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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 271 records · Page 15
All sourcesNASA NTRSDOE OSTI
NASA NTRS1975

Lightweight fuel cell powerplant for Tug

The design and characteristics of a lightweight powerplant based on advanced cell technology to meet the requirements of the Space Tug are described. The powerplant can be operated off low-pressure hydrogen and oxygen rocket propellant tanks and avoid the need for a dedicated reactant supply. Product water can be condensed or not, depending on vehicle or payload requirements. The heart of the unit, the fuel cell power section, consist of lightweight, series-connected, alkaline cells, while the power section contains accessory components for reactant conditioning, distribution, and venting, coolant circulation, passive product water removal and electric control. The proposed design offers at least a 50 per cent saving in powerplant weight, so that the total estimated powerplant dry weight including structure, tubing, wiring, interface connectors, and interface heat exchanger is 48 lb.

Handley, L. M.↗
NASA NTRS1979

Contour measurement system

A measurement system for measuring the departures from a straight line of discrete track sections of a track along a coal face in a mine employing a vehicle having a pair of spaced wheel assemblies which align with the track is presented. A reference arm pivotally connects between the wheel assemblies, and there is indicating means for measuring the angle of pivot between the arm and each of the wheel assemblies. The length of the device is less than the length of a track section, and thus when one of the wheel assemblies is on one track section and one is on an adjoining track section, the sum of the indicated angles will be indicative of the angle between track sections. Thus, from the length of a track section and angle, the departure of each track section from the line may be calculated.

Currie, J. R.↗
NASA NTRS1993

Development and evaluation of a profile negotiation process for integrating aircraft and air traffic control automation

The development and evaluation of the profile negotiation process (PNP), an interactive process between an aircraft and air traffic control (ATC) that integrates airborne and ground-based automation capabilities to determine conflict-free trajectories that are as close to an aircraft's preference as possible, are described. The PNP was evaluated in a real-time simulation experiment conducted jointly by NASA's Ames and Langley Research Centers. The Ames Center/TRACON Automation System (CTAS) was used to support the ATC environment, and the Langley Transport Systems Research Vehicle (TSRV) piloted cab was used to simulate a 4D Flight Management System (FMS) capable aircraft. Both systems were connected in real time by way of voice and data lines; digital datalink communications capability was developed and evaluated as a means of supporting the air/ground exchange of trajectory data. The controllers were able to consistently and effectively negotiate nominally conflict-free vertical profiles with the 4D-equipped aircraft. The actual profiles flown were substantially closer to the aircraft's preference than would have been possible without the PNP. However, there was a strong consensus among the pilots and controllers that the level of automation of the PNP should be increased to make the process more transparent. The experiment demonstrated the importance of an aircraft's ability to accurately execute a negotiated profile as well as the need for digital datalink to support advanced air/ground data communications. The concept of trajectory space is proposed as a comprehensive approach for coupling the processes of trajectory planning and tracking to allow maximum pilot discretion in meeting ATC constraints.

Green, Steven M.↗
NASA NTRS2003

Variability in Ocean Color Associated with Phytoplankton and Terrigenous Matter: Time Series Measurements and Algorithm Development at the FRONT Site on the New England Continental Shelf

Fronts in the coastal ocean describe areas of strong horizontal gradients in both physical and biological properties associated with tidal mixing and freshwater estuarine output (e.g. Simpson, 1981 and O Donnell, 1993). Related gradients in optically important constituents mean that fronts can be observed from space as changes in ocean color as well as sea surface temperature (e.g., Dupouy et al., 1986). This research program is designed to determine which processes and optically important constituents must be considered to explain ocean color variations associated with coastal fronts on the New England continental shelf, in particular the National Ocean Partnership Program (NOPP) Front Resolving Observational Network with Telemetry (FRONT) site. This site is located at the mouth of Long Island sound and was selected after the analysis of 12 years of AVHRR data showed the region to be an area of strong frontal activity (Ullman and Cornillon, 1999). FRONT consists of a network of modem nodes that link bottom mounted Acoustic Doppler Current Profilers (ADCPs) and profiling arrays. At the center of the network is the Autonomous Vertically Profiling Plankton Observatory (AVPPO) (Thwaites et al. 1998). The AVPPO consists of buoyant sampling vehicle and a trawl-resistant bottom-mounted enclosure, which holds a winch, the vehicle (when not sampling), batteries, and controller. Three sampling systems are present on the vehicle, a video plankton recorder, a CTD with accessory sensors, and a suite of bio-optical sensors including Satlantic OCI-200 and OCR-200 spectral radiometers and a WetLabs ac-9 dual path absorption and attenuation meter. At preprogrammed times the vehicle is released, floats to the surface, and is then winched back into the enclosure with power and data connection maintained through the winch cable. Communication to shore is possible through a bottom cable and nearby surface telemetry buoy, equipped with a mobile modem, giving the capability for near-real time data transmission and interactive sampling control.

