SEARCH · Search NASA

Results for “Deployable radiator”

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.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 199 records · Page 11

All sources NASA NTRS DOE OSTI

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 NTRS1977

Atmospheric braking to circularize an elliptical Venus orbit

The use of atmospheric drag to circularize an elliptical spacecraft orbit at Venus is analyzed parametrically for the Venus Orbital Imaging Radar Mission (VOIR) in 1983. Navigation, maneuver, and guidance requirements are discussed for the decay of a 24-hr orbit to a close circular orbit in about 30-60 days. A prototype 'Aerobrake' is described which is approximately 5 m in diameter and 25 kg in mass and which replaces a chemical retroengine of about 1300 kg in mass (delta V = 2.5 km/s) by a 700 kg in-orbit mass. The aerobrake, a light deployable Inconel sheet, shields the spacecraft from the flow and radiates the aerodynamic heating.

Mcronald, A. D.↗

NASA NTRS1982

Polymer coating of glass microballoons levitated in a focused acoustic field

Inertial confinement fusion (ICF) glass microballoons (GMBs) levitated in a focusing radiator acoustic device can be coated with liquid materials by deploying the liquid into the levitation field with a stepped-horn atomizer. The GMB can be forced to the center of the coating liquid with a strong acoustically generated centering force. Water solutions of organic polymers, UV-curable liquid organic monomers, and paraffin waxes have been used to prepare solid coatings on the surface of GMBs using this technique.

Young, A. T.↗

NASA NTRS1984

Technology needs of advanced Earth observation spacecraft

Remote sensing missions were synthesized which could contribute significantly to the understanding of global environmental parameters. Instruments capable of sensing important land and sea parameters are combined with a large antenna designed to passively quantify surface emitted radiation at several wavelengths. A conceptual design for this large deployable antenna was developed. All subsystems required to make the antenna an autonomous spacecraft were conceptually designed. The entire package, including necessary orbit transfer propulsion, is folded to package within the Space Transportation System (STS) cargo bay. After separation, the antenna, its integral feed mast, radiometer receivers, power system, and other instruments are automatically deployed and transferred to the operational orbit. The design resulted in an antenna with a major antenna dimension of 120 meters, weighing 7650 kilograms, and operating at an altitude of 700 kilometers.

Herbert, J. J.↗

NASA NTRS1983

A concept for an advanced earth observation spacecraft

Remote sensing missions have been synthesized which could contribute significantly to the understanding of global environmental parameters. Instruments capable of sensing important land and sea parameters are combined with a large antenna designed to passively quantify surface emitted radiation at several wavelengths. A conceptual design for this large deployable antenna has been developed. All subsystems required to make the antenna an autonomous spacecraft have been conceptually designed. The entire package, including necessary orbit transfer propulsion, is folded to package within the Space Transportation System (STS) cargo bay. After separation the antenna, its integral feed mast, radiometer receivers, power system, and other instruments are automatically deployed and transferred to the operational orbit. The design resulted in an antenna with a major antenna dimension of 120 meters, weighting 7650 kilograms, and operating at an altitude of 700 kilometers.

Lovelace, U. M.↗

NASA NTRS1987

Development of a dome Fresnel lens/gallium arsenide photovoltaic concentrator for space applications

A novel photovoltaic concentrator system is currently being developed. Phase I of the program, completed in late 1986, produced a conceptual design for the concentrator system, including an array weight and performance estimates based on optical, electrical, and thermal analyses. Phase II of the program, just underway, concerns the fabrication and testing of prototype concentrator panels of the design. The concentrator system uses dome Fresnel lenses for optical concentration; gallium arsenide concentrator cells for power generation; prismatic cell covers to eliminate gridline obscuration losses; a backplane radiator for heat rejection; and a honeycomb structure for the deployable panel assembly. The conceptual design of the system, its anticipated performance, and its estimated weight are reported.

O'Neill, Mark J.↗

NASA NTRS2001

Raman Lidar Water Vapor Measurements at the DOE SGP CART Site

The NASA/GSFC Scanning Raman Lidar (SRL) was deployed to the Department of Energy's (DOE) Cloud and Radiation Testbed site in northern Oklahoma September - December, 2000 for two DOE sponsored field campaigns: 1) the Water Vapor Intensive Operations Experiment 2000 and 2) the Atmospheric Radiations Measurement First International Satellite Cloud Climatology Experiment Experiment (AFWEX). WvIOP2000 focussed on water vapor measurements in the lower troposphere while AFWEX focussed on upper tropospheric water vapor. For the first time ever, four water vapor lidars were operated simultaneously: one airborne and three ground-based systems. Intercomparisons of these measurements and others will be presented at the meeting.

Whiteman, David N.↗

NASA NTRS2006

Deployable antenna

A deployable antenna and method for using wherein the deployable antenna comprises a collapsible membrane having at least one radiating element for transmitting electromagnetic waves, receiving electromagnetic waves, or both.

