THE rapid growth of personnel and activities at Ames during 1962-1963 produced severe strains on service facilities, some of which were already overburdened. A new cafeteria was built in 1963-1964, and construction of a large addition to the instrument research laboratory was undertaken in 1964 and completed in February 1965. The old cafeteria, under the auditorium, was converted to office space. At the same time the administrative responsibilities of the Center had grown as a result not only of the increase in personnel but also of the multiplicity of directives emanating from a mushrooming Headquarters organization, and in 1964 a large administrative management building was put under construction. This new structure, completed late in 1965 at a cost of $1,200,000, was located on Bush Circle and in design and location was almost the mirror image of the data reduction building. In the meantime an extension of the administration building annex was being made to house the OART Mission Analysis Division.
The 10- by 14-inch tunnel was disassembled in 1962-1963 and crated up for transplantation into the 3.5-foot-tunnel building. The transplantation was not completed, and throughout this period the tunnel remained crated with no prospect of reassembly.
In September 1963 the failure of a fan blade in the 14-foot tunnel compressor resulted in a decision to replace all 96 blades. Although contracting was the rule of the day, the replacement of the blades eventually turned out to be another job for Red Betts' blade-carving machine. At the end of 1965, however, the reblading task was still not completed and would not, it was expected, be finished before May 1966. Since its completion in 1955 at a cost of $11 million, the 14-foot tunnel had been used considerably; but now, with the long layup due to blade failure, one might be led to recall Carl  Bioletti's remark, "a damned waste of money," made in 1950 when construction of the tunnel was being considered. Carl, of course, had not foreseen Space Age situations in which some bit of essential design information obtained in the tunnel could readily mean the difference between success and failure of a space shot costing $50 million or more. Owing to the huge financial gamble of space exploration, supporting laboratory research facilities, at whatever cost, represented a prudent investment. In what it had revealed concerning hammerhead missiles alone, the 14-foot tunnel had easily paid for itself.
The 3.5-foot tunnel shared with the 14-foot the distinction of being one of the two most expensive tunnels ever built at Ames.1 It had made important contributions in the field of spacecraft aerothermodynamics, yet it was rather new and still in the process of justifying itself. The realization of its considerable potential for testing large models at high speeds had been somewhat hindered by the rather unsatisfactory performance of its pebblebed heater. A search for a more satisfactory material for the "pebbles" had been undertaken in a pilot heater located in a small addition to the 10- by 14-inch tunnel building. From such studies a cored brick made of yttria-stabilized zirconia seemed promising, but the cost and difficulty of rebricking the huge 3.5-foot pebble-bed heater were large and Ames management was reluctant to make the necessary investment of time and money without more assurance regarding the superiority of the new material.
Another modification of the 3.5-foot, however, seemed desirable. This modification, undertaken in 1963-1964 and completed in 1965, made it possible to operate the tunnel with gases (nitrogen, carbon dioxide, etc.) representing the atmospheres of certain other planets 2 in our solar system. The modification represented a practical substitute for a "hypersonic planetary gas test facility" (HPGTF) which in 1961 was in preliminary design and considered as a possible auxiliary for the new gas-dynamics facility. As a result of this substitution, the HPGTF was never completed.
At this time numerous facilities had been built for investigating reentry heating, but only the hypervelocity free-flight facilities lent themselves to studies of the purely aerodynamic factors of extreme speed, and in these severe restrictions were imposed by the requirements of small, simple models and short operating time. The idea thus arose at Ames of building a very fast, Mach 50, helium tunnel in which models of reasonable size could be tested for fairly long periods. Although preheating had not heretofore been used in helium tunnels, it was nevertheless necessary in the Mach 50 helium tunnel which, at a cost of $1.5 million, was built at Ames during 1965. The tunnel had just been completed as the year ended and not much was known about its operating characteristics except that it had so far attained a Mach  number of 45. Even while the Mach-50 helium tunnel was under construction, the interest of Ames engineers in helium tunnels continued to wane, and by the end of 1965 it was at fairly low ebb. The use of helium was accepted as being tricky and some felt it impractical except perhaps for checking out certain theoretical concepts. The monatomic character of the helium molecule, with all of its thermodynamic implications including the absence of chemical dissociation, was generally believed to limit the usefulness of helium for simulating the aerothermodynamic environment of high-speed reentry. Thus, while retaining a tantalizing potential for achieving high Mach numbers, the helium tunnel, at Ames, remained a concept of somewhat dubious overall practicality.
Here it should be said that the development of new research facilities is an integral part of any research effort and is thus subject to the same risks and gambles as the research itself. A perfect record of success in research-facility design carries with it the strong implication that the agency making the record has been guilty of conservatism quite untiefitting a research institution.
