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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 559 records · Page 31
All sourcesNASA NTRSDOE OSTI
NASA NTRS1993

Mirror fusion propulsion system: A performance comparison with alternate propulsion systems for the manned Mars Mission

The performance characteristics of several propulsion technologies applied to piloted Mars missions are compared. The characteristics that are compared are Initial Mass in Low Earth Orbit (IMLEO), mission flexibility, and flight times. The propulsion systems being compared are both demonstrated and envisioned: Chemical (or Cryogenic), Nuclear Thermal Rocket (NTR) solid core, NTR gas core, Nuclear Electric Propulsion (NEP), and a mirror fusion space propulsion system. The proposed magnetic mirror fusion reactor, known as the Mirror Fusion Propulsion System (MFPS), is described. The description is an overview of a design study that was conducted to convert a mirror reactor experiment at Lawrence Livermore National Lab (LLNL) into a viable space propulsion system. Design principles geared towards minimizing mass and maximizing power available for thrust are identified and applied to the LLNL reactor design, resulting in the MFPS. The MFPS' design evolution, reactor and fuel choices, and system configuration are described. Results of the performance comparison shows that the MFPS minimizes flight time to 60 to 90 days for flights to Mars while allowing continuous return-home capability while at Mars. Total MFPS IMLEO including propellant and payloads is kept to about 1,000 metric tons.

Schulze, Norman R.↗
NASA NTRS2005

Ka-Band Wide-Bandgap Solid-State Power Amplifier: Hardware Validation

Motivated by recent advances in wide-bandgap (WBG) gallium nitride (GaN) semiconductor technology, there is considerable interest in developing efficient solid-state power amplifiers (SSPAs) as an alternative to the traveling-wave tube amplifier (TWTA) for space applications. This article documents proof-of-concept hardware used to validate power-combining technologies that may enable a 120-W, 40 percent power-added efficiency (PAE) SSPA. Results in previous articles [1-3] indicate that architectures based on at least three power combiner designs are likely to enable the target SSPA. Previous architecture performance analyses and estimates indicate that the proposed architectures can power combine 16 to 32 individual monolithic microwave integrated circuits (MMICs) with >80 percent combining efficiency. This combining efficiency would correspond to MMIC requirements of 5- to 10-W output power and >48 percent PAE. In order to validate the performance estimates of the three proposed architectures, measurements of proof-of-concept hardware are reported here.

Epp, L.↗
NASA NTRS1976

Advanced space system concepts and their orbital support needs (1980 - 2000). Volume 4: Detailed data. Part 2: Program plans and common support needs (a study of the commonality of space vehicle applications to future national needs

The methodology of alternate world future scenarios is utilized for selecting a plausible, though not advocated, set of future scenarios each of which results in a program plan appropriate for the respective environment. Each such program plan gives rise to different building block and technology requirements, which are analyzed for common need between the NASA and the DoD for each of the alternate world scenarios. An essentially invariant set of system, building block, and technology development plans is presented at the conclusion, intended to allow protection of most of the options for system concepts regardless of what the actual future world environment turns out to be. Thus, building block and technology needs are derived which support: (1) each specific world scenario; (2) all the world scenarios identified in this study; or (3) generalized scenarios applicable to almost any future environment. The output included in this volume consists of the building blocks, i.e.: transportation vehicles, orbital support vehicles, and orbital support facilities; the technology required to support the program plans; identification of their features which could support the DoD and NASA in common; and a complete discussion of the planning methodology.

Bekey, I.↗
NASA NTRS2015

Continued Advancement of Supported Liquid Membranes for Carbon Dioxide Control in Extravehicular Activity Applications

