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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 415 records · Page 23
All sourcesNASA NTRSDOE OSTI
NASA NTRS2006

Alignment Measurement of the New Horizons (NH) High Gain Antenna (HGA) in the Thermal/Vacuum Chamber using Photogrammetry

The New Horizons (NH) spacecraft, launched in January, 2006, is the first mission to explore the planet Pluto and the icy bodies at the edge of the Solar system making up the Kuiper belt. NH utilizes a shaped parabolic High Gain Antenna (HGA) to transmit and receive data over the vast 3 billion mile distance it will travel. Proper maintenance of the HGA shape and alignment at cryogenic temperatures (90 K) is a critical element to ensure mission success. We describe the hardware and methods that were used to validate the displacement/deformation predictions of the HGA reflector during thermal/vacuum testing of the HGA system. The smallest deformation predictions to be measured on the HGA were on the order of +/-0.015 inches. Measurement of the resulting change of the HGA system boresight due to the HGA deformation was also desired. Performance of these alignment measurements inside a thermal/vacuum chamber could not be performed with conventional alignment equipment, namely due to the inability to send personnel into the chamber to perform the measurements due to the temperature extremes and vacuum. The Photogrammetry (PG) system was chosen to perform the measurements since it is a non-contact measurement system, measurements can be made relatively quickly and accurately, and the camera can be operated remotely. This method had been previously proven for WMAP. The hardware and methods developed to perform the NH alignment measurements using PG proved to be successful. The measured increase in the HGA RMS surface distortion as a result of going cold was approx. 0.012 inches, indicating that the +/-0.015 inches RF requirement was met. This measured deformation resulted in a change in alignment of the HGA system boresight of less than 0.008 degrees, meeting the requirement of 0.020 degrees.

Hill, Michael D.↗
NASA NTRS2005

Space Suit Spins

Space is a hostile environment where astronauts combat extreme temperatures, dangerous radiation, and a near-breathless vacuum. Life support in these unforgiving circumstances is crucial and complex, and failure is not an option for the devices meant to keep astronauts safe in an environment that presents constant opposition. A space suit must meet stringent requirements for life support. The suit has to be made of durable material to withstand the impact of space debris and protect against radiation. It must provide essential oxygen, pressure, heating, and cooling while retaining mobility and dexterity. It is not a simple article of clothing but rather a complex modern armor that the space explorers must don if they are to continue exploring the heavens

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NASA NTRS2006

Material Concerns: Evaluating Sulfur Concrete for use in the Lunar Environment

On Earth sulfur "concrete" is an established construction material that has good mechanical properties, generally better than Portland cement, and can be used in corrosive environments. Troilite (FeS) has been found on the moon and raises the question of using extracted sulfur as a lunar construction material, an attractive alternative to conventional concrete as it does not require water. Troilite reduction to elemental sulfur and using it to make concrete in a lunar setting has been previously discussed. However, little has been experimentally done to evaluate its performance in the extreme lunar environment. This study subjected sets of sulfur concrete samples, prepared using JSC-1 lunar simulant, to I ) extended periods of high vacuum and 2) extreme temperature cycles. Here an overview of sulfur concrete and experimentally assessed properties, put in context of the lunar environment, is presented and discussed.

Grugel, Richard N.↗
NASA NTRS2005

Cognitive Performance in Operational Environments

Optimal cognition during complex and sustained operations is a critical component for success in current and future military operations. "Cognitive Performance, Judgment, and Decision-making" (CPJD) is a newly organized U.S. Army Medical Research and Materiel Command research program focused on sustaining operational effectiveness of Future Force Warriors by developing paradigms through which militarily-relevant, higher-order cognitive performance, judgment, and decision-making can be assessed and sustained in individuals, small teams, and leaders of network-centric fighting units. CPJD evaluates the impact of stressors intrinsic to military operational environments (e.g., sleep deprivation, workload, fatigue, temperature extremes, altitude, environmental/physiological disruption) on military performance, evaluates noninvasive automated methods for monitoring and predicting cognitive performance, and investigates pharmaceutical strategies (e.g., stimulant countermeasures, hypnotics) to mitigate performance decrements. This manuscript describes the CPJD program, discusses the metrics utilized to relate militarily applied research findings to academic research, and discusses how the simulated combat capabilities of a synthetic battle laboratory may facilitate future cognitive performance research.

