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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 433 records · Page 24
All sourcesNASA NTRSDOE OSTI
NASA NTRS2012

Thermographic Imaging of the Space Shuttle During Re-Entry Using a Near Infrared Sensor

High resolution calibrated near infrared (NIR) imagery of the Space Shuttle Orbiter was obtained during hypervelocity atmospheric re-entry of the STS-119, STS-125, STS-128, STS-131, STS-132, STS-133, and STS-134 missions. This data has provided information on the distribution of surface temperature and the state of the airflow over the windward surface of the Orbiter during descent. The thermal imagery complemented data collected with onboard surface thermocouple instrumentation. The spatially resolved global thermal measurements made during the Orbiter s hypersonic re-entry will provide critical flight data for reducing the uncertainty associated with present day ground-to-flight extrapolation techniques and current state-of-the-art empirical boundary-layer transition or turbulent heating prediction methods. Laminar and turbulent flight data is critical for the validation of physics-based, semi-empirical boundary-layer transition prediction methods as well as stimulating the validation of laminar numerical chemistry models and the development of turbulence models supporting NASA s next-generation spacecraft. In this paper we provide details of the NIR imaging system used on both air and land-based imaging assets. The paper will discuss calibrations performed on the NIR imaging systems that permitted conversion of captured radiant intensity (counts) to temperature values. Image processing techniques are presented to analyze the NIR data for vignetting distortion, best resolution, and image sharpness. Keywords: HYTHIRM, Space Shuttle thermography, hypersonic imaging, near infrared imaging, histogram analysis, singular value decomposition, eigenvalue image sharpness

Zalameda, Joseph N.↗
NASA NTRS1998

Thermal Modeling of a Space Inteferometer Siderostat Bay

Thermal stability of critical instrument components is of serious concern for the Space Interferometer Mission (SIM). Within the SIM siderostat bay, thermal distortion of the siderostat mirror and the telescope primary and secondary mirrors must be controlled to ensure success of the mission.

Thermal Modeling Sun and Earth temperatures↗
NASA NTRS2023

Phyllosilicate Decomposition on Bennu Due to Prolonged Surface Exposure

The Origins, Spectral Interpretation, Resource Identification, and Security–Regolith Explorer (OSIRIS-REx) mission to carbonaceous asteroid (101955) Bennu performed detailed mapping with a suite of instruments to characterize the composition and geology of its surface. Here we use data from the OSIRIS-REx Thermal Emission Spectrometer (OTES) instrument to investigate the relationship of OTES-derived spectral indices to other derived data products from OTES, the OSIRIS-REx Camera Suite (OCAMS), and the OSIRIS-REx Visible and InfraRed Spectrometer (OVIRS) at global and local scales. We quantitatively confirm that high values of the OTES silicate stretching slope (from ∼10 to ∼12 μm) in midday spectra that are indicative of thin and/or patchy dust cover are strongly associated with low thermal inertia (high porosity), low albedo boulders on Bennu. These high porosity boulders have brecciated textures with embedded clasts that likely originated on Bennu's parent body or during its disruption. The high porosity of these boulders is a key factor in the local production of the dust or its entrapment, as some large, brecciated boulders with a lower porosity have little evidence of dust. A second OTES spectral parameter, the silicate bending band depth near 22.7 μm applied to early evening spectra, is not correlated to thermal inertia, but is weakly to strongly correlated to albedo, OVIRS-derived 1.05 μm and 2.74 μm band depths, OVIRS-derived hydrogen abundance, and modeled nanophase troilite abundance. In several regions on Bennu there is a strong spatial relationship between these parameters, whereby areas with shallower silicate bending bands also have shallower 1.05 μm and 2.74 μm bands and lower albedo with higher nanophase troilite abundances. These correlations, combined with analysis of the silicate bending band in laboratory experiments of space weathered and mildly heated carbonaceous chondrites, suggests that decreased silicate bending band depths signify decomposition of phyllosilicates, likely Fe-bearing, due to space weathering or mild heating (<600 °C) via solar radiation during Bennu's time in near-Earth space. There is a strong association of larger silicate bending band depths in areas dominated by small rocks and unresolved material and in areas with small (≤ 25 m) craters identified as the spectrally reddest on Bennu, suggesting that this material has been more recently exposed due to impact and/or mass wasting processes. The shallowest silicate bending depths are associated with larger rocks and boulders that appear to have the longest surface exposure history, although there is band depth variation among them suggesting either initial composition variation that resulted in different responses to space weathering or heating, or varied exposure history of individual boulders themselves. We predict that any grains returned from Bennu with a significant surface exposure history will be characterized by shallower 22.7 μm, 1.05 μm and 2.7 μm band depths and increased sulfide (troilite) abundance, as well as textural and chemical evidence for phyllosilicate dehydration.

