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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 NTRS1993

Radioastron flight operations

Radioastron is a space-based very-long-baseline interferometry (VLBI) mission to be operational in the mid-90's. The spacecraft and space radio telescope (SRT) will be designed, manufactured, and launched by the Russians. The United States is constructing a DSN subnet to be used in conjunction with a Russian subnet for Radioastron SRT science data acquisition, phase link, and spacecraft and science payload health monitoring. Command and control will be performed from a Russian tracking facility. In addition to the flight element, the network of ground radio telescopes which will be performing co-observations with the space telescope are essential to the mission. Observatories in 39 locations around the world are expected to participate in the mission. Some aspects of the mission that have helped shaped the flight operations concept are: separate radio channels will be provided for spacecraft operations and for phase link and science data acquisition; 80-90 percent of the spacecraft operational time will be spent in an autonomous mode; and, mission scheduling must take into account not only spacecraft and science payload constraints, but tracking station and ground observatory availability as well. This paper will describe the flight operations system design for translating the Radioastron science program into spacecraft executed events. Planning for in-orbit checkout and contingency response will also be discussed.

Altunin, V. I.↗
NASA NTRS1993

EOS ground data systems: A description and interface overview

The Earth Observing System (EOS) is planned as a space-based measurement system, earth-science research program, and data and information system (EOSDIS). It will consist of several high data rate spacecraft with multiple earth sensing instruments which provide investigators with a thorough, longterm view of the earth's environment. Up to seven spacecraft may be supported at once, either in operational, checkout, or testing phases; and the average data rate from the EOS satellites in orbit at any one time is expected to be from 18 to 60 Mbps. Providing the data processing and flight operations support for EOS will be the EOSDIS Core System (ECS). The ECS will command and control the spacecraft; process and store the EOS data; provide access to the data for years; and support researchers. The data processing aspects of the ECS consist of a collection of Distributed Active Archive Centers (DAAC's) which perform the product generation, data archive and distribution, and information management services. Flight operations aspects will be provided by the EOS Operations Center, by instrument control centers, and by widely distributed instrument support terminals. The communications and system management aspects will be provided by the EOSDIS Science Network and the System Management Center. In addition to the EOS satellite data, other data sets from earlier earth science missions are also to be added to designated DAAC's. Other ground data systems which will provide support to EOS for acquiring, transporting, processing, and distributing the transformed spacecraft data are currently being defined or are being upgraded for the EOS era. These systems include the Space Network consisting of the Tracking and Data Relay Satellite System (TDRSS), the TDRSS Ground Terminals, and the Network Control Center as well as the night Dynamics Facility, the EOS Data and Operations System, and EOS Communications. This paper briefly describes data handling by the ECS, the support data systems, their interfaces, and their roles.

Smith, Gene↗
NASA NTRS1993

Modeling of PCG fluid dynamics: Salient results

Materials processing in space-based laboratories has already yielded higher quality crystals during previous space flights, and opportunities for several fluids experiments are anticipated during the extended duration missions planned for the future. Crystal growth in space benefits not only from its reduced gravity environment but also from the absence of the hydrostatic pressure which assists certain crystal growth and refinement methods. Gravity-driven phenomena are thus reduced in strength, and a purely diffusive fluid's behavior can be attained. In addition, past materials science experiments have shown that microgravity can also help produce larger crystals. While gravity-related effects are definitely curtailed in space, they are nevertheless present to some degree due to the acceleration environment onboard the spacecraft. This residual acceleration level is comprised of quasi-steady, oscillatory, and transient components, and is caused by a variety of mechanisms. For example, gravity gradient forces produce low frequency disturbances, and the operation of machinery, control thrusters, solar panels, human activity, etc. contribute to higher frequency accelerations. These disturbances are collectively referred to as g-jitter, and they can be deleterious to certain experiments where the minimization of the acceleration level is important. Advanced vibration isolation techniques can be utilized to actively filter out some of the detrimental frequencies and help in obtaining optimum results. However, the successful application of this technology requires the detailed analysis of candidate fluids experiments to gauge their response to g-jitter and to determine their acceleration sensitivities. Several crystal growth experiments in the Protein Crystal Growth (PCG) area, besides others, are expected to be carried out on future shuttle flights and on Space Station Freedom. The need for vibration isolation systems or components for microgravity science experiments can be expected to grow as experiments and available hardware becomes more complex. This technology will also find increased application as the science community develops an awareness of their specific needs relative to the environment available in manned space missions. Vibration isolation research strives to develop a microgravity environment requirement that defines tolerance limits on the allowable g-level, and provides the required technology to achieve it. This effort will assist in establishing the tolerable acceleration levels for specific fluids experiments. The primary effort is directed towards modeling PCG and the approach undertaken for this investigation is outlined. The objectives of this research are: (1) to computationally determine vibration sensitivity of protein crystal growth experiments; (2) determine if these experiments can benefit from vibration isolation techniques; and (3) provide realistic requirements for vibration isolation technology.

