SEARCH · Engineering Papers

Results for “thermal instruments”

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 469 records · Page 26

All sources NASA NTRS DOE OSTI

NASA NTRS1981

Feasibility study of the solar scientific instruments for Spacelab/Orbiter

The feasibility and economics of mounting and operating a set of solar scientific instruments in the backup Skylab Apollo Telescope Mount (ATM) hardware was evaluated. The instruments used as the study test payload and integrated into the ATM were: the Solar EUV Telescope/Spectrometer; the Solar Active Region Observing Telescope; and the Lyman Alpha White Light Coronagraph. The backup ATM hardware consists of a central cruciform structure, called the "SPAR', a "Sun End Canister' and a "Multiple Docking Adapter End Canister'. Basically, the ATM hardware and software provides a structural interface for the instruments; a closely controlled thermal environment; and a very accurate attitude and pointing control capability. The hardware is an identical set to the hardware that flow on Skylab.

Leritz, J.↗

NASA NTRS1988

Airborne Visible/Infrared Imaging Spectrometer (AVIRIS): Inflight radiometric calibration and the determination of surface reflectance

The inflight radiometric performance of AVIRIS is presented together with a comparison of methods of recovering surface spectral reflectance from the data. Performance is evaluated by comparing radiance predicted from AVIRIS with radiance generated from the LOWIRAN 6 atmospheric model and measured surface reflectance. Comparisons show apparent agreement to within a few percent between 1800 and 2450 nm. Between 600 and 1800 nm the response of AVIRIS is systematically low by as much as 70 percent, and between 400 and 600 nm it is higher than expected. These problems are traced to thermal distortions of the instrument, and to detachment during flight of optical fibers connecting foreoptics to two of four spectrometers in the instrument. Of three methods studied, an empirical one involving calibration curves constructed from field reflectance measurements returns accurate predictions of the surface reflectance independent of the actual radiometric significance of the flight data.

Conel, J. E.↗

NASA NTRS1988

Spacecraft and mission design for the SP-100 flight experiment

The design and performance of a spacecraft employing arcjet nuclear electric propulsion, suitable for use in the SP-100 Space Reactor Power System (SRPS) Flight Experiment, are outlined. The vehicle design is based on a 93 kW(e) ammonia arcjet system operating at an experimentally measured specific impulse of 1031 s and an efficiency of 42.3 percent. The arcjet/gimbal assemblies, power conditioning subsystem, propellant feed system, propulsion system thermal control, spacecraft diagnostic instrumentation, and the telemetry requirements are described. A 100 kW(e) SRPS is assumed. The spacecraft mass is baselined at 5675 kg excluding the propellant and propellant feed system. Four mission scenarios are described which are capable of demonstrating the full capability of the SRPS. The missions considered include spacecraft deployment to possible surveillance platform orbits, a spacecraft storage mission, and an orbit raising round trip corresponding to possible orbit transfer vehicle (OTV) missions.

Deininger, William D.↗

NASA NTRS1989

Baseline spacecraft and mission design for the SP-100 flight experiment

The design and performance of a spacecraft employing arcjet nuclear electric propulsion, suitable for use in the SP-100 Space Reactor Power System (SRPS) Flight Experiment, are outlined. The vehicle design is based on a 93 kWe ammonia arcjet system operating at an experimentally-measured specific impulse of 1030 s and an efficiency of 42 percent. The arcjet/gimbal assemblies, power conditioning subsystem, propellant feed system, propulsion system thermal control, spacecraft diagnostic instrumentation, and the telemetry requirements are described. A 100 kWe SRPS is assumed. The total spacecraft mass is baselined at 5675 kg excluding the propellant and propellant feed system. Four mission scenarios are described which are capable of demonstrating the full capability of the SRPS. The missions considered include spacecraft deployment to possible surveillance platform orbits, a spacecraft storage mission and an orbit raising round trip corresponding to possible orbit transfer vehicle missions. Launches from Kennedy Space Center using the Titan IV expendable launch vehicle are assumed.

Deininger, William D.↗

NASA NTRS1988

Spacecraft and mission design for the SP-100 flight experiment

The design and performance of a spacecraft employing arcjet nuclear-electric propulsion, suitable for use in the SP-100 space-reactor power-system (SRPS) flight experiment, are outlined. The vehicle design is based on a 93-kWe ammonia arcjet system operating at an experimentally measured specific impulse of 1031 sec and an efficiency of 42.3 percent. The arcjet/gimbal assemblies, power conditioning subsystem, propellant feed system, propulsion system thermal control, spacecraft diagnostic instrumentation, and the telemetry requirements are described. A 100-kWe SRPS is assumed. The spacecraft mass is baselined at 5675 kg, excluding the propellant and propellant feed system. Four mission scenarios are described which are capable of demonstrating the full capability of the SRPS.

