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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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NASA NTRS1984

Intelligent interfaces for tactical airborne platforms

Enhanced capabilities of tactical airborne platforms have resulted in increased number of aircrew tasks, greater task complexity, and increased time-stress in task performance. Embedded intelligence in the aircrew-vehicle interface (AVI) can help alleviate aircrew workload and enhance aircrew performance by: (1) optimizing the exchange of information between the aircrew and the onboard automation; and (2) adaptively allocating functions between aircrew and automation in response to situational demands. Intelligent interface issues are addressed in this report such as: (1) how to ensure that the aircrew can cope with the information influx; (2) how to present/portray both situational and internal status information; (3) how to allocate functions between the aircrew and the onboard automation; and (4) how to explain reasoning processes employed by onboard intelligence to the aircrew.

Madni, A.↗

NASA NTRS1985

Space Technology Experiments Platform (STEP) Status: an In-space Test Facility

Designed for utilization of the space transportation system for technology experiments in space, the space technology experiment platform (STEP) is a shuttle-borne experiment support facility for use primarily for structures, structural dynamics, and control flexible structures technology flight experiments. The STEP concept is discussed as well as shows its relationship to broad NASA goals and objectives. The development chronology is presented and the current system capability in block diagram format is described. The STEP development schedule is included.

Harris, J. E.↗

NASA NTRS1984

Some methods of computing platform transmitter terminal location estimates

A position estimation algorithm was developed to track a humpback whale tagged with an ARGOS platform after a transmitter deployment failure and the whale's diving behavior precluded standard methods. The algorithm is especially useful where a transmitter location program exists; it determines the classical keplarian elements from the ARGOS spacecraft position vectors included with the probationary file messages. A minimum of three distinct messages are required. Once the spacecraft orbit is determined, the whale is located using standard least squares regression techniques. Experience suggests that in instances where circumstances inherent in the experiment yield message data unsuitable for the standard ARGOS reduction, (message data may be too sparse, span an insufficient period, or include variable-length messages). System ARGOS can still provide much valuable location information if the user is willing to accept the increased location uncertainties.

Hoisington, C. M.↗

NASA NTRS1985

Thermal management system options for high power space platforms

Thermal Management System (TMS) design options for a high power (75kWe), low earth orbit, multimodule space platform were investigated. The approach taken was to establish a baseline TMS representative of current technology, and to make incremental improvements through successive subsystem trades that lead to a candidate TMS. The TMS trades included centralized and decentralized transport, single-phase and two-phase transport, alternate working fluids, liquid loop and heat pipe radiators, deployed fixed, body mounted and steerable radiators, and thermal storage. The subsystem options were evaluated against criteria such as weight, TMS power requirement, reliability, system isothermality penalty, and growth potential.

Sadunas, J. A.↗

NASA NTRS1986

Deployable Construction Platform

Structure folds compactly for transportation but opens into large work and storage area. Platform central location for building structures, storing equipment and parts, and servicing and checking out space vehicles. Provides electrical power, lighting, and tools. Developed for use on space station, includes folding structural parts adaptable to portable or field-assembled terrestrial structures.

Gates, R. M.↗

NASA NTRS1985

Space platform expendables resupply concept definition study

NASA has recognized that the capability for remote resupply of space platform expendable fluids will help transition space utilization into a new era of operational efficiency and cost/effectiveness. The emerging Orbital Maneuvering System (OMV) in conjunction with an expendables resupply module will introduce the capability for fluid resupply enabling satellite lifetime extension at locations beyond the range of the Orbiter. This report summarizes a supplemental study to the original Phase A study and is presented as addenda to that study.

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NASA NTRS1984

Space platform expendables resupply concept definition study. Volume 1: Executive summary

NASA has recognized that the capability for remote resupply of space platform expendable fluids will help transition space utilization into a new era of operational efficiency and cost/effectiveness. The emerging Orbital Maneuvering System (OMV) in conjunction with an expendables resupply module will introduce the capability for fluid resupply enabling satellite lifetime extension at locations beyond the range of the Orbiter. This report summarizes a Phase A study of a remote resupply module for the OMV. Volume 1 is the executive summary.

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NASA NTRS1984

Space platform expendables resupply concept definition study, volume 2

NASA has recognized that the capability for remote resupply of space platform expendable fluids will help transition space utilization into a new era of operational efficiency and cost/effectiveness. The emerging Orbital Maneuvering System (OMV) in conjunction with an expendables resupply module will introduce the capability for fluid resupply enabling satellite lifetime extension at locations beyond the range of the Orbiter. This report summarizes a Phase A study of a remote resupply module for the OMV. Volume 2 represents study results.

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NASA NTRS1986

The Science and Applications Tethered Platform (SATP) project

The capabilities of tether systems in orbit are going to be demonstrated by the first planned flights of the Tethered Satellite System (TSS). These test flights will investigate the properties of tether systems as low altitude atmospheric research facilities and as electric power generators. Studies are being conducted with the purpose of testing a variety of concepts and approaches. A comparative analysis of results will allow the choosing of the most promising ideas for further development. The broad range of applications presently under study include applications in electrodynamics, transportation, microgravity in addition to basic research. The SATP project definition study is now about midway through its first phase. The analyses conducted have led to an appraisal of users interest in the project and to a deeper understanding of the problems associated with large, long-lived tether systems in space. In addition, two specialized platform designs, devoted to microgravity and precise pointing applications, are being studied because of their potential usefulness and the promise of technical feasibility.