Ramachandran, N.↗
NASA NTRS1993

Investigating pyrolysis/incineration as a method of resource recovery from solid waste

Pyrolysis/incineration (P/I) is a physicochemical method for the generation of recoverable resources from solid waste materials such as inedible plant biomass (IPB), paper, plastics, cardboard, etc. P/I permits the collection of numerous gases with a minimal amount of solid residue. Pyrolysis, also known as starved air incineration, is usually conducted at relatively high temperatures (greater than 500 deg C) in the absence of oxygen. Incineration is conducted at lower temperatures in the presence of oxygen. The primary purpose of this study was to design, construct, and test a model P/I. The system design includes safety requirements for temperature and pressure. The objectives of this study were: (1) to design and construct a P/I system for incorporation with the Hybrid Regenerative Water Recovery System; (2) to initiate testing of the P/I system; (3) to collect and analyze P/I system data; (4) to consider test variables; and (5) to determine the feasibility of P/I as an effective method of resource recovery. A P/I system for the recovery of reuseable resources from solid waste materials was designed, constructed, and tested. Since a large amount of inedible plant biomass (IPB) will be generated in a space-based habitat on the lunar surface and Mars, IPB was the primary waste material tested in the system. Analysis of the effluent gases was performed to determine which gases could be used in a life support system.

Robertson, Bobby J.↗
NASA NTRS1993

Reducing the cognitive workload - Trouble managing power systems

The complexity of space-based systems makes monitoring them and diagnosing their faults taxing for human beings. When a problem arises, immediate attention and quick resolution is mandatory. To aid humans in these endeavors we have developed an automated advisory system. Our advisory expert system, Trouble, incorporates the knowledge of the power system designers for Space Station Freedom. Trouble is designed to be a ground-based advisor for the mission controllers in the Control Center Complex at Johnson Space Center (JSC). It has been developed at NASA Lewis Research Center (LeRC) and tested in conjunction with prototype flight hardware contained in the Power Management and Distribution testbed and the Engineering Support Center, ESC, at LeRC. Our work will culminate with the adoption of these techniques by the mission controllers at JSC. This paper elucidates how we have captured power system failure knowledge, how we have built and tested our expert system, and what we believe its potential uses are.

Manner, David B.↗
NASA NTRS1991

Implementation issues for a compact 6 degree of freedom force reflecting handcontroller with cueing of modes

