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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.

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At least 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRS1981

Relocation of the Deep Space Network Maintenance Center

The Jet Propulsion Laboratory maintains a Deep Space Network (DSN) maintenance center (DMC), whose task is to engineer and manage the repair and calibration program for the electronic and mechanical equipment used in the tracking stations located at Madrid, Spain, and Canberra, Australia. The DMC also manages the Goldstone complex maintenance facility (GCMF), whose task is to repair and calibrate the Goldstone electronic and mechanical equipment. The rationale for moving the facility to Barstow, California, and the benefits derived from the move are discussed.

Beutler, K. F.↗
NASA NTRS1988

A simulation program for the analysis of on-orbit Space Station maintenance and logistics operations

This paper describes the analysis approach adopted by NASA's Space Station Maintenance Planning and Analysis (MPA) Study and focuses on the development and use of a simulation program called Simulation of Manned Space System Logistics Support (SIMSYLS) for modeling the Space Station operations environment. The basic assumptions and groundrules used in the development of SIMSYLS are presented, including its capabilities, limitations and samples of analyses performed. Finally, a proposed simulation outgrowth entitled Space Applications System Simulation (SASS) is described. SIMSYLS will constitute the foundation for SASS which will provide a full system operational RAM analysis tool for Space Station and its logistics support environment.

Furlong, Kelly L.↗
NASA NTRS1991

Maintenance of Space Station Freedom - The role of mission controllers

The key roles played in the on-orbit maintenance of Space Station Freedom by mission controllers working in the Space Station Control Center are discussed. Responsibilities ranging from planning and procedure development to training and real-time support are addressed. The organization of the Mission Operations Directorate is described.

Watson, J. K.↗
NASA NTRS1990

Human exercise capabilities in space

Maintenance of rest and exercise performance are prime requirements for all astronauts during flight, not only for maintaining day-to-day productivity, but also for coping with unlikely emergencies. Indirect estimates of submaximal work capacity (oxygen uptake) made from changes in the heart rates of 27 Apollo astronauts (less than 15-day flights) indicated a reduction in work capacity (maximal oxygen uptake) of 17 to 21 percent. This percentage decrease was similar to that measured in middle-aged men after 21 to 30 days of -6 deg head-down bed-rest deconditioning without exercise training. Heart-rate changes during submaximal exercise in the nine Skylab astronauts suggested that they were better able to maintain their work capacity because of longer and more intensive in-flight exercise training. The strength of the flexor and extensor muscle groups decreased by 2 to 9 percent in the elbow and by 6 to 20 percent in the knee in the Skylab astronauts, also similar to the decreases in men undergoing 30 days of bed-rest deconditioning. Exercise protocols have been devised that result in maintenance of work capacity and muscular strength during 30 to 49 days of bed-rest deconditioning.

Greenleaf, John E.↗
NASA NTRS1989

Hubble Space Telescope maintenance and refurbishment planning analysis

This paper presents an updated analytical approach toward the identification of Hubble Space Telescope system failures and downstates, maintenance requirements, and overall support to maintenance mission planning. Different sparing options of Orbital Replacement Units are evaluated, and the optimum spares complement that satisfies the expected servicing requirements is identified. Specific Space Telescope Reliability and maintenance Simulation Computer Program (SPATEL) updates and refinements are reported, and input data updates relevant to failure rates, downstate ground rules, and maintenance policy are addressed. A summary of the latest SPATEL outputs is provided along with maintenance analysis results.

Pizzano, F.↗
NASA NTRS1992

Applying reliability models to the maintenance of Space Shuttle software

Software reliability models provide the software manager with a powerful tool for predicting, controlling, and assessing the reliability of software during maintenance. We show how a reliability model can be effectively employed for reliability prediction and the development of maintenance strategies using the Space Shuttle Primary Avionics Software Subsystem as an example.

