saturn to NASA was behind the transfer of von Braun’s group.* ⁴⁷

Spokesmen for von Braun’s group led the defense of the “assembly-in-orbit approach” at Goett Committee meetings during 1959, with strong backing from George M. Low, who urged study of “vehicle staging so that Saturn could be used for manned lunar landing without complete reliance on Nova.” The committee supported von Braun’s request for a NASA contract to study orbital operations (his group then still belonged to the Army), and Low, who was highly placed in the NASA Headquarters Office of Space Flight Development, helped push it through.⁴⁸ Von Braun’s group studied Saturn’s role in lunar landing missions, both manned and unmanned, under NASA auspices during the last half of 1959. The new findings confirmed what an earlier report had concluded, “that a manned circumlunar satellite could be launched from the earth’s surface, but some other technique will have to be used for a manned lunar landing with the present state of the art.” Most of the chapter on “Manned Circumlunar Flights and Lunar Landings” in the 1959 study report was devoted to the role of orbital operations in these missions.⁴⁹

Joining NASA did nothing to alter this Center’s viewpoint. Until well into 1960, however, Marshall’s leanings toward orbital operations produced little work specifically on rendezvous.⁵⁰ Concerned mainly with development programs, especially Saturn, Marshall had few resources to devote to the kind research needed to locate and solve basic problems of technique. Such studies, in any case, more properly fell to one of NASA’s research centers, which could focus on rendezvous itself rather than on the missions that the technique might open up. This was where Langley entered the picture, for whatever these missions might be, in true space flight “there will undoubtedly be space rendezvous requirements.”⁵¹

Rendezvous research centered on guidance and propulsion at Langley, where two groups were working more or less independently during 1959. In the Aerospace Mechanics Division, John M. Eggleston and his colleagues were looking at the mechanics of orbital rendezvous. And in the Theoretical Mechanics Division, a group headed by John D. Bird was studying launch windows and trajectories for rendezvous.⁵² The spokesman for Langley in the Goett Committee agreed that lunar landing ought to be “the `ultimate’ manned mission for present consideration.” But he also voiced Langley’s belief that some form of manned space laboratory was “a necessary intermediate step” as a focus for research. That meant a space ferry, and a space ferry meant rendezvous.⁵³

Late in 1959 this concern generated a space station committee at Langley, with a subcommittee on rendezvous headed by John C. Houbolt, then assistant chief of the Dynamic Loads Division. Houbolt was fresh from a successful attack on the problems that had caused several Lockheed Electras to crash. Despite, or perhaps because of, his inexperience in spacecraft technology, Houbolt zealously espoused rendezvous. Although his subcommittee had been formed to look at rendezvous in the context of space stations, Houbolt insisted from the start that it study rendezvous in the broadest terms, since that technique would play a large role in almost any advanced space mission. Loosely organized and largely unscheduled, the subcommittee became a meeting ground for everyone at Langley concerned with any aspect of rendezvous.** ⁵⁴

When Langley hosted the Goett Committee in December 1959, Houbolt was among the space-station committee members invited to describe their work. He concluded by urging a rendezvous-satellite experiment “to define and solve the problems more clearly,”⁵⁵ the first of many such pleas Houbolt was to make with as little response. Space station thinking still guided rendezvous work at Langley over the next six months.

In May 1960, Langley was once more host to a meeting, this time of lesser scope but greater impact. Bernard Maggin, from the Office of Aeronautical and Space Research in NASA Headquarters, had called the meeting to discuss space rendezvous and served as its chairman; he was the only member from Headquarters. Maggin had intended to invite to the meeting only the NASA research centers - Langley, Ames, and Lewis - which his office directed. He soon learned, however, that rendezvous had excited wider interest, so he invited the development centers - Marshall and Goddard - as well. The meeting was designed to give the centers a chance to acquaint each other with current research and to exchange thoughts on future prospects.⁵⁶

Most of the first day was given over to a series of technical papers on propulsion, guidance, and trajectories, which mainly reviewed work in progress.⁵⁷ They revealed two salient facts about NASA rendezvous research in mid-1960: work centered on rendezvous between space station and ferry, and Langley was doing most of it.