Russo, Michael↗
NASA NTRS2006

Reflecting on Space Benefits: A Shining Example

NASA has long been known for having developed the thin, shiny reflective material used to insulate everything from the Hubble Space Telescope to hikers, from the Mars rovers to marathon runners, from computers to campers, from satellites to sun shields, and from rockets to residences. It is one of the simplest, yet most versatile spinoffs to come out of the Agency. The insulating material, a strong, plastic, vacuum-metallized film with a highly-efficient, infrared-reflective, vapor-deposited coating of aluminum, was created to be very lightweight in order to minimize weight impact on vehicle payload while also protecting spacecraft, equipment, and personnel from the extreme temperature fluctuations of space. It has been employed on virtually all manned and unmanned NASA missions. The shiny insulation which coated the base of the Apollo lunar landing vehicles is perhaps one of the most memorable early displays of this technology, and the bright, reflective honeycomb on the James Webb Space Telescope prototype is a testament to its lasting usefulness.

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NASA NTRS2006

Robust, Thin Optical Films for Extreme Environments

The environment of space presents scientists and engineers with the challenges of a harsh, unforgiving laboratory in which to conduct their scientific research. Solar astronomy and X-ray astronomy are two of the more challenging areas into which NASA scientists delve, as the optics for this high-tech work must be extremely sensitive and accurate, yet also be able to withstand the battering dished out by radiation, extreme temperature swings, and flying debris. Recent NASA work on this rugged equipment has led to the development of a strong, thin film for both space and laboratory use.

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NASA NTRS2007

Life Support Requirements and Challenges for NASA's Constellation Program

NASA's Constellation Program, which includes the mission objectives of establishing a permanently-manned lunar Outpost, and the exploration of Mars, poses new and unique challenges for human life support systems that will require solutions beyond the Shuttle and International Space Station state of the art systems. In particular, the requirement to support crews for 210 days duration at the lunar outpost with limited resource resupply capability wilt require closed-loop regenerative life support systems with minimal expendables. Planetary environmental conditions such as lunar dust and extreme temperatures, as well as the capability to support frequent and extended-duration EVA's will be particularly challenging. This presentation will summarize the key program and mission life support requirements for the Constellation Program and the unique challenges they present for technology and architecture development.

Carasquillo, Robyn↗
NASA NTRS2007

Optical Property Measurements on the Stardust Sample Return Capsule

The Advanced Materials for Exploration (AME) task Materials Analysis of Returned Hardware from Stardust received funding to perform non-destructive analyses of the non-primary science hardware components of the Stardust sample return capsule. These components were (a) the blunt body reentry heatshield, encased in Phenolic Impregnated Carbon Ablator (PICA); (b) the backshell of Super Lightweight Ablator 561 (SLA-561) material handpacked into phenolic Flexcore and coated with CV-1100 silicone; (c) the rope seal used in between the heatshield and backshell; (d) the internal multi-layer insulation (MLI) blankets; and (e) parts of the Kevlar straps left attached to the backshell. These components were analyzed to determine the materials' durability in the space environment. The goals of the task were (a) to determine how the various materials from which the components were built weathered the extreme temperatures and harsh space environment during the capsule's nearly 7-year voyage to and from its rendezvous with Comet Wild 2 and (b) to provide lessons-learned data for designers of future missions.

Finckenor, Miria↗
NASA NTRS1995

Flexible reusable mandrels

A reusable laminate mandrel which is unaffected by extreme temperature changes. The flexible laminate mandrel is comprised of sheets stacked to produce the required configuration, a cover wrap that applies pressure to the mandrel laminate, maintaining the stack cross-section. Then after use, the mandrels can be removed, disassembled, and reused. In the method of extracting the flexible mandrel from one end of a composite stiffener, individual ones of the laminae of the flexible mandrel or all are extracted at the same time, depending on severity of the contour.

Willden, Kurtis S.↗
NASA NTRS2006

Sulfur "Concrete" for Lunar Applications - Sublimation Concerns

Melting sulfur and mixing it with an aggregate to form "concrete" is commercially well established and constitutes a material that is particularly well-suited for use in corrosive environments. Discovery of the mineral troilite (FeS) on the moon poses the question of extracting the sulfur for use as a lunar construction material. This would be an attractive alternative to conventional concrete as it does not require water. However, the viability of sulfur concrete in a lunar environment, which is characterized by lack of an atmosphere and extreme temperatures, is not well understood. Here it is assumed that the lunar ore can be mined, refined, and the raw sulfur melded with appropriate lunar regolith to form, for example, bricks. This study evaluates pure sulfur and two sets of small sulfur concrete samples that have been prepared using JSC-1 lunar stimulant and SiO2 powder as aggregate additions. Each set was subjected to extended periods in a vacuum environment to evaluate sublimation issues. Results from these experiments are presented and discussed within the context of the lunar environment.