Fink, Patrick W.↗

NASA NTRS2004

Strain-Gauge Measurement of Weight of Fluid in a Tank

A method of determining the amount of fluid in a tank is based on measurement of strains induced in tank supports by the weight of the fluid. Unlike most prior methods, this method is nonintrusive: there is no need to insert instrumentation in the tank and, hence, no need to run wires, cables, or tubes through the tank wall. Also unlike most prior methods, this method is applicable even if the fluid in the tank is at supercritical pressure and temperature, because it does not depend on the presence of a liquid/gas interface (as in liquid-level-measuring methods). The strain gauges used in this method may be of two types: foil and fiber-optic. Four foil gauges (full bridge) are mounted on each of the tank-supporting legs. As the tank is filled or emptied, the deformation in each leg increases or decreases, respectively. Measured deformations of all legs are added to obtain a composite deformation indicative of the change in weight of the tank plus fluid. An initial calibration is performed by recording data at two points (usually, empty and full) for which the mass or weight of fluid is known. It is assumed that the deformations are elastic, so that the line passing through the two points can be used as a calibration curve of mass (or weight) of fluid versus deformation. One or more fiber-optic gauges may be used instead of the foil gauges. The resolution of the fiber-optic and foil gauges is approximately the same, but the fiber-optic gauges are immune to EMI (electromagnetic interference), are linear with respect to temperature over their entire dynamic range (as defined by the behavior of the sample), and measure thermally induced deformations as predictable signals. Conversely, long term testing has demonstrated that the foil gauges exhibit an erratic behavior whenever subjected to direct sun radiation (even if protected with a rubberized cover). Henceforth, for deployment in outdoor conditions, fiber-optic gauges are the only option if one is to rely on the system for an extended period of time when a recalibration procedure may not be acceptable. A set of foil gauges had been tested on the supports of a 500-gallon (1,900-liter) tank. The gauges were found to be capable of measuring the deformations (up to 22 micro-strain) that occurred during filling and emptying of the tank. The fluid masses calculated from the gauge readings were found to be accurate within 4.5 percent. However, the reliability of the foil gauges over a few hours was not acceptable. Therefore, the foil sensor system is acceptable for use only in controlled environments (complete shade, or indoors).

Figueroa, Jorge↗

NASA NTRS2020

Optical Design of the Earth Surface Mineral Dust Source Investigation (EMIT) Imaging Spectrometer

The Earth Surface Mineral Dust Source Investigation (EMIT) instrument is a high fidelity imaging spectrometer developed to characterize surface mineralogy of the Earth’s dust source regions over the spectral range of 380- 2500 nm and spectral sampling of 7.4 nm. EMIT will close the current knowledge gap in dust source mineral composition by collecting over 1 billion high signal-to-noise ratio spectra in this region of our planet. These new measurements will be used in conjunction with state-of-the-art Earth System Models to understand and reduce the uncertainty in the radiative forcing effect of mineral dust aerosols. EMIT will be deployed on the International Space Station that has an orbit that is well suited for measuring the arid land regions of the Earth. The optical design utilizes a Dyson spectrometer to reduce volume and mass for a fast (F/1.8) and wide swath (1240 samples) optical system. An overview of the EMIT optical design, development, and current status are discussed.

Green, Robert O.↗

NASA NTRS1989

Coherent Cerenkov radiation from the Spacelab 2 electron beam

The plasma environment of the Spacelab 2 mission was investigated through the deployment of the Plasma Diagnostics Package (PDP) by the Space Shuttle Orbiter and the Orbiter's ejection of a continuous 1-keV/50-mA electron beam along a field line. As the PDP flew by the beam, its plasma-wave instrument detected intense whistler-mode radiation originating from the beam. A detailed model has been developed of the coherent Cerenkov emission process, using a one-dimensional computer simulation of the beam to model the expected phase space structure of the electrons. The power calculated for the modeled 200-m beam segment can easily account for the measured whistler mode wave power.

Farrell, W. M.↗

NASA NTRS1982

Large scale model measurements of airframe noise using cross-correlation techniques

Cross-correlation techniques are used to measure the sound radiated by wing/flap airfoil configurations in the NASA-Ames 40 x 80 ft wind tunnel using a 6.7-m semispan model with three deployed flaps. The dominant source of flap noise is identified as the flap side edges, which exceeds that radiated by the midspan region by more than 10 dB. The turbulent surface eddies at the flap side edge have scales on the order of one-half the flap chord. The installation of flap actuator fairings at the flap side edge reduces the noise radiated from that location by 10 to 15 dB. The cross-correlation technique extracts airframe noise radiated by specific surface locations from the tunnel background noise, even when the noise is 25 dB higher than the measured airframe noise level.