All NASA rendezvous research was in-house; NASA had yet to provide contract funds for industrial or academic studies. This was one of the chief topics at the round-table talks on future rendezvous requirements that took up the second day of the meeting. Lack of funding was ascribed to strong resistance within NASA to any program aimed solely at the modest goal of proving a new technique or advancing the state of the art. To win funds, a research program on rendezvous needed larger ends. Everyone at the meeting believed that NASA ought to begin to develop and prove rendezvous techniques, because all were convinced that the need for rendezvous was going to become urgent within the next few years. What had to be done, then, was to find a context for rendezvous, and the best choice for the task was Marshall, since “resistance to . . . rendezvous [was] currently strong” in both Goddard Space Flight Center and the Space Task Group, NASA’s other two development organizations.⁵⁸

This may have been the most important by-product of the conference - the conclusion that Marshall had both the capacity and the desire to carry through an orbital operations and rendezvous program. In September 1960, Marshall’s Future Projects Office was able to tell a gathering of industrial representatives that it had $3.1 million in study contracts to award during fiscal year 1961, a number of them related to rendezvous and orbital operations.⁵⁹ By the end of the fiscal year, the office had issued $817,422 in contracts to ten corporations and four universities for studies ranging from the broad problems of satellite rendezvous to the design of orbital refueling systems for Saturn.⁶⁰

Marshall’s commitment to the principle of orbital operations began to produce in late 1960 specific studies of rendezvous and orbital mechanics, much as the first proposal of the idea in 1949 had done. As befitted a development center, Marshall’s research was mission oriented. Its role in the study of rendezvous hinged on how the technique might best be used in manned space missions, in particular a manned landing on the Moon.

The focus of work at Langley also shifted, as Houbolt and his coworkers succumbed to the fascination of a novel application of rendezvous technique, rendezvous in lunar orbit. The essence of the idea was to leave that part of the equipment and fuel needed for the return to Earth in lunar orbit while only a small landing craft descended to the lunar surface, later to rejoin the orbiting mother ship before starting the trip home. In one form or another, this idea had appeared in the work of Oberth, Kondratyuk, and the British Interplanetary Society, to say nothing of later writers. But it reached Langley’s rendezvous subcommittee via a brief paper by William II. Michael, Jr., little more than a week after the rendezvous conference at Langley had adjourned.

Michael was part of a small group in the Theoretical Mechanics Division that had been working on trajectories for lunar and planetary missions. The group outlined some of its findings in a pamphlet that made the local rounds near the end of May 1960. Michael’s contribution was a brief calculation of the amount of weight that might be saved in a lunar landing mission by parking the return propulsion and part of the spacecraft in lunar orbit.⁶¹ The idea hit Houbolt like revealed truth:

I can still remember the “back of the envelope” type of calculations I made to check that the scheme resulted in a very substantial savings in earth boost requirements. Almost spontaneously, it became clear that lunar orbit rendezvous offered a chain reaction simplification on all back effects: development, testing, manufacturing, erection, countdown, flight operations, etc. . . . All would be simplified. The thought struck my mind, “This is fantastic. If there is any idea we have to push, it is this one!” I vowed to dedicate myself to the task.⁶²

And dedicate himself he did. Houbolt and a band of disciples embarked on a crusade to convert the rest of NASA to the truth that lunar orbit rendezvous was the quickest and cheapest road to the Moon.

Rendezvous found an important ally in NASA Headquarters late in 1960, when Robert C. Seamans, Jr., arrived in Washington to fill the post of Associate Administrator. Seamans, whose formal appointment dated from 1 September, came to NASA from the Radio Corporation of America, where he had been chief engineer of the Missile Electronics and Controls Division in Burlington, Massachusetts.⁶³ Seamans’ division had been one of two Air Force contractors to study requirements for an unmanned satellite interceptor (Saint) during 1959. In 1960, when Saint moved from study to development, RCA got the Air Force contract to develop its final stage and inspection payload and to demonstrate its rendezvous and inspection capability.⁶⁴

Saint was part of a quiet but far-reaching Air Force program, much of it concerned with rendezvous and orbital operations, intended to carve out a larger military role in space. Reading the minutes of a November 1960 meeting of the Air Force Scientific Advisory Board, at which both the Air Force and Marshall reviewed rendezvous work and plans, convinced a Space Task Group observer that Air Force planning and progress toward orbital operations “is much further ahead (2 to 3 years) than the NASA Program at MSFC.”⁶⁵

Seamans thus came to NASA with a solid background in rendezvous work. He spent most of his first month as Associate Administrator touring NASA’s field centers. At Langley, he talked to Houbolt. Seamans was deeply impressed by Houbolt’s account of the weight savings to be achieved even if only the spacecraft heatshield remained in a lunar parking orbit.⁶⁶ Seamans invited Houbolt to Washington for a more formal hearing before the Headquarters staff. Houbolt and some of his Langley colleagues presented the case for putting rendezvous into the national space program in a mid-December briefing at NASA Headquarters.** ⁶⁷