Morrison, John R.↗
NASA NTRS1998

Vehicle and Mission Design Options for the Human Exploration of Mars/Phobos Using "Bimodal" NTR and LANTR Propulsion

The nuclear thermal rocket (NTR) is one of the leading propulsion options for future human missions to Mars because of its high specific impulse (Isp-850-1000 s) capability and its attractive engine thrust-to-weight ratio (approximately equal 3-10). To stay within the available mass and payload volume limits of a "Magnum" heavy lift vehicle, a high performance propulsion system is required for trans-Mars injection (TMI). An expendable TMI stage, powered by three 15 thousand pounds force (klbf) NTR engines is currently under consideration by NASA for its Design Reference Mission (DRM). However, because of the miniscule burnup of enriched uranium-235 during the Earth departure phase (approximately 10 grams out of 33 kilograms in each NTR core), disposal of the TMI stage and its engines after a single use is a costly and inefficient use of this high performance stage. By reconfiguring the engines for both propulsive thrust and modest power generation (referred to as "bimodal" operation), a robust, multiple burn, "power-rich" stage with propulsive Mars capture and reuse capability is possible, A family of modular "bimodal" NTR (BNTR) vehicles are described which utilize a common "core" stage powered by three 15 klbf BNTRs that produce 50 kWe of total electrical power for crew life support, an active refrigeration / reliquification system for long term, "zero-boiloff" liquid hydrogen (LH 2 ) storage, and high data rate communications. An innovative, spine-like "saddle truss" design connects the core stage and payload element and is open underneath to allow supplemental "in-line" propellant tanks and contingency crew consumables to be easily jettisoned to improve vehicle performance. A "modified" DRM using BNTR transfer vehicles requires fewer transportation system elements, reduces IMLEO and mission risk, and simplifies space operations. By taking the next logical step--use of the BNTR for propulsive capture of all payload elements into Mars orbit--the power available in Mars orbit grows to 150 kWe compared to 30 kWe for the DRM. Propulsive capture also eliminates the complex, higher risk aerobraking and capture maneuver which is replaced by a simpler reentry using a standardized, lower mass "aerodescent" shell. The attractiveness of the "all BNTR" option is further increased by the substitution of the lightweight, inflatable "TransHab" module in place of the heavier, hard-shell hab module. Use of TransHab introduces the potential for propulsive recovery and reuse of the BNTR/ERV. It also allows the crew to travel to and from Mar on the same BNTR transfer vehicle thereby cutting the duration of the ERV mission in half--from approximately 4.7 to 2.5 years. Finally, for difficult Mars options, such as Phobos rendezvous and sample return missions, volume (not mass) constraints limit the performance of the "all LH 2 " BNTR stage. The use of "LOX-augmented" NTR (LANTR) engines, operating at a modest oxygen-to-hydrogen mixutre ratio (MR) of 0.5, helps to increase "bulk" propellant density and total thrust during the TMI burn. On all subsequent burns, the bimodal LANTR engines operate on LH 2 only (MR=0) to maximize vehicle performance while staying within the lift capability of two Magnum launches.

