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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 811 records · Page 45
All sourcesNASA NTRSDOE OSTI
NASA NTRS1993

The extreme ultraviolet spectrograph: A radial groove grating, sounding rocket-borne, astronomical instrument

The design, calibration, and sounding rocket flight performance of a novel spectrograph suitable for moderate-resolution EUV spectroscopy are presented. The sounding rocket-borne instrument uses a radial groove grating to maintain a high system efficiency while controlling the aberrations induced when doing spectroscopy in a converging beam. The instrument has a resolution of approximately 2 A across the 200-330 A bandpass with an average effective area of 2 sq cm. The instrument, called the Extreme Ultraviolet Spectrograph, acquired the first EUV spectra in this wavelength region of the hot white dwarf G191-B2B and the late-type star Capella.

Wilkinson, Erik↗
NASA NTRS2026

Landsat Instrument Suite (LandIS) Sensor Design for the Landsat 10 Mission

Landsat 10 will be the upcoming mission in the 50+ year Landsat series of Earth observation platforms. The centerpiece of the observatory will be a super-spectral imager known as the Landsat Instrument Suite (LandIS). The sensor will feature 26 spectral channels from the visible through near-, short-wave, and thermal infrared wavelengths with spatial resolutions of 10, 20, and 60 meters on the ground, depending on the band. These enhancements over the legacy Landsat instruments will ensure data continuity with the existing archive and will expand upon the core Landsat capabilities to enable new applications in Earth science. After a competitive procurement, NASA selected the design submitted by the Raytheon Company for the LandIS instrument. The innovative Raytheon instrument concept utilizes an advanced whiskbroom architecture to fulfill the strict radiometric, spatial, and geometric image quality requirements demanded by the Landsat 10 mission and fits within restrictive mass, volume, and power constraints. The instrument will continue the Landsat directive to image all daylit land and near-shore water areas, along with select nighttime imaging. On-board calibration source data will ensure high radiometric and geometric accuracy and stability consistent with previous missions to enable continuity in data products available to users. This paper discusses the driving requirements for LandIS and provides a description of the chosen design and operations concept of the instrument.

Requirements↗
NASA NTRS1982

Mars Orbiter Study. Volume 1: Summary

Spacecraft system and subsystem designs were developed at the conceptual level to perform either of two Mars orbiter missions, a climatology mission and an aeronomy mission. The HS 376 spacecraft is the basis for the design because it has the lowest cost due to its production line status. The mission design, science instrument accommodation, and spacecraft design are summarized.

Drean, R.↗
NASA NTRSDate not supplied

A Simplified Model of VIPER Thermal Management System. Part I: Loop Heat Pipe

NASA’s Volatiles Investigating Polar Exploration Rover (VIPER) uses a combination of loop heat pipes (LHPs) and heaters as the primary hardware to modulate the temperature of the electronic boxes and payloads instruments. LHPs have been designed and instrumented to be capable of passive and active shutdown. The goal of the passive shutdown, using a thermal control valve (TCV) to limit the flow of the working fluid, is to preserve thermal energy and avoid unnecessary heat leaks during lunar night. The goal of the active shutdown on the other hand, is to forcefully increase the vehicle internal temperature to bakeout the payload instruments. Several numerical modeling tools are available to analyze LHP performance under the complex set of operational requirements and environments levied on the VIPER Thermal Management System (TMS). Yet, while those numerical modeling tools are capable of detailed performance analysis, they tend to take large computational resources and long computational time. In this paper, a model of a single LHP developed based on control volume approach is presented. By using the control volume approach, the complex geometry of the LHP, and the components attached to it, are reduced to thermal lump capacitances, thus reducing the computation effort. This paper also describes the effort to correlate the proposed LHP model using thermal vacuum (TVAC) test data.

Loop Heat Pipe↗
NASA NTRSDate not supplied

A Simplified Model of VIPER Thermal Management System. Part I: Loop Heat Pipe

NASA’s Volatiles Investigating Polar Exploration Rover (VIPER) uses a combination of loop heat pipes (LHPs) and heaters as the primary hardware to modulate the temperature of the electronic boxes and payloads instruments. LHPs have been designed and instrumented to be capable of passive and active shutdown. The goal of the passive shutdown, using a thermal control valve (TCV) to limit the flow of the working fluid, is to preserve thermal energy and avoid unnecessary heat leaks during lunar night. The goal of the active shutdown on the other hand, is to forcefully increase the vehicle internal temperature to bakeout the payload instruments. Several numerical modeling tools are available to analyze LHP performance under the complex set of operational requirements and environments levied on the VIPER Thermal Management System (TMS). Yet, while those numerical modeling tools are capable of detailed performance analysis, they tend to take large computational resources and long computational time. In this paper, a model of a single LHP developed based on control volume approach is presented. By using the control volume approach, the complex geometry of the LHP, and the components attached to it, are reduced to thermal lump capacitances, thus reducing the computation effort. This paper also describes the effort to correlate the proposed LHP model using thermal vacuum (TVAC) test data.