So by the end of 1960 NASA Headquarters had been exposed to the idea of orbital operations, to the potential value of rendezvous techniques in manned space missions other than those related to space stations. It had also been introduced to the case for lunar orbit rendezvous as a basis for manned flight to the Moon. These ideas had worked their way up from the field, chiefly from the von Braun group at Marshall and Houbolt and his colleagues at Langley. The once unchallenged assumption that a lunar mission, if it were to be undertaken, would be launched directly from Earth’s surface had now been called into question; and the questions multiplied in the following months.

Mercury as Prologue

Throughout 1959 and 1960, Mercury was the first and only approved American manned space flight program. From the very start, however, few people expected it to be last. The Mercury capsule was essentially experimental, an attempt to master the problems of manned space flight. Someday spacecraft would do more than go up, circle Earth a few times, and then come down. They would have to be maneuverable, both in space and after they returned to the air. They should be able to fly to a landing, and preferably on land rather than in the water. They should be easy to test and repair, if space flight were ever to be put on something like a routine basis. NASA was ready to suggest research along these lines in its first hastily prepared budget for fiscal year 1960, submitted to Congress early in 1959.

Mercury was an engineering project. Its major goal was “to achieve at the earliest practicable date orbital flight and successful recovery of a manned satellite.”⁶⁸ This dictated utmost reliance on the best-known techniques: a ballistic reentry capsule - blunt, cone-shaped, with almost no aerodynamic lift, recovered by parachute after it returned to the atmosphere.⁶⁹ But it also excluded some promising alternatives, two of which took tentative shape in NASA’s 1960 budget. One was the so-called environmental satellite, a kind of small temporary space station able to sustain one or more men in orbit for several weeks or even months. The other was a maneuverable spacecraft, one equipped with rocket motors to change its path in orbit and endowed with enough aerodynamic lift to alter its flight-path in the atmosphere.

NASA asked for $300,000 to study design changes that might turn Mercury into an orbiting laboratory and for $1 million to study a Mercury refined to make it maneuverable and flyable. Looking toward a real space station, NASA also asked for $3 million to study space rendezvous techniques.⁷⁰ These modest sums signalled no great commitment. When NASA ran into budget problems, this effort was simply shelved and the money diverted to more pressing needs.⁷¹

The view from Space Task Group, the Mercury team, was different. Even during the first hectic months, while Mercury was still moving from the drawing boards into the laboratories, some people in STG were turning their thoughts to what might come next. Although a ballistic capsule might get the job done quickly, it also had patent shortcomings, not the least of which was “that it will be very difficult to control the landing point within a distance of perhaps the order of a hundred miles each way.”⁷² The ballistic capsule had been only one of three basic types under study in 1958 for a manned satellite program. The others were a winged glider and a lifting body, so shaped that even without wings it still had enough lift to allow the pilot some control.⁷³ For later missions, either offered a clear edge over Mercury. The winged glider, which could be flown much like an airplane once it was back in the atmosphere, had been preempted by the Air Force in its Dyna-Soar program.

Dyna-Soar was a development project of the Air Research and Development Command (ARDC). The project received its name in October 1957 and Air Force Headquarters approval in November, some four years after study had begun on vehicles boosted into orbit by rocket and gliding back to Earth under pilot control. Much of the work had been done under contract by Bell Aircraft Company. NACA joined the project in May 1958 to provide technical advice and help to the Air Force-directed and -funded program, an arrangement reaffirmed by NASA in November 1958. ARDC’s consolidated Dyna-Soar development plan in October 1958 aimed the project specifically at developing a winged glider for return from orbit. Later X-20 replaced Dyna-Soar as the project’s name.⁷⁴ Leaving gliders to the Air Force was no hardship since many in NASA, especially in the research centers, preferred the lifting-body approach.⁷⁵ As early as June 1959, STG could report promising results from studies of building some lift into a Mercury capsule.⁷⁶