A problem regarded as inherent in wind-tunnel testing arose from the flow interference produced by the structure (sting) that supported the model. This problem was, of course, not present in facilities using gun-launched models and during this period the idea developed that it might also be avoided in conventional high-speed wind tunnels, especially since the techniques for making free-flight measurements were now highly developed. For example, in a vertical tunnel, with the airstream going upward, a model, originally supported, could be dropped and its weight might thus nearly balance the upward air force. The model would thus remain for some time, in free flight, in front of the viewing window. This scheme had been used in the Langley spin tunnels in the 1930's. Alternatively, in a horizontal tunnel, the model might at first be held just downstream of the test section and then, at the right time, propelled forward in front of the viewing window with just enough force to balance the air drag for a few seconds. Drag and stability could be determined, as in the case of a gun-launched model, by observing the motions of the model. At the same time information on pressures and temperatures could be obtained, Ames engineers found, by telemeter. The idea for the technique as applied to supersonic wind tunnels had come from Caltech; but at Ames it was developed to a state of practicality through tests in the 6- by 6-foot tunnel, in the 14-inch helium tunnel, and in a vertical arc-jet tunnel located in the fluid mechanics building. This Ingenious development was carried on by a number of men including John McDevitt, Joseph Kemp, Ronald Hruby, and Lionel Levy and is reported in such papers as TN D-3319 (ref. C-28) by Hruby, McDevitt, Coon, Harrison, and Kemp, and TM X-1154 by Kemp. A paper on the subject by Levy,....
.....McDevitt, and Fletcher was also presented at an AGARD meeting in Brussels in September 1964.
Gun development as a science in itself had advanced continuously and at Ames, perhaps, had reached a higher level of refinement than anywhere else in the world. Most of the guns at Ames were now of the deformable-piston type. Their speed had been raised to an impressive 37,000 feet per second; this peak speed, a world's record, was obtained in 1965 with a gun used in the impact range.3 Notably, it was also earth-escape speed and thus the Ames gun was theoretically capable of firing a bullet so fast that it would leave the earth forever.
Further increases in the speed of guns would not come easily. Nevertheless, despite anticipated design difficulties, there was still hope that guns having higher speeds-perhaps as high as 50,000 feet per second-could he developed. Perhaps if an inner wall of the driver tube could, by an exploding charge, be collapsed sideways, higher gas pressures and velocities could be  obtained than by pushing the gas lengthwise from rear to front. The problem was being studied by the Stanford Research Institute under an Ames contract.
Material and structural limits were being pushed in gun design. In the case of air guns-more commonly known as shock tunnels or shock tubes- the diaphragm separating the driving from the driven gas had become a particularly troublesome design problem. Such diaphragms were expected to burst at the design pressure with the pieces, held at the periphery, bending backward and thus providing the minimum resistance to the flowing gas. Above all, they must not shatter with the pieces flying downstream. Difficulties increased as the diaphragms were made thicker to resist higher operating pressures and the problem was particularly difficult in the case of the shock tunnel. To achieve the desired bursting performance in the shock tunnel, it was necessary to score the diaphragm along the desired bursting lines and then to initiate the bursting by means of an explosive charge placed in the scored grooves. A study of the diaphragm design problem was reported by Robert Dannenberg and David Stewart in TN D-2735.
Don Gault, of the Space Sciences Division, had been using the impact range to study the pattern of material ejected from an impact crater. One problem he had encountered arose from the fact that the force of gravity was at right angles to the line of fire and thus it was not possible to reproduce the ejecta patterns that were evident around the craters of the moon. What was needed was a range in which the gun could be fired downward toward a horizontal target surface. In 1964 this need was met by the construction of the vertical impact range. It was located in the old 10- by 14-inch wind-tunnel building, which had been largely taken over by the Space Sciences Division and renamed the space technology building annex.
The vertical impact range was designed to use any of several guns which could shoot at the target at selected angles ranging from the vertical to the horizontal. First operation, with conventional power guns, occurred late in 1964. Light-gas guns were later installed and the most advanced of these, the deformable-piston gun, was installed and ready for operation in November 1965. To study ejecta trajectories and the sequential phases of crater formation, a special camera capable of taking pictures at the rate of 4 million frames a second and capable also of taking stereographic pictures was provided for use with the vertical impact range. The effect of reduced gravity' such as prevailed on the moon, was obtained by dropping the target at the time of impact.
Research interest at Ames was moving toward increasingly higher reentry speeds and thus much design attention was being given to the means by which extreme reentry conditions could be simulated in the laboratory. The man-carrying Apollo spacecraft, returning from its planned trip to the....
