Results for “maintainability” — Page 7

NASA NTRS1989

Ballast system for maintaining constant pressure in a glove box

A ballast system is disclosed for a glove box including a fixed platform on which is mounted an inflatable bag on top of which resides a cover and a weight. The variable gas volume of the inflatable bag communicates with that of the glove box via a valved tube. The weight and the gas volume are selected to maintain a relatively constant pressure in the glove box despite variations in the glove box volume while avoiding the use of complicated valving apparatus.

Shlichta, Paul J.↗

NASA NTRS1989

The role of diabatic heating in maintaining the upper-tropospheric baroclinic zone in the South Pacific

The four-dimensional structure of a region that encompasses the South Pacific Convergence Zone (SPCZ) is presently examined using a modified set of FGGE level III-b analyses, during the January 10-18, 1979 period when two cyclones formed in the tropics and propagated southeastward along the SPCZ to middle latitudes. An effort is made to ascertain the significance of kinematic and thermodynamic processes in maintaining the the upper baroclinic region coincident with the subtropical jet. A partitioned form of the frontogenetical function, used to diagnose the adiabatic and diabatic contributions to the maintenance of baroclinicity in the SPCZ's vicinity, indicates a major balance between the frontogenetical contribution by differential diabatic heating and the opposing diabatic tilting processes.

Robertson, Franklin R.↗

NASA NTRS1989

Maintaining human productivity during Mars transit

This paper addresses the special nature of the human-machine relationship during a trip to Mars. In particular, the potential for monotony and boredom during a long-duration space voyage and the effect on motivation and productivity can be important considerations to the health and welfare of the crew. For the voyage to Mars, a design may be considered that will purposefully maintain some level of workload for the crew as a preventive measure for the deterioration of productivity that comes with boredom. This paper speculates on these considerations, on the appropriate level of workload for maximum productivity, and on what might be done during the mission to alleviate the problems caused by monotony and boredom.

Statler, Irving C.↗

NASA NTRS1989

The role of diabatic heating in maintaining the upper-tropospheric baroclinic zone in the South Pacific

The four-dimensional structure of the region in the South Pacific convergence zone (SPCZ) during January 10-18, 1979 is studied using a modified set of ECMWF FGGE level III-b analyses. The effects of kinematic and thermodynamic processes on maintaining the upper baroclinic region corresponding with the subtropical jet are analyzed. The role of adiabatic and diabatic processes in the maintenance of baroclinicity in the area of the SPCZ is examined using the frontogenetical function. It is observed that the processes affecting the evolution of baroclinicity in the SPCZ region differ from those in the middle latitude; possible reasons for these differences are proposed.

Robertson, Franklin R.↗

NASA NTRS1991

ETARA PC version 3.3 user's guide: Reliability, availability, maintainability simulation model

A user's manual describing an interactive, menu-driven, personal computer based Monte Carlo reliability, availability, and maintainability simulation program called event time availability reliability (ETARA) is discussed. Given a reliability block diagram representation of a system, ETARA simulates the behavior of the system over a specified period of time using Monte Carlo methods to generate block failure and repair intervals as a function of exponential and/or Weibull distributions. Availability parameters such as equivalent availability, state availability (percentage of time as a particular output state capability), continuous state duration and number of state occurrences can be calculated. Initial spares allotment and spares replenishment on a resupply cycle can be simulated. The number of block failures are tabulated both individually and by block type, as well as total downtime, repair time, and time waiting for spares. Also, maintenance man-hours per year and system reliability, with or without repair, at or above a particular output capability can be calculated over a cumulative period of time or at specific points in time.

Hoffman, David J.↗

NASA NTRS1991

Maintaining technical excellence requires a national plan

To meet the challenge of technical excellence, AIA established a rocket propulsion committee to develop the National Rocket Propulsion Strategic Plan. Developing such a plan required a broad spectrum of experience and disciplines. The Strategic Plan team needed the participation of industry, government, and academia. The plan provides, if followed, a means for the U.S. to maintain technical excellence and world leadership in rocket propulsion. To implement the National Rocket Propulsion Strategic Plan is to invest in the social, economic, and technological futures of America. The plan lays the basis for upgrading existing propulsion systems and a firm base for future full scale development, production, and operation of rocket propulsion systems for space, defense, and commercial applications.

