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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 NTRS2000

Feasibility Activities Completed for the Direct Data Distribution (D(sup )3) Experiment

The Direct Data Distribution (D(sup 3)) project being designed at the NASA Glenn Research Center at Lewis Field will demonstrate a high-performance communications system that transmits information at up to 1.2 gigabits per second (Gbps) from an advanced technology payload carried by the space shuttles in low Earth orbit to small (0.9-m) autonomously tracking terminals on the Earth. The flight communications package features a solid-state, phased-array antenna operating in the commercial K-band frequency that electronically steers two independently controlled downlink beams toward low-cost tracking ground terminals. The array enables agile, vibration-free beam steering at reduced size and weight with increased reliability over traditional mechanically steered reflectors. The flight experiment will also demonstrate efficient digital modulation technology that allows transmission of substantially increased amounts of latency-tolerant data (up to 72 Gb of data per minute of contact time) with very high quality (10(exp -11) bit error rate). D(sup 3) enables transmission from low-Earth-orbit science spacecraft, the shuttles, or the International Space Station directly to NASA field centers and principle investigator sites, or directly into the commercial terrestrial telecommunications network for remote distribution and archive. The ground terminal features a cryocooled receiver for ultralow noise and a reduced antenna aperture as well as open-loop tracking for unattended operations. The D(sup 3) technology validation and service demonstration will help to facilitate NASA's transition from using Government-owned communications assets to using commercially provided services.

Wald, Lawrence W.↗

NASA NTRS1973

Navigation, guidance, and control systems for V/STOL aircraft.

The development of digital autopilots and integrated avionics systems, applicable to many classes of vehicles and missions, was undertaken by Sperry Flight Systems in the mid-sixties. The first application of the system was planned for automatic flight control in the U.S. supersonic transport; the termination of that program, however, thwarted any flight experience. The second application, which has additional navigation and energy management functions, is an airborne simulator of the space shuttle vehicle. The latter system underwent a series of successful flight tests in a CV-990 aircraft under contract with NASA. The third application, which has new electronic displays, air data computation, and time-constrained guidance (i.e., specified position and altitude at a specified time), is in the DOT/NASA STOLAND test program. The STOLAND system is described specifically in this paper.

Osder, S. S.↗

NASA NTRS1985

The evolution of the spaceborne imaging radar system toward Eos

Progress to date and intended goals in the development of the Spaceborne Imaging Radar (SIR), a SAR remote sensing instrument targeted for carriage on one of the three polar orbiting earth observation system (EOS) platforms in the 1990s, are described. The Shuttle is the current testbed for the SIR, with spaceborne trials being used for testing continually upgraded versions of the three major components of the SIR: the electronics, the antenna and the digital data system. Experimentation is being performed in X-, K-, C- and P-bands in terms of the SNR, view angle, resolution and specific terrestrial features. The test flights are also serving to identify the most effective orbits, with consideration given to the capabilities of other instrumentation being developed for the EOS.

Cimino, J.↗

NASA NTRS1985

Detectors for high energy cosmic rays on Spacelab

Two instruments designed to determine the spectra of the individual cosmic-ray components at very high energies are described. One of these (CRNE) uses a combination of gas Cerenkov counters and transition radiation detectors for the cosmic-ray nuclei lithium to nickel; the other (TRIC) is optimized for the light cosmic rays (electrons, protons, helium) and uses a transition-radiation/ionization-calorimeter combination. The CRNE instrument, constructed at the University of Chicago, was delivered to NASA for a first Shuttle flight on Spacelab-2 in summer 1985. Some of the technical and programmatic requirements encountered during the hardware construction and integration are discussed, and the expected scientific return and the prospects of using such instrumentation on the Space Station are considered.

Lheureux, J.↗

NASA NTRS1988

Experimental characterization of hollow-cathode plasma sources at Frascati

An experimental characterization has been conducted for hollow cathodes applicable as plasma contactors on Space Shuttle-based experiments. The diagnostics tests were conducted in an 0.5 cu m vacuum chamber by means of Langmuir probes at various distances from the source. Two electron populations are noted, one in the 0.3-1 eV and the other in the 7-11 eV temperature range. Current developments in the design of plasma chambers incorporating magnetic field compensation are noted.