Deininger, William D.↗

NASA NTRS1990

Flight motor set 360L006 (STS-34). Volume 1: System overview

Flight motor set 360L006 was launched at approximately 11:54 a.m. Central Daylight Time (CDT) on 18 October 1989 as part of NASA space shuttle mission STS-34. As with all previous redesigned solid rocket motor launches, overall motor performance was excellent. All ballistic contract end item (CEI) specification parameters were verified with the exceptions of ignition interval and rise rates. Ignition interval and rise rates could not be verified due to the elimination of developmental flight instrumentation from fourth flight and subsequent, but the low sample rate data that were available showed nominal propulsion performance. All ballistic and mass property parameters closely matched the predicted values and were well within the required CEI specification levels that could be assessed, with the exception of the RH-motor vacuum-delivered specific impulse. It exceeds the upper-limit CEI specification due to a bias imposed on the raw data by the OPT/Taber gage measurement differences. Evaluation of the ground environment instrumentation measurements again verified thermal model analysis data and showed agreement with predicted environmental effects. No launch commit criteria thermal violations occurred. Postflight inspection again verified superior performance of the insulation, phenolics, metal parts, and seals. Postflight evaluation indicated both nozzles performed as expected during flight, although splashdown loads tore the left-hand, 45-deg actuator bracket from the nozzle. All combustion gas was contained by insulation in the field and nozzle-to-case joints. Recommendations were made concerning improved thermal modeling and measurements. The rationale for these recommendations, the disposition of all anomalies, and complete result details are contained.

Garecht, Diane M.↗

NASA NTRS1990

Flight motor set 360L008 (STS-32R). Volume 1: System overview

Flight motor set 360L008 was launched as part of NASA space shuttle mission STS-32R. As with all previous redesigned solid rocket motor launches, overall motor performance was excellent. All ballistic contract end item specification parameters were verified with the exception of ignition interval and rise rates, which could not be verified due to elimination of developmental flight instrumentation. But the available low sample rate data showed nominal propulsion performance. All ballistic and mass property parameters closely matched the predicted values and were well within the required contract end item specification levels that could be assessed. All field joint heaters and igniter joint heaters performed without anomalies. Redesigned field joint heaters and the redesigned left-hand igniter heater were used on this flight. The changes to the heaters were primarily to improve durability and reducing handling damage. Evaluation of the ground environment instrumentation measurements again verified thermal mode analysis data and showed agreement with predicted environmental effects. No launch commit criteria violation occurred. Postflight inspection again verified superior performance of the insulation, phenolics, metal parts, and seals. Postflight evaluation indicated both nozzles performed as expected during flight. All combustion gas was contained by insulation in the field and case-to-nozzle joints. Recommendations were made concerning improved thermal modeling and measurements. The rationale for these recommendations and complete result details are presented.

Garecht, D. M.↗

NASA NTRS1989

Characteristics of the GOES I-M imager and sounder

The key features and operational characteristics of the thermal imaging and sounding instruments included into the next-generation GOES spacecraft (GOES I-M) are described. The GOES Imager's censor module has five spectral channels, including an eigth-element visible channel, three IR channels, and a water-vapor channel. The GOES Sounder's detector and filter arrangement makes use of four spectral bands: long-wave, mid-wave, short-wave, and visible. Tables of the Imager and the Sounder sensing performance characteristics are presented together with diagrams of the Imager optic parts and the Imager and the Sounder field and scan patterns.

Koenig, Edward W.↗

NASA NTRS1990

Flight motor set 360L009 (STS-36). Volume 1: System overview

Flight Motor Set 360L009, as part of NASA Space Shuttle Mission STS-36, a Department of Defence mission, was launched after two launch attempts. One launch was scrubbed following the failure of a ground-based Range Safety computer and one was scrubbed due to cloud cover at the return to launch landing site. As with all previous redesigned solid rocket motor launches, overall motor performance was excellent. There were no debris concerns from either motor. All ballistic and mass property parameters that could be assessed, closely matched the predicted values and were well within the required contract item specification levels. All field joint heaters and igniter joint heaters performed without anomalies. Evaluation of the ground environment instrumentation measurements again verified thermal model analysis data and showed agreement with predicted environmental effects. No launch commit criteria violations occurred. Postflight inspection again verified nominal performance of the insulation, phenolics, metal parts, and seals. Postflight evaluation indicated that both nozzles performed as expected during flight. All combustion gas was contained by insulation in the field and case-to-nozzle joints. Recommendations were made concerning improved thermal modeling and measurements. The rationale for these recommendations and complete result details are presented.