Loop Heat Pipe↗
NASA NTRS2011

Phaeton Mast Dynamics: On-Orbit Characterization of Deployable Masts

This presentation discusses the Phaeton Mast Dynamics (PMD) instrument architecture and design, including design constraints, design solutions, and instrument results. Since the design and build phases were completed with PMD as a NuSTAR payload, the presentation discusses NuSTAR's constraints and initial accommodations. The instrument results presented here are independent of the host mission, but the effects of a host mission's data handling design on PMD capabilities is discussed in 2011 IEEEAC Paper 1305.

Nuclear Spectroscopic Telescope Array (NuSTAR)↗
NASA NTRS1980

Space Telescope - A versatile new instrument

The design, in-orbit operation and projected performance of the Space Telescope are discussed. The telescope will be in a moderately low earth orbit and communicate with the earth through the Tracking and Data Relay Satellite and directly for a few minutes each orbit. The optical system contains a 2.4-m mirror in a standard Cassegrain configuration, with four axial instrument positions and one radial and a fine guidance sensor which will allow the maintenance of telescope pointing during an observation to seven thousandths of an arcsec. The satellite will be launched by the Space Shuttle, and is capable of being serviced in space or recaptured and brought back to earth for more extensive modifications. The telescope employs a fairly standard Ritchey-Chretian optical design with a primary field of view of 18 arcmin and good mirror reflection of wavelengths from 1100 A to 1 mm. Image quality will be very insensitive to wavelength, with image size on the order of 0.04 arcsec. Instruments to be carried on the first launch include a guidance system for astrometry, a wide-field and planetary camera, a faint object camera, a high resolution spectrograph, a faint object spectrograph and a high-speed photometer.

Roman, N.↗
NASA NTRS2004

Radiometric Performance Model for AVIRIS

This slide presentation reviews the radiometric performance model for Airborne Visible/Infrared Imaging Spectrometer (AVIRIS). This model allows for an estimation of the signal throughput and noise properties of AVIRIS for the components. This understanding can point to areas for improvements of the components.. The signal to noise ratio properties may be estimated. An accurate radiometric performance model is essential for the use of existing instruments and the design of new instruments. Included in the presentation is a design view and a picture of the AVIRIS instrument. There is discussion of the signal, the signal area solid angle product, aspects of area solid angle time, the idealized radiometer photon calculation and noise both instrument read and photon counting noise. Graphs of signal throughput efficiency, input radiance, photons at the detector, signal e-, noise e- and the signal to noise ratio are presented.

imaging spectroscopy↗
NASA NTRS2005

Characterization of Custom-Designed Charge-Coupled Devices for Applications to Gas and Aerosol Monitoring Sensorcraft Instrument

Custom-designed charge-coupled devices (CCD) for Gas and Aerosols Monitoring Sensorcraft instrument were developed. These custom-designed CCD devices are linear arrays with pixel format of 512x1 elements and pixel size of 10x200 sq m. These devices were characterized at NASA Langley Research Center to achieve a full well capacity as high as 6,000,000 e-. This met the aircraft flight mission requirements in terms of signal-to-noise performance and maximum dynamic range. Characterization and analysis of the electrical and optical properties of the CCDs were carried out at room temperature. This includes measurements of photon transfer curves, gain coefficient histograms, read noise, and spectral response. Test results obtained on these devices successfully demonstrated the objectives of the aircraft flight mission. In this paper, we describe the characterization results and also discuss their applications to future mission.

Refaat, Tamer F.↗
NASA NTRS1972

A pilot's opinion - VTOL control design requirements for the instrument approach task.

This paper presents pilot opinion supported by test data concerning flight control and display concepts and control system design requirements for VTOL aircraft in the instrument approach task. Material presented is drawn from research flights in the following aircraft: Dornier DO-31, Short SC-1, LTV XC-142A, and Boeing-Vertol CH-46. The control system concepts and mechanizations employed in the above aircraft are discussed, and the effect of control system augmentation is shown on performance. Operational procedures required in the instrument approach task are described, with comments on need for automation and combining of control functions.