Davidson, T. F.↗

NASA NTRS1991

Maintaining consistency in distributed systems

In systems designed as assemblies of independently developed components, concurrent access to data or data structures normally arises within individual programs, and is controlled using mutual exclusion constructs, such as semaphores and monitors. Where data is persistent and/or sets of operation are related to one another, transactions or linearizability may be more appropriate. Systems that incorporate cooperative styles of distributed execution often replicate or distribute data within groups of components. In these cases, group oriented consistency properties must be maintained, and tools based on the virtual synchrony execution model greatly simplify the task confronting an application developer. All three styles of distributed computing are likely to be seen in future systems - often, within the same application. This leads us to propose an integrated approach that permits applications that use virtual synchrony with concurrent objects that respect a linearizability constraint, and vice versa. Transactional subsystems are treated as a special case of linearizability.

Birman, Kenneth P.↗

NASA NTRS1992

Support activities to maintain SUMS flight readiness

The Shuttle Upper Atmosphere Mass Spectrometer (SUMS), a component experiment of the NASA Orbital Experiments Program (OEX), was flown aboard the shuttle Columbia (OV102) mounted at the forward end of the nose landing gear well with an atmospheric gas inlet system fitted to the lower fuselage (chin panel) surface. The SUMS was designed to provide atmospheric data in flow regimes inaccessible prior to the development of the Space Transportation System (STS). The experiment mission operation began about one hour prior to shuttle de-orbit entry maneuver and continued until reaching 1.6 torr (about 86 km altitude). The SUMS mass spectrometer consists of the spare unit from the Viking mission to Mars. Bendix Aerospace under contract to NASA LaRC incorporated the Viking mass spectrometer, a microprocessor based logic card, a pressurized instrument case, and the University of Texas at Dallas provided a gas inlet system into a configuration suited to interface with the shuttle Columbia. The SUMS experiment underwent static and dynamic calibration as well as vacuum maintenance before and after STS 40 shuttle flight. The SUMS flew a total of 3 times on the space shuttle Columbia. Between flights the SUMS was maintained in flight ready status. The flight data has been analyzed by the NASA LaRC Aerothermodynamics Branch. Flight data spectrum plots and reports are presented in the Appendices to the Final Technical Report for NAS1-17399.

Wright, Willie↗

NASA NTRS1992

Support activities to maintain SUMS flight readiness, volume 2. Attachment A: Flight 61-C report

The Shuttle Upper Atmosphere Mass Spectrometer (SUMS), a component experiment of the NASA Orbital Experiments Program (OEX), was flown aboard the shuttle Columbia (OV102) mounted at the forward end of the nose landing gear well with an atmospheric gas inlet system fitted to the lower fuselage (chin panel) surface. The SUMS was designed to provide atmospheric data in flow regimes inaccessible prior to the development of the Space Transportation system (STS). The experiment mission operation begins about 1 hour to shuttle de-orbit entry maneuver and continues until reaching 1.6 torr (about 86 km altitude). The SUMS flew a total of three missions, 61C, STS-35, and STS-40. Between flights, the SUMS was maintained in flight ready status. The flight data has been analyzed by the NASA LaRC Aerothermodynamics Branch. Flight data spectrum plots and reports are presented in the Appendices to the Final Technical Report for NAS1-17399. This volume is the flight data report for flight 61-C.

Wright, Willie↗

NASA NTRS1992

Support activities to maintain SUMS flight readiness, volume 3. Attachment B: Flight STS-35 report, section A

The Shuttle Upper Atmosphere Mass Spectrometer (SUMS), a component experiment of the NASA Orbital Experiments Program (OEX), was flown aboard the shuttle Columbia (OV102) mounted at the forward end of the nose landing gear well with an atmospheric gas inlet system fitted to the lower fuselage (chin panel) surface. The SUMS was designed to provide atmospheric data in flow regimes inaccessible prior to the development of the Space Transportation System (STS). The experiment mission operation begins about 1 hour prior to shuttle de-orbit entry maneuver and continues until reaching 1.6 torr (about 86 km altitude). The SUMS flew a total of three missions, 61C, STS-35, and STS-40. Between flights, the SUMS was maintained in flight ready status. The flight data has been analyzed by the NASA LaRC Aerothermodynamics Branch. Flight data spectrum plots and reports are presented in the Appendices to the Final Technical Report for NAS1-17399. This volume presents flight data for flight STS-35 in graphical format.