Garecht, Diane M.↗

NASA NTRS1990

Flight Motor Set 360T010 (STS-31R). Volume 1: System Overview

Flight motor set 360T010 was launched at approximately 7:34 a.m. CST (090:114:12:33:50.990 GMT) on 24 Apr. 1990 after one launch attempt (attempt on 10 Apr. 1990 was scrubbed following an indication of erratic operation of the Orbiter No. 1 Auciliary Power Unit No. 1). There were no problems with the solid rocket motor launches, overall motor performance was excellent. There were no debris concerns from either motor. Nearly all ballistic contract end item specification parameters were verified with the exception of ignition interval, pressure rise rate, and ignition time thrust imbalance. These could not be verified due to elimination of developmental flight instrumentation on 360L004 (STS-30R) and subsequent, but low sample rate data that were available showed nominal propulsion performance. All ballistic and mass property parameters that could be assessed closely matched the predicted values and were well within the required contract end item specification levels. All field joint heaters and igniter joint heaters performed without anomalies. Evaluation of the ground environment instrumentation measurements again verified thermal model analysis data and showed agreement with predicted environmental effects. No launch commit criteria violations occurred. Postflight inspection again verified nominal performance of the insulation, phenolics, metal parts, and seals. Postflight evaluation indicated both nozzles performed as expected during flight. All combustion gas was contained by insulation in the field and case-to-nozzle joints.

Garecht, Diane↗

NASA NTRS1990

Characteristics of the GOES I-M Imager and Sounder

The design and the parameters of the improved thermal-imaging and sounding instruments (the Imager and the Sounder) that will be part of the instrument complements of the next-generation Geostationary Operational Environmental Satellite (GOES I-M) are discussed. The new design incorporates many features that enhance instrumental reliability over the previous GOES radiometric instruments, such as independently functioning Sounder and Imager, redundancy, and more reliable position sensors and lubrication methods. Tables are presented which list the instrument parameters of the GOES I-M Imager and Sounder and the performance characteristics of the two instruments.

Ernst, Thomas J.↗

NASA NTRS1995

Composite Cocured Modular Eggcrate-Core Sandwich Structure

Lightweight composite-material (e.g., graphite fiber/epoxy matrix) cocured sandwich panels with eggcratelike cores developed for use as principal components of optical benches and other structures that support precise optical instruments. Structures offer greater thermal and mechanical stability. Advantages include easier fabrication and better mechanical properties.

Magurany, Charles J.↗

NASA NTRS1997

Ion Outflow and Convection in the Polar Cap and Cleft as Measured by Tide, EFI, MFE and Timas

This study examines high-latitude ion outflows and velocities perpendicular to the magnetic field derived from moments of ion distributions measured by the TIDE (Thermal Ion Dynamics Experiment) instrument on the Polar satellite. Hydrogen and oxygen ions are shown to be E X B drifting in the polar cap and cleft regions with a speed of about 5-20 km/s at apogee (approximately 9 Re) and a speed of 1-2 km/s at perigee (approximately 1. 8 Re). E X B drifts are calculated from electric fields measured by EFI (Electric Field Instrument) and magnetic fields measured by MFE (Magnetic Field Experiment) both of which are also on Polar. How convection at Polar's perigee relates to potential patterns of the ionosphere will be discussed. In the cusp/cleft the distribution of hydrogen extends over a large enough range of energy to be measured by both TIDE and the Toroidal Imaging Mass-Angle Spectrograph (TIMAS). Such comparisons will be also be presented.

Elliott, H. A.↗

NASA NTRS1999

Detection of Crystalline Hematite Mineralization on Mars by the Thermal Emission Spectrometer: Evidence for Near-surface Water

The Thermal Emission Spectrometer (TES) instrument on the Mars Global Surveyor (MGS) mission has discovered a remarkable accumulation of crystalline hematite ((alpha-Fe2O3) that covers an area with very sharp boundaries approximately 350 by 350-750 km in size centered near 2 S latitude between 0 and 5 W longitude (Sinus Meridiani). Crystalline hematite is uniquely identified by the presence of fundamental vibrational absorption features centered near 300, 450, and >525/cm, and by the absence of silicate fundamentals in the 1000/cm region. Spectral features resulting from atmospheric CO2, dust, and water ice were removed using a radiative transfer model. The spectral properties unique to Sinus Meridiani were emphasized by removing the average spectrum of the surrounding region. The depth and shape of the hematite fundamental bands show that the hematite is crystalline and relatively coarse grained (>5-10 micron). Diameters up to and greater than 100s of micrometers are permitted within the instrumental noise and natural variability of hematite spectra. Hematite particles <5-10 micron in diameter (either as an unpacked or hard-packed powders) fail to match the TES spectra. The spectrally-derived areal abundance of hematite varies with particle size from approximately 10% for particles >30 micron in diameter to 40-60% for unpacked 10 micron powders. The hematite in Sinus Meridiani is thus distinct from the fine-grained (diameter <5-10 micron), red, crystalline hematite considered, on the basis of visible, near-IR data, to be a minor spectral component in Martian bright regions like Olympus-Amazonis. Sinus Meridiani hematite is closely associated with a smooth, layered, friable surface that is interpreted to be sedimentary in origin. This material may be the uppermost surface in the region, indicating that it could be a late-stage sedimentary unit, or it could be a layered portion of the heavily cratered plains units. We consider five possible mechanisms for the formation of coarse-grained, crystalline hematite. These processes fall into two classes depending on whether they require a significant amount of near-surface water: (1) chemical precipitation that includes origin by (a) precipitation from oxygenated, Fe-rich water (iron formations), (b) hydrothermal extraction and crystal growth.