Nuclear thermal rocket↗
NASA NTRS2002

Vehicle and Mission Design Options for the Human Exploration of Mars/Phobos Using "Bimodal" NTR and LANTR Propulsion

The nuclear thermal rocket (NTR) is one of the leading propulsion options for future human missions to Mars because of its high specific impulse (lsp~850-1000 s) capability and its attractive engine thrust-to-weight ratio (~3-10). To stay within the available mass and payload volume limits of a “Magnum” heavy lift vehicle, a high performance propulsion system is required for trans-Mars injection (TMI). An expendable TMI stage, powered by three 15 thousand pounds force (klbf) NTR engines is currently under consideration by NASA for its Design Reference Mission (DRM). However, because of the miniscule burnup of enriched uranium-235 during the Earth departure phase (~10 grams out of 33 kilograms in each NTR core), disposal of the TMI stage and its engines after a single use is a costly and inefficient use of this high performance stage. By reconfiguring the engines for both propulsive thrust and modest power generation (referred to as “bimodal” operation), a robust, multiple burn, “power-rich” stage with propulsive Mars capture and reuse capability is possible. A family of modular “bimodal” NTR (BNTR) vehicles are described which utilize a common “core” stage powered by three 15 klbf BNTRs that produce 50 kWe of total electrical power for crew life support, an active refrigeration / reliquification system for long term, zero-boiloff liquid hydrogen (LH 2 ) storage, and high data rate communications. An innovative, spine-like “saddle truss” design connects the core stage and payload element and is open underneath to allow supplemental “in-line” propellant tanks and contingency crew consumables to be easily jettisoned to improve vehicle performance. A “modified” DRM using BNTR transfer vehicles requires fewer transportation system elements, reduces IMLEO and mission risk, and simplifies space operations. By taking the next logical step—use of the BNTR for propulsive capture of all payload elements into Mars orbit—the power available in Mars orbit grows to 150 kWe compared to 30 kWe for the DRM. Propulsive capture also eliminates the complex, higher risk aerobraking and capture maneuver which is replaced by a simpler reentry using a standardized, lower mass “aerodescent” shell. The attractiveness of the “all BNTR” option is further increased by the substitution of the lightweight, inflatable “TransHab” module in place of the heavier, hard-shell hab module. Use of TransHab introduces the potential for propulsive recovery and reuse of the BNTR / Earth return vehicle (ERV). It also allows the crew to travel to and from Mars on the same BNTR transfer vehicle thereby cutting the duration of the ERV mission in half—from ~4.7 to 2.5 years. Finally, for difficult Mars options, such as Phobos rendezvous and sample return missions, volume (not mass) constraints limit the performance of the “all LH 2 ” BNTR stage. The use of “LOX-augmented” NTR (LANTR) engines, operating at a modest oxygen-to-hydrogen mixture ratio (MR) of 0.5, helps to increase “bulk” propellant density and total thrust during the TMI burn. On all subsequent burns, the bimodal LANTR engines operate on LH 2 only (MR=0) to maximize vehicle performance while staying within the mass limits of two Magnum launches.

Nuclear thermal rocket↗
NASA NTRS1989

Johnson Space Center CFD overview

Recent applications and development of CFD technology have focused on flow problems that are critically important to the operation and design of space flight vehicles. The main effort is spent on the Space Shuttle in order to provide an understanding of the cryogenic fluid in the duct connecting the External Tank and the Main Engines, the subsonic flow surrounding the Orbiter during crew egress maneuvers, the transonic aerodynamic forces on the Orbiter fuselage and wing, the high angle-of-attack abort flight, and the aerodynamic heating during entry. To provide in-depth analyses for such diverse problems within a timely schedule, matured panel codes and a state-of-the-art incompressible turbulent flow code were adapted. Collaboration with Ames Research Center has resulted in a Shuttle ascent aerodynamic code; and a viscous chemical nonequilibrium code is being developed for predicting Orbiter real-gas aerodynamics and finite-catalytic heating. The remaining activities are devoted to the prediction of the flow environment around the Aeroassist Flight Experiment vehicle at hypersonic speeds and high altitudes. A thermochemical nonequilibrium Navier-Stokes code has been developed on the basis of two- temperature and 11-species models for solving both the shock layer and near wake. After validating the code against wind-tunnel aerodynamic, pressure and heating data, the code is being used to supplement the ground test facilities in predicting a more realistic flight environment. CFD technology is being relied upon by other programs as well in the consideration of candidate configurations.