Merlina, P.↗

NASA NTRS1984

Optical system design considerations for interplanetary platforms

Considerations fundamental to the design of optical systems for interplanetary platforms are discussed with regard to the degree that they require departures from ground-based optical technology. Spectral availability, radiation and thermal cycles, microgravity, and space transportation constraints are considered, and new optical technologies are reviewed for their potential impact on the planetary missions planned for the rest of this century.

Miller, E. A.↗

NASA NTRS1986

High-resolution observations of low contrast phenomena from an advanced geosynchronous platform

Present technology allows radiometric monitoring of the earth, ocean and atmosphere from a geosynchronous platform with good spatial, spectral and temporal resolution. The proposed system could provide a capability for multispectral remote sensing with a 50 m nadir spatial resolution in the visible bands, 250 m in the 4 micron band and 1 km in the 11 micron thermal infrared band. The diffraction limited telescope has a 1 m aperture, a 10 m focal length (with a shorter focal length in the infrared) and linear and area arrays of detectors. The diffraction limited resolution applies to scenes of any brightness but for a dark low contrast scenes, the good signal to noise ratio of the system contribute to the observation capability. The capabilities of the AGP system are assessed for quantitative observations of ocean scenes. Instrument and ground system configuration are presented and projected sensor capabilities are analyzed.

Maxwell, M. S.↗

NASA NTRS1986

Geostationary communications platform payload concepts

The types of operational communications payloads that could be appropriate for a large geostationary facility in the middle to late 1990s are examined. A description of each type of payload is given, and various key issues and economic factors are discussed. A comparison with existing satellites indicates that large platforms may offer cost advantages.

Driggers, T. F.↗

NASA NTRS1985

The Galileo scan platform pointing control system - A modern control theoretic viewpoint

The current Galileo scan platform pointing control system (SPPCS) is described, and ways in which modern control concepts could serve to enhance it are considered. Of particular interest are: the multi-variable design model and overall control system architecture, command input filtering, feedback compensator and command input design, stability robustness constraint for both continuous time control systems and for sampled data control systems, and digital implementation of the control system. The proposed approach leads to the design of a system that is similar to current Galileo SPPCS configuration, but promises to be more systematic.

Sevaston, G. E.↗

NASA NTRS1986

Space Station polar orbiting platform - Mission analysis and planning

The Space Station Polar Orbiting Platform will be a serviceable spacecraft supporting a range of missions. The planning and analysis of these missions is investigated. The subjects of STS compatibility, rendezvous strategy, and requisite launch windows are addressed. General, as well as, two specific cases are detailed with respect to their incremental velocity requirements.

Miller, P. A.↗

NASA NTRS1987

Turbulence control on an airborne laser platform

An active flow control device to generate large-scale, periodic structures in a turbulent shear flow is developed. Together with adaptive optics, the device may be used on airborne laser platforms to reduce or eliminate optical distortion caused by the turbulence in the aircraft's boundary layer. A cyclic jet issuing from a spanwise slot is used to collect the turbulent boundary layer for a finite time and then release all of the flow instantaneously in one large eddy that convects downstream. Flow visualization and hot-film probe measurements are used together with pattern recognition algorithms to demonstrate the viability of the flow control method. A flat plate towed in a water channel is used as a test bed. The instantaneous velocity signal is used to compute important statistical quantities of the random velocity field, such as the mean, the root-mean-square, the spectral distribution, and the probability density function. When optimized for a given boundary layer, it is shown that the cyclic jet will produce periodic structures that are similar to the random, naturally occurring ones. These structures seem to trigger the onset of bursting events near the wall of the plate. Thus, the present device generates periodic structures in both the outer and inner regions of a turbulent boundary layer.

Gad-El-hak, Mohamed↗

NASA NTRS1987

Digital data from shuttle photography: The effects of platform variables

Two major criticisms of using Shuttle hand held photography as an Earth science sensor are that it is nondigital, nonquantitative and that it has inconsistent platform characteristics, e.g., variable look angles, especially as compared to remote sensing satellites such as LANDSAT and SPOT. However, these criticisms are assumptions and have not been systematically investigated. The spectral effects of off-nadir views of hand held photography from the Shuttle and their role in interpretation of lava flow morphology on the island of Hawaii are studied. Digitization of photography at JSC and use of LIPS image analysis software in obtaining data is discussed. Preliminary interpretative results of one flow are given. Most of the time was spent in developing procedures and overcoming equipment problems. Preliminary data are satisfactory for detailed analysis.

Davis, Bruce E.↗

NASA NTRS1986

Design of a single-axis platform for balloon-borne remote sensing

The design of two telescope pointing systems for remote optical sensing of the stratosphere from a balloone-borne gondola is described. The telescope pointing accuracy is + or - 0.02 deg in elevation, from a gondola which has static and dynamic tilts up to + or - 3 deg. Each system consists of a telescope, an elevation control subsystem, and a pitch-stabilized single-axis reference platform.

Coyle, L. M.↗

NASA NTRS1986

Performance of a single-axis platform for balloon-borne remote sensing

The balloon flight performance of the Mark I single-axis platform and telescope is presented. Three performance indicators are examined: inclinometer output, gyro output, and infrared detector signal. The gondola itself experiences periodic angular disturbances with maximum amplitudes in the 0.1-2.0 deg range, with peaks occurring at periods of about 1, 2, 7, 20, and 250 s. The 2- and 20-s oscillations are identified with simple and compound pendulum motions, while the 250-s oscillations are speculated to be caused by atmospheric waves. The system meets the basic goal of providing a stable pointing direction within an uncertainty which is much less than the 0.3 deg telescope beam diameter.

Traub, W. A.↗

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