Vannaroni, G.↗

NASA NTRS2011

Putting the Power of Configuration in the Hands of the Users

Goal was to reduce the overall cost of human space flight while maintaining the most demanding standards for safety and mission success. In support of this goal, a project team was chartered to replace 18 legacy Space Shuttle nonconformance processes and systems with one fully integrated system Problem Reporting and Corrective Action (PRACA) processes provide a closed-loop system for the identification, disposition, resolution, closure, and reporting of all Space Shuttle hardware/software problems PRACA processes are integrated throughout the Space Shuttle organizational processes and are critical to assuring a safe and successful program Primary Project Objectives Develop a fully integrated system that provides an automated workflow with electronic signatures Support multiple NASA programs and contracts with a single "system" architecture Define standard processes, implement best practices, and minimize process variations

Al-Shihabi, Mary-Jo↗

NASA NTRS2000

Evaluation of Trapped Radiation Model Uncertainties for Spacecraft Design

The standard AP8 and AE8 models for predicting trapped proton and electron environments have been compared with several sets of flight data to evaluate model uncertainties. Model comparisons are made with flux, dose, and activation measurements made on various U.S. low-Earth orbit satellites (APEX, CRRES, DMSP. LDEF, NOAA) and Space Shuttle flights, on Russian satellites (Photon-8, Cosmos-1887, Cosmos-2044), and on the Russian Mir space station. This report gives a summary of the model-data given in a companion report. Results from the model comparisons with flight data show, for example, that the AP8 model underpredicts the trapped proton flux at low altitudes by a factor of about two (independent of proton energy and solar cycle conditions), and that the AE8 model overpredict the flux in the outer electron belt be an order of magnitude or more.

Armstrong, T. W.↗

NASA NTRS1995

In vitro chick pre-cardiac explant tissue differentiation during spaceflight on SpaceHab-02

Chick precardiac tissue explants were cultured on the 8-day mission of STS-60, space shuttle Discovery. Development of in vitro cultures of precardiac chick tissue from embryo stages 5 though 8 (H-H) were initiated during orbit and were terminated after approximately fifteen hours of 37 degree C culture. Transmission electron microscopy and tritiated thymidine studies were performed postflight. No significant differences in cell proliferation were observed between flight and ground controls. Electron-microscopic studies revealed stage 8 explants were capable of differentiation during flight in a pattern which matched ground control tissues. As anticipated, stage 7 explant tissues had differentiated to a lesser extent compared to stage 8 tissues. Interestingly, stage 7 precardiac explant flight tissue differentiation was less than ground control tissue. This difference in differentiation between flight and ground cultures was enhanced in stage 6 tissues, as high levels of myofibril organization were only seen in ground controls. Other cellular components such as Golgi apparatus, junctional complexes, and mitochondria were present and appeared normal and healthy.

NASA Program NSCORT↗

NASA NTRS1983

Science and technology results from the OSS-1 payload on the Space Shuttle

The OSS-1 Payload of nine experiments was carried on the STS-3 Space Shuttle flight in March of 1982. The OSS-1 Payload contained four instruments that evaluated specific aspects of the Orbiter's environment, including the levels of particulate, gaseous and electromagnetic emissions given off by the Orbiter, and the interactions between the Orbiter and the surrounding plasma. In addition to these environmental observations, these instruments performed scientific investigations in astronomy and in space plasma physics, including active experiments in electron beam propagation. Other experiments were in the areas of solar physics, plant growth, micrometeorite studies and the technology of actively controlled heat pipes. We present the initial results from these experiments, with some implications of these results for future operation of space experiments from the Shuttle payload bay. One major result was the unexpected discovery of a faint surface-induced optical glow created near the Shuttle surfaces by impacts of ambient atmospheric atoms and molecules.

short duration↗

NASA NTRS2000

Evaluation of Trapped Radiation Model Uncertainties for Spacecraft Design

The standard AP8 and AE8 models for predicting trapped proton and electron environments have been compared with several sets of flight data to evaluate model uncertainties. Model comparisons are made with flux, dose, and activation measurements made on various U.S. low-Earth orbit satellites (APEX, CRRES, DMSP, LDEF, NOAA) and Space Shuttle flights, on Russian satellites (Photon-8, Cosmos-1887, Cosmos-2044), and on the Russian Mir Space Station. This report gives a summary of the model-data comparisons-detailed results are given in a companion report. Results from the model comparisons with flic,ht data show, for example, the AP8 model underpredicts the trapped proton flux at low altitudes by a factor of about two (independent of proton energy and solar cycle conditions), and that the AE8 model overpredicts the flux in the outer electron belt by an order of magnitude or more.