....moon, was expected to reenter the earth's atmosphere at a speed of about 35,000 feet per second. Reentry from missions to nearby planets such as Mars and Venus could, by the use of special techniques, be accomplished at speeds of no more than 50,000 feet per second; and reentry from a trip to a more remote planet such as Jupiter could possibly, through the use of similar techniques, he accomplished at speeds of 65,000 feet per second. Such speeds appeared to represent the maximum that might be encountered for some time to come. Flights to celestial bodies beyond our solar system seemed likely to be of such long duration 4 that return and reentry were only of far-out academic interest.
Thus at Ames there existed an urge to develop facilities capable of simulating entry speeds of 50,000 feet per second or more. The pilot hypervelocity free-flight (HFF) facility came closest to filling this need but still fell far short of the goal. By 1963, however, guns and shock tunnels, as well as free-flight testing techniques, had reached a state of development and sophistication which made possible the planning of a very advanced HFF facility having speed potentialities well beyond that of the pilot HFF facility. What  was actually designed in 1963 was a laboratory building housing three large and powerful test devices. This complex, which was to cost over $5 million, was put under construction in 1964 and was largely completed in 1965. It was named the hypervelocity free-flight facility which, somewhat confusingly, was the name of the individual test devices of which it was composed. The test devices incorporated in the main facility were:
The aerodynamic HFF facility, the largest of the test units, was a counterflow arrangement capable of generating relative speeds between air and model of 50,000 feet per second and stagnation enthalpies of 50,000 Btu per pound. Test Reynolds numbers up to 80 million per foot of model length could be reached. As indicated by its name, the aerodynamic facility was to be used for aerodynamic studies, the measuring of forces and moments; whereas the radiation HFF facility, also a counterflow device and having the same performance as the aerodynamic HFF facility, was to be used for studying radiation in the gas cap and wake. The gun-development facility, as its name implies, was to be used for gun-development tests and did not include a counterflow shock tunnel. The aerodynamic facility had a total length of about 400 feet, a test-section length of 75 feet, a test-section diameter of 3.5 feet, and a gun length of 145 feet. Corresponding figures for the radiation facility were 260, 18, 3.5, and 145. The radiation and gun-development facilities became operational in 1965, but the larger and somewhat more complicated aerodynamics facility would not be ready for use until early 1966.
As the speed of HFF facilities increased, testing techniques became painfully difficult. Arranging a meeting, at a prescribed point in the test section, of a model traveling at 30,000 feet per second with a short pulse of air traveling in the opposite direction at 20,000 feet per second required controls that were fantastically precise and photographic devices that had shutter speeds of only a few billionths of a second. Moreover, the boundary-layer thickness and the pressure of the air pulse continuously varied as it passed along the test section and thus the Reynolds number of a test was dependent on where, along the test section, the model intercepted the air pulse. All of this technical complication was endured, however, as the HFF was the only facility at Ames, or elsewhere, in which both the aerodynamic and the heating phenomena of extreme reentry speeds could be truly represented.
The possibility of using the shock tunnel for the testing of fixed models had been demonstrated through the development and operation, at Ames, of the 1-foot shock tunnel. As earlier mentioned, the operation of this facility was a slow and messy business-the mess resulting from the condensation of Steam generated by the burning of hydrogen and oxygen in the driver tube.
 Consideration had been given by the 3.5-foot-tunnel staff to the development of a new shock tunnel which would have a higher performance than the old tunnel and be cleaner and easier to operate. These worthy goals were to be accomplished by eliminating combustion as a source of power. In the new tunnel, which was under construction in 1965, the driver gas, helium, was to be heated by a tremendous surge of electric-arc power. The electrical energy, equivalent to over 10 million horsepower acting for 1/10,000 second, was to be obtained through the discharge of a bank of capacitors. The new facility, which might be called an electric-arc shock tunnel, was believed to have potentialities for generating air speeds up to 40,000 feet per second. Unfortunately the duration of the air pulse produced would only be a couple of milliseconds and the air as it passed over the model, having just received such a frightful shock, would likely be completely out of chemical and thermal equilibrium. The device was thus considered unsuitable for use in a counterflow, HFF, arrangement.
