Search NASA⌕ Search

Engineering topics

Humphries, W. R.

Publications and source records attributed to Humphries, W. R..

At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2001

Launch Vehicle Design Process: Characterization, Technical Integration, and Lessons Learned

Engineering design is a challenging activity for any product. Since launch vehicles are highly complex and interconnected and have extreme energy densities, their design represents a challenge of the highest order. The purpose of this document is to delineate and clarify the design process associated with the launch vehicle for space flight transportation. The goal is to define and characterize a baseline for the space transportation design process. This baseline can be used as a basis for improving effectiveness and efficiency of the design process. The baseline characterization is achieved via compartmentalization and technical integration of subsystems, design functions, and discipline functions. First, a global design process overview is provided in order to show responsibility, interactions, and connectivity of overall aspects of the design process. Then design essentials are delineated in order to emphasize necessary features of the design process that are sometimes overlooked. Finally the design process characterization is presented. This is accomplished by considering project technical framework, technical integration, process description (technical integration model, subsystem tree, design/discipline planes, decision gates, and tasks), and the design sequence. Also included in the document are a snapshot relating to process improvements, illustrations of the process, a survey of recommendations from experienced practitioners in aerospace, lessons learned, references, and a bibliography.

Blair, J. C.↗
NASA NTRS1992

Interdisciplinary analysis from the spacecraft thermal analyst's viewpoint

Interdisciplinary analyses performed at the Marshall Space Flight Center based on multidiscipline data flows are reviewed. Particular attention is given to global software packages for allowing efficient interdisciplinary data exchange, the use of a number of smaller individual packages, specific software programs utilized by the various interfacing disciplines to perform calculations in terms of interface compatibility, and tasks based on thermal evaluations integral. Recommendations for improvements in the MSFC equipment, software, and organization are proposed.

Humphries, W. R.↗
NASA NTRS1990

Past and present environmental control and life support systems on manned spacecraft

The spacecraft environmental control and life support systems (ECLSS) for Mercury, Gemini, Apollo, Skylab, Spacelab, the Space Shuttle Orbiter, and Space Station Freedom are reviewed, in addition to the ECLSS on Soviet spacecraft Vostok, Voskhod, Soyuz, Salyut Space Stations, the Buran Space Shuttle, and the Mir Space Station. Focus is placed on atmosphere control and supply, atmosphere revitalization, potable and supply water systems, waste-management systems, temperature and humidity control, water recovery and management, and fire detection and suppression. It is noted that the ECLSS evolution will continue during the lifetime of Space Station Freedom, leading to further simplifications and closure of the system which will become a controlled ecological life support system (CELSS).

Diamant, Bryce L.↗
NASA NTRS1990

Space Station Freedom Environmental Control and Life Support System design - A status report

Space Station Freedom (S.S. Freedom) has entered into the Preliminary Design Review (PDR) phase of the program. This paper outlines the Environmental Control and Life Support System (ECLSS) design with emphasis on the systems aspects of the ECLSS. Interactions with other distributed systems, such as data management and electrical power are described. The integration of the ECLSS into the S.S. Freedom pressurized elements and truss are addressed.

Humphries, W. R.↗
NASA NTRS1989

Microgravity sensitivities for Space Station ECLS subsystems

This report presents a review of the Space Station Environmental Control and Life Support subsystems (ECLSS) for sensitivity to low gravity environments. The object of this review is to categorize sensitivity areas and to quantify the risks. This review addresses all processes from a top level view and then examines in more detail those areas which were considered potential risks. The study has concentrated on the primary function of the subsystems which may be significant to the performance of the particular component and does not address integration of the subsystem and/or the mechanical aspects of the designs. The areas of primary concern were the Atmosphere Revitalization (AR), Water Recovery and Management (WRM), and the Waste Management (WM) subsystems.

Bangham, M. E.↗
NASA NTRS1988

Process material management in the Space Station environment

The Space Station will provide a unique facility for conducting material-processing and life-science experiments under microgravity conditions. These conditions place special requirements on the U.S. Laboratory for storing and transporting chemicals and process fluids, reclaiming water from selected experiments, treating and storing experiment wastes, and providing vacuum utilities. To meet these needs and provide a safe laboratory environment, the Process Material Management System (PMMS) is being developed. Preliminary design requirements and concepts related to the PMMS are addressed, and the MSFC PMMS breadboard test facility and a preliminary plan for validating the overall system design are discussed.

Perry, J. L.↗
NASA NTRS1988

Preliminary design of the Space Station environmental control and life support system

This paper outlines the current status of the Space Station Enrivonmental Control and Life Support System (ECLSS). The seven subsystem groups which comprise the ECLSS are identified and their functional descriptions are provided. The impact that the nominal and safe haven operating requirements have on the physical distribution, sizing, and number of ECLSS subsystems is described. The role that the major ECLSS interfaces with other Space Station systems and elements play in the ECLSS design is described.

Reuter, J. L.↗
NASA NTRS1986

Growth evolution of the Space Station ECLSS

This paper discusses the planned evolution and growth of the Space Station ECLSS. It discusses the planning on-going at the early design stages to enable growth from a man-tended configuration of the Space Station (wherein the Space Station would be manned only when visited by the Orbiter) to a fully operational configuration (called Initial Operational Capability - IOC) which includes a permanently manned, fully operational Space Station. The paper then also discusses how the IOC Space Station ECLSS can evolve to account for increase in crew sizes, increase in the number of attached modules, increase in the capability to handle more payload/customer support, and potential evolution of the ECLSS technologies.

