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The various sources of loads of importance in the design of launch vehicles are discussed generally. The natural vibration modes, which are an essential ingredient in all loads problems, are described for the Saturn vehicle as obtained from a structural replica model. The effects of fuel loading on the structural modes are considered and the results obtained on the model are compared with full-scale results. Launch-vehicle buffeting is discussed and the buffeting characteristics of a manned lunar vehicle configuration are described. Some evaluations of buffeting scaling laws obtained with this configuration are presented. Estimates of the acoustic environment on the spacecraft associated with engine noise at lift-off and with aerodynamic noise due to buffeting are shown. The steady and vibratory loads due to ground winds as determined from wind-tunnel tests of a Saturn model are presented.

A facility was designed to burst scale model propellant tanks in the form of 6-in. diameter cylinders and which contained liquid hydrogen. The cylinders were machined from 2014-T6 extruded aluminum tubing and had notches of various radii. Conventional uniaxial notched tensile specimens were fabricated from the same tubing and the data were correlated with the burst results from the biaxially stressed cylinders.

A questionnaire study was conducted to determine the present state-of-the-art in the field of design tool (research and development) flight simulators. The major concern at this time appears to be the simulation of realistic external displays for visual reference by the pilot. Advance study is vitally necessary in the fields of VTOL/ STOL performance.stability and control, and instrumentation and/ or displays for terrain clearance and avoidance during high speed, low altitude flight. Also required are studies of g forces, zero g environment, and the use of drugs or hypnosis to control specific channels of communication in man during studies of his more significant sensors.

The unusual features of the Ultrahigh Altitude Rocket Cell J-2A at Arnold Engineering Development Center are described with emphasis on the cryogenic systems for cooling the diffuser and chamber liner to liquid-nitrogen temperature and the helium-refrigerated cryopumping surfaces to 20 K. It is concluded that space simulation testing of large rocket engines under actual firing conditions is possible.

This paper discusses operation of the Flarescan controller used by the FAA as part of the program to evaluate the Flarescan guidance system for all-weather landing. A throttle control system compatible with Flarescan is described. Simulation studies of the basic system parameters such as transmitter location, glide slope angle, scan rate, winds, beam noise, and early and late flare engagements are also presented. A flight test evaluation of Flarescan and the problem areas discovered in this test are discussed. Changes in coupler design are proposed, to reduce the dispersions due to the variations in system parameters.

The problem of accurately evaluating the performance of earthmoving tools has been for many years severely handicapped by the variability of field soils. The machine operator also contributes to the variability of field test data, since he cannot accurately reproduce adjustments of the cutting element on successive tests. Minimizing these two factors has been of prime consideration in the establishment of an indoor scale-model testing facility for earthmoving tools, described here. In addition there is a discussion of the soils used, the testing technique, and the type of test results that can be obtained.

THIS PAPER PRESENTS a theoretical analysis of the ideal adiabatic Otto cycle engine. The analysis was made to examine the influence of compression ratio and dissociation on engine thermal efficiency over an extreme range of compression ratios (that is, 4–300) to see if chemical dissociation could limit Otto cycle engine thermal efficiency. Assuming isooctane, benzene, ethyl alcohol, and nitromethane to be the fuels being consumed, the effects of compression ratio and mixture strength on the thermodynamic properties and equilibrium species concentration of the working fluid at every step in the ideal Otto cycle were computed. The calculations were made using a mathematical model of the ideal adiabatic engine which had been programmed to an IBM 704 digital computer. With the model, the effect of compression ratio on engine thermal efficiency was calculated over a wide range of operating conditions.

The object of this investigation was to determine the magnitude of the catalytic effects of all the commonly used thermocouple materials in lean mixtures of hydrogen, carbon monoxide, propane, and methane in air. Up to 1800 F, wires of platinum, palladium, iridium, platinum plus 15% iridium, and the two elements of the Platinel thermocouple were found to catalyze the combustion of mixtures of hydrogen, carbon monoxide, and propane in air. Gold, silver, Chromel, Alumel, and constantan wires showed no catalysis of any mixture. Base-metal thermocouples are therefore recommended for accurate determinations of temperatures of gaseous mixtures containing combustible materials.

Government agencies and industries are presently in search of new approaches to lightweight, high-strength solid rocket motor cases. Republic Aviation Corporation has been investigating the suitability of high-strength steel bonded cases based on metal design allowables up to 350,000 psi. To accomplish this end, various structural adhesives were evaluated, process techniques were developed, and motor case scale models were built and tested. Tests have shown that conventional adhesives can function in a solid rocket motor case in which the metal adherent is stressed to 250,000 psi. To improve this value even further, the adhesive should be designed so that its shear modulus varies along the bonded joint. A varying shear modulus adhesive was prepared and tested on a 6-in. overlap and compared to a constant shear modulus adhesive. The former showed, at failure, a 25% higher load carrying capability under similar conditions of test.

Using the return-to-earth portion of an interplanetary mission as an example, this paper describes the series of maneuvers required to land a manned space vehicle at a predesignated airfield on the earth. The objectives of the maneuvers, the types of control and stabilization systems which can be used in each external environment, and the sources of moments which disturb the orientation of the vehicle are discussed. Results of analog computer simulation studies conducted at the U.A.C. Research Laboratories are included to illustrate some of the stability and control problems which result from rapid changes in the external environment of the vehicle.

Presented in this paper is a brief review of momentum exchange theory for Jet Noise Suppression. “Experimental Results from Scale Model Tests” are included. These data exhibit peak to peak attenuation of 20 db along maximum exhaust noise azimuths at a nozzle pressure ratio of 3.1.

The design criteria and performance requirements for an adaptive circuit which compensates flight control systems over a wide range of flight conditions and aerodynamic parameters such as encountered during re-entry into the earth’s atmosphere are described. A theoretical analysis is presented which shows how the aerodynamic and structural bending characteristics of the vehicle establish these criteria and requirements and affect the choice of an adaptive circuit for an automatic flight control system. The adaptive circuit described includes a linear gain-changing element which maintains the rate loop of the flight control system at its neutrally stable point. A mathematical model of the adaptive circuit loop is derived by considering small perturbations about an operating point.

In 1957 Chrysler Defense Engineering began the development of an aerial jeep vehicle. Within security limitations, this paper discusses the progress made thus far on the project. The aerial jeep is essentially a hovering and low speed vehicle. No means have been provided for propelling it on the ground. The role or mission of the vehicle with respect to helicopters and ground vehicles is explained. Its application initially will be military, but the implication for civilian use seems obvious. While the Chrysler aerial jeep may outwardly resemble others currently under development, the similarity is only superficial. Two features make this vehicle unique in its class: the application of a rigid, fixed-pitch propeller and the use of simple vanes as a means of control. Problems involved in the development of a workable vehicle configuration are described, together with research work for their solution.