Armstrong, T. W.↗

NASA NTRS1992

Ionizing radiation exposure of LDEF (pre-recovery estimates)

The long duration exposure facility (LDEF), launched into a 258 nautical mile orbit with an inclination of 28.5 degrees, remained in space for nearly 6 yr. The 21,500 lb NASA satellite was one of the largest payloads ever deployed by the Space Shuttle. LDEF completed 32,422 orbits and carried 57 major experiments representing more than 200 investigators from 33 private companies, 21 universities and nine countries. The experiments covered a wide range of disciplines including basic science, electronics, optics, materials, structures and power and propulsion. A number of the experiments were specifically designed to measure the radiation environment. These experiments are of specific interest, since the LDEF orbit is essentially the same as that of the Space Station Freedom. Consequently, the radiation measurements on LDEF will play a significant role in the design of radiation shielding of the space station. The contributions of the various authors presented here attempt to predict the major aspects of the radiation exposure received by the various LDEF experiments and therefore should be helpful to investigators who are in the process of analyzing experiments which may have been affected by exposure to ionizing radiation. The paper discusses the various types and sources of ionizing radiation including cosmic rays, trapped particles (both protons and electrons) and secondary particles (including neutrons, spallation products and high-LET recoils), as well as doses and LET spectra as a function of shielding. Projections of the induced radioactivity of LDEF are also discussed.

Flight Experiment↗

NASA NTRS1982

Explosive Separation of Electrical Connectors

Concept proposed for separating electrical cable that connects the Space Shuttle to deployable payloads could be used to sever electrical connections in other inaccessible environments. Although triggered explosively, connector would not release combustion products that could damage sensitive electronics. Suggested applications are undersea exploration, chemical processing and areas with high levels of radiation.

Barbour, R. T.↗

NASA NTRS1982

Large sounding rockets as a base for probing the distant magnetosphere

The Echo program's use of large sounding rockets to inject electron beams into the outer trapping region where the earth's plasma sheet interacts with the inner magnetosphere is discussed. The beams pass through the plasma sheet and the trapping region, reflect at the southern hemisphere conjugate point and return to the vicinity of the rocket where they are detected and analyzed for acceleration and diffusion processes which may also be responsible for the radiation belts. The motion of electron beams in the magnetosphere is discussed from the standpoint of single particle motion, and the trajectories of electrons injected with known energy, known angle between the electron velocity vector and the local magnetic field vector, and known position are examined. The interaction between the rocket motion and the electron drift motion is described, and the advantages and drawbacks of beam detection by optical methods and by throwaway detectors are compared. Planned Echo experiments using the Space Shuttle are discussed

Winckler, J. R.↗

NASA NTRS1984

Research study of pressure instrumentation

To obtain a more vibration resistant pressure sensor for use on the Space Shuttle Main Engine, a proximity probe based, diaphragm type pressure sensor breadboard was developed. A fiber optic proximity probe was selected as the sensor. In combination with existing electronics, a thermal stability evaluation of the entire probe system was made. Based upon the results, a breadboard design of the pressure sensor and electronics was made and fabricated. A brief series of functional experiments was made with the breadboard to calibrate, thermally compensate, and linearize its response. In these experiments, the performance obtained in the temperature range of -320 F (liquid N2) to +200 F was comparable to that of the strain gage based sensor presently in use on the engine. In tests at NASA-Marshall Space Flight Center (MSFC), after some time at or near liquid nitrogen temperatures, the sensor output varied over the entire output range. These large spurious signals were attributed to condensation of air in the sensing gap. In the next phase of development of this sensor, an evaluation of fabrication techniques toward greater thermal and mechanical stability of the fiber probe assembly must be made. In addition to this, a positive optics to metal seal must be developed to withstand the pressure that would result from a diaphragm failure.

Hoogenboom, L.↗

NASA NTRS1986

Oxidation and emittance of superalloys in heat shield applications

Recently developed superalloys that form alumina coatings have a high potential for heat shield applications for advanced aerospace vehicles at temperatures above 1095C. Both INCOLOY alloy MA 956 (of the Inco Alloys International, Inc.), an iron-base oxide-dispersion-strengthened alloy, and CABOT alloy No. 214 (of the Cabot Corporation), an alumina-forming nickel-chromium alloy, have good oxidation resistance and good elevated temperature strength. The oxidation resistance of both alloys has been attributed to the formation of a thin alumina layer (alpha-Al2O3) at the surface. Emittance and oxidation data were obtained for simulated Space Shuttle reentry conditions using a hypersonic arc-heated wind tunnel. The surface oxides and substrate alloys were characterized using X-ray diffraction and scanning and transmission electron microscopy with an energy-dispersive X-ray analysis unit. The mass loss and emittance characteristics of the two alloys are discussed.