Asteroids, surfaces↗
NASA NTRS2000

TES Observations of the Martian Surface and Atmosphere

The Thermal Emission Spectrometer (TES) instrument is a Fourier transform Michelson interferometer operating with 10 or 5 cm(exp -1) sampling in the thermal infrared spectral region from 1700 to 200 cm(exp -1) (-6 to 50 micrometers) where virtually all minerals have characteristic fundamental vibrational absorption bands. The TES data used in this paper are among the 6 x 10(exp 7) spectra collected during the early mapping phase of the Mars Global Surveyor (MGS) mission from southern hemisphere winter to early summer (aerocentric longitude, L(sub s), 107 deg to 297 deg. The methodology for separating the surface and atmospheric components of the radiance from Mars, which allows detailed analysis and interpretation of surface mineralogy, is described in previous paper. Additional information is contained in original extended abstract.

Christensen, P. R.↗
NASA NTRS2004

Test of the Equivalence Principle in an Einstein Elevator

The scientific goal of the experiment is to test the equality of gravitational and inertial mass (i.e., to test the Principle of Equivalence) by measuring the independence of the rate of fall of bodies from their compositions. The measurement is accomplished by measuring the relative displacement (or equivalently acceleration) of two falling bodies of different materials which are the proof masses of a differential accelerometer spinning about an horizontal axis to modulate a possible violation signal. A non-zero differential acceleration appearing at the signal frequency will indicate a violation of the Equivalence Principle. The goal of the experiment is to measure the Eotvos ratio og/g (differential acceleration/common acceleration) with a targeted accuracy that is about two orders of magnitude better than the state of the art (presently at several parts in 10(exp 13). The analyses carried out during this first grant year have focused on: (1) evaluation of possible shapes for the proof masses to meet the requirements on the higher-order mass moment disturbances generated by the falling capsule; (2) dynamics of the instrument package and differential acceleration measurement in the presence of errors and imperfections; (3) computation of the inertia characteristic of the instrument package that enable a separation of the signal from the dynamics-related noise; (4) a revised thermal analysis of the instrument package in light of the new conceptual design of the cryostat; (5) the development of a dynamic and control model of the capsule attached to the gondola and balloon to define the requirements for the leveling mechanism (6) a conceptual design of the leveling mechanism that keeps the capsule aligned before release from the balloon; and (7) a new conceptual design of the customized cryostat and a preliminary valuation of its cost. The project also involves an international cooperation with the Institute of Space Physics (IFSI) in Rome, Italy. The group at IFSI is in charge of prototyping the differential accelerometer and carrying out precursor laboratory measurements. During this grant year, our partners analyzed and then designed a new prototype of differential accelerometer that has several characteristics in common with the flight accelerometer at this point of the instrument development. The highlights of these activities are documented in a section of this report.

Shapiro, Irwin I.↗
NASA NTRS2020

Psyche Magnetometer Engineering Model Test and Thermal Model Correlation to Validate Operational Thermal Requirement

Psyche Fluxgate Magnetometer candidate fabricated by UCLA has a critical temperature gradient requirement inside the magnetometer sensor head. Since the temperature gradient requirement is a driving factor for the magnetometer operation and science data collection at 16 Psyche, it is critical to validate and verify this requirement via modeling and test. In this work, a thermal vacuum test was completed for Psyche flight-like magnetometer engineering model. Flight-like environments were simulated for a hot operational case (after launch), a cold survival case (cruise), and two cold operational cases to characterize thermal performance of the instrument. An additional, non-flight, steady-state test case was completed to better correlate the magnetometer thermal model. During the test, sensitive Cernox temperature sensors with accuracy of ±0.1°C were used to precisely characterize the temperature gradient and correlate the model to the best accuracy. Collected test data indicated power consumption of 28% lower than predicted. The temperature gradient measured met the expected value and the requirement. Test data indicated the magnetometer also met the AFTs in relevant hot and cold environments. Test Results were used to correlate the thermal model. The correlated thermal model will be integrated to the spacecraft thermal model to predict magnetometer thermal performance while collecting science data in Psyche orbits.