Li, Chien P.↗
NASA NTRS2011

Launch Control Systems: Moving Towards a Scalable, Universal Platform for Future Space Endeavors

The redirection of NASA away from the Constellation program calls for heavy reliance on commercial launch vehicles for the near future in order to reduce costs and shift focus to research and long term space exploration. To support them, NASA will renovate Kennedy Space Center's launch facilities and make them available for commercial use. However, NASA's current launch software is deeply connected with the now-retired Space Shuttle and is otherwise not massively compatible. Therefore, a new Launch Control System must be designed that is adaptable to a variety of different launch protocols and vehicles. This paper exposits some of the features and advantages of the new system both from the perspective of the software developers and the launch engineers.

Sun, Jonathan↗
NASA NTRS1979

Automatic circuit interrupter

In technique, voice circuits connecting crew's cabin to launch station through umbilical connector disconnect automatically unused, or deadened portion of circuits immediately after vehicle is launched, eliminating possibility that unused wiring interferes with voice communications inside vehicle or need for manual cutoff switch and its associated wiring. Technique is applied to other types of electrical actuation circuits, also launch of mapped vehicles, such as balloons, submarines, test sleds, and test chambers-all requiring assistance of ground crew.

Dwinell, W. S.↗
NASA NTRS1977

Navigation capability for an ion drive rendezvous with Halley's Comet

An analysis has been conducted in connection with plans for a study of Halley's Comet during its 1986 apparition. The use of low-thrust vehicles, utilizing an ion drive system, is being considered for a comet rendezvous mission. A preliminary trajectory for the Halley rendezvous mission calls for launch on June 20, 1982, followed by rendezvous on December 21, 1985. The navigation analysis described focuses on the terminal approach to Halley, the 60-day period preceding rendezvous. Navigation analysis assumptions are examined, taking into account navigation error sources, radio tracking, onboard optical data, earth-based comet observations, and orbit determination and guidance strategies. The preliminary mission design considers a rendezvous at approximately 56,000 km from the comet nucleus (6,000 km outside the dust envelope). Navigation performance is measured in terms of comet-relative position and velocity errors at encounter. Variations to the baseline navigation study provide illustrations concerning the close link between delivery accuracy and stochastic thrust errors.

Thornton, C. L.↗
NASA NTRS1979

Conceptual design study of improved automotives gas turbine powertrain

Twenty-two candidate engine concepts and nineteen transmission concepts. Screening of these concepts, predominantly for fuel economy, cost and technical risk, resulted in a recommended powertrain consisting of a single-shaft engine, with a ceramic radial turbine rotor, connected through a differential split-power transmission utilizing a variable stator torque converter and a four speed automatic gearbox. Vehicle fuel economy and performance projections, preliminary design analyses and installation studies in a were completed. A cost comparison with the conventional spark ignited gasoline engine showed that the turbine engine would be more expensive initially, however, lifetime cost of ownership is in favor of the gas turbine. A powertrain research and development plan was constructed to gain information on timing and costs to achieve the required level of technology and demonstrate the engine in a vehicle by the year 1983.

Source record↗
NASA NTRS1983

Preliminary evaluation of large area bonding processes for repair of graphite/polyimide composites

It is pointed out that graphite/polyimide (Gr/PI) composites are potential candidates for primary and secondary structural components in the next generation of reusable space vehicles and supersonic aircraft which are to possess operational capabilities involving the temperature range from 400 to 600 F. In connection with the considered applications, it is necessary to establish economic and reliable methods for the repair of Gr/PI composite components which have been damaged. The present investigation is concerned with the results of research conducted to develop a bonding process applicable to the repair of large areas in Gr/PI composite structural components. Attention is given to five repair techniques for Gr/PI composite materials. The techniques were employed to fabricate large panels from which flexure and short-beam-shear specimens were machined.

Deaton, J. W.↗
NASA NTRS1984

Extended mission life support systems

The life support systems employed in manned space missions have generally been based on the use of expendables, such as, for instance, liquid oxygen. For the conducted space missions, such systems have advantages related to volume, weight, and economy of power consumption. However, this situation will change in connection with Shuttle Orbiter missions of extended duration, permanent manned facilities in low-earth orbit, and ultimately manned planetary vehicles. A description is given of suitable regenerative life support systems for such extended manned space missions. Attention is given to advanced life support systems technology, air revitalization, CO2 reduction, oxygen generation, nitrogen generation, trace contaminant control, air revitalization system integration, control/monitor instrumentation, water reclamation, solid waste management, manned testing and life support integration, an enhanced duration orbiter, a space operations center, manned interplanetary life support systems, and future development requirements.