The arc-jet, in which an arc heats the airstream but is not its primary driving means, continued in a rather rapid state of development during this period. The arc-jet installations by the end of 1965 included three in the fluid mechanics building, two or three in the space technology building, two in the gas dynamics laboratory, and one in the Mach 50 helium wind-tunnel facility. The one in the Mach 50 facility, known as the 1-inch constricted-arc supersonic jet, was perhaps the most sophisticated of all and had the highest performance of any arc-jet yet built at Ames. It could be operated with any desired mixture of air, nitrogen, and carbon dioxide; and, while the Mach number of the gas stream was only 3, its temperature was so high that enthalpy values of up to 200,000 Btu per pound were potentially obtainable. One of the newer units in the fluid mechanics building, a unit called the entry heating simulator, was particularly notable because in it the test model was to be exposed not only to the heat of the arc-heated airstream but also to a separate source of radiative heat produced by arcs and focusing mirrors. The auxiliary radiation source was to be used to simulate the radiating gas cap which the arc-jet, owing to its low Mach number, was itself unable to produce.
The use of a separate source of radiation in the entry heating simulator was, indeed, evidence of a basic weakness of all arc-jet facilities. In such facilities it had not been possible to obtain high enthalpy and high Mach number at the same time. Howard Stine, who together with Charles Shepard and Velvin Watson had received a NASA award in 1965 for his major contributions to arc-jet development, freely admitted this weakness of the arc-jet as a research tool. As yet, he said, no one had fully learned how to control the vast amount of electric power that is poured into an arc-jet- how to keep the power from reducing the arc-jet structure to a puddle of molten metal. In the operation of arc-jets, to avoid overheating the structure...
....it had been necessary to reduce the pressure (thus the density) of the airstream as its temperature (enthalpy) was increased. In other words, extremely hot air molecules were tolerable if they were sufficiently few in number. One may recall having held one's hand in the shower of sparks emanating from a Fourth of July sparkler and feeling nothing more than a mild warmth-because the sparks, though white hot, were relatively few and small. The sparkler flux was obviously of high enthalpy (Btu per pound), but inasmuch as the density was low not many pounds struck the hand and little heating resulted.
In the most critical heating phase of spacecraft reentry, the air in the gas cap is both hot and fairly dense and the resulting heating condition lasts for seconds, if not minutes. Owing to the low density of its airstream, the arc-jet had not been able to duplicate the high heating rate of the gas cap  but had, nevertheless, been able to maintain a very high heating rate for a prolonged period of time. The HFF facility, on the other hand, could duplicate the high heating rate of the gas cap but could not maintain the heating long enough to represent actual reentry flight conditions. Thus it was clear that, in the simulation of reentry heating, the arcjet and the HFF facility represented two imperfect, and distinctly different, approaches which by virtue of their differences possessed advantages that were complementary.
Further comparisons of the arc-jet with the HFF facility might be noted:
It might be added, as an incidental note, that Stine's work on arc-jets, while aimed at the development of a research tool, had revealed certain possibilities for the application of the arc-jet as an efficient power plant for spacecraft. In 1965 experimentation was under way on the use of a transverse magnetic field to accelerate the flow of plasma issuing from an arc-jet.
In the design of space vehicles, engineers were continually encountering problems arising from the limitations of materials. At Ames, research that bore on the subject of materials began in 1959-1960. In early 1963 a Materials Branch was formed under Charles Hermach and Bernard Cunningham, and in 1964 construction commenced on a materials research laboratory. This laboratory, called the space environmental research facility, was completed at a cost of $3,530,000 and put into use in March 1965. The new facility was provided with excellent equipment, including spectroscopes, an electron microscope, and several ion accelerators. Among the latter were instruments that the Physics Branch had developed for sputtering research an activity which had now been taken over by the Materials Branch.
 Under construction within the new space environment research facility late in 1965 was a test chamber in which certain important aspects of the environment of space could be simulated. This device, called a combined environment chamber, consisted of a large vacuum chamber incorporating three proton accelerators having beam energies ranging from 2 to 300 MeV. Through the use of a combination of oil-diffusion pumps and condensers cooled by liquid nitrogen and liquid helium, it was expected that the chamber could be evacuated to the extremely low pressure of 10-10 millimeters of mercury. A smaller vacuum chamber, thought to be capable of reproducing the low pressures existing between earth and moon (about 10-13 mm mercury), already had been completed but no way had been found for measuring that degree of vacuum.
Ames' long-standing interest in wing flutter was transferred early in the Space Age to an interest in the dynamic structural loads of spacecraft and their launching vehicles. A Structural Dynamics Branch, which had been created in 1960 under Al Erickson and Henry Cole, undertook research on a number of problems such as launch-vehicle instability, landing-impact attenuation, and fuel-sloshing loads. This work had so expanded by 1963 as to....
 ....require a new facility. Construction of this facility, known as the structural dynamics laboratory, began in 1964 and was largely completed by the end of 1965. Its cost was about $1,650,000.