Patton, J. M., Jr.↗
NASA NTRS2011

The Planned Soil Moisture Active Passive (SMAP) Mission L-Band Radar/Radiometer Instrument

The Soil Moisture Active/Passive (SMAP) mission is a NASA mission identified by the NRC 'decadal survey' to measure both soil moisture and freeze/thaw state from space. The mission will use both active radar and passive radiometer instruments at L-Band. In order to achieve a wide swath at sufficiently high resolution for both active and passive channels, an instrument architecture that uses a large rotating reflector is employed. The instrument system has completed the preliminary design review (PDR) stage, and detailed instrument design has begun. In addition to providing an overview of the instrument design, two recent design modifications are discussed: 1) The addition of active thermal control to the instrument spun side to provide a more stable, settable thermal environment for the radiometer electronics, and 2) A 'sequential transmit' strategy for the two radar polarization channels which allows a single high-power amplifier to be used.

radiometer↗
NASA NTRSDate not supplied

Optical Design of Multi-field Integral Field Unit Spectrograph for the ORCAS Keck Instrument Development II (ORKID II) Instrument

We have designed an Integral Field Unit Spectrometer for the ORCAS Keck Instrument Development II (ORKID II) Instrument. Building on the success of the ORKID instrument (which achieved 15.1 masec FWHM visible spectrum imaging), ORKID II will add Integral Field Spectroscopy to analyze Active Galactic Nuclei (AGN), Supernovae redshift and brightness, and other science observations. Several design options have been explored based on image slicers manufactured by the Canon Corporation’s machining process. Field layouts can include up to three disparate spatial sampling, with a lower limit of 6.7 masec. Spectral resolutions are considered from R 100 to R 10,000. The modular design of the concept allows for configuring the instrument for various observing campaigns.

Instrumentation and Photography↗
NASA NTRS1986

Shutter mechanism for calibration of the cryogenic diffused infrared background experiment (DIRBE) instrument

The design requirements, the design, the assembly and alignment, and the test program for a shutter mechanism which must operate at cryogenic temperature and draw less than 1.0 milliwatt are discussed. The design solution to meet these requirements is a device that positions a mirror with repeated accuracy, has no wearing surfaces, and operates at 2.0 K. The unique feature of this device is the simplicity of the mechanism, thus obtaining high reliability.

Tyler, Allen↗
NASA NTRS1986

Direct measurement of skin friction with a new instrument

The design and performance of a small belt-type skin-friction gage to measure wall shear-stress coefficients in wind-tunnel testing are described, summarizing the report of Vakili and Wu (1982). The sensor employs a flexible belt of variable surface characteristics; this belt, wrapped tightly around two cylinders mounted on frictionless flexures, is equipped with strain gages to estimate the deflection of the belt by the flow. An alternative approach uses IR illumination, optical fibers, and a photosensitive transistor, permitting direct measurement of the belt deflection. Drawings, diagrams, and graphs of sample data are provided.

Vakili, A. D.↗
NASA NTRS1987

A geostationary imaging spectrometer TOMS instrument

One design for a geostationary Total Ozone Mapping Spectrometer (TOMS) with many desirable features is an imaging spectrometer. A preliminary study makes use of a 0.25 m Czerny-Turner spectrometer with which the Earth is imaged on a charge-coupled device (CCD) in dispersed light. The wavelength is determined by a movable grating which can be set arbitrarily by ground control. The signal integration time depends on wavelength but this system allows arbitrary timing by command. Special circumstances such as a requirement to track a low-lying sulfur dioxide cloud or a need to discriminate high level ozone from total ozone at midlatitudes could be obtained by adding a particular wavelength to the normally pre-programmed time sequence. The incident solar irradiance is measured by deploying a diffuser plate in the field of view. Individual detector elements correspond to scene elements in which the several wavelengths are serially sampled and the Earth radiance is compared to the incident sunlight. Thus the problem of uncorrelated drift of multiple detectors is removed.

Krueger, Arlin J.↗
NASA NTRS1989

IR optical fiber-based noncontact pyrometer for drop tube instrumentation

The design of a two color pyrometer with infrared optical fiber bundles for collection of the infrared radiation is described. The pyrometer design is engineered to facilitate its use for measurement of the temperature of small, falling samples in a microgravity materials processing experiment using a 100 meter long drop tube. Because the samples are small and move rapidly through the field of view of the pyrometer, the optical power budget of the detection system is severly limited. Strategies for overcoming this limitation are discussed.

May, R. G.↗