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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 361 records · Page 20
All sourcesNASA NTRSDOE OSTI
NASA NTRS1979

Ion propulsion cost effectivity

Ion propulsion modules employing 8 cm thrusters and 30 cm thrusters were studied for Multimission Modular Spacecraft (MMS) applications. Recurring and non-recurring cost elements were generated for these modules. As a result, ion propulsion cost drivers were identified to be Shuttle charges, solar array, power processing, and thruster costs. Cost effective design approaches included short length module configurations, array power sharing, operation at reduced thruster input power (reduced solar array size), simplified power processing units, and power processor output switching.

Zafran, S.↗
NASA NTRS1980

An overview of the solar maximum mission

The Solar Maximum Mission (SMM), devoted to the study of active solar phenomena is expected to be launched in February 1980 and operate throughout the peak of the current maximum of solar activity. The SMM observatory consists of two main sections: the instrument module which houses the solar payload instruments and the Fine Pointing Sun Sensor System, and the Multimission Modular Spacecraft (MMS) which carries the spacecraft subsystem modules. The entire observatory is 4m long and 2.3m in diameter. The SMM will carry a payload of six instruments specifically selected to study the short wavelength and coronal manifestations of flares. These include: gamma ray spectrometer, hard X-ray burst spectrometer, hard-X-ray imaging spectrometer, soft X-ray polychromator, UV spectrometer and polarimeter, coronagraph/polarimeter and solar constant monitoring package which will measure the total solar irradiance to an accuracy of 0.1 percent. Specific scientific objectives will include: chromospheric evaporation, thermalization, electron acceleration and flare build-up. Complementary studies will be made as part of an SMM Guest Investigator Program. The SMM observation program will be operated on a 24 hour cycle.

Chipman, E. C.↗
NASA NTRS1979

Predictions of induced background radiations at gamma/X-ray experiment envelopes in NASA spacecraft

This work seeks to predict secondary radiation levels induced in spacecraft structures by space protons. The radiations analyzed are secondary neutrons from spallation and evaporation reactions and gamma and beta rays from the decay of induced radioactivity, as sources of interfering background to spaceborne measurements of galactic and planetary gamma rays below 10 MeV. The spacecraft considered are the Multi-Mission Spacecraft (MMS) and the Space Shuttle, modeled as spherical shells. The proton environment is that of the South Atlantic Anomaly, as well as cosmic ray protons. The induced radioactivity is analyzed in terms of its interference with various gamma-ray lines of astrophysical interest, as well as its contribution to several spectral regions of the gamma-ray continuum. The buildup of the line and continuum radioactivity background is predicted for a period of nearly 9 months in orbit (approximately 4100 orbits). In addition, background contributions from cosmic ray electron bremsstrahlung and earth gamma-ray albedo are estimated.

Fischbein, W. L.↗
NASA NTRS1980

Initial guidelines and estimates for a power system with inertial (flywheel) energy storage

The starting point for the assessment of a spacecraft power system utilizing inertial (flywheel) energy storage. Both general and specific guidelines are defined for the assessment of a modular flywheel system, operationally similar to but with significantly greater capability than the multimission modular spacecraft (MMS) power system. Goals for the flywheel system are defined in terms of efficiently train estimates and mass estimates for the system components. The inertial storage power system uses a 5 kw-hr flywheel storage component at 50 percent depth of discharge (DOD). It is capable of supporting an average load of 3 kw, including a peak load of 7.5 kw for 10 percent of the duty cycle, in low earth orbit operation. The specific power goal for the system is 10 w/kg, consisting of a 56w/kg (end of life) solar array, a 21.7 w-hr/kg (at 50 percent DOD) flywheel, and 43 w/kg power processing (conditioning, control and distribution).

Slifer, L. W., Jr.↗
NASA NTRS1981

The origin of the Crab Nebula and the electron capture supernova in 8-10 M solar mass stars

The chemical composition of the Crab Nebula is compared with several presupernova models. The small carbon and oxygen abundances in the helium-rich nebula are consistent with only the presupernova model of the star whose main sequence mass was MMS approximately 8-9.5 M. More massive stars contain too much carbon in the helium layer and smaller mass stars do not leave neutron stars. The progenitor star of the Crab Nebula lost appreciable part of the hydrogen-rich envelope before the hydrogen-rich and helium layers were mixed by convection. Finally it exploded as the electron capture supernova; the O+Ne+Mg core collapsed to form a neutron star and only the extended helium-rich envelope was ejected by the weak shock wave.

Nomoto, K.↗
NASA NTRS1980

Multimission Modular Spacecraft Ground Support Software System (MMS/GSSS) state-of-the-art computer systems/ compatibility study

The compatibility of the Multimission Modular Spacecraft (MMS) Ground Support Software System (GSSS), currently operational on a ModComp IV/35, with the VAX 11/780 system is discussed. The compatibility is examined in various key areas of the GSSS through the results of in depth testing performed on the VAX 11/780 and ModComp IV/35 systems. The compatibility of the GSSS with the ModComp CLASSIC is presented based upon projections from ModComp supplied literature.