Wright, Willie↗

NASA NTRS1992

Support activities to maintain SUMS flight readiness, volume 4. Attachment B: Flight STS-35 report, section B

The Shuttle Upper Atmosphere Mass Spectrometer (SUMS), a component experiment of the NASA Orbital Experiments Program (OEX), was flown aboard the shuttle Columbia (OV102) mounted at the forward end of the nose landing gear well with an atmospheric gas inlet system fitted to the lower fuselage (chin panel) surface. The SUMS was designed to provide atmospheric data in flow regimes inaccessible prior to the development of the Space Transportation System (STS). The experiment mission operation begins about 1 hour prior to shuttle de-orbit entry maneuver and continues until reaching 1.6 torr (about 86 km altitude). The SUMS flew a total of three missions, 61C, STS-35, STS-40. Between flights, the SUMS was maintained in flight ready status. The flight data has been analyzed by the NASA LaRC Aerothermodynamics Branch. Flight data spectrum plots and reports are presented in the Appendices to the Final Technical Report for NAS1-17399. This volume present spectra graphs of the reentry of flight STS-35.

Wright, Willie↗

NASA NTRS1992

Support activities to maintain SUMS flight readiness, volume 5. Attachment B: Flight STS-35 report, section C

The Shuttle Upper Atmosphere Mass Spectrometer (SUMS), a component experiment of the NASA Orbital Experiments Program (OEX), was flown aboard the shuttle Columbia (OV102) mounted at the forward end of the nose landing gear well with an atmospheric gas inlet system fitted to the lower fuselage (chin panel) surface. The SUMS was designed to provide atmospheric data in flow regimes inaccessible prior to the development of the Space Transportation System (STS). The experiment mission operation begins about 1 hour prior to shuttle de-orbit entry maneuver and continues until reaching 1.6 torr (about 86 km altitude). The SUMS flew a total of three missions, 61C, STS-35, and STS-40. Between flights, the SUMS was maintained in flight ready status. The flight data has been analyzed by the NASA LaRC Aerothermodynamics Branch. Flight data spectrum plots and reports are presented in the Appendices to the Final Technical Report for NAS1-17399. This volume presents spectral graphs of the reentry of flight STS-35.

Wright, Willie↗

NASA NTRS1992

Support activities to maintain SUMS flight readiness, volume 6. Attachment B: Flight STS-35 report, section D

The Shuttle Upper Atmosphere Mass Spectrometer (SUMS), a component experiment of the NASA Orbital Experiments Program (OEX), was flown aboard the shuttle Columbia (OV102) mounted at the forward end of the nose landing gear well with an atmospheric gas inlet system fitted to the lower fuselage (chin panel) surface. The SUMS was designed to provide atmospheric data in flow regimes inaccessible prior to the development of the Space Transportation System (STS). The experiment mission operation begins about 1 hour prior to shuttle de-orbit entry maneuver and continues until reaching 1.6 torr (about 86 km altitude). The SUMS flew a total of three missions, 61C, STS-35, STS-40. Between flights, the SUMS was maintained in flight ready status. The flight data has been analyzed by the NASA LaRC Aerothermodynamics Branch. Flight data spectrum plots and reports are presented in the Appendices to the Final Technical Report for NAS1-17399. This volume presents spectral graphs of the reentry of flight STS-35.

Wright, Willie↗

NASA NTRS1992

Support activities to maintain SUMS flight readiness, volume 7. Attachment B: Flight STS-35 report, section E

The Shuttle Upper Atmosphere Mass Spectrometer (SUMS), a component experiment of the NASA Orbital Experiments Program (OEX), was flown aboard the shuttle Columbia (OV102) mounted at the forward end of the nose landing gear well with an atmospheric gas inlet system fitted to the lower fuselage (chin panel) surface. The SUMS was designed to provide atmospheric data in flow regimes inaccessible prior to the development of the Space Transportation System (STS). The experiment mission operation begins about 1 hour prior to shuttle de-orbit entry maneuver and continues until reaching 1.6 torr (about 86 km altitude). The SUMS flew a total of three missions, 61C, STS-35, STS-40. Between flights, the SUMS was maintained in flight ready status. The flight data has been analyzed by the NASA LaRC Aerothermodynamics Branch. Flight data spectrum plots and reports are presented in the Appendices to the Final Technical Report for NAS1-17399. This volume presents data from the reentry of flight STS-35 in tabular and graphical format.