The new structural dynamics laboratory provided a wide array of conventional and special structural research equipment as well as some badly needed office space. The most imposing element of the laboratory, however, was a 100-foot-tall concrete tower to be used principally for tests of launch vehicles but additionally for drop tests of spacecraft landing gears. A launch vehicle tested in the tower could be exposed to an environment simulating in many structurally important respects what the vehicle would normally encounter as it ascended through the earth's atmosphere. The environment would include a moderate vacuum (10 mm mercury or less), heating (infrared radiation sources totaling 12 1/2 megawatts), vibration (by means of variable-frequency shakers), and noise such as produced by a rocket motor. The tower was given a pentagonal cross section, to preclude the development of a strong standing wave pattern, and was separately mounted on a 6-foot-thick block of concrete floating, without benefit of piles, in the rather mucky soil of Moffett Field. This manner of mounting was expected to isolate the tower from external vibrations, but certain congenital skeptics on the Ames staff could not refrain from speculating that it might create a leaning tower rivaling the one in Pisa.
Soon after the Space Sciences Division and the Life Sciences Directorate were formed, they found themselves severely hampered for lack of office and laboratory space. Both made extensive use of trailers and the Life Sciences Directorate was forced to find temporary housing for some of its activities, in the nearby town of Mountain View. While the Space Sciences Division continued to have a housing shortage, steps were initiated in 1963 to relieve the more critical need of the Life Sciences Directorate.
The first building created for the biological interests at Ames was a bioscience laboratory built in 1963-1964 and located just north of the 6- by 6-foot tunnel. Although this facility provided office and laboratory space in a two-story building, its main feature was a vivarium-more commonly known as an animal shelter-providing accommodation for experimental animals such as monkeys, apes, and dogs. Accommodations for smaller animals (cats, rabbits, rats, etc.) were provided in air-conditioned trailers adjacent to the bioscience laboratory.
The animal shelter served both the Life Sciences and the Biosatellite interests at Ames. By the end of 1965, the shelter, in behalf of the Biosatellite project alone, cared for several hundred Macaca nemestrina (monkeys) which, because of their short tails, were called "pig-tailed" macaques. Caring for the monkeys was Don Warner, manager of the clinical, biochemistry,  and vivarium section of Project Biosatellite. The animals were treated with all due consideration; Dr. Dale Smith to whom Warner reported was, indeed, a member of the National Animal Care Panel whose function it is to assure the humane treatment of experimental animals. The bioscience laboratory had a surgery, a recovery room, and isolation wards, and its stainlesssteel animal cages were scrupulously cleaned with superheated steam at frequent intervals.
The monkeys arriving from southeast Asia were suspected of harboring germs of possibly dangerous tropical diseases. Extreme precautions were taken to avoid transmittal of disease germs from monkey to handler and also from handler to monkey. Before working with the monkeys, the handler was required to shower and change into a freshly laundered and sterilized uniform. On finishing the handling task, he was required to shower and disinfect himself carefully before changing into street clothes. Food for the monkeys consisted of no less than Purina Monkey Chow, a relative of the dog and cat chows with which pet lovers are familiar. Surplus or over-age animals were turned over to National Institutes of Health centers, such as the National Center for Primate Biology run by the University of California at Davis, California.
Although the main purpose of Project Biosatellite was to conduct biological experiments in space, there was, nevertheless, a need for certain preliminary, ground-based investigations to assure the success of the flight experiment. For example, it was considered desirable to subject the flight experimental packages to a realistic simulation of the longitudinal accelerations and noise levels anticipated during launch and recovery The facility needed for such a simulation-a centrifuge-was put under construction in 1963 and completed in 1964. This facility, known as the Biosatellite centrifuge, was located under the return passage of the 40- by 80-foot tunnel. Its 50-foot-diameter rotating arm could provide accelerations up to 15 g, reached at a controlled rate of up to 2 g per second, for payload packages of up to 1200 pounds located at either or both ends of the arm. Arrangements for providing a noise environment for the payload were also available.
It was recognized during 1963, or before, that the Life Sciences Directorate would require a major office-laboratory facility quite beyond anything of the kind that the bioscience laboratory might provide. Such a facility was put under construction in 1964 and completed in 1965. On December 30, 1965, it was dedicated in a special ceremony attended by Congressmen Miller and Gubser of California, Dr. Mac C. Adams who was the new head of OART, Professor Harold Urey of the University of California, Professor Joshua Lederberg of Stanford, and other notables.
