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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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Methods of predicting the state of health and human efficiency during space flight are discussed. Diversity of reactions to the same conditions, development of extrapolation methods of prediction, and isolation of informative physiological indexes are among the factors considered.
A comprehensive survey of the flight experiments conducted in conjunction with the United States Materials Processing in Space Program is presented. Also included are a brief description of the conditions prevailing in an orbiting spacecraft and the research implications provided by this unique environment. What was done and what was learned are summarized in order to serve as a background for future experiments. It is assumed that the reader has some knowledge of the physical sciences but no background in spaceflight experimentation or in the materials science per se.
On-board rear-optimal climb-dash energy management, optimal symmetric flight with an intermediate vehicle model, and energy states are presented.
Peripheral Vision Horizon Device (PVHD) theory states that the likelihood of pilot disorientation in flight is reduced by providing an artificial horizon that provides orientation information to peripheral vision. In considering the validity of the theory, three areas are explored: the use of an artificial horizon device over some other flight instrument; the use of peripheral vision over foveal vision; and the evidence that peripheral vision is well suited to the processing of orientation information.
This report presents the results of a study aimed at developing a basis for applying artificial intelligence to the flight deck environment of commercial transport aircraft. In particular, the study was comprised of four tasks: (1) analysis of flight crew tasks, (2) survey of the state-of-the-art of relevant artificial intelligence areas, (3) identification of human factors issues relevant to intelligent cockpit aids, and (4) identification of artificial intelligence areas requiring further research.
As the United States is approaching an operational space station era, flight simulators are required to investigate human design and performance aspects associated with orbital operations. Among these are proximity operations (PROX OPS), those activities occurring within a 1-km sphere of Space Station including rendezvous, docking, rescue, and repair. The Space Station Proximity Operations Simulator at NASA Ames Research Center was modified to provide the capability for investigations into human performance aspects of proximity operations. Accurate flight equations of motion were installed to provide the appropriate visual scene to test subjects performing simulated missions. Also, the flight control system was enhanced by enabling pilot control over thruster acceleration values. Currently, research is under way to examine human performance in a variety of mission scenarios.
Although space research is still in an embryonic state, a combination of Earth based and space flight experiments are being coupled to yield a better understanding of the complex interaction of heat and fluid flow on the dynamics of crystal growth. Continued efforts on the ground as well as additional flight opportunities are needed to continue the drive to fully understand the advantages, both scientifically and economically, of microgravity crystal growth.
It is not sufficient to optimize a rotor design in terms of a single noise level calculated for a single flight condition and a single measurement location. The various noise sources, their frequency content, amplitude, and directivity as a function of operating condition must be considered. A summary of the frequency ranges, directivity patterns and the most important operational and design parameters for major rotor noise sources is presented. It is difficult to generalize design requirements for rotor noise because the acoustic output varies so widely depending on the noise source, flight condition, measurement location, and frequency range. However, assuming the rotor must lift a fixed nominal payload and operate over a wide range of flight conditions, three general design guidelines can be stated: (1) minimize tip Mach number; (2) minimize blade thickness in the tip region; and (3) minimize gradients in the spanwise lift distribution in the tip region. Constraints on blade thickness, maximum values for hover tip Mach number, advancing tip Mach number and spanwise lift coefficient gradient will be specified during the aerodynamic, dynamic and structural optimization process. The rotor noise sources to be considered include the low frequency loading and thickness noise, and the higher frequency noise due to blade-vortex interactions (BVI). The analyses to be employed will include the comprehensive rotor analysis and design program CAMRAD and the rotor noise prediction program WOPWOP.
The computational modeling of the transition process characteristic of flows over swept wings are described. Specifically, the crossflow instability and crossflow/T-S wave interactions are analyzed through the numerical solution of the full three-dimensional Navier-Stokes equations including unsteadiness, curvature, and sweep. This approach is chosen because of the complexity of the problem and because it appears that linear stability theory is insufficient to explain the discrepancies between different experiments and between theory and experiments. The leading edge region of a swept wing is considered in a three-dimensional spatial simulation with random disturbances as the initial conditions. The work has been closely coordinated with the experimental program of Professor William Saric, examining the same problem. Comparisons with NASA flight test data and the experiments at Arizona State University were a necessary and an important integral part of this work.
The current state of development of the NASA/GSFC (Goddard Space Flight Center) Split-Rail Parallel Gripper (SRPG) is described. The SPRG has been shown to be a high performance gripper for industrial robots. It has a precise wide throw and at the same time, it is light, simple, compact, rugged, and jam-proof against side loads. Originated at the National Bureau of Standards (NBS), this gripper is undergoing further development at NASA/GSFC in pursuit of two goals: as a potential gripper for robots in space and as the basis for sensory-interactive industrial gripper as part of NASA's technology utilization program. The gripper design features, its principles of operation and how it is constructed are described. Test results are included.
The current status for manned Mars missions and the associated challenges are summarized. Mission benefits are considered to increase with increasing Mars entry velocity. However, significant benefits accrue at moderate entry velocities between 7 and 8 km/sec, which is the realistically achievable range in view of g-limits and heating constraints. Blunt, low mass/drag coefficient (reference area) vehicles with L/Ds from 0.3 to 0.5 are found to be the preferred configurations, taking into account their adequate control authority and good payload packaging characteristics. The overall design characteristics of Mars aerocapture vehicles can be established with good confidence, using flight and ground test data and the state-of-the-art flow field analysis techniques. The principal challenges are identified as follows: to refine the knowledge of the Martian atmosphere in order to reduce design conservatism, to extend present stagnation region heating analyses to the entire vehicle forebody, and to develop reflective low-wall-catalycity TPS systems for enabling reusable vehicles.