Christensen, P. R.↗

NASA NTRS1999

A Proposed Landing Site for the 2001 Lander in a Hematite-Rich Region in Sinus Meridiani

The Thermal Emission Spectrometer (TES) instrument on the Mars Global Surveyor (MGS) mission has identified an accumulation of crystalline hematite (alpha-Fe2O3) that covers an area with very sharp boundaries approximately 350 by 350-750 km in size centered near 2 S latitude between 0 and 5 W longitude (Sinus Meridiani). The depth and shape of the hematite fundamental bands in the TES spectra show that the hematite is relatively coarse grained (> 5-10 microns). The spectrally-derived areal abundance of hematite varies with particle size from approx. 10% for particles > 30 microns in diameter to 40-60% for unpacked 10 micron powders. The hematite in Sinus Meridiani is thus distinct from the fine-grained (diameter < 5-10 microns), red, crystalline hematite considered, on the basis of visible and near-IR data, to be a minor spectral component in Martian bright regions. A map of the hematite index has been constructed using TES data from 11 orbits, including the six in which hematite was detected and five orbits that passed nearby that showed no evidence of hematite. The boundaries of the hematite-rich region are sharp at spatial scales of about 10 km. Within this region there are spatial variations in spectral band depth of a factor of two to three. At the present time the hematite-rich region has not been completely mapped. However, by using the bounding orbits to the east and west in which hematite was not detected, we can establish that this region covers an area that is between 350 and 750 km in length and over -350 km in width (1.2 x 10(exp 5) to 2.6 x 10(exp 5 sq km). The hematite-rich surface discovered by TES closely corresponds with smooth-surfaced unit ('sm') that appears to be the surface of a layered sequence. The presence of small mesas superposed on 'sm' and the degraded nature of the small impact craters suggests that material has been removed from this unit. These layered materials do not appear to be primary volcanic products (i.e., lava flows) because there are no associated lava flow lobes, fronts or pressure ridges; there are no fissures or calderae, nor any other features that can be interpreted as volcanic within 'sm'. Bowl-shaped depressions in 'sm' and the remnant mesas on top of a portion of this unit suggest that deflation has removed material that was once above the present surface of 'sm'. The most likely cause of the deflation is wind, which suggests that the layered materials are relatively friable. In summary, Sinus Meridiani hematite is closely associated with a smooth, layered, friable surface that is interpreted to be sedimentary in origin.

Christensen, Philip R.↗

NASA NTRS2001

The TES Hematite-Rich Region in Sinus Meridiani: A Proposed Landing Site for the 2003 Rover

Christensen, Philip R.↗

NASA NTRS2002

A Sublimation Model for the Martian Polar Swiss-Cheese Features. Observational and Modeling Studies of the South Polar Residual Cap

In their pioneering work Leighton and Murray argued that the Mars atmosphere, which is 95 percent CO2 today, is controlled by vapor equilibrium with a much larger polar reservoir of solid CO2. Here we argue that the polar reservoir is small and cannot function as a long-term buffer to the more massive atmosphere. Our work is based on modeling the circular depressions (Swiss-cheese features) in the south polar cap. We argue that a solid CO2 layer approximately 8 meters thick is being etched away to reveal water ice underneath. Preliminary results from the THEMIS (Thermal Emission Imaging System) instrument seem to confirm our model.

Byrne, Shane↗

NASA NTRS2003

Thermal Vacuum Test Performance of the Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) Variable Conductance Heat Pipe Assembly

The Variable Conductance Heat Pipe (VCHP) Assembly of the HST Wide Field Camera 3 was subjected to thermal vacuum (TN) environmental testing. The test program included both maximum and minimum environments as well as simulated on-orbit cycling. Elements of the VCHP assembly included a VCHP, an optical bench cold plate with an imbedded constant conductance heat pipe, and a VCHP reservoir radiator with a proportionally controlled heater. The purpose of the test was to characterize and demonstrate the assembly s ability to control the temperature of the cold plate, which provides a stable thermal environment for the instrument s optical bench. This paper discusses the VCHP Assembly control performance and control authority during the dynamic hot and cold 90-minute orbit cycling test phases.

Cleveland, Paul E.↗