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Experimental data on performance and cooling from sea level and altitude firing tests of fluorine/oxygen mixtures with light-hydrocarbon fuels are presented. The majority of the work has been oriented toward pressure-fed rocket applications, with testing at 5000-lb vacuum thrust and 100-psia chamber pressure. Work in progress is at chamber pressures of 250 and 500 psia, being oriented toward pump-fed rocket applications. High delivered specific impulse levels have been demonstrated. One problem, apparently unique to these propellants, is that performance at the optimum mixture ratio is extremely sensitive to incomplete mixing.

Through an examination of NASA functions and space program areas and their interrelationship, it is shown that the objectives of MSA earth orbital programs are: to develop space systems that will contribute to the solution of basic national problems by exploiting space for human welfare and knowledge, to exploit space for the advancement of science and technology, and to develop space capabilities precursor to planetary exploration. The role of a space station in the earth orbital program is that of a manned orbital research facility capable of exploiting the unique features of the space environment in combination with the capabilities of man as an onboard investigator to accomplish a broad spectrum of research and development in all areas of interest. Man's role in the orbiting research facility is similar to his role in a research laboratory on earth.

Unmanned satellites have now been used for almost a decade in useful earth-oriented applications; communication, navigation, geodetic survey, meteorology. In the coming 1970-1980 era, these applications are expected to increase in number and expand in scope; and to be augmented by additional applications having to do with the discovery and monitoring of the earth's natural resources, and of other phenomena of interest to man -- disasters, patterns of cultural development, oceanic traffic, and others. These latter tasks fall within the functional category of “observation” tasks wherein the principal role of a space system will be the collection of information, both by direct observation and by gathering data emitted from sensors deployed over the earth's surface. Eventually, these observation functions will be complemented by satellite-directed surface activity -- ships, aircraft, land vehicles.

The paper is composed of two parts. The first reviews some implications of hypersonic performance with special emphasis on return of logistics spacecraft from orbit to the continental U.S. Among the factors considered are quick return, delayed return with varying and fixed wait time, relation of wait time to return opportunities, relation of maneuverability to clear-weather recovery and night landing, propulsive orbit phasing, propulsive plane change, and recovery costs. Some observations of the whole are made in relation to current spacecraft capability and future needs. The second part of the paper surveys representative vehicle concepts ranging from low to high hypersonic lift-drag ratios. Particular attention is centered on landing modes and their implications. Among the concepts discussed are fixed and variable geometry for runway landers, and decoupled modes, such as parawing and sailwing devices, deployable rotors, and propulsive lift.

The United States initiated man's first close-up observations of the planets, Venus and Mars, with successful Mariner missions in 1962, 1964-1965, and in 1967. With the rapid development of rockets, communications, technologies, scientific instruments, and space-flight operations capabilities, we are now in a position to plan a planetary program for the 1970s with specific goals and objectives. Such a plan is outlined, including goals and objectives for the effort, some of the experiments to be performed, the phasing of missions, some indication of alternate possibilities, and the desirable advances in technologies required. For basic reference in discussing characteristics of the 1970 plans, Mariner spacecraft and missions of the 1960s will be reviewed.

The Mariner V mission to and past the planet Venus in 1967 is described and some scientific results are summarized. The engineering challenge and process of physically converting a machine designed to conduct a Mars flyby into one suitable for the Venus mission are discussed, and particular technical problems and solutions arising from this conversion or other aspects of the 1967 flight mission are examined. Finally, some results of a study of test effectiveness in this project are considered.

This paper describes two particular hydrostatic power-splitting transmission packages (an “input-coupled” planetary and an “output-coupled” hydraulic differential). It discusses their construction, installation in experimental tractors, and resulting performance of each. Peak performance of both was very close, but the “output-coupled” hydraulic differential transmission provided higher operating efficiency over a broader speed range.

Design requirements and operational constraints are reviewed for a small manually controlled flying vehicle which could provide astronauts with mobility for lunar exploration. Numerous flight trajectories and the vehicle performance have been analyzed and are presented. It is concluded that to attain the desired flight ranges, the flight velocities must be relatively high (200 fps or more). The range of thrust level required is determined. Flyer configuration is highly dependent on the method of control (either mechanical engine gimballing or kinesthetic control); the optimum method is still unresolved.

A spectrum of lunar roving vehicles has been developed and shown to be compatible with the manned launch system using the Extended Lunar Module and the unmanned launch system using the Lunar Logistics Lander. Also shown is a single-roving-vehicle concept, which satisfies the requirements of both unmanned and manned missions. A general description and performance characteristics are given for each roving-vehicle system covered in the spectrum. The roving vehicles suggested in this paper could fulfill a variety of missions, thus providing the mission planners with the many options from which a roving vehicle could be selected to fit the mission and program needs.