Grugel, Richard N.↗
NASA NTRS2008

Sulfur 'Concrete' for Lunar Applications - Environmental Considerations

Commercial use of sulfur concrete on Earth is well established, particularly in corrosive, e.g., acid and salt, environments. Having found troilite (FeS) on the Moon raises the question of using extracted sulfur as a lunar construction material, an attractive alternative to conventional concrete as it does not require water. For the purpose of this Technical Memorandum, it is assumed that lunar ore is mined, refined, and the raw sulfur processed with appropriate lunar regolith to form, for example, bricks. With this stipulation, it is then noted that the viability of sulfur concrete in a lunar environment, which is characterized by lack of an atmosphere and extreme temperatures, is not well understood. The work presented here evaluates two sets of small sulfur concrete samples that have been prepared using JSC-1 lunar simulant as an aggregate addition. One set was subjected to extended periods in high vacuum to evaluate sublimation issues, and the other was cycled between room and liquid nitrogen temperatures to investigate their subsequent mechanical integrity. Results are presented from both investigations, discussed, and put into the context of the lunar environment.

Grugel, R. N.↗
NASA NTRS2008

Liquid Space Lubricants Examined by Vibrational Micro-Spectroscopy

Considerable effort has been expended to develop liquid lubricants for satellites and space exploration vehicles. These lubricants must often perform under a range of harsh conditions such as vacuum, radiation, and temperature extremes while in orbit or in transit and in extremely dusty environments at destinations such as the Moon and Mars. Historically, oil development was guided by terrestrial application, which did not provide adequate space lubricants. Novel fluids such as the perfluorinated polyethers provided some relief but are far from ideal. With each new fluid proposed to solve one problem, other problems have arisen. Much of the work performed at the National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) in elucidating the mechanisms by which chemical degradation of space oils occur has been done by vibrational micro-spectroscopic techniques such as infrared and Raman, which this review details. Presented are fundamental lubrication studies as well as actual case studies in which vibrational spectroscopy has led to millions of dollars in savings and potentially prevented loss of mission.

Street, Kenneth W., Jr.↗
NASA NTRS2008

Technology Developments in Radiation-Hardened Electronics for Space Environments

The Radiation Hardened Electronics for Space Environments (RHESE) project consists of a series of tasks designed to develop and mature a broad spectrum of radiation hardened and low temperature electronics technologies. Three approaches are being taken to address radiation hardening: improved material hardness, design techniques to improve radiation tolerance, and software methods to improve radiation tolerance. Within these approaches various technology products are being addressed including Field Programmable Gate Arrays (FPGA), Field Programmable Analog Arrays (FPAA), MEMS, Serial Processors, Reconfigurable Processors, and Parallel Processors. In addition to radiation hardening, low temperature extremes are addressed with a focus on material and design approaches. System level applications for the RHESE technology products are discussed.

Keys, Andrew S.↗
NASA NTRS2008

NASA Tech Briefs, December 2008

Topics covered include: Crew Activity Analyzer; Distributing Data to Hand-Held Devices in a Wireless Network; Reducing Surface Clutter in Cloud Profiling Radar Data; MODIS Atmospheric Data Handler; Multibeam Altimeter Navigation Update Using Faceted Shape Model; Spaceborne Hybrid-FPGA System for Processing FTIR Data; FPGA Coprocessor for Accelerated Classification of Images; SiC JFET Transistor Circuit Model for Extreme Temperature Range; TDR Using Autocorrelation and Varying-Duration Pulses; Update on Development of SiC Multi-Chip Power Modules; Radio Ranging System for Guidance of Approaching Spacecraft; Electromagnetically Clean Solar Arrays; Improved Short-Circuit Protection for Power Cells in Series; Electromagnetically Clean Solar Arrays; Logic Gates Made of N-Channel JFETs and Epitaxial Resistors; Improved Short-Circuit Protection for Power Cells in Series; Communication