Humphries, W. R.↗
NASA NTRS1986

Status of the Space Station environmental control and life support system design concept

The current status of the Space Station (SS) environmental control and life support system (ECLSS) design is outlined. The concept has been defined at the subsystem level. Data supporting these definitions are provided which identify general configuratioons for all modules. Requirements, guidelines and assumptions used in generating these configurations are detailed. The basic 2 US module 'core' Space Station is addressed along with system synergism issues and early man-tended and future growth considerations. Along with these basic studies, also addressed here are options related to variation in the 'core' module makeup and more austere Station concepts such as commonality, automation and design to cost.

Ray, C. D.↗
NASA NTRS1985

Space station environmental control and life support systems conceptual studies

It is pointed out that the establishment of a permanent manned Space Station requires the development of a comprehensive approach which combines new technologies and existing spacecraft subsystem capabilities into an optimum design. The present paper is concerned with studies which were conducted in connection with the development of the regenerative Environmental Control and Life Support Systems (ECLSS) for the Space Station. Attention is given to the current state of the ECLSS subsystems and system level analytical selection and group studies related to the integrated system conceptual design.

Humphries, W. R.↗
NASA NTRS1985

Performance of the Spacelab Astro-1 mission heat pipe radiator

This paper describes the design and performance of the Astro Integrated Radiator System (IRS). The system was recently ground tested and proven successful in rejecting approximately 400 watts of heat. The radiator was constructed from an aluminum panel configured to form two orthogonal planes. Heat pipes were adhesively bonded and riveted to the radiator to isothermalize the surface. The IRS was subjected to a full thermal vacuum test to validate the thermal math model and to qualify the radiator for space flight. The thermal performance met prescribed temperature limits with margins at both extremes, and no mechanical failures occurred.

Humphries, W. R.↗
NASA NTRS1984

Flight evaluation of Spacelab 1 payload thermal/ECS interfaces

The Spacelab (SL-1) thermal/Environmental Control Systems (ECS) are discussed. Preflight analyses and flight data are compared in order to validate payload to Spacelab interfaces as well as corroborate modeling/analysis techniques. In doing so, a brief description of the Spacelab 1 payload configuration and the interactive Spacelab thermal/ECS systems are given. In particular, these interfaces address equipment cooling air, thermal and fluid conditions, humidity levels, both freon and water loop temperatures and load states, as well as passive radiant environment interfaces.

Ray, C. D.↗
NASA NTRS1983

Thermal design and analysis in the Orbiter bay

Thermal design and integration of payloads located in the Orbiter bay are addressed. Methods used to satisfy equipment thermal requirements are discussed with particular emphasis on passive thermal control. Both fixed and tiltable payload configurations are covered. Design methodology, integration techniques, constraints and mission peculiar requirements are presented. Past and future Spacelab missions, including those utilizing the instrument pointing system are of special interest. The OSS-1 payload flown on STS-3 is presented in some detail. Design concepts for the 'all-up' thermal modeling techniques for this payload are discussed. A brief summary of orbital results for OSS-1 are given. Finally, as a special topic, a low power independent pumping system is described in some depth.

Humphries, W. R.↗
NASA NTRS1981

Effects of the specular Orbiter forward radiators on a typical Spacelab payload thermal environment

Orbiter radiators, having a specular reflection, must be considered when determining the design environment for payloads which can view the forward deployed radiators. Unlike most surfaces on the Orbiter, which reflect energy diffusely, the radiators are covered with a highly specular silverized Teflon material, with high emissivity, and have a concave contour, producing a local concentration of reflected energy towards the region of angle incidence. The combined effects of radiator specularity and geometry were analyzed using the Thermal Radiation Analysis System (TRASYS II), a specialized ray trace program, and a generalized Monte-Carlo-based thermal radiation program. Data given for a 0 deg payload inclination angle at orbital noon at 3.454 m indicate that the maximum total flux and average flux can increase 173% and 63%, respectively, when compared to diffuse radiators.

Turner, L. D.↗
NASA NTRS1979

Solar simulator test facility

Discusses facility constructed at Marshall Space Flight Center to evaluate performance of solar energy collectors under simulated outdoor conditions. Facility simulates sunfall properties such as radiation intensity, spectrum, collimation, uniformity, and direction.

Humphries, W. R.↗
NASA NTRS1978

Design and operation of a solar heating and cooling system for a residential size building

The first year of operation of solar house is discussed. Selected design information, together with a brief system description is included. The house was equipped with an integrated solar heating and cooling system which uses fully automated state-of-the art. Evaluation of the data indicate that the solar house heating and cooling system is capable of supplying nearly 100 percent of the thermal energy required for heating and approximately 50 percent of the thermal energy required to operate the absorption cycle air conditioner.

Littles, J. W.↗
NASA NTRS1978

Use of the Marshall Space Flight Center solar simulator in collector performance evaluation

Actual measured values from simulator checkout tests are detailed. Problems encountered during initial startup are discussed and solutions described. Techniques utilized to evaluate collector performance from simulator test data are given. Performance data generated in the simulator are compared to equivalent data generated during natural outdoor testing. Finally, a summary of collector performance parameters generated to date as a result of simulator testing are given.

Humphries, W. R.↗