The Development of a new, robust, portable life support system (PLSS) is currently a high NASA priority in order to support longer and safer extravehicular activity (EVA) missions that will be necessary as space travel extends to near-Earth asteroids and eventually Mars. One of the critical PLSS functions is maintaining the carbon dioxide (CO2) concentration in the suit at acceptable levels. The Metal Oxide (MetOx) canister has a finite CO2 adsorption capacity and therefore in order to extend mission times, the unit would have to be larger and heavier, which is undesirable; therefore new CO2 control technologies must be developed. While recent work has centered on the use of alternating sorbent beds that can be regenerated during the EVA, this strategy increases the system complexity and power consumption. A simpler approach is to use a membrane that vents CO2 to space but retains oxygen(O2). A membrane has many advantages over current technology: it is a continuous system with no theoretical capacity limit, it requires no consumables, and it requires no hardware for switching beds between absorption and regeneration. Conventional gas separation membranes do not have adequate selectivity for use in the PLSS, but the required performance could be obtained with a supported liquid membrane (SLM), which consists of a microporous film filled with a liquid that selectively reacts with CO2 over oxygen (O2). In a recently completed Phase II Small Business Innovative Research project, Reaction Systems developed a new reactive liquid that has effectively zero vapor pressure, making it an ideal candidate for use in an SLM. Results obtained with the SLM in a flat sheet configuration with representative pressures of CO2, O2, and water (H2O) have shown that the CO2 permeation rate and CO2/O2 selectivity requirements have been met. In addition, the SLM vents moisture to space very effectively. The SLM has also been prepared and tested in a hollow fiber form, which will be necessary to meet size requirements in the PLSS. In initial tests, the required CO2 permeance values have been obtained, while the current CO2/O2 selectivity values are somewhat lower than needed. However, the performance of the SLM is a strong function of the method used to impregnate the sorbent in the hollow fiber walls and rapid progress is being made in that area.

Wickham, David T.↗
NASA NTRS1975

Future long-range transports - Prospects for improved fuel efficiency

A status report is provided on current thinking concerning potential improvements in fuel efficiency and possible alternate fuels. Topics reviewed are: historical trends in airplane efficiency; technological opportunities including supercritical aerodynamics, vortex diffusers, composite materials, propulsion systems, active controls, and terminal-area operations; unconventional design concepts, and hydrogen-fueled airplane.

Nagel, A. L.↗
NASA NTRS1975

Hydrogen for the subsonic transport

Relations between air travel and fuel requirements are examined. Alternate fuels considered in connection with problems related to a diminishing supply of petroleum include synthetic jet fuel, methane, and hydrogen. A cruise flight of a subsonic aircraft on a hydrogen-fueled jet engine was demonstrated in 1957. However, more development work is required to provide a sound engineering base for a complete air transportation system using hydrogen as fuel. Aircraft designs for alternate fuels are discussed, giving attention to hydrogen-related technology already available and new developments which are needed.

Korycinski, P. F.↗
NASA NTRS1978

Directional laser velocimeter with doppler velocity simulator

Technique uses phase-shift networks at optical and baseband frequencies and, as such, is optical adaptation of previously-existing microwave technology. Application is planned for wind-tunnel velocity measurements. Alternative configuration produces finite fringes that move in one direction or other as measured particle approaches or recedes.

Franke, J. M.↗
NASA NTRS1984

Crew and life support: ECLSS

The schedule NASA has proposed has four main elements. The focal point of all the life support activity is demonstrator for the initial space station. The demonstrator is composed of items that are ready for Phase C and D development. Technical options are scheduled during the early years to provide alternatives because the capability to substitute must be maintained. Growth technology and supporting research and technology (SR&T) will continue throughout the program life, and as new items emerge, the space station capability will be updated.

Drake, G.↗
NASA NTRS1986

Full-scale tilt-rotor hover performance

The hover performance of three full-scale rotors was measured at the Ames Outdoor Aerodynamic Research Facility. The rotors, all designed for tilt-rotor aircraft, were the original metal blades for the XV-15 Tilt Rotor Research Aircraft, a set of composite, advanced technology blades for the XV-15, and a 0.658-scale model of the proposed V-22A Osprey (JVX) rotor. The composite advanced technology blades for the XV-15 were tested with several alternate blade root and blade tip configurations. This paper presents the performance of these three rotors, shows the effects of tip Mach number and root and tip configuration changes on rotor performance, and presents data on rotor wake velocity distributions and tip vortex geometry. Measured rotor performance is compared with theoretical predictions, and the discrepancies are discussed.