Miller, W. R.↗

NASA NTRS2005

Flexible Metal-Fabric Radiators

Flexible metal-fabric radiators have been considered as alternative means of dissipating excess heat from spacecraft and space suits. The radiators also may be useful in such special terrestrial applications as rejecting heat from space-suit-like protective suits worn in hot work environments. In addition to flexibility and consequent ease of deployment and installation on objects of varying sizes and shapes, the main advantages of these radiators over conventional rigid radiators are that they weigh less and occupy less volume for a given amount of cooling capacity. A radiator of this type includes conventional stainless-steel tubes carrying a coolant fluid. The main radiating component consists of a fabric of interwoven aluminum-foil strips bonded to the tubes by use of a proprietary process. The strip/tube bonds are strong and highly thermally conductive. Coolant is fed to and from the tubes via flexible stainless-steel manifolds designed to accommodate flexing of, and minimize bending forces on, the fabric. The manifolds are sized to minimize pressure drops and distribute the flow of coolant evenly to all the tubes. The tubes and manifolds are configured in two independent flow loops for operational flexibility and protective redundancy.

Cross, Cynthia↗

NASA NTRS2020

Current Active Detectors for Dosimetry and Spectrometry on the International Space Station

We present a high-level overview of two of the most important radiation detection systems currently flying aboard the International Space Station(ISS), ISS-RAD and Timepix. ISS-RAD is a single, large unit that is capable of detecting both chargedand neutral high-energy particles. For most of its first three and a half years of operations onboard Station, ISS-RAD has been periodically moved to different modules, includingtheUSLab, Columbus, JEM, Node2, and Node3. In contrast, the much smaller Timepix-based detectors are deployed in several locations around the station. The first generation of these units were known as REMs, or Radiation Environment Monitors. A second generation has recently been deployed, known as REM-2 units. We will briefly describe the technologies used in these systems and their capabilities.

Cary Zeitlin↗

NASA NTRSDate not supplied

Understanding the Impact of Long Duration Space Radiation on Biology and Nutrients in Food

No food or bioregenerative life support system (BLSS) is likely to be deployed on Mars prior to being fully vetted on lunar long duration missions. BLSS systems developed for lunar missions will trade well in terms of up mass and volume with prepackaged food for Mars missions, but only if they are reliable. There are significant differences in the gravitational and radiation environments between the moon and Mars, and one key challenging aspect for a BLSS on Mars missions is the extremely long durations. This results in the exposure of seeds, spores, or other dormant stages of organisms to both natural and radiation induced degradation over time frames of two or more years before they might be needed for growth. This can result in poor or no germination and sickly crops. A poorly functioning BLSS represents a threat to crew health. To ensure that a BLSS food production system will function well, we need to understand, at an early stage, the impact of these long missions on the biology. This is important to meet the Mars Exploration Program Analysis Group (MEPAG) goals.

C. D. Quincy↗

NASA NTRSDate not supplied

Multifaceted Considerations for Fission Surface Power Radiation Shielding Design

The purpose of the Fission Surface Power (FSP) nuclear system is to provide energy on the Moon and Mars for supporting their exploration and colonization. The FSP design and deployment can leverage the past research and development work in areas, such as reactor design, but such crucial components as radiation shielding and instrumentation still need material and manufacturing studies, modeling, and testing. The shielding components are needed for the protection of humans, electronics, and sensitive components. They are essential system components, but they are often the heaviest components of the system for which each kilogram matters. Different material combinations and layouts are possible. The studies presented were focused on the evaluation of several options. The initial analysis included their performance assessment, initial temperature distribution evaluation and manufacturability considerations. Several feasible shield design options were identified and discussed in this paper, as well.

Fission Surface Power↗

NASA NTRS1986

Radiation effects on high performance polymers

Polymer matrix materials are candidates for use in large space antennas and space platforms that may be deployed in geosynchronous orbit 22,500 miles above the Earth. A principal concern is the long term effects of an environment that is hostile to organic polymers, including high energy electromagnetic radiation, bombardment by charged particles, and large abrupt changes in temperature. Two polyarylene ethers which might be utilized as models for polymers in space applications were subjected to dosages of 70 keV electrons up to 3.4 x 10 to the 10th power rad. The irradiated films were then examined to determine the effects of the high-energy electrons.

Orwoll, R. A.↗

NASA NTRS1997

The Effects of Water Vapor and Clouds on the Spectral Distribution of Solar Radiation at the...

During the Subsonic Contrail and Cloud Effect Special Study (SUCCESS) a Solar Spectral Flux Radiometer was deployed at the surface in a zenith observing position. The instrument measured the solar spectral downwelling irradiance between 350 and 2500 nm with 10 nm resolution. From April 12 through April 29 approximately 18000 spectra were acquired, under a variety of meteorological conditions including cloud free, cirrus, Stearns, and cumulonimbus clouds. This study focuses on the effect of cirrus and cirrus contrails on the spectral distribution of solar irradiance at the surface and on inferring cirrus properties from their spectral transmittance. The observations have also proven to be useful for comparing the solar spectral irradiance measurements with model predictions, and in particular, for inferring the amount of solar radiation absorbed in the clear and cloudy atmosphere.

Pilewskie, P.↗