Engineering topics

Gartrell, Charles F.

Publications and source records attributed to Gartrell, Charles F..

9 records

NASA NTRS1992

1992 NASA Life Support Systems Analysis workshop

The 1992 Life Support Systems Analysis Workshop was sponsored by NASA's Office of Aeronautics and Space Technology (OAST) to integrate the inputs from, disseminate information to, and foster communication among NASA, industry, and academic specialists. The workshop continued discussion and definition of key issues identified in the 1991 workshop, including: (1) modeling and experimental validation; (2) definition of systems analysis evaluation criteria; (3) integration of modeling at multiple levels; and (4) assessment of process control modeling approaches. Through both the 1991 and 1992 workshops, NASA has continued to seek input from industry and university chemical process modeling and analysis experts, and to introduce and apply new systems analysis approaches to life support systems. The workshop included technical presentations, discussions, and interactive planning, with sufficient time allocated for discussion of both technology status and technology development recommendations. Key personnel currently involved with life support technology developments from NASA, industry, and academia provided input to the status and priorities of current and future systems analysis methods and requirements.

Evanich, Peggy L.↗

NASA NTRS1992

1991 NASA Life Support Systems Analysis workshop

The 1991 Life Support Systems Analysis Workshop was sponsored by NASA Headquarters' Office of Aeronautics and Space Technology (OAST) to foster communication among NASA, industrial, and academic specialists, and to integrate their inputs and disseminate information to them. The overall objective of systems analysis within the Life Support Technology Program of OAST is to identify, guide the development of, and verify designs which will increase the performance of the life support systems on component, subsystem, and system levels for future human space missions. The specific goals of this workshop were to report on the status of systems analysis capabilities, to integrate the chemical processing industry technologies, and to integrate recommendations for future technology developments related to systems analysis for life support systems. The workshop included technical presentations, discussions, and interactive planning, with time allocated for discussion of both technology status and time-phased technology development recommendations. Key personnel from NASA, industry, and academia delivered inputs and presentations on the status and priorities of current and future systems analysis methods and requirements.

Evanich, Peggy L.↗

NASA NTRS1991

Technology for increased human productivity and safety on orbit

Technologies are addressed that can facilitate the efficient performance of station operations on the Space Station Freedom (SSF) and thereby optimize the utilization of SSF for scientific research. The dedication of SSF capabilities to scientific study and to the payload-user community is a key goal of the program. Robotics applications are discussed in terms of automating the processing of experiment materials on-orbit by transferring ampules to a furnace system or by handling plant-tissue cultures. Noncontact temperature measurement and medical support technology are considered important technologies for maximizing time for scientific purposes. Detailed examinations are conducted of other technologies including advanced data systems and furnace designs. The addition of the listed technologies can provide an environment in which scientific research is more efficient and accurate.

Ambrus, Judith↗

NASA NTRS1990

Space Station Freedom resource allocation accommodation of technology payload requirements

An overview of the Office of Aeronautics, Exploration, and Technology (OAET) Space Station Freedom Technology Payload Development Program is provided, and the OAET Station resource requirements are reviewed. The requirements are contrasted with current proposed resource allocations. A discussion of the issues and conclusions are provided. It is concluded that an overall 20 percent resource allocation is appropriate to support OAET's technology development program, that some resources are inadequate even at the 20 percent level, and that bartering resources among U.S. users and international partners and increasing the level of automation may be viable solutions to the resource constraint problem.

Avery, Don E.↗

NASA NTRS1989

Using space for technology development - Planning for the Space Station era

Experience with the Shuttle and free-flying satellites as technology test-beds has shown the feasibility and desirability of using space assets as a facility for technology development. Thus, by the time the Space Station era will have arrived, the technologist will be ready for an accessible engineering facility in space. As the 21st century is approached, it is expected that virtually every flight to the Space Station Freedom will be required to carry one or more research, technology, and engineering experiments. The experiments planned will utilize both the pressurized volume, and the external payload attachment facilities. A unique, but extremely important, class of experiments will use the Space Station itself as an experimental vehicle. Based upon recent examination of possible Space Station Freedom assembly sequences, technology payloads may well utilize 20-30 percent of available resources.

Ambrus, Judith H.↗

NASA NTRS1989

Space-based test-bed concept

The space test-bed (STB) conceptual design proposed as a basis for the long-term experimental development of advanced spacecraft bus technology with minimum technological risk consists of a main spacecraft bus, whose subsystems furnish the common support functions for the entire facility, and attachable/detachable experimental pallets. The STB design requires only modest enhancements of current systems and techniques, with many off-the-shelf components. The economics of the STB are presently emphasized.

Gartrell, Charles F.↗

NASA NTRS1988

Expert systems for adaptive control of large space structures

It is expected that space systems for the future will evolve to structures of unprecedented size with associated extreme control requirements. A method is necessary that is sufficiently general to initiate stable control of a vehicle and subsequently learn the true nature of the structure. It is suggested that a suitable constructed expert system (ES) would be capable of learning by appending observations to a knowledge base. To verify that an ES can control a large space structure, numerical simulations of a simple structure subjected to periodic vibrations and the performance of a classical controllers were performed. The ES was then exercised to show its ability to truthfully mimic nominal control and to demonstrate its superiority to the classical controller, given sensor failures. An ES generating software package, The Intelligent Machine Model, was employed. It uses the pattern matching technique. Results of this program are discussed.

Gartrell, Charles F.↗

NASA NTRS1988

In-space research, technology and engineering experiments and Space Station

The NASA Space Station will serve as a technology research laboratory, a payload-servicing facility, and a large structure fabrication and assembly facility. Space structures research will encompass advanced structural concepts and their dynamics, advanced control concepts, sensors, and actuators. Experiments dealing with fluid management will gather data on such fundamentals as multiphase flow phenomena. As requirements for power systems and thermal management grow, experiments quantifying the performance of energy systems and thermal management concepts will be undertaken, together with expanded efforts in the fields of information systems, automation, and robotics.

Tyson, Richard↗

NASA NTRS1987

Spacecraft technology trends - A view from the past

Future spacecraft will be sent on missions to complete the exploration of the solar system, to return samples from celestial bodies, record the process of creation of stars, galaxies, and the universe itself, to provide a continuous record of earth processes, and to maintain vital space communications. A key ingredient to projecting the future is to comprehend the historic record and to understand the significance of trends. This paper focuses on spacecraft cost and life trends, as well as those of the major subsystems. Throughout the history of the 'space age' there has been significant progress in the performance of spacecraft and their subsystems. However, various aspects of spacecraft performance lag behind what is technically feasible by a considerable margin. In addition, examination of the historical trend implies that future spacecraft will likely continue to be relatively unique in their design features. This is in contrast to the technically realizable future attributes such as large space platforms, modularity, system autonomy and on-orbit repair and servicing.

Hudson, Wayne R.↗