STG was also looking into a more radical approach to controlled spacecraft landing. Between 1945 and 1958, a Langley engineer named Francis M. Rogallo had been working at home on a flexible kite, its lifting surface draped from an inflated fabric frame. In contrast to other flexible aerial devices like parachutes, a load-bearing Rogallo wing produced more lift than drag, though not as much as a conventional wing. But rigid wings could not be folded neatly away when not in use, and they were inherently far heavier. Rogallo first realized what this might mean in 1952, when he chanced across an article on space travel

with beautiful illustrations depicting rigid-winged gliders mounted on top of huge rockets. I thought that the rigid-winged gliders might better be replaced by vehicles with flexible wings that could be folded into small packages during the launching.⁷⁷

Rogallo’s efforts to promote his insight met scant success until late 1958, when the new American commitment to explore space furnished him a willing audience. In December, the Langley Committee on General Aerodynamics heard him describe his flexible wing and how it might be used in “space ship landing.”⁷⁸ The group responded warmly, and work on the concept moved from Rogallo’s home to laboratories at Langley.

A few months later, STG asked Rogallo for an informal meeting to discuss his research. Some of STG’s top people, Manager Gilruth among them, showed up on 30 March 1959 to hear what Rogallo had to say.⁷⁹ Gilruth was impressed enough to suggest at a staff meeting two months later that some study go into a follow-on Mercury using maneuverable capsules for land landing.⁸⁰

In the meantime, STG was spreading the news about its “preliminary thinking about Project Mercury follow-ups.” H. Kurt Strass of STG’s Flight Systems Division reported to the Goett Committee on some ideas for a larger, longer-lived Mercury capsule. STG’s thinking ranged from an enlarged capsule to carry two men in orbit for three days, through adding a three-meter cylinder behind the capsule to support a two-week mission, to cabling the combined capsule and cylinder to a booster’s final stage and rotating them to provide artificial gravity. This was modest compared to the more sophisticated “environmental satellite” favored by Langley, “a true orbiting space laboratory with crew and equipment exchangeable” via ferry.⁸¹

The Goett Committee divided on just how large the next step ought to be but agreed that some such step belonged between Mercury and a lunar mission.⁸² So did the NASA planners, who, during 1959, were drawing up a long-range-plan for manned space flight. Although NASA’s future program was “directed heavily toward manned lunar exploration” there was still a place in it for developing maneuverability and a long-life capsule, both based on modifying Mercury.⁸³

In seeking to explore the possibilities of improving Mercury to fit it for more advanced missions, STG was moving beyond the limits of its charter. It had been formed for only one purpose: to manage Project Mercury. By mid-1959, the initial group of 45 had grown eight-fold, and Gilruth’s title had changed from Manager to Director of Project Mercury. Despite this rapid expansion, STG felt understaffed. An STG study in June 1959 concluded that 223 people should be added to the 388 authorized, just “to maintain the schedule set for PROJECT MERCURY.” But simply keeping pace was not enough.

In addition, . . . some attention should be given to advanced or follow-on systems to MERCURY. It is estimated that a staff of approximately 20 additional professional personnel should be built up during the next year in order that a year or more gap will not occur in NASA manned space flight operations at the conclusion of the presently planned MERCURY Program.* ⁸⁴

Gilruth foresaw a total strength of some 900 by 1 July 1960, less than half of them working directly on Project Mercury. The rest would be divided among three other projects - a maneuverable manned satellite, a manned orbiting laboratory, and a manned lunar expedition - and a supporting program in biotechnology and human factors. The maneuverable manned satellite project accounted for 302 of the 485 new positions, showing which goal STG though should he pursued immediately after Mercury.⁸⁵

During the same month, June 1959, Kurt Strass argued that the time had come to stop just thinking about these projects and to start actually designing one. He proposed forming a group to work out the preliminary design of “a relatively sophisticated space laboratory providing living accommodations for two men for two weeks,” ready to fly by late 1962.⁸⁶ Strass found a sympathetic ear in the chief of the Flight Systems Division (FSD), Maxime A. Faget, who appointed him to head a New Projects Panel within the Division.** It met for the first time on 12 August 1959, and Strass told his fellow Panelists they were there to plan a manned lunar landing through a series of graded steps, the first of which was to define “an intermediate practical goal to focus attention on problems to be solved, and thus serve to guide new technological developments.”⁸⁷

The panel floundered a bit, not quite certain of the direction it should take, but soon zeroed in on the design of an advanced spacecraft suited to the lunar mission, the first step on the road that led to the Apollo spacecraft. That still left a sizable gap in the manned space flight program, which a new engineering report by McDonnell Aircraft Corporation, prime contractor for the Mercury capsule, suggested some ways to fill. The panel decided to take a close look.⁸⁸