Wiedemann, K. E.↗

NASA NTRS1993

Automated propellant leak detection

An automated hydrogen leak detection system is being developed for earth-to-orbit rocket engine applications. The system consists of three elements, a sensor array, a signal processing unit, and a diagnostic processor. The sensor array consists of discrete solid state sensors which are located at specific potential leak sites and in potential leak zones. The signal processing unit provides excitations power for the sensors and provides analog to digital data conversion of the sensor signals. The diagnostic computer analyzes the sensor outputs to determine leak sources and magnitude. Leak data from the sensor network is interpreted using knowledge based software and displayed on-line through a graphical user interface including 3-D leak visualization. The system requirements have been developed assuming eventual application to the Space Shuttle Main Engine which requires approximately 72 measurement locations. A prototype system has been constructed to demonstrate the operational features of the system. This system includes both prototype electronics and data processing software algorithms. Experiments are in progress to evaluate system operation at conditions which simulate prelaunch and flight. The prototype system consists of a network using 16 sensors within a testbed which simulates engine components. Sensor response, orientation, and data analysis algorithms are being evaluated using calibrated leaks produced within the testbed. A prototype flight system is also under development consisting of 8 sensors and flight capable electronics with autonomous control and data recording.

Makel, D. B.↗

NASA NTRS2001

Space flight affects magnocellular supraoptic neurons of young prepuberal rats: transient and permanent effects

Effects of microgravity on postural control and volume of extracellular fluids as well as stress associated with space flight may affect the function of hypothalamic neurosecretory neurons. Since environmental modifications in young animals may result in permanent alterations in neuroendocrine function, the present study was designed to determine the effect of a space flight on oxytocinergic and vasopressinergic magnocellular hypothalamic neurons of prepuberal rats. Fifteen-day-old Sprague-Dawley female rats were flown aboard the Space Shuttle Columbia (STS-90, Neurolab mission, experiment 150) for 16 days. Age-matched litters remained on the ground in cages similar to those of the flight animals. Six animals from each group were killed on the day of landing and eight animals from each group were maintained under standard vivarium conditions and killed 18 weeks after landing. Several signs of enhanced transcriptional and biosynthetic activity were observed in magnocellular supraoptic neurons of flight animals on the day of landing compared to control animals. These include increased c-Fos expression, larger nucleoli and cytoplasm, and higher volume occupied in the neuronal perikaryon by mitochondriae, endoplasmic reticulum, Golgi apparatus, lysosomes and cytoplasmic inclusions known as nematosomes. In contrast, the volume occupied by neurosecretory vesicles in the supraoptic neuronal perikarya was significantly decreased in flight rats. This decrease was associated with a significant decrease in oxytocin and vasopressin immunoreactive levels, suggestive of an increased hormonal release. Vasopressin levels, cytoplasmic volume and c-Fos expression returned to control levels by 18 weeks after landing. These reversible effects were probably associated to osmotic stimuli resulting from modifications in the volume and distribution of extracellular fluids and plasma during flight and landing. However, oxytocin levels were still reduced at 18 weeks after landing in flight animals compared to controls. This indicates that space flight during prepuberal age may induce irreversible modifications in the regulation of oxytocinergic neurons, which in turn may result in permanent endocrine and behavioral impairments.

NASA Experiment Number 9301150↗

NASA NTRS1982

Science and technology results from the OSS-1 Payload on the Space Shuttle

The OSS-1 Payload of nine experiments was carried on the STS-3 Space Shuttle flight in March of 1982. The OSS-1 Payload contained four instruments that evaluated specific aspects of the Orbiter's environment, including the levels of particulate, gaseous and electromagnetic emissions given off by the Orbiter, and the interactions between the Orbiter and the surrounding plasma. In addition to these environmental observations, these instruments performed scientific investigations in astronomy and in space plasma physics, including active experiments in electron beam propagation. Other experiments were in the areas of solar physics, plant growth, micrometeorite studies and the technology of actively controlled heat pipes. A description is given of the initial results from these experiments, with some implications of these results for future operation of space experiments from the Shuttle payload bay. One major result was the unexpected discovery of a faint surface-induced optical glow created near the Shuttle surfaces by impacts of ambient atmospheric atoms and molecules.

Chipman, E.↗