Felker, F. F.↗
NASA NTRS1988

The 1988 overview of free-piston Stirling technology for space power at the NASA Lewis Research Center

The completion of the Space Power Demonstrator Engine (SPDE) testing is discussed, terminating with the generation of 25 kW of engine power from a dynamically-balanced opposed-piston Stirling engine at a temperature ratio of 2.0. Engine efficiency was greater than 22 percent. The SPDE recently was divided into 2 separate single cylinder engines, Space Power Research Engine (SPRE), that serves as test beds for the evaluation of key technology disciplines, which include hydrodynamic gas bearings, high efficiency linear alternators, space qualified heat pipe heat exchangers, oscillating flow code validation, and engine loss understanding. The success of the SPDE at 650 K has resulted in a more ambitious Stirling endeavor, the design, fabrication, test, and evaluation of a designed-for-space 25 kW per cylinder Stirling Space Engine (SSE) to operate at a hot metal temperature of 1050 K using superalloy materials. This design is a low temperature confirmation of the 1300 K design. It is the 1300 K free-piston Stirling power conversion system that is the ultimate goal. The first two phases of this program, the 650 K SPDE and the 1050 K SSE are emphasized.

Slaby, Jack G.↗
NASA NTRS1989

Preliminary assessment of rover power systems for the Mars Rover Sample Return Mission

Four isotope power system concepts were presented and compared on a common basis for application to on-board electrical prime power for an autonomous planetary rover vehicle. A representative design point corresponding to the Mars Rover Sample Return (MRSR) preliminary mission requirements (500 W) was selected for comparison purposes. All systems concepts utilize the General Purpose Heat Source (GPHS) isotope heat source developed by DOE. Two of the concepts employ thermoelectric (TE) conversion: one using the GPHS Radioisotope Thermoelectric Generator (RTG) used as a reference case, the other using an advanced RTG with improved thermoelectric materials. The other two concepts employed are dynamic isotope power systems (DIPS): one using a closed Brayton cycle (CBC) turboalternator, and the other using a free piston Stirling cycle engine/linear alternator (FPSE) with integrated heat source/heater head. Near-term technology levels have been assumed for concept characterization using component technology figure-of-merit values taken from the published literature. For example, the CBC characterization draws from the historical test database accumulated from space Brayton cycle subsystems and components from the NASA B engine through the mini-Brayton rotating unit. TE system performance is estimated from Voyager/multihundred Watt (MHW)-RTG flight experience through Mod-RTG performance estimates considering recent advances in TE materials under the DOD/DOE/NASA SP-100 and NASA Committee on Scientific and Technological Information programs. The Stirling DIPS system is characterized from scaled-down Space Power Demonstrator Engine (SPDE) data using the GPHS directly incorporated into the heater head. The characterization/comparison results presented here differ from previous comparison of isotope power (made for LEO applications) because of the elevated background temperature on the Martian surface compared to LEO, and the higher sensitivity of dynamic systems to elevated s

Bents, D. J.↗
NASA NTRS1989

COLD-SAT orbital experiment configured for Atlas launch

The design and requirements for the proposed cryogenic on-orbit liquid depot storage, acquisition, and transfer (COLD-SAT) satellite experiment, which is to be launched by Atlas I, are examined. The COLD-SAT experiments are categorized as class I and II; class I involves technology related to space transportation missions and class II represents alternative fluid management operations and data. The hardware for the COLD-SAT experiments consists of three hydrogen tanks contained in the experimental module; the experimental module is connected to a three-axis-controlled spacecraft bus, and thrusters are positioned on the forward and aft ends of the spacecraft and on the cylindrical portion of the experimental module. The components and systems of the experiment module and the types of experiments that can be conducted in each tank are described. Diagrams of the spacecraft configuration are provided.

Shuster, J. R.↗
NASA NTRS1989

Space station Simulation Computer System (SCS) study for NASA/MSFC. Volume 1: Overview and summary

NASA's Space Station Freedom Program (SSFP) planning efforts have identified a need for a payload training simulator system to serve as both a training facility and as a demonstrator to validate operational concepts. The envisioned Marshall Space Flight Center (MSFC) Payload Training Complex (PTC) required to meet this need will train the space station payload scientists, station scientists, and ground controllers to operate the wide variety of experiments that will be onboard the Space Station Freedom. The Simulation Computer System (SCS) is the computer hardware, software, and workstations that will support the Payload Training Complex at MSFC. The purpose of this SCS study is to investigate issues related to the SCS, alternative requirements, simulator approaches, and state-of-the-art technologies to develop candidate concepts and designs. This study was performed August 1988 to October 1989. Thus, the results are based on the SSFP August 1989 baseline, i.e., pre-Langley configuration/budget review (C/BR) baseline. Some terms, e.g., combined trainer, are being redefined. An overview of the study activities and a summary of study results are given here.