Our present scientific knowledge of the four nearer planets, Mercury, Venus, Mars, and Jupiter, has been obtained from ground-based experiments as well as from planetary missions. We find the planets to be quite different, and each one gives opportunities for studying the basic questions of planetary exploration: How did the solar system come into being, and does life of any kind exist within it? It seems that at least a ten year program of automated planetary spacecraft will be needed, carrying an increasing degree of complexity in the scientific experiments. The exobiological experiments require that we maintain planetary quarantine, and this constraint has to be allowed for. The possibility of manned approaches to Mars, though far in the future, also affects the strategy of a program of scientific exploration.

Despite the success of the space sciences satellites and the imminent payoff of the Apollo manned missions, we have seen a de-emphasis on the space program. De-emphasis, here, really means no new starts rather than cut-backs in existing programs. Two courses for the future exist - earth orbital missions or manned planetary exploration. Defense, one of the original objectives of the space program, is best served by satellite and near-earth manned operations. This emphasis, if selected, might not produce the best possible research effort, however. The 1967 President's Science Advisory Report, in dealing with funding for the year 1972, notes this dilemma. It suggests that the ultimate objective must be a balanced program aimed at the expectation of eventual manned planetary exploration. Even though, we are not yet in a position to make a rational decision on which planet to explore.

Discussed in detail are the basic manufacturing operaions for three types of tires: mixing of materials, tread extrusion, fabric calendering, cutting, building, and vulcanizing. For each manufacturing step, cost comparisons are made between two-ply, two-ply bias belted, and two-ply radial constructions. The two-ply tire is the least expensive, with its 9 components, followed by the bias belted tire with 13 components and the radial ply with 18. As the technology advances, the latter two will undoubtably become simpler in construction and, therefore, cheaper.

The bias belted and radial tire concepts offer advancement in tire performance which cannot be met with the conventional bias tire. A review of the materials and construction of a conventional bias tire is included as a direct comparison to the materials and construction features of the radial and bias belted tires. A brief history of the evolution of tire materials is also given.

The thin wall polypropylene battery has reached production status and is presently being marketed commercially. The polypropylene-polyethylene copolymer has the ideal properties that make it the best material for a battery cover and container. Polypropylene containers are molded with thin partitions and thin walls. The added available acid volume makes possible higher capacities for given sizes or new compact battery designs.

This paper describes the development of a thin wall polypropylene cased battery. The electrical capability has improved in several areas: watt-hours/pound of battery, watt-hours/cubic inch of battery, terminal voltage over full range of electrical load, engine cranking power, and engine cranking energy.

This paper describes and illustrates some of the manufacturing techniques being used to produce steel spur gears, helical gears, and splines. Applications of these techniques and their suitability based upon the end use of the product are also indicated. The paper closes with a brief discussion of recent developments in manufacturing techniques relating to this type of hardware.

Gear design is discussed in terms of drive system requirements; preliminary design considerations; analysis of gear capacity by means of tooth strength rating, surface durability rating, scoring hazard rating, and allowable stress index; computer design analysis; design optimization and kinematic action analysis by computer; and special design considerations. Equations and graphic illustrations are presented.

Inspection for quality control of spur and helical gears and splines involves the ability to obtain information at a proper precision level, and to use this information as related to requirements. Measurements of gears and splines provide information on the active elements as produced, that is, profile, lead, and index. These factors combined indentify a map of the surf ace of the active elements. Analysis of this map provides optimum quality control application.

Various causes for the failure of gears and splines are discussed. These include scoring, wear, tooth breakage, tooth pitting, and lubrication. Among the more promising test methods is the radioactive technique; data obtained from such tests are presented. Equations for determining gear, beam bending, and surface contact stresses are given, and tests to obtain such data are described.

An approximate analysis is given for the individual stress components and combined stresses existing in multiple disc clutch teeth, including those stresses resulting from the existence of spline friction. Two tooth forms, the trapezoid and the parabolic cut-out, are considered, and any actual tooth profile may be idealized to one or the other. Equations are given for the position and values of maximum stress. The effects of changes in tooth geometry are considered and tabulated. These analyses can be used for the purposes of rational design or failure analysis. An industrial empirical disc diameter-thickness relation is examined and shown to actually represent a maximum shear stress criterion, which takes into account the presence of spline friction.