Caron, Ryan↗
DOE OSTI2021

Demonstrate the Out-of-Pile Performance of a Real-Time Measurement System to Measure Thermal Conductivity Based on Photo Thermal Radiometry

SUMMARY The goal of this project is to develop a fiber-based instrument to perform in-reactor thermal conductivity measurements of fuels and materials. This instrument is based on photothermal radiometry (PTR) and involves heating a sample locally and measuring the induced temperature gradient by collecting blackbody radiation [2]. Thermal conductivity of the sample is extracted by comparing experimental results with a continuum-based model [3,4]. As a laser-based technique, PTR is a non-contact measurement technique that can be performed remotely and non-destructively. In addition, it has several advantages over other photothermal techniques, making it an ideal approach for in-situ measurement of thermal conductivity of nuclear fuels. Because blackbody radiation increases with emissivity and temperature, the PTR technique works well with unprepared surfaces, and measurement accuracy increases with temperature. Moreover, this approach is capable of measuring samples with irregular or poorly defined boundary conditions, which is a common situation for friable spent fuels.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
NASA NTRS1999

MOD Tool (Microwave Optics Design Tool)

The Jet Propulsion Laboratory (JPL) is currently designing and building a number of instruments that operate in the microwave and millimeter-wave bands. These include MIRO (Microwave Instrument for the Rosetta Orbiter), MLS (Microwave Limb Sounder), and IMAS (Integrated Multispectral Atmospheric Sounder). These instruments must be designed and built to meet key design criteria (e.g., beamwidth, gain, pointing) obtained from the scientific goals for the instrument. These criteria are frequently functions of the operating environment (both thermal and mechanical). To design and build instruments which meet these criteria, it is essential to be able to model the instrument in its environments. Currently, a number of modeling tools exist. Commonly used tools at JPL include: FEMAP (meshing), NASTRAN (structural modeling), TRASYS and SINDA (thermal modeling), MACOS/IMOS (optical modeling), and POPO (physical optics modeling). Each of these tools is used by an analyst, who models the instrument in one discipline. The analyst then provides the results of this modeling to another analyst, who continues the overall modeling in another discipline. There is a large reengineering task in place at JPL to automate and speed-up the structural and thermal modeling disciplines, which does not include MOD Tool. The focus of MOD Tool (and of this paper) is in the fields unique to microwave and millimeter-wave instrument design. These include initial design and analysis of the instrument without thermal or structural loads, the automation of the transfer of this design to a high-end CAD tool, and the analysis of the structurally deformed instrument (due to structural and/or thermal loads). MOD Tool is a distributed tool, with a database of design information residing on a server, physical optics analysis being performed on a variety of supercomputer platforms, and a graphical user interface (GUI) residing on the user's desktop computer. The MOD Tool client is being developed using Tcl/Tk, which allows the user to work on a choice of platforms (PC, Mac, or Unix) after downloading the Tcl/Tk binary, which is readily available on the web. The MOD Tool server is written using Expect, and it resides on a Sun workstation. Client/server communications are performed over a socket, where upon a connection from a client to the server, the server spawns a child which is be dedicated to communicating with that client. The server communicates with other machines, such as supercomputers using Expect with the username and password being provided by the user on the client.

Katz, Daniel S.↗
NASA NTRS1981

Thermal design of the Space Shuttle External Tank

The history of the engineering and manufacturing requirements leading to the final Thermal Protection System (TPS) for the External Tank (ET) is presented. The thermal design for the ET must be optimized, based on considerations of cost, weight, and application of the TPS. The significant thermal requirements include the structural and component temperature limits, the propellant quality, the minimization of ice and frost, no air liquefaction, and no film boiling. The TPS materials selected to meet the requirements are a low density closed cell foam (CPR-488) and two light-weight ablators (SLA-56 and MA-25s). The first four flights of the Space Shuttle (1981) will measure and evaluate external environmental, structural, propulsion, electrical, and engine performance data. The ET will be instrumented to measure acoustics, pressures, heat transfer, vibration, temperatures, and structural strains. TPS weight reductions are planned for future ETs through the use of a comprehensive thermal instrumentation system.