Quattrone, P. D.↗
NASA NTRS1985

Evaluation of thermal control surface on-orbit servicing methods for long term missions

Future activities of NASA will include the long-term (10 - 30 years) operation of space vehicles. For this reason, there will be an urgent need to provide the basic technology for space vehicle thermal control surfaces and their functional maintenance for future long-term missions. One of the problems arising in connection with such missions is related to contamination which can degrade operational design parameters of critical and thermal control surfaces. All Space Based Payloads will arrive on orbit with a certain level of contamination from ground handling, and, on orbit, will be subjected to some level of contamination over their mission life. For the extension of mission life, it appears practical to institute surface refurbishment procedures for contaminated and degraded surfaces. Potential resurfacing methods are evaluated, taking into account three potential processes. The most promising of these is a cleaning procedure based on the utilization of atomic oxygen.

Saylor, W.↗
NASA NTRS1992

Robots Would Couple And Uncouple Fluid And Electrical Lines

Robots make and break connections between umbilical plates and mating connectors on rockets about to be launched. Sensing and control systems include vision, force, and torque subsystems. Enhances safety by making it possible to couple and uncouple umbilical plates quickly, without exposing human technicians to hazards of leaking fuels and oxidizers. Significantly reduces time spent to manually connect umbilicals. Robots based on similar principles used in refueling of National AeroSpace Plane (NASP) and satellites and orbital transfer vehicles in space.

Del Castillo, Eduardo Lopez↗
NASA NTRS1999

Wireless Augmented Reality Prototype (WARP)

Initiated in January, 1997, under NASA's Office of Life and Microgravity Sciences and Applications, the Wireless Augmented Reality Prototype (WARP) is a means to leverage recent advances in communications, displays, imaging sensors, biosensors, voice recognition and microelectronics to develop a hands-free, tetherless system capable of real-time personal display and control of computer system resources. Using WARP, an astronaut may efficiently operate and monitor any computer-controllable activity inside or outside the vehicle or station. The WARP concept is a lightweight, unobtrusive heads-up display with a wireless wearable control unit. Connectivity to the external system is achieved through a high-rate radio link from the WARP personal unit to a base station unit installed into any system PC. The radio link has been specially engineered to operate within the high- interference, high-multipath environment of a space shuttle or space station module. Through this virtual terminal, the astronaut will be able to view and manipulate imagery, text or video, using voice commands to control the terminal operations. WARP's hands-free access to computer-based instruction texts, diagrams and checklists replaces juggling manuals and clipboards, and tetherless computer system access allows free motion throughout a cabin while monitoring and operating equipment.

Devereaux, A. S.↗
NASA NTRS1977

Baseline tests of the power-train electric delivery van

Vehicle maximum speed, range at constant speed, range over stop-and-go driving schedules, maximum acceleration, gradeability, gradeability limit, road energy consumption, road power, indicated energy consumption, braking capability, battery charger efficiency, and battery characteristics were determined for a modified utility van powered by sixteen 6-volt batteries connected in series. A chopper controller actuated by a foot accelerator pedal changes the voltage applied to the 22-kilowatt (30-hp) series-wound drive motor. In addition to the conventional hydraulic braking system, the vehicle has hydraulic regenerative braking. Cycle tests and acceleration tests were conducted with and without hydraulic regeneration.

Lumannick, S.↗
NASA NTRS1975

Self-contained heat rejection module for future spacecraft

This paper discusses development of a Self-Contained Heat Rejection Module (SHRM) which can be used on a wide variety of future spacecraft launched by the space shuttle orbiter. The SHRM contains radiators which are deployed by a scissor-mechanism and the flow equipment including pumps, accumulator, by-pass valves, and controllers necessary to reject heat from those radiators. Heat transfer between SHRM and the parent vehicle is effected by a contact heat exchanger. This device provides heat transfer between two separate flow loops through a mechanical connection. This approach reduces the time required to attach the SHRM to the payload, and increases the reliability of the SHRM flow loop since breaking into the fluid system in the field is not required. The SHRM concept also includes a refrigeration system to increase heat rejection capacity in adverse environments, or to provide for a lower return temperature, down to -23 C.

Fleming, M. L.↗