Schneidewind, Norman F.↗
NASA NTRSDate not supplied

Autonomous In-space Construction, Maintenance, and Reconfiguration Using Programmable Meta-Material

NASA ARC's Coded Structures Laboratory (CSL) is developing autonomous construction, maintenance, and reconfiguration technologies to meet long-duration and deep space infrastructure needs, in accordance with long-term NASA goals of "in-space reliance" and "mass-less exploration." We seek to achieve these capabilities by utilizing a "programmable meta-material" approach that integrates emerging advances in materials (mechanical meta-materials), manufacturing (cooperative mobile robotics), and autonomy (multi-agent planning algorithms). Through the ARMADAS project, we have shown assembly of high-performance engineered cellular materials using multiple cooperating mobile robotic assemblers. In this paper, we describe how such a programmable meta-material architecture may shift the paradigm of how we design, build, manufacture, and operate future space infrastructure and assets. The core of a programmable meta-material architecture consists of 3 main technology sub-areas: the structure, the assembly agents, and the assembly algorithms. We co-design these systems to ensure an adaptable system that can create and reconfigure structures from a base set of building block components. From this core technology, we can branch out and expand the capability of the system through additional secondary component types and robotic agents to perform activities such as inspections, maintenance, repair, payload installation, or perform power and communications interconnect. As these technologies mature, future designers will be able to utilize the system to rapidly integrate and operate assets in space or on planetary surfaces from a set of well-tested part library, or create their own modules to integrate into the system. A core trait to the development of this system is the automation approach. Because of the modular and functional discrete (pixel-like) nature of the structural system, a diverse set of powerful algorithms for analysis, planning, and simulation can be adapted and leveraged to optimize construction, maintenance, and dynamic reorganization (as hardware with programmable form and function). With an ability to free the design space from launch vehicle constraints and fundamentally shift how a mission is designed and conducted, we discuss the influence of a programmable meta-material architecture on mission design, build, and operations. For the "design phase", we discuss project lifecycle effects, costs, time, and performance. For the "build phase", we discuss reusability, ISRU, manufacturing, material logistics, and scalability. And for "operations", we discuss autonomy, maintenance and upgrades, reliability, and reconfiguration. Autonomy and modularity are the primary enabling traits of this system. Engineering systems that utilize a modular and reconfiguration building block approach such as digital communication and computation systems, currently lead all other areas of technology in size and complexity scalability. NASA is extending the benefits and flexibility of digital systems to hardware systems, to optimize materials lifecycle management and expand our space exploration mission capabilities.

in space assembly↗
NASA NTRS1980

Space Telescope design for maintenance

The Space Telescope is the first free-flying spacecraft designed to be serviced and repaired by EVA astronauts performing in-orbit maintenance tasks necessary to replace failed or worn-out components. The Telescope's operational profile anticipates in-orbit maintenance approximately two and one half years after initial launch, spacecraft return to ground after five years, and relaunch about one year later. Component design for in-orbit maintenance is being verified by 1-G and neutral buoyancy simulation techniques. Skylab experience led to the implementation of this approach which has significant economic benefits compared to 'one-time-use' space hardware.

Field, E. L.↗
NASA NTRS1976

Initial technical environmental, and economic evaluation of space solar power concepts. Volume 2: Detailed report

The SPS concepts which appear to be technically feasible are discussed in terms of the economic viability and competitive costs with other energy sources. The concepts discussed include: power station, microwave reception and conversion, space construction and maintenance, space transportation, and program costs and analysis. The conclusions presented include: (1) The maximum output of an individual microwave transmission link to earth is about 5 GW. (2) The mass of 10 GW SPS is between 47,000,000 and 124,000,00 kg. (3) The silicon solar cell arrays make up well over half the weight and cost of the satellite. (4) The SPS in equatorial orbit will be eclipsed by the earth and by other satellites.

Source record↗
NASA NTRS1993

Forecasting the impact of virtual environment technology on maintenance training

To assist NASA and the Air Force in determining how and when to invest in virtual environment (VE) technology for maintenance training, we identified possible roles for VE technology in such training, assessed its cost-effectiveness relative to existing technologies, and formulated recommendations for a research agenda that would address instructional and system development issues involved in fielding a VE training system. In the first phase of the study, we surveyed VE developers to forecast capabilities, maturity, and estimated costs for VE component technologies. We then identified maintenance tasks and their training costs through interviews with maintenance technicians, instructors, and training developers. Ten candidate tasks were selected from two classes of maintenance tasks (seven aircraft maintenance and three space maintenance) using five criteria developed to identify types of tasks most likely to benefit from VE training. Three tasks were used as specific cases for cost-benefit analysis. In formulating research recommendations, we considered three aspects of feasibility: technological considerations, cost-effectiveness, and anticipated R&D efforts. In this paper, we describe the major findings in each of these areas and suggest research efforts that we believe will help achieve the goal of a cost-effective VE maintenance training system by the next decade.