Warmbrod, J. D.↗
NASA NTRS1982

Planar ion trap (retarding potential analyzer) experiment for atmosphere explorer

The retarding potential analyzer and drift meter were carried aboard all three Atmosphere Explorer spacecraft. These instruments measure the total thermal ion concentration and temperature, the bulk thermal ion velocity vector and some limited properties of the relative abundance of H(+), He(+), O(+) and molecular ions. These instruments functioned with no internal failures on all the spacecraft. On AE-E there existed some evidence for external surface contamination that damaged the integrity of the RPA sweep grids. This led to some difficulties in data reduction and interpretation that did not prove to be a disastrous problem. The AE-D spacecraft functioned for only a few months before it re-entered. During this time the satellite suffered from a nutation about the spin axis of about + or - 2 deg. This 2 deg modulation was superimposed upon the ion drift meter horizontal ion arrival angle output requiring the employment of filtering techniques to retrieve the real data.

Hanson, W. B.↗
NASA NTRS2003

In-Flight Thermal Performance of the Geoscience Laser Altimeter System (GLAS) Instrument

The Geoscience Laser Altimeter System (GLAS) instrument is NASA Goddard Space Flight Center's first application of Loop Heat Pipe technology that provides selectable/stable temperature levels for the lasers and other electronics over a widely varying mission environment. GLAS was successfully launched as the sole science instrument aboard the Ice, Clouds, and Land Elevation Satellite (ICESat) from Vandenberg AFB at 4:45pm PST on January 12, 2003. After SC commissioning, the LHPs started easily and have provided selectable and stable temperatures for the lasers and other electronics. This paper discusses the thermal development background and testing, along with details of early flight thermal performance data.

Grob, Eric↗
NASA NTRS2005

Tracking Retreat of the North Seasonal Ice Cap on Mars: Results from the THEMIS Investigation

The CO2 ice caps on Mars advance and retreat with the seasons. This phenomenon was first observed by Cassini and then confirmed by numerous ground based observations in 19th and 20th centuries. With the advent of the space age observations of the seasonal ice cap were done by all orbiting spacecraft starting with Mariner 7. Viking Orbiters and more recently the Mars Global Surveyor (particularly Mars Orbiter Camera (MOC) and Thermal Emission Spectrometer (TES) instruments) have accumulated significant data on the retreat of the CO2 seasonal cap. During Mars year 2 of THEMIS operations at Mars, we planned an observational campaign in which the THEMIS instrument (onboard the Mars Odyssey spacecraft) repeatedly observed the north seasonal polar cap from midwinter to late spring. THEMIS allows simultaneous observations in both Thermal IR (12.57 m) and Visible wavelengths (0.65 m). One of the goals for this work is to initiate an interannual program for observations of the seasonal ice caps using the THEMIS instrument. The most efficient way to detect the edge between frost and bare ground is directly onboard of the spacecraft. Prior to onboard software design effort, we have developed two groundbased algorithms for automatically finding the edge of the seasonal polar cap in THEMIS IR data. The first algorithm relies on fully calibrated data and can be used for highly reliable groundbased analyses. The second method was specifically developed for processing raw, uncalibrated data in a highly efficient way. It has the potential to enable automatic, onboard detections of the seasonal cap retreat. We have experimentally confirmed that both methods produce similar results, and we have validated both methods against a model constructed from the MGS TES data from the same season.

Ivanov, A. B.↗
NASA NTRS2020

Design and Analysis of V-Groove Passive Cryogenic Radiators for Space-borne Telescopes & Instruments

V-groove passive radiators are extremely efficient passive designs to thermally isolate a cryogenic telescope or instrument from warm environments in space, like the Sun, Earth, Moon or Spacecrafts. Compared to traditional multi-layer insulation blankets employed for thermal isolation, the V-Groove radiators provide as much as an order of magnitude improvement. The V-Groove design typically constitutes three low emissivity, lightweight and thin aluminized Mylar/Kapton sheets angled from each other by just few degrees. These successively reflect heat from warmer shields to space via their angular openings, thus minimizing heat flow into the cryogenic system. Thermal analysis of these V-Groove radiators is typically performed by sophisticated thermal software that uses hundreds of thousands of rays to simulate radiative heat flow between successive shields via reflections, which can be very time & resource intensive. We have arrived at very simple closed form equations to predict the thermal behavior of these radiators, that includes their radiative heat transfer factors and temperatures as a function of their basic thermo-optical properties and inter-shield angles. These predictions can be done by hand calculators or in spreadsheet tools like MS-Excel. They compare very well to those from sophisticated computer programs. The ease in the use of these simple equations allow for instantaneous predictions of cryogenic temperatures and their trends for design options and trade studies. A case study of this was utilized for the telescope project that is currently being designed for an all sky spectral survey of the universe. This paper will describe the derivations of these equations, their comparison with computer software results and their applicability for current and future cryogenic space telescope and instrument missions

Bhandari, Pradeep↗