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Hamilton, J. T.

Publications and source records attributed to Hamilton, J. T..

The space shuttle ascent vehicle aerodynamic challenges configuration design and data base development

The phase B Space Shuttle systems definition studies resulted in a generic configuration consisting of a delta wing orbiter, and two solid rocket boosters (SRB) attached to an external fuel tank (ET). The initial challenge facing the aerodynamic community was aerodynamically optimizing, within limits, this configuration. As the Shuttle program developed and the sensitivities of the vehicle to aerodynamics were better understood the requirements of the aerodynamic data base grew. Adequately characterizing the vehicle to support the various design studies exploded the size of the data base to proportions that created a data modeling/management challenge for the aerodynamicist. The ascent aerodynamic data base originated primarily from wind tunnel test results. The complexity of the configuration rendered conventional analytic methods of little use. Initial wind tunnel tests provided results which included undesirable effects from model support tructure, inadequate element proximity, and inadequate plume simulation. The challenge to improve the quality of test results by determining the extent of these undesirable effects and subsequently develop testing techniques to eliminate them was imposed on the aerodynamic community. The challenges to the ascent aerodynamics community documented are unique due to the aerodynamic complexity of the Shuttle launch. Never before was such a complex vehicle aerodynamically characterized. The challenges were met with innovative engineering analyses/methodology development and wind tunnel testing techniques.

Dill, C. C.

The space shuttle launch vehicle aerodynamic verification challenges

The Space Shuttle aerodynamics and performance communities were challenged to verify the Space Shuttle vehicle (SSV) aerodynamics and system performance by flight measurements. Historically, launch vehicle flight test programs which faced these same challenges were unmanned instrumented flights of simple aerodynamically shaped vehicles. However, the manned SSV flight test program made these challenges more complex because of the unique aerodynamic configuration powered by the first man-rated solid rocket boosters (SRB). The analyses of flight data did not verify the aerodynamics or performance preflight predictions of the first flight of the Space Transportation System (STS-1). However, these analyses have defined the SSV aerodynamics and verified system performance. The aerodynamics community also was challenged to understand the discrepancy between the wind tunnel and flight defined aerodynamics. The preflight analysis challenges, the aerodynamic extraction challenges, and the postflight analyses challenges which led to the SSV system performance verification and which will lead to the verification of the operational ascent aerodynamics data base are presented.

Wallace, R. O.

Launch vehicle aerodynamic data base development comparison with flight data

The aerodynamic development plan for the Space Shuttle integrated vehicle had three major objectives. The first objective was to support the evolution of the basic configuration by establishing aerodynamic impacts to various candidate configurations. The second objective was to provide continuing evaluation of the basic aerodynamic characteristics in order to bring about a mature data base. The third task was development of the element and component aerodynamic characteristics and distributed air loads data to support structural loads analyses. The complexity of the configurations rendered conventional analytic methods of little use and therefore required extensive wind tunnel testing of detailed complex models. However, the ground testing and analyses did not predict the aerodynamic characteristics that were extracted from the Space Shuttle flight test program. Future programs that involve the use of vehicles similar to the Space Shuttle should be concerned with the complex flow fields characteristics of these types of complex configurations.

Hamilton, J. T.

Space shuttle launch vehicle aerodynamic uncertainties: Lessons learned

The chronological development and evolution of an uncertainties model which defines the complex interdependency and interaction of the individual Space Shuttle element and component uncertainties for the launch vehicle are presented. Emphasis is placed on user requirements which dictated certain concessions, simplifications, and assumptions in the analytical model. The use of the uncertainty model in the vehicle design process and flight planning support is discussed. The terminology and justification associated with tolerances as opposed to variations are also presented. Comparisons of and conclusions drawn from flight minus predicted data and uncertainties are given. Lessons learned from the Space Shuttle program concerning aerodynamic uncertainties are examined.

Hamilton, J. T.

Transfer of space technology to industry

Some of the most significant applications of the NASA aerospace technology transfer to industry and other government agencies are briefly outlined. The technology utilization program encompasses computer programs for structural problems, life support systems, fuel cell development, and rechargeable cardiac pacemakers as well as reliability and quality research for oil recovery operations and pollution control.

Hamilton, J. T.

Space shuttle: Preliminary pressure distributions on the 049 orbiter, orbiter in presence of H/O tank and orbiter in launch configuration

The 049 orbiter and launch configurations were tested in a trisonic wind tunnel to obtain preliminary loads information on the orbiter alone, orbiter in presence of the H/O tank and orbiter in the full launch configuration. The orbiter consisted of the baseline 049 double-delta wing, twin vertical stabilizers, seven degrees of dihedral and included abort rockets. The orbiter was mounted at minus 1.50 degree of incidence (fuselage centerline relative to H/O tank centerline) in the launch configuration. The solid rocket motors were mounted at a radial location of 21 degrees from the horizontal centerline of the H/O tank. The test was conducted over a Mach number range of 0.6 to 4.96. Nominal angle of attack and angle of sideslip ranges of minus 6 to plus 6 degrees were tested. In addition, the orbiter alone was tested over an angle of attack range of minus 6 to plus 26 degrees.

Hamilton, J. T.

Aerospace technology as a source of new ideas.

It is shown that technological products and processes resulting from aeronautical and space research and development can be a significant source of new product or product improvement ideas. The problems associated with technology transfer are discussed. As an example, the commercialization of NASTRAN, NASA's structural analysis computer program, is discussed. Some other current application projects are also outlined.

Hamilton, J. T.

NASA's experiences in technology transfer.

NASA's programs to transfer its technological advances have evolved from a passive dissemination of technical information and service to one of active product development for public needs. The rational and development difficulties involved in the firemen's breathing system is the case example chosen to demonstrate the need for advanced technological design improvements for urban products. Emphasis is given to the total need and requirements for the improved product and the mechanism chosen to insure their direct involvement in the design and development effort. Technology transfer, involving the capabilities of NASA people, is identified as a key factor in the process.

Hamilton, J. T.