Schlager, Mark S.↗
NASA NTRS1978

Test evaluation of space station ECLSS maintenance concepts

The Space Station Prototype (SSP) Environmental Control and Life Support System (ECLSS) hardware was designed and built to be maintainable by the flight crew. To achieve this goal, subsystems were designed for ease of component removal and installation, which included accessibility to component fasteners and connectors, adequate tool clearance, minimum fluid loss during changeout, positive capture of loose parts during changeout, replacement by one crewman, and protection of adjacent parts during maintenance. During testing of this hardware, many day-to-day problems arose which allowed the evaluation of the maintenance concepts under actual maintenance conditions. This paper briefly discusses the maintenance objectives of the hardware design. Specific maintenance designs and their test evaluations are discussed. A removable cartridge valve concept for liquid line components and threaded mechanical fittings and V-band couplings for gaseous line components are critiqued. Other maintenance devices are also evaluated.

Reysa, R. P.↗
NASA NTRS1990

Psychological Health Maintenance on Space Station Freedom

The scheduling of crew rotations for up to 180 days on Space Station Freedom presents a special challenge for behavioral scientists who are tasked with providing psychological support for the crews, their families, and mission flight controllers. Preflight psychological support planning may minimize the negative impact of psychological and social issues on mission success, as well as assist NASA management in making real-time mission planning decisions in the event of a significant social event (for example, the death of a family member). During flight, the combined psychological, emotional, and social stressors on the astronauts must be monitored, along with other aspects of their health. The Health Maintenance Facility (HMF) will have the capability of providing preventive, diagnostic, and therapeutic assistance for significant psychiatric and interpersonal problems which may develop. Psychological support will not end with the termination of the mission. Mental health professionals must be part of the team of medical personnel whose job will be to facilitate the transition—physical and mental—from the space environment back to planet Earth. This paper reviews each phase of mission planning for Space Station Freedom and specifies those factors that may be critical for psychological health maintenance on extended-duration space missions.

Patricia A Santy↗
NASA NTRS2005

Integrated Systems Health Management for Space Exploration

Integrated Systems Health Management (ISHM) is a system engineering discipline that addresses the design, development, operation, and lifecycle management of components, subsystems, vehicles, and other operational systems with the purpose of maintaining nominal system behavior and function and assuring mission safety and effectiveness under off-nominal conditions. NASA missions are often conducted in extreme, unfamiliar environments of space, using unique experimental spacecraft. In these environments, off-nominal conditions can develop with the potential to rapidly escalate into mission- or life-threatening situations. Further, the high visibility of NASA missions means they are always characterized by extraordinary attention to safety. ISHM is a critical element of risk mitigation, mission safety, and mission assurance for exploration. ISHM enables: In-space maintenance and repair; a) Autonomous (and automated) launch abort and crew escape capability; b) Efficient testing and checkout of ground and flight systems; c) Monitoring and trending of ground and flight system operations and performance; d) Enhanced situational awareness and control for ground personnel and crew; e) Vehicle autonomy (self-sufficiency) in responding to off-nominal conditions during long-duration and distant exploration missions; f) In-space maintenance and repair; and g) Efficient ground processing of reusable systems. ISHM concepts and technologies may be applied to any complex engineered system such as transportation systems, orbital or planetary habitats, observatories, command and control systems, life support systems, safety-critical software, and even the health of flight crews. As an overarching design and operational principle implemented at the system-of-systems level, ISHM holds substantial promise in terms of affordability, safety, reliability, and effectiveness of space exploration missions.

Uckun, Serdar↗
NASA NTRS1987

Health maintenance on Space Station

Medical support for extended manned missions aboard such spacecraft as the NASA Space Shuttle must encompass prevention, diagnosis, and therapy capabilities in the preflight and postflight as well as actual mission phases. An evaluation is presently made of the technological and management challenges that must be met in order to furnish an adequate inflight health care delivery system that possesses adequate inflight health care, real-time environmental monitoring, physiological countermeasures, and medical rescue/recovery facilities for ill or injured crew members.

Logan, J. S.↗