Teleoperated control requires a master human interface device that can provide haptic input and output which reflect the responses of a slave robotic system. The effort reported in this paper addresses the design and prototyping of a six degree-of-freedom (DOF) Cartesian coordinate hand controller for this purpose. The device design recommended is an XYZ stage attached to a three-roll wrist which positions a flight-type handgrip. Six degrees of freedom are transduced and control brushless DC motor servo electronics similar in design to those used in computer controlled robotic manipulators. This general approach supports scaled force, velocity, and position feedback to aid an operator in achieving telepresence. The generality of the device and control system characteristics allow the use of inverse dynamics robotic control methodology to project slave robot system forces and inertias to the operator (in scaled form) and at the same time to reduce the apparent inertia of the robotic handcontroller itself. The current control design, which is not multiple fault tolerant, can be extended to make flight control or space use possible. The proposed handcontroller will have advantages in space-based applications where an operator must control several robot arms in a simultaneous and coordinated fashion. It will also have applications in intravehicular activities (within the Space Station) such as microgravity experiments in metallurgy and biological experiments that require isolation from the astronauts' environment. For ground applications, the handcontroller will be useful in underwater activities where the generality of the proposed handcontroller becomes an asset for operation of many different manipulator types. Also applications will emerge in the Military, Construction, and Maintenance/Manufacturing areas including ordnance handling, mine removal, NBC (Nuclear, Chemical, Biological) operations, control of vehicles, and operating strength and agility enhanced machines. Future avionics applications including advanced helicopter and aircraft control may also become important.

Jacobus, Heidi↗
NASA NTRS1993

Asteroseismology of planetary nebula nuclei

Nine planetary nebula nuclei (PNNS) are now known to be pulsating variables. All of them are O VI or PG 1159-type objects, with extreme hydrogen deficiency and high abundances of C and O. They are non-radial pulsators, with typical periods of 10 to 30 min, and their probable descendants are the shorter-period GW Vir (PG 1159-035) pulsating white dwarfs whose PNe have presumably dispersed. The pulsating PNNs are promising candidates for asteroseismological study, although there are already indications that such analyses will be complicated by highly variable power spectra. We present preliminary results from two campaigns of global photometry on the pulsating nuclei of NGC 1501 and Sanduleak 3, and from ground- and space-based searches for radial-mode pulsations in PNNs and white dwarfs.

Bond, Howard E.↗
NASA NTRS1993

Education, training, and human engineering in aerospace; SAE Aerotech '93, Costa Mesa, CA, Sep. 27-30, 1993

Advances in simulation technology are discussed by a number of government and industry experts, for both training and research and development applications. Advanced techniques, such as helmet-mounted information displays, neurocontrollers, automated training systems, and simulation for space-based systems are included. Advances in training methodology for air transportation are covered by a group of experts in that field, including discussions of advanced flight deck transition training, new training tools, and effective low cost alternatives for part-task training. With the ever-increasing emphasis on human factors in cockpit and cabin design, the section on research, advances, and certification criteria in that field is pertinent. NASA, aircraft manufacturing, and FAA representatives have compiled an informative group of presentations concerning active topics and considerations in human factors design.

Shapiro, Diane C.↗
NASA NTRS1992

The EOS Data and Information System (EOSDIS)

The Earth Observing System (EOS) is the centerpiece of NASA's Mission to Planet Earth initiative. It is a pivotal part of the U.S. Global Change Research Program and hence of the international effort to understand global change and the increasing demands of human activity. EOS consists of a space-based observing system, a Data and Information System (EOSDIS) and a scientific research program. The space component consists of two series of polar-orbiting spacecraft, the first scheduled for launch in 1998, that will collect data for 15 years. EOS is completing its conceptual design phase and is preparing to enter the design phase with the selection and construction of the instruments for the first platform. EOSDIS will allow researchers to quickly and easily access data about the Earth system. Development of EOSDIS has already begun; it will support research and analysis with existing data. Geophysical and biological products will be created from the satellite data to be used to a broad range of the scientific community. NASA has also committed to providing smaller missions - called Earth Probes - dedicated to near-term observations of specific Earth processes. The scientific research program was initiated in 1990, with funding for 28 interdisciplinary teams, to begin development of models that will use EOS data and define the data requirements from the instruments, nine facility instruments and their science teams, 23 instrument investigations and definition studies for a synthetic-aperture radar.