The new facility, called the life sciences research laboratory, was a three-story, wall-equipped unit costing over $4 million. In appearance it was Strikingly different from the other Ames buildings. From the first, Ames  architecture had been characterized by two-story arrangements, simple horizontal lines, and flat unpainted concrete surfaces. This was the pattern originally established by NACA designers and later carried on at the Center's request by contracting architectural firms. In the case of the life sciences research laboratory, however, the architect was not bound by the usual requirement of style conformance and perhaps felt there was some advantage in making more intensive use of the diminishing building space available at the Center. He shunned the traditional long lines and used instead a not unattractive arrangement of rectangular masses, the external surfaces of which were dimpled like a lunar landscape.
It was the interior, not the exterior, of the life sciences research laboratory that was, in any case, important. The research facilities were outstanding. The exobiology laboratory on the third floor, for example, contained in addition to the usual laboratory instruments a mass spectrometer and a rather large collection (a dozen or more) of gas chromatographs. It contained a separate enzyme laboratory and on the whole was regarded by the Chief of the Exobiology Division as being the best equipped laboratory in the world for detecting traces of organic elements.
Still uncompleted at the end of 1965 was a "high bay" building associated with the life sciences research laboratory. This building, it was planned, would provide space for some of the larger items of research equipment including, in particular, biological research simulators required by the Biotechnology Division. One of the simulators, under construction in 1965 but not scheduled for completion until 1966, was a man-carrying rotation device in which investigations could be made of human reactions to angular accelerations and velocities about any selected axis.
The Life Sciences Directorate, in 1962-1963, had built a small centrifuge in the basement of the instrument research building. This centrifuge was mainly used by Dr. Ogden's Environmental Biology Division for small animal investigations.
The 1959 Headquarters ruling transferring all flight testing, except that involving V/STOL aircraft, to the Flight Research Station at Edwards accelerated the steps Ames was already taking in the development and use of flight simulators. The ruling, however, was not wholly practicable, and by 1963-1964 some of the proscribed airplanes were being returned to the Center. Among these was the F-100 variable-stability airplane for which, in 1965, a flight-research program was being readied. Other airplanes arriving at Ames were a Douglas F5D required for a special wing test, a Lockheed C-130 partially adapted for variable-stability work, a Convair 340 adapted for a blind-flying study, and a Convair 990 four-engine transport purchased by NASA for use by the Center as a flying research laboratory. There was....
....also a small LearJet which the Center owned and used for both research and research support.
Although the airplanes were returning to Ames, the Center continued to press its flight-simulator development work and by the end of 1965 the simulator facilities in use and under construction were quite impressive. No longer was it necessary for Center engineers to build simulators, without Headquarters knowledge, out of spare parts scrounged from wherever obtainable. Many millions of dollars were now being spent on the construction of some very sophisticated devices. These expenditures appeared prudent in view of the possible saving of human lives and the tremendous cost of the aircraft (such as the SST) and the spacecraft (such as the Apollo) for which the simulators were to provide essential design information.
It had been found, moreover, that in the solution of stability and control problems of specific aircraft, the ground-based simulator and the wind tunnel worked well as a team, enhancing each other's effectiveness. First, the aerodynamic coefficients of the original airplane configuration, as obtained in the wind tunnel, would be programed into the computer of the simulator. Simulator runs would then suggest desirable changes in the configuration. These changes would then be checked out in the wind tunnel and the new coefficients obtained. This cycle, repeated, would rapidly home in on an optimum configuration.
Ames' simulator equipment had become very extensive by 1965 and completely filled the original NACA hangar, which now was called the space flight simulation laboratory. Simulators were normally composed of a number  of basic units: the computer, the cockpit display and controls, the motion generator, and now, in the newer simulators, the device for providing the external visual cues simulating the external scene that the pilot would normally see through the windshield of his airplane. The heart of the simulator was, of course, the computer, which was programed to represent the dynamics of the aircraft or spacecraft being simulated and which controlled the cockpit instruments, the motion generator, and the external-visual-cue device.
The computer equipment was expensive, but fortunately the same equipment could often be made to serve alternately more than one simulator. Such equipment was usually composed of analog units of which by 1965 Ames had assembled a vast array including over 1000 amplifiers. In a recent simulation, an attempt had been made to augment the analog equipment with an IBM 7094 digital computer tied in through a long cable reaching to its remote location. Also, combined analog and digital computing equipment was to be provided for some of the sophisticated simulators which, at the end of 1965, were under construction.
The motion generator was usually the largest and most expensive component of a simulator and as time went on more and more realistic motion simulation was demanded. To satisfy the simulation requirements of V/STOL aircraft, there was built, in 1963, at a cost of $640,000, a motion generator providing six degrees of freedom including large (± 10 feet) translational motions along each axis. This facility was called the all-axes....