Source record↗
NASA NTRS1991

The real-time control of planetary rovers through behavior modification

It is not yet clear of what type, and how much, intelligence is needed for a planetary rover to function semi-autonomously on a planetary surface. Current designs assume an advanced AI system that maintains a detailed map of its journeys and the surroundings, and that carefully calculates and tests every move in advance. To achieve these abilities, and because of the limitations of space-qualified electronics, the supporting rover is quite sizable, massing a large fraction of a ton, and requiring technology advances in everything from power to ground operations. An alternative approach is to use a behavior driven control scheme. Recent research has shown that many complex tasks may be achieved by programming a robot with a set of behaviors and activation or deactivating a subset of those behaviors as required by the specific situation in which the robot finds itself. Behavior control requires much less computation than is required by tradition AI planning techniques. The reduced computation requirements allows the entire rover to be scaled down as appropriate (only down-link communications and payload do not scale under these circumstances). The missions that can be handled by the real-time control and operation of a set of small, semi-autonomous, interacting, behavior-controlled planetary rovers are discussed.

Miller, David P.↗
NASA NTRS1991

Component technology for stirling power converters

NASA Lewis Research Center has organized a component technology program as part of the efforts to develop Stirling converter technology for space power applications. The Stirling Space Power Program is part of the NASA High Capacity Power Project of the Civil Space Technology Initiative (CSTI). NASA Lewis is also providing technical management for the DOE/Sandia program to develop Stirling converters for solar terrestrial power producing electricity for the utility grid. The primary contractors for the space power and solar terrestrial programs develop component technologies directly related to their goals. This Lewis component technology effort, while coordinated with the main programs, aims at longer term issues, advanced technologies, and independent assessments. An overview of work on linear alternators, engine/alternator/load interactions and controls, heat exchangers, materials, life and reliability, and bearings is presented.

Thieme, Lanny G.↗
NASA NTRS1992

New inertial actuator provides isolation and stabilization in microgravity conditions

Experiments in materials and fluids processing have been conducted, or are planned, that take advantage of the low-g environment offered by space-based platforms. While the specific goals of the experiments vary, a common objective is to see improved results from the processes over those that would be obtained from similar ground-based experiments. While the space-based processing environment does offer a low-g environment, it is not disturbance free. Results of experiments already conducted, particularly those in manned vehicles, show that spacecraft induced disturbances still limit what can be achieved in materials processing. The duration of actual micro-g level environments is shorter than desired and periods of milli-g activity levels are not uncommon. While small scale experiments can be configured to overcome some of the vehicle disturbance sources, larger scale processing devices and commercial activities will require alternative methods to reduce the influences of spacecraft vibrations. Applied Technology Associates, Inc., (ATA), in cooperation with NASA Lewis Research Center, is developing hardware to provide a sustained micro-g experiment environment. This work is being sponsored under a Small Business Innovation Research (SBIR) program, which is currently in the Phase 2 development stage. ATA's approach is based on an inertial actuator, which when used as part of a closed-loop stabilization system, rejects unwanted disturbances to the experiment package. A prototype of the actuator has been fabricated and used in a laboratory demonstration to prove the principle of operation. ATA's presentation emphasized the development and testing of the Digital Materials Processing Experiment (DAMPER) inertial actuator. Physical and performance characteristics of the device are presented. Technical issues, including further optimization of the actuator's performance and plans for additional laboratory experiments, are also covered.

Blackburn, John↗
NASA NTRS1990

Space Station Simulation Computer System (SCS) study for NASA/MSFC. Concept document

NASA's Space Station Freedom Program (SSFP) planning efforts have identified a need for a payload training simulator system to serve as both a training facility and as a demonstrator to validate operational concepts. The envisioned MSFC Payload Training Complex (PTC) required to meet this need will train the Space Station Payload of experiments that will be onboard the Space Station Freedom. The simulation will support the Payload Training Complex at MSFC. The purpose of this SCS Study is to investigate issues related to the SCS, alternative requirements, simulator approaches, and state-of-the-art technologies to develop candidate concepts and designs.

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