Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Design Study”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 919 records · Page 51
All sourcesNASA NTRSDOE OSTI
NASA NTRS1994

Self Assembling Mars Transfer Vehicles: The Preferred Concept of the Space Transfer Concepts and Analysis for Explorations Missions Study

Recently, one of the most comprehensive design studies of conceptual manned Mars vehicles, conducted since the Apollo era Mars mission studies of the 1960's, was completed. One of the tasks of the study involved the analysis of nuclear thermal propulsion spacecraft for Manned Mars exploration missions. This paper describes the specific effort aimed at vehicle configuration design. Over the course of the four year study, three configuration baselines were developed, each reflecting trade study cycle results of sequential phases of the study. Favorable attributes incorporated into the final concept, including a capability for on-orbit self-assembly and ease of launch vehicle packability, represent design solutions to configuration deficiencies plaguing nuclear propulsion Mars spacecraft design since the vehicle archetype originated in the 1950's. This paper contains a narrative summary of significant milestones in the effort, describes the evolution to the preferred configuration, and set forth the benefits derived from its utilization.

Donahue, Benjamin↗
NASA NTRS1973

Study to design and develop remote manipulator system

Human performance measurement techniques for remote manipulation tasks and remote sensing techniques for manipulators are described for common manipulation tasks, performance is monitored by means of an on-line computer capable of measuring the joint angles of both master and slave arms as a function of time. The computer programs allow measurements of the operator's strategy and physical quantities such as task time and power consumed. The results are printed out after a test run to compare different experimental conditions. For tracking tasks, we describe a method of displaying errors in three dimensions and measuring the end-effector position in three dimensions.

Hill, J. W.↗
NASA NTRS1974

Study to design and develop remote manipulator system

Modeling of human performance in remote manipulation tasks is reported by automated procedures using computers to analyze and count motions during a manipulation task. Performance is monitored by an on-line computer capable of measuring the joint angles of both master and slave and in some cases the trajectory and velocity of the hand itself. In this way the operator's strategies with different transmission delays, displays, tasks, and manipulators can be analyzed in detail for comparison. Some progress is described in obtaining a set of standard tasks and difficulty measures for evaluating manipulator performance.

Hill, J. W.↗
NASA NTRS1973

Study and design of cryogenic propellant acquisition systems. Volume 2: Supporting experimental program

Areas of cryogenic fuel systems were identified where critical experimental information was needed either to define a design criteria or to establish the feasibility of a design concept or a critical aspect of a particular design. Such data requirements fell into three broad categories: (1) basic surface tension screen characteristics; (2) screen acquisition device fabrication problems; and (3) screen surface tension device operational failure modes. To explore these problems and to establish design criteria where possible, extensive laboratory or bench test scale experiments were conducted. In general, these proved to be quite successful and, in many instances, the test results were directly used in the system design analyses and development. In some cases, particularly those relating to operational-type problems, areas requiring future research were identified, especially screen heat transfer and vibrational effects.

Burge, G. W.↗
NASA NTRS1974

Study of design and control of remote manipulators. Modeling manipulator arms with distributed flexibility for design and control

The interactions of control system and distributed flexible structural dynamics is explored for mechanical arms. A modeling process using 4 x 4 transfer matrices is described which permits the closed loop response of many current arm configurations to be evaluated. Root locus, frequency response, modal shapes, and time impulse response have all been obtained from the digital computer implementation of this model, which is oriented to arm design and allows for easy variation of the arm configuration through data cards. The model corresponds with experimentally observed natural frequencies with an average error of less than 5% in the first three flexible modes in the seven cases considered. The model was used to explore the limits imposed by structural flexibility on a nondimensionalized two link arm with one and two joints for planar motion.

Book, W. J.↗
NASA NTRS1973

Study and design of a cryogenic propellant acquisition system

The development of an acquisition system for supplying subcooled liquid hydrogen and liquid oxygen under in-orbit conditions is discussed. The system will be applied to the integrated cryogenic feed requirements for space systems such as a space shuttle cryogenic auxiliary propulsion system (APS) and main propulsion for an advanced spacecraft propulsion module (ASPM). Concepts that use the favorable surface tension characteristics of fine mesh screens are emphasized. The specific objectives of the program are: (1) to evolve conceptual designs for candidate acquisition systems, (2) to formulate the analytical models needed to analyze the systems, and (3) to generate parametric data on overall candidate system performance, characteristics, and operational features in sufficient depth to establish critical design problems and criteria to support a sound system design and evaluation.

Burge, G. W.↗