Engineering topics

Craig, M. K.

Publications and source records attributed to Craig, M. K..

8 records

NASA NTRS1986

Definition status of the U.S. Space Station system

The configuration, design, and capabilities of the Space Station are briefly reviewed. In particular, attention is given to the truss structure, photovoltaic and solar dynamic power generation systems, pressurized habitation and laboratory modules, and provisions for extravehicular activity. The discussion covers the Space Station assembly sequence, and the main elements of the power, communication, environmental, and life support systems of the Space Station.

Craig, M. K.↗

NASA NTRS1985

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.↗

NASA NTRS1983

Shuttle launch debris: Sources, consequences, solutions

Following the first space shuttle flight, the shuttle program established a team to identify and eliminate sources of debris which had caused serious damage to the orbiter thermal protection tiles. An approach was developed for debris identification which involved pre- and post-flight vehicle and pad inspections, analytic assessment of debris transport and impact phenomena, and analysis of various photographic records of the flight. Debris sources identified by this approach were classified as being either hazards to flight or sources of damage which increased vehicle refurbishment costs without having any safety implications. As a result of this assessment, all known hazardous debris sources on the launch vehicle and pad were eliminated; other sources are being removed in a cost effective manner as appropriate.

Craig, M. K.↗

NASA NTRS1981

An analytical tool for simulating Large AMplitude Propellant Slosh

The development of a multiple-mass, nonlinear, finite-element analytical model - the Large AMplitude Propellant Slosh model (LAMPS) in two- and three-dimensional versions, is described. The model is used in predicting the forces on the Space Shuttle external tank caused by large amplitude motion of propellant fluid. Comparisons between measured propellant reorientation forces and those predicted by the LAMPS models are presented, and it is concluded that the model provides a cost effective, experimentally verified approach to a complicated nonlinear problem.

Berry, R. L.↗

NASA NTRS1981

Measurement of forces due to liquid motion in a propellant tank

This paper presents the results of a study to develop an analytical model capable of predicting the forces acting on a tank caused by large-amplitude propellant motion. This effort contributed to an analysis of the influence of propellant dynamics on separation of the External Tank from the space shuttle orbiter. This paper is concerned with an experimental investigation that aided in development and verification of the analytical model. A scaling approach was developed that allowed the liquid motion to be simulated in subscale tanks. Liquid reorientation forces were measured using two test systems. One operated in the low-gravity environment produced in a drop tower and the second operated aboard the KC-135 'zero-g' test aircraft. The manner of liquid motion, influence of various factors, and the measured forces are discussed.

Tegart, J. R.↗

NASA NTRS1978

Shuttle small self-contained payloads - 'Getaway' to the educational opportunities of space

The Space Shuttle Small Self-Contained Payload Program is described, as are ways in which high schools and universities can be helped to take advantage of its unique educational potential. The mechanics of obtaining payload space are presented. Suggestions for aiding educational institutions establish payload experiment programs are discussed. To illustrate suggestions, examples are given of programs established to date and of experiments which are being considered for participation.

Craig, M. K.↗

NASA NTRS1973

An analysis of atmospheric entry trajectories for manned and unmanned missions to the planet Venus

A unified atmospheric density model is presented for the planet Venus, and this model is compatible with Russian and American data obtained during the 1967 Venus launch opportunity. Trajectory characteristics involved in atmospheric entry are discussed with reference to roll-control modulation and entry corridor. Subsequent to a trajectory-oriented discussion of potential Venus mission characteristics, a parametric analysis of manned and unmanned vehicle entry trajectories into the Venusian atmosphere is presented. A sensitivity analysis with reference to atmospheric density deviations is included to show the dependence of corridor depth on the atmospheric density profile.

Craig, M. K.↗

NASA NTRS1972

Vehicle performance impact on space shuttle design and concept evaluation

The continuing examination of widely varied space shuttle concepts makes an understanding of concept interaction with vehicle performance imperative. The estimation of vehicle performance is highly appurtenant to all aspects of shuttle design and hence performance has classically been a key indicator of overall concept desirability and potential. Vehicle performance assumes the added role of defining interactions between specific design characteristics, the sum total of which define a specific concept. Special attention is given to external tank effects.

Craig, M. K.↗