The McDonnell report of September 1959, “Follow On Experiments, Project Mercury Capsules,” was the result of a summer’s work by a small advanced project group.** ⁸⁹ It proposed six experiments that might be conducted with practical modifications of the Mercury capsule, to explore some problems of space flight beyond those to be attacked in Project Mercury.⁹⁰ The New Projects Panel found none of the McDonnell ideas wholly satisfactory but agreed that parts of the first three “could be combined into a new proposal which could offer increased performance and an opportunity to evaluate some advanced mission concepts at the earliest opportunity.”⁹¹

All three experiments dealt with spacecraft maneuverability and guidance. The first sought to achieve some control of landing by adding an external trim-flap device to the capsule, coupled with a simple radar guidance technique or, alternatively, with a more sophisticated inertial guidance system to reduce the capsule’s dependence on ground facilities. The second aimed at maneuvering in orbit by adding to the capsule a special adapter to carry a propulsion system, with guidance provided by either a Mercury system or an inertial guidance system. The third experiment was designed to test the inertial guidance system that might be used with either of the first two experiments. The system - inertial platform, computer, and star tracker - would allow the capsule to guide itself toward an orbital rendezvous, to control its touchdown point more precisely, and to navigate on lunar and interplanetary missions. All three experiments used a modified one-man Mercury launched by an Atlas, with minimum changes.⁹²

The panel saw the prospect of a useful test vehicle in joining an adapter-borne propulsion system to an inertial guidance system. Maneuverable in both space and atmosphere, a capsule so equipped might then be used to develop advanced system components, such as environmental systems for long-term missions, auxiliary power systems, and photographic reconnaissance. These were parts of McDonnell’s suggested fourth and fifth experiments. The fourth was a 14-day mission, using an adapter to carry both a propulsion system and the extra supplies and equipment to support the extended time in orbit, with fuel cells substituted for batteries to supply electrical power. The fifth mainly involved adding a camera to the Mercury periscope system to allow the pilot to photograph Earth’s surface from orbit.** The panel asked for “authority to initiate this program to continue with the least possible delay” after the Mercury program.⁹³

The time, however, was not yet ripe. The attractive possibilities of experimenting with a modified Mercury capsule paled in comparison with the far more exciting prospect of designing an advanced spacecraft for a trip to the Moon. When STG’s top management met a month later, on 2 November 1959, it was the advanced spacecraft rather than the modified Mercury that they decided to pursue.# ⁹⁴

That was the story of STG planning for better than a year. Although engineers were still thinking about an improved Mercury, that thought took second place to work on a new lunar spacecraft.⁹⁵ Lifting reentry was still seen as an important objective, a point stressed by NASA witnesses in budget hearings early in 1960, but not necessarily as part of the Mercury program.⁹⁶ By April 1960, the central aim of advanced vehicle development had become “lunar reconnaissance.” The possibility of a lifting Mercury received only passing mention, as advanced planning focused on a spacecraft able to orbit the Moon, “a logical intermediate step toward future goals of landing men on the moon and other planets.”⁹⁷ This was the program that officially became “Apollo” in July 1960. As then conceived, it did not go beyond circumlunar flight, although lunar landing was the ultimate goal.⁹⁸

What was becoming clear was that any advanced Mercury program, such as lifting reentry, was likely to become a major undertaking in its own right.⁹⁹ In March 1960, STG’s summary of projected funding needs for manned space flight programs put the cost of a lifting Mercury project at over $34 million during fiscal years 1960 through 1962.¹⁰⁰ STG did go on with its lifting Mercury plans into April 1960, getting as far as a preliminary specification for the reentry control system and plans to solicit contractor proposals for the system.¹⁰¹

Lifting reentry, in principle, had NASA Headquarters approval. Still lacking was a firm commitment based on a specific proposal with clearly defined costs.¹⁰² That commitment failed to materialize. In May 1960, Administrator Glennan’s budget analysis team turned down STG’s request for funds to pursue advanced technical development of Mercury-type capsules. Glennan conceded the probability of Mercury flights beyond the three-orbit mission then authorized, to avoid a break in manned space flights, if nothing else. But thinking about somewhat longer missions was one thing; approving a lifting capsule was something else.¹⁰³

That decision put a temporary halt to STG efforts to improve Mercury. Mounting problems in the project itself, especially during the last quarter of 1960, kept STG busy, and such advanced work as time allowed was limited to Apollo.