Dozier, J.↗
NASA NTRS1993

Vehicle health management for guidance, navigation and control systems

The objective of the program was to architect a vehicle health management (VHM) system for space systems avionics that assures system readiness for launch vehicles and for space-based dormant vehicles. The platforms which were studied and considered for application of VHM for guidance, navigation and control (GN&C) included the Advanced Manned Launch System (AMLS), the Horizontal Landing-20/Personnel Launch System (HL-20/PLS), the Assured Crew Return Vehicle (ACRV) and the Extended Duration Orbiter (EDO). This set was selected because dormancy and/or availability requirements are driving the designs of these future systems.

Radke, Kathleen↗
NASA NTRS1993

JSC Director's Discretionary Fund 1992 Annual Report

Annual report of the Johnson Space Center Director's Discretionary Fund documenting effective use of resources. The $1,694,000 funding for FY92 was distributed among 27 projects. The projects are an overall aid to the NASA mission, as well as providing development opportunities for the science and engineering staff with eventual spinoff to commercial uses. Projects described include space-based medical research such as the use of stable isotopes of deuterium and oxygen to measure crew energy use and techniques for noninvasive motion sickness medication. Recycling essentials for space crew support is conducted in the Regenerative Life Support and the Hybrid Regenerative Water Recovery test beds. Two-phase fluid flow simulated under low-gravity conditions, hypervelocity particle impact on open mesh bumpers, and microcalorimetry to measure the long-term hydrazine/material compatibility were investigated. A patent application was made on a shape-memory-alloy release nut. Computer estimate of crew accommodations for advanced concepts was demonstrated. Training techniques were evaluated using multimedia and virtual environment. Upgrades of an electronic still camera provide high resolution images from orbit are presented.

Jenkins, Lyle↗
NASA NTRS1989

Super Smooth Optics for Extra-Solar Planet Detection

The goal of imaging planets around the nearby stars has important scientific significance but requires the use of advanced methods of controlling diffracted and scattered light. Over the last three years we have undertaken a study of coronagraphic methods of controlling diffracted light and of figuring hyper-contrast optics. Progress in these two general areas have led to a proposed space-based, 1.9 meter diameter coronagraphic telescope designed specifically for very high performance in the imaging of faint objects near bright sources. This instrument, called the Circumstellar Imaging Telescope (CIT), relies on a new high efficiency coronagraph design and the careful control of scattered light by extremely smooth optics. The high efficiency coronagraph uses focal plane apodization in order to concentrate diffracted light more efficiently in the pupil. This allows convenient removal of the diffracted light by masking off parts of the telescope pupil while not sacrificing the center of the field. Reductions of diffracted light by factors exceeding 1000 are not only possible but are required in order to detect extra-solar planets. Laboratory experiments with this new design have confirmed the theoretical diffraction reductions to the limits of the optics used (factors of about 300) . The extremely high efficiency of this coronagraph puts strong constraints on the narrow angle scattered light due to figure errors in the telescope mirror. Since planets orbiting nearby stars are expected at angular distances of about 1 arcsecond, it is in this small angular range in which scattering must be controlled. The figure errors responsible for scattering in this range come from mid-spatial frequencies corresponding to correlation lengths of about 10 cm on the primary mirror. A primary mirror about 15 times smoother than the Hubble Space Telescope mirror is required for the CIT. Laboratory experiments indicate that small test mirrors can be fabricated with existing technology which come within a factor of two of this requirement.

Terrile, Richard J.↗
NASA NTRS1989

Cryogenics for Space Observatories: Technology, Requirements, Issues

The ability to provide cooling at cryogenic temperatures is a critical enabling technology for many of the next generation of space-based observatories and instruments. This report discusses the state of cryogenics technology and identifies and categorizes the various methods of cooling.