Source record↗
NASA NTRS1982

Economic and technical aspects of repair, servicing, and retrieval of low earth orbit free flying spacecraft

The economic and technical aspects of the Solar Maximum Observatory Repair Mission at NASA are presented, in an effort to demonstrate the Space Shuttle capability to rendezvous with and repair on-orbit the Solar Maximum Observatory (SMM). A failure in the Attitude Control Subsystem (ACS) after 10 months of operation caused a loss in precision pointing capability. The Multimission Modular Spacecraft (MMS) used for the mission, was designed with on-orbit repairability, and to correct various instrument anomalies, repiar kits such as an electronics box, a thermal aperture closure, and a high energy particle reflection baffle will be used. In addition, a flight support system will be used to berth, electrically safe, and support all the repair activities. A two year effort is foreseen, and the economic return on SMM will be $176 M, in addition to two to three years of solar observation. The mission will eventually conduct studies on flare as a function of solar cycle.

Cepollina, F. J.↗
NASA NTRS1982

Space Shuttle payloads - An overview

A review is made of historical developments of NASA-launched payloads as a basis for projecting payload operations configured to fit the Shuttle's capabilities, and the impetus for new spacecraft and applications designs is discussed. Payloads have experienced a growth in size and weight, capacity and lifetime, and have increasingly featured more automation, microminiaturized circuitry, and data processing systems. Launches by the DoD and NASA have averaged about 20/yr. Spacecraft specifically configured for Shuttle launch have had to wait due to development schedule delays. Partial compensation has occurred by the use of the MMS, which fits into both the Delta nose cone and the Orbiter bay. The Landsat-4 and SMM are cited as examples. Successful demonstration of in-orbit servicing of satellites is required in order to attract spacecraft designers who will make full use of the Shuttle's capabilities. Finally, increased standardization of spacecraft shape, interfaces, and components is foreseeen.

Edgecombe, D. S.↗
NASA NTRS1984

Integrated cockpit design for the Army helicopter improvement program

The main Army Helicopter Improvement Program (AHIP) mission is to navigate precisely, locate targets accurately, communicate their position to other battlefield elements, and to designate them for laser guided weapons. The onboard navigation and mast-mounted sight (MMS) avionics enable accurate tracking of current aircraft position and subsequent target location. The AHIP crewstation development was based on extensive mission/task analysis, function allocation, total system design, and test and verification. The avionics requirements to meet the mission was limited by the existing aircraft structural and performance characteristics and resultant space, weight, and power restrictions. These limitations and night operations requirement led to the use of night vision goggles. The combination of these requirements and limitations dictated an integrated control/display approach using multifunction displays and controls.

Drennen, T.↗
NASA NTRS1985

Timber Resources Inventory and Monitoring Joint Research Project

Primary objectives were to develop remote sensing analysis techniques for extracting forest related information from LANDSAT Multispectral Scanner (MMS) and Thematic Mapper data and to determine the extent to which International Paper Company information needs can be addressed with remote sensing information. The company actively manages 8.4 million acres of forest land. Traditionally, their forest inventories, updated on a three year cycle, are conducted through field surveys and aerial photography. The results reside in a digital forest data base containing 240 descriptive parameteres for individual forest stands. The information in the data base is used to develop seasonal and long range management strategies. Forest stand condition assessements (species composition, age, and density stratification) and identification of silvicultural activities (site preparation, planting, thinning, and harvest) are addressed.

Hill, C. L.↗
NASA NTRS1985

The upper atmosphere research satellite

The Upper Atmosphere Research Satellite (UARS) will provide, for the first time, data on a global basis for the study of the physical processes acting witin and upon the stratosphere, mesosphere, and lower thermosphere. Specifically, the areas of scientifc study to be addressed are energy input and loss, photochemistry, dynamics, and the coupling among processes and between atmospheric regions. The UARS is a single observatory consisting of a multimission modular spacecraft (MMS) and an instrument module containing 10 scientific instruments. The satellite will be Shuttle launched and placed in a 57 deg inclined orbit at 600 km altitude. A Central Data Handling Facility (CDHF) will receive data from the satellite and process these data into atmospheric quantities for use by the science team. The 'processed' data will be stored at the CDHF and will be available via communication lines for analysis by the investigators at their home laboratories using remote computers. Together with other satellite programs, balloons, sounding rockets, and laboratory efforts, UARS will make available the opportunity for extensive coordination of data devoted to solar terrestrial study.

Burr, P. T.↗
NASA NTRS1986

Toxicological safeguards in the manned Mars missions

Safeguards against toxic chemical exposures during manned Mars missions (MMMs) will be important for the maintenance of crew health and the accomplishment of mission objectives. Potential sources include offgassing, thermodegradation or combustion of materials, metabolic products of crew members, and escape of chemical from containment. Spacecraft maximum allowable concentration (SMAC) limits will have to be established for potential contaminants during the MMMs. The following factors will be used in establishing these limits: duration of mission, simultaneous exposure to other contaminants, deconditioning of crew members after long periods of reduced gravity, and simultaneous exposure to ionizing radiation. Atmospheric contaminant levels in all compartments of the transit spacecraft and Manned Mars Station (MMS) will be monitored at frequent intervals with a real time analyzer. This analyzer will be highly automated, requiring minimal crew time and expertise. The atmospheric analyzer will find other usages during the MMMs such as analyzing Martian atmospheres and soils, exhaled breath and body fluids of crew members, and reaction products in chemical processing facilities.