....motion generator or, when combined with other simulator elements, the six-degrees-of-freedom simulator.
Among other smaller simulators built during the 1962-1964 period were the moving-cab transport simulator-a refined version of an earlier device -and a midcourse navigation simulator. The latter device, intended for use in spaceflight navigation studies, consisted in part of an Apollo-sized crew compartment mounted on an air bearing in such a way as to allow small angular motions in pitch, roll, and yaw. The compartment contained appropriate instrumentation; and an externally simulated star field, made visible by room darkening, provided the visual reference points required for navigational exercises. The cabin motion could be controlled manually by air jets or automatically, in a closed loop, by a computer.
While the simulators just mentioned were being put to use, plans were in preparation for the design and construction of much more pretentious facilities for simulating the flight of both aircraft and spacecraft. Bill Harper had in 1962 proposed the construction of a large centrifuge for simulation work at Ames, but the proposal was rejected by Headquarters on the basis that the request should have been for a more comprehensive, spaceflight guidance facility of which the centrifuge was a part. When, the following year, a suitably augmented proposal was submitted to Headquarters, it was approved A further augmentation was later approved, with the result that  the final plan encompassed a complex of four facilities. These facilities were being designed during the latter half of 1963, were being built and checked out at the factory during 1964-1965, and were scheduled for installation at Ames in 1966.
The new simulators were to be installed in a building especially constructed for the purpose on a site bordering the airfield near the existing space flight simulation laboratory. Named the space flight guidance research laboratory (SFGRL), the building and its complement of four facilities cost over $13 million. The facilities comprising the SFGRL were:
All four were designed to make use, as needed, of a common analog-digital computer system. All, it was planned, would ultimately be used for spaceflight simulation purposes, except that the flight simulator for advanced aircraft would for several years serve the development needs of the Nation's supersonic jet transport.
The flight simulator for advanced aircraft, costing about $2.6 million, was expected to be the largest and most sophisticated airplane flight simulator ever built. Unfortunately the delay entailed by the long process of procurement would curtail its contributions to the supersonic transport project. Within its three-man cabin (replica of transport cabin), the crew would be subjected, in simulated form, to all of the meaningful sensations they could expect to encounter in the flight of the supersonic transport. The simulator was designed to provide all six degrees of angular and translational motion. Moreover, the range of lateral motion was made unusually large (±50 feet) to properly simulate the extensive sweeps of sidewise motion which the crew would experience in their location far ahead of the wing in the long nose of the airplane.
The equipment for providing the external visual cues-the external scene as viewed from the cabin-was rather elaborate and expensive ($285,000) . By means of a projector mounted atop the cabin, the simulated external scene would be projected in color on a screen mounted in front of the cabin. The projected scene would be obtained from a color television camera moving, as controlled by the computer, over a model landscape. The computer-controlled camera would follow the motions of the computer-controlled cabin, thus giving the proper picture orientation and distance.
The man-carrying motion generator, costing about $9.8 million, was the most expensive item of equipment to be located in the space flight guidance research laboratory. It was a huge centrifuge which, when coupled with the computer, with the visual-cue apparatus, and with other auxiliaries,....
....was capable of providing a spacecraft crew with all of the sensations, except weightlessness, they would experience in a flight from the earth to the moon or to Mars. In particular, it would simulate not only the accelerations of takeoff and landing but also the angular and vertical motions, the external scene, solar radiation, and cabin environment-temperature, pressure, gas composition, and vibration, all of which were to be controllable.
At the end of a 50-foot arm, driven by an 18,600-horsepower dc motor, the three-man cabin could be accelerated by the centrifuge to a level of 20 g at rates up to 7 1/2 g per second. An alternate, one-man cabin which was being provided could be accelerated up to 50 g, if unmanned, or otherwise to the limit of human tolerance. In addition to the rotation provided by the centrifuge, the cabin was to have unlimited motion about the roll, pitch, and yaw axes, as well as a vertical motion of ±2 feet. It was expected that the cabin motions would normally be controlled by the computer, in a closed-loop system, but manual control without benefit of computer-except possibly for a small on-board computer-would also be possible.
The midcourse navigation simulator, the third facility in the space flight guidance research laboratory, was to be a refined version of the one earlier described. Its cost is included with that of the centrifuge. The device was a manned-flight simulator, either computer or manually controlled, in which it would be possible to conduct deep-space navigational exercises on earth. Its three-man cabin, or capsule, mounted on a spherical air bearing, would allow limited (up to ±13°) angular motion about all three axes. For the use intended, the simulation of translational motions was unnecessary. The environment provided in the cabin was to include the same variety of controlled conditions as were available in the cabin of the centrifuge. Also to be provided were celestial screens on one of which simulated stars, precisely located, would realistically transmit their light in narrow beams of parallel rays.