Schember, Helene↗
NASA NTRS1986

FASAC Technical Assessment Report: Soviet Space Science Research

This report is the work of a panel of eight US scientists who surveyed and assessed Soviet research in the spare sciences. All of the panelists were very familiar with Soviet research through their knowledge of the published scientific literature and personal contacts with Soviet and other foreign colleagues. In addition, all of the panelists reviewed considerable additional open literature--scientific, and popular, including news releases. The specific disciplines of Soviet space science research examined in detail for the report were: solar-terrestrial research, lunar and planetary research, space astronomy and astrophysics, and, life sciences. The Soviet Union has in the past carried out an ambitious program in lunar exploration and, more recently, in studies of the inner planets, Mars and especially Venus. The Soviets have provided scientific data about the latter planet which has been crucial for studies of the planet's evolution. Future programs envision an encounter with Halley's Comet, in March 1986, and missions to Mars and asteroids. The Soviet programs in the life sciences and solar-terrestrial research have been long-lasting and systematically pursued. Much of the ground-based and space-based research in these two disciplines appears to be motivated by the requirement to establish long-term human habitation in near-Earth space. The Soviet contributions to new discoveries and understanding in observational space astronomy and astrophysics have been few. This is in significant contrast to the very excellent theoretical work contributed by Soviet scientists in this discipline.

Lanzerotti, L. J.↗
NASA NTRS1981

Yacht Race Monitoring

Observer Single-handed Transatlantic Race (OSTAR) participants were aided by a French-American space-based monitoring system which reported the yacht's positions throughout the race, and also served as an emergency locator service. Originating from NASA's Nimbus 6 Satellite, use of this system, called ARGOS made the OSTAR competition the most accurately reported sea race ever conducted. Each boat carried a portable transmitter allowing 88 new sources of oceanographic data available during the race.

Source record↗
NASA NTRS1988

Physical considerations relevant to HZE-particle transport in matter

High-energy, highly charged (HZE) heavy nuclei may seem at first sight to be an exotic type of radiation, only remotely connected with nuclear power generation. On closer examination it becomes evident that heavy-ion accelerators are being seriously considered for driving inertial confinement fusion reactors, and high-energy heavy nuclei in the cosmic radiation are likely to place significant constraints on satellite power system deployment and space-based power generation. The use of beams of heavy nuclei in an increasing number of current applications, as well as their importance for the development of the state of the art of the future, makes it necessary to develop at the same time a good understanding of their transport through matter.

NASA Program Biomedical Research↗
NASA NTRS1990

Binding of isolated plant lectin by rhizobia during episodes of reduced gravity obtained by parabolic flight

Development of a legume root nodule is a complex process culminating in a plant/bacterial symbiosis possessing the capacity for biological dinitrogen fixation. Formation of root nodules is initiated by the binding and stabilization of rhizobia to plant root hairs, mediated in part by a receptor/ligand recognition system composed of lectins on the plant root surface and lectin-binding sites on the rhizobial cell surface. The dinitrogen fixation activity of these root nodules may be an important feature of enclosed, space-based life support systems, and may provide an ecological method to recycle nitrogen for amino acid production. However, the effects on nodule development of varied gravitational fields, or of root nutrient delivery hardware, remain unknown. We have investigated the effects of microgravity on root nodule formation, with preliminary experiments focused upon the receptor/ligand component. Microgravity, obtained during parabolic flight aboard NASA 930, has no apparent effect on the binding of purified lectin to rhizobia, a result that will facilitate forthcoming experiments using intact root tissues.

manned↗
NASA NTRS1991

Waste treatment integration in space

The circumstances and criteria for space-based waste treatment bioregenerative life-support systems differ in many ways from those needed in terrestrial applications. In fact, the term "waste" may not even be appropriate in the context of nearly closed, cycling, ecosystems such as those under consideration. Because of these constraints there is a need for innovative approaches to the problem of "materials recycling". Hybrid physico-chemico-biological systems offer advantages over both strictly physico-chemico or biological approaches that would be beneficial to material recycling. To effectively emulate terrestrial cycling, the use of various microbial consortia ("assemblies of interdependent microbes") should be seriously considered for the biological components of such systems. This paper will examine the use of consortia in the context of a hybrid-system for materials recycling in space.

Waste Management/methods↗