Coleman, Martin E.↗
NASA NTRS1986

Influence of the Yukon River on the Bering Sea

The purpose is to use satellite data to study relationships between discharge of the Yukon River to currents and biologic productivity in the northern Bering Sea. Amended specific objectives are: to develop thermal, sediment and chlorophyll surface maps using thematic mapping (TM) data of the discharge of the Yukon River and the Alaska Coastal Current during the ice free season; to develop a historical model of the distribution of the Yukon River discharge and the Alaska Coastal Current using LANDSAT multispectral scanner (MMS) and NOAA satellite imagery; and to use high resolution TM data to define the surface dynamics of the front between the Alaska Coastal Current and the Bering Shelf/Anadyr Current. LANDSAT MSS and TM, and Advanced Very High Resolution Radiometer (AVHRR) data were recorded during the 1985 ice-free period. The satellite data coincided with shipboard measurements acquired by Inner Self Transfer and Recycling scientists. Circumstances were such, that on July 5 and July 22, all three sensors recorded data that has been registered to a common map projection and map base, then contrast stretched, color composited, and density sliced.

Dean, K.↗
NASA NTRS1987

Servicer system demonstration plan and capability development

An orbital maneuvering vehicle (OMV) front end kit is defined which is capable of performing in-situ fluid resupply and modular maintenance of free flying spacecraft based on the integrated orbital servicing system (IOSS) concept. The compatibility of the IOSS to perform gas and fluid umbilical connect and disconnect functions utilizing connect systems currently available or in development is addressed. A series of tasks involving on-orbit servicing and the engineering test unit (ETU) of the on-orbit service were studied. The objective is the advancement of orbital servicing by expanding the Spacecraft Servicing Demonstration Plan (SSDP) to include detail demonstration planning using the Multimission Modular Spacecraft (MMS) and upgrading the ETU control.

Source record↗
NASA NTRS1989

Improving the on-board computing capability of the NASA Multimission Modular Spacecraft

This paper presents the development of onboard computing improvements for NASA's Multimission Modular Spacecraft. The first MMS spacecraft being enhanced by an additional flight computer is the Explorer Platform. The selection process for both the flight hardware (MIL-STD-1750A Co-Processor) and flight software (Ada high level language) are discussed, followed by the lessons learned during the last three years.

Scott, Barbara↗
NASA NTRS1991

Horizontal wind fluctuations in the stratosphere during large-scale cyclogenesis

The meteorological measurement system (MMS) on the U-2 aircraft measured pressure, temperature, and the horizontal wind during a cyclogenesis event over western United States on April 20, 1984. The mean horizontal wind in the stratosphere decreases monotonically with altitude. Superimposed on the mean stratospheric wind is a perturbation wind vector, which is an elliptically polarized wave with an amplitude of 4 to 10 m/s and a vertical wavelength of 2 to 3 km. The perturbation wind vector rotates anticyclonically (clockwise) with altitude and produces alternating advection in the plane of the aircraft flight path. This differential advection folds surfaces of constant tracer mixing ratio and contributes to the observed tracer laminar structures and inferred cross-jet transport.

Chan, K. R.↗
NASA NTRS1990

The ER-2 meteorological measurement system

The objectives of ER-2 Meteorological Measurement System (MMS) are: (1) to measure the meteorological parameters (pressure, temperature, and the three dimensional wind vector) accurately; (2) to provide high resolution data on atmospheric state variables and aircraft flight track to ER-2 investigators on a timely basis; and (3) to conduct collaborative research in atmospheric dynamics and chemistry. A summary of progress and results are presented.

Chan, K. Roland↗
NASA NTRS1990

Data analysis and archival

The purpose of this task is the acquisition, distribution, archival, and analysis of data collected during and in support of the Upper Atmospheric Research Program (UARP) field experiments. Meteorological and U2 data from the 1984 Stratosphere-Troposphere Exchange Project (STEP) was analyzed to determine characteristics of internal atmospheric waves. CDROM's containing data from the 1987 STEP, 1987 Airborne Antarctic Ozone Expedition (AAOE), and the 1989 Airborne Arctic Stratospheric Expedition (AASE) were produced for archival and distribution of those data sets. The AASE CDROM contains preliminary data and a final release is planned for February 1990. Comparisons of data from the NASA ER-2 Meteorological Measurement System (MMS) with radar tracking and radiosonde data show good agreement. Planning for a Meteorological Support Facility continues. We are investigating existing and proposed hardware and software to receive, manipulate, and display satellite imagery and standard meteorological analyses, forecasts, and radiosonde data.

Danielsen, Edwin F.↗