 The satellite attitude control facility, the fourth item in the space flight guidance research laboratory, was a device to be used in studying attitude control, or stabilization, systems such as are required by certain types of unmanned satellites. One such satellite is the Orbiting Astronomical Observatory, the attitude of which must be very precisely controlled to allow the telescope it carries to be pointed at the star, or other heavenly object, to be observed. In other cases, spacecraft are required to keep their solar panels pointed at the sun or their radio antennas or instruments pointed at the earth or their payload pointed in some prescribed direction. The devices that provide the stabilization derive their power from such sources as air jets, reaction wheels, gravity, gyroscopic forces, or geomagnetism and refer their actions mainly to celestial bodies, including the earth and its gravitational and magnetic fields.
In the Ames facility, it was planned that the stabilizing devices to be investigated would be mounted on an 8-foot-diameter table floating frictionlessly on a spherical air bearing inside an evacuated 22-foot-diameter sphere. The motions of the simulated satellite (table) around the earth....
 ....were to be represented by moving an earth model around the table in circular or elliptical paths according to the orbit desired. Other external references or influences would include a star screen, coils for producing a magnetic field corresponding to that of the simulated earth, and a heater for simulating earth infrared radiation. A simulated sun was also to be provided at a later date. As in the case of the other three facilities in the laboratory the attitude-control facility was designed so that it could be operated in a closed loop with a computer. Its cost, incidentally, was about $1.2 million.
Much had been, and much remained to be, learned about the atmospheres and the surface characteristics of solar-system planets from the spectrographic analysis of radiation emanating from the planets. However, accurate interpretation of the spectrographic data required a knowledge of the absorption and emission characteristics, at various pressures and temperatures, of the planetary atmospheres. These were matters of great concern to the Ames Space Sciences Division and were matters about which much could be learned in a ground-based laboratory if proper facilities could be provided. One such facility, conceived by Ames scientists in 1964 was a long, enclosed chamber through which a beam of selected radiation could repeatedly be passed to obtain the absorption characteristics of the gas with which the chamber was filled.
The device just mentioned, called the Ames long-path gas cell, was completed early in 1965. Although only 25 meters long, the chamber was equipped with a system of mirrors by means of which the beam of radiation, introduced at one end, could be bounced back and forth for a total path length up to 1 kilometer before it fell on the detector. The chamber was so designed and equipped that it could be charged with any gas, or combination of gases, at any pressure in the range from 104 to 10-5 millimeters of mercury. As 1965 ended, the long-path gas cell was being used to obtain infrared absorption spectra of gases known or suspected to be present in extraterrestrial planetary atmospheres. Such information, it was expected, would be utilized in later spectrographic studies aimed at determining the pressure and temperature of planetary atmospheres and the abundance of the various gases of which they are composed.
The capital equipment of the Ames Research Center had greatly expanded during the NASA regime.5 In October 1958, Ames contributed to the new agency a plant valued at about $80 million. By the end of 1965, the  cost value of Ames facilities, including the space flight guidance research laboratory, had grown to about $175 million. As a result of modifications and improvements, the value of many of the facilities had risen far above the original cost. For example, the 1- by 3-foot tunnel, which originally cost $1.2 million, had by 1965 increased in value to $4.1 million. Corresponding figures, in millions, for other facilities are: supersonic free-flight tunnel ($0.23 to $1.7); 6- by 6-foot tunnel ($4.5 to $6.4); 12-foot tunnel ($3.8 to $5.1); 40- by 80-foot tunnel ($7.1 to $8.9); Unitary Plan tunnels ($24.8 to $32.2). Some of the facilities, of course, were obsolete by 1965 and their true value had fallen to essentially zero.
The accelerated building program of the Ames Research Center during the period 1963-1965 required more land than the 115 acres which, at the end of 1962, were owned and occupied by NASA. On being apprised of this problem, the Navy granted Ames a license 6 to use an additional 110.7 acres of land at the base. The ownership of this parcel was permanently transferred to NASA on January 22, 1965, bringing the Administration's holdings at Moffett Field to a total of approximately 226 acres.
1 Unitary cost more hut constituted three tunnels.
2 For example, Mars and Venus.
3 Later to be described in this work.
4 Dryden had estimated that it might take 160,000 years for a round trip to the nearest star.
5 See app. A.
6 License NO. NOy (R) 65159, dated May 1, 1964.