Wright, Willie↗

NASA NTRS1992

Support activities to maintain SUMS flight readiness, volume 8. Attachment B: Flight STS-35 report, section F

The Shuttle Upper Atmosphere Mass Spectrometer (SUMS), a component experiment of the NASA Orbital Experiments Program (OEX), was flown aboard the shuttle Columbia (OV102) mounted at the forward end of the nose landing gear well with an atmospheric gas inlet system fitted to the lower fuselage (chin panel) surface. The SUMS was designed to provide atmospheric data in flow regimes inaccessible prior to the development of the Space Transportation System (STS). The experiment mission operation begins about 1 hour prior to shuttle de-orbit entry maneuver and continues until reaching 1.6 torr (about 86 km altitude). The SUMS flew a total of three missions, 61C, STS-35, STS-40. Between flights, the SUMS was maintained in flight ready status. The flight data has been analyzed by the NASA LaRC Aerothermodynamics Branch. Flight data spectrum plots and reports are presented in the Appendices to the Final Technical Report for NAS1-17399. This volume presents tabular and graphical spectral data of the reentry of flight STS-35.

Wright, Willie↗

NASA NTRS1992

Support activities to maintain SUMS flight readiness, volume 9. Attachment C: Flight STS-40 report. Attachment D: SUMS software listing

The Shuttle Upper Atmosphere Mass Spectrometer (SUMS), a component experiment of the NASA Orbital Experiments Program (OEX), was flown aboard the shuttle Columbia (OV102) mounted at the forward end of the nose landing gear well with an atmospheric gas inlet system fitted to the lower fuselage (chin panel) surface. The SUMS was designed to provide atmospheric data in flow regimes inaccessible prior to the development of the Space Transportation System (STS). The experiment mission operation begins about 1 hour prior to shuttle de-orbit entry maneuver and continues until reaching 1.6 torr (about 86 km altitude). The SUMS flew a total of three missions, 61C, STS-35, STS-40. Between flights, the SUMS was maintained in flight ready status. The flight data has been analyzed by the NASA LaRC Aerothermodynamics Branch. Flight data spectrum plots and reports are presented in the Appendices to the Final Technical Report for NAS1-17399. This volume provides a software listing and graphical data gathered from flight STS-40.

Wright, Willie↗

NASA NTRS1994

Endangered and potentially endangered wildlife on John F. Kennedy Space Center and faunal integrity as a goal for maintaining biological diversity

Buffer zones for space operations provide for a wildlife diversity unsurpassed among most federal facilities in the continental U.S. demonstrating the coexistence possible with one of man's greatest technological achievements. This document ranks 119 resident or migratory wildlife species that are endangered or declining. The ranking system herein was based on species' vulnerability to extinction and the relevance of Kennedy Space Center (KSC) for maintaining populations in the U.S. and Florida. One amphibian, 19 reptiles, 80 birds, and 19 mammals were considered endangered or declining. KSC is an integral area for regional species diversity being the focus of the Merritt Island/Cape Canaveral/Turnbull Ecosystem which is part of the Indian River Lagoon watershed, an estuary of national significance. Many species that use this system also use the nearby St. Johns River Basin ecosystem. These two ecosystems are biological corridors between temperate Carolinian and tropical/subtropical Caribbean biotic provinces. Threats to biological diversity on KSC were also reviewed. Traditional environmental assessments, resulting from environmental regulation guidelines, focus on environmental contaminants and habitat lost due to construction. However, this review suggested that small population sizes, isolation of populations, ecosystem and habitat fragmentation, road mortality, and other edge effects may represent more critical threats to biological diversity than the traditional topics.

Breininger, David R.↗

NASA NTRS1995

Radiation Propulsion For Maintaining Orbits

Brief report proposes radiative propulsion systems for maintaining precise orbits of spacecraft. Radiation from electrical heaters directed outward by paraboloidal reflectors to produce small forces to oppose uncontrolled drag and solar-radiative forces perturbing orbits. Minimizes or eliminates need to fire rocket thrusters to correct orbits.

Richter, Robert↗