An airborne information management system is being developed at the NASA Dryden Flight Research Facility. This system will improve the state of the art in management data acquisition on-board research aircraft. The design centers around highly distributable, high-speed microprocessors that allow data compression, digital filtering, and real-time analysis. This paper describes the areas of applicability, approach to developing the system, potential for trouble areas, and reasons for this development activity. System architecture (including the salient points of what makes it unique), design philosophy, and tradeoff issues are also discussed.
The overall scope of the NASA Lewis High Performance Aircraft Propulsion Research Program is presented. High performance fighter aircraft of interest include supersonic flights with such capabilities as short take off and vertical landing (STOVL) and/or high maneuverability. The NASA Lewis effort involving STOVL propulsion systems is focused primarily on component-level experimental and analytical research. The high-maneuverability portion of this effort, called the High Alpha Technology Program (HATP), is part of a cooperative program among NASA's Lewis, Langley, Ames, and Dryden facilities. The overall objective of the NASA Inlet Experiments portion of the HATP, which NASA Lewis leads, is to develop and enhance inlet technology that will ensure high performance and stability of the propulsion system during aircraft maneuvers at high angles of attack. To accomplish this objective, both wind-tunnel and flight experiments are used to obtain steady-state and dynamic data, and computational fluid dynamics (CFD) codes are used for analyses. This overview of the High Performance Aircraft Propulsion Research Program includes a sampling of the results obtained thus far and plans for the future.
Near term flight applications of arc jet and ion thruster satellite station-keeping systems as well as development activities in Europe, Japan, and the United States are reviewed. At least two arc jet and three ion propulsion flights are scheduled during the 1992-1995 period. Ground demonstration technology programs are focusing on the development of kW-class hydrazine and ammonia arc jets and xenon ion thrusters. Recent work at NASA LeRC on electric thruster and system integration technologies relating to satellite station keeping and repositioning will also be summarized.
The overall scope of the NASA Lewis High Performance Aircraft Propulsion Research Program is presented. High performance fighter aircraft of interest include supersonic flights with such capabilities as short take off and vertical landing (STOVL) and/or high maneuverability. The NASA Lewis effort involving STOVL propulsion systems is focused primarily on component-level experimental and analytical research. The high-maneuverability portion of this effort, called the High Alpha Technology Program (HATP), is part of a cooperative program among NASA's Lewis, Langley, Ames, and Dryden facilities. The overall objective of the NASA Inlet Experiments portion of the HATP, which NASA Lewis leads, is to develop and enhance inlet technology that will ensure high performance and stability of the propulsion system during aircraft maneuvers at high angles of attack. To accomplish this objective, both wind-tunnel and flight experiments are used to obtain steady-state and dynamic data, and computational fluid dynamics (CFD) codes are used for analyses. This overview of the High Performance Aircraft Propulsion Research Program includes a sampling of the results obtained thus far and plans for the future.
Charge transfer at electron-volt energies between multiply charged atomic ions and neutral atoms and molecules is of considerable importance in astrophysics, plasma physics, and in particular, fusion plasmas. In the year covered by this report, several major tasks were completed. These include: (1) the re-calibration of the ion gauge to measure the absolute particle densities of H2, He, N2, and CO for our current measurements; (2) the analysis of data for charge transfer reactions of N(exp 2 plus) ion and He, H2, N2, and CO; (3) measurement and data analysis of the charge transfer reaction of (Fe(exp 2 plus) ion and H2; (4) charge transfer measurement of Fe(exp 2 plus) ion and H2; and (5) redesign and modification of the ion detection and data acquisition system for the low energy beam facility (reflection time of flight mass spectrometer) dedicated to the study of state select charge transfer.
Mammalian gravity receptors (maculas) are morphologically organized for weighted, parallel distributed processing of information. There are two basic circuits: 1) highly channeled, type I cell to calyx; and 2) distributed modifying, type II cells to calyces and processes. The latter circuit should be the more adaptable since it modifies final output. To test this hypothesis, rats were flown in microgravity for 9 days aboard a space shuttle and euthanized shortly after landing. Hair cells and ribbon synapses from maculas of 3 flight and 3 ground control rats were studied ultrastructurally in blocks of 50 serial sections. Synapses increased by approximately 41% in type I cells and by approximately 55% in type II cells in flight animals. There was a shift toward the spherular form of ribbon synapse in both types of hair cells in flight animals. Current findings tend to support the stated hypothesis and indicate that mature utricular hair cells retain synaptic plasticity, permitting adaptation to an altered gravitational environment.
The Materials Science Research Facility (MSRF) is a modular facility designed to accommodate the current and evolving cadre of peer-reviewed materials science investigations selected to conduct research in the microgravity environment of the International Space Station (ISS). The MSRF concept consists of three Materials Science Research Racks (MSRR-1, MSRR-2, and MSRR-3) which will be developed for phased deployment into the United States Laboratory Module beginning on the third Utilization Flight (UF-3). The facility will house the materials processing apparatus and common subsystems required for operating each device, and will use the ISS Active Rack Isolation System (ARIS). Each MSRR is an autonomous rack and will be comprised of on-orbit replaceable Experiment Modules, Module Inserts, investigation unique apparatus, and/or multi-user generic processing apparatus. The MSRF will be the primary apparatus for satisfying near-term and long-range materials science discipline goals and objectives with each MSRR supporting a wide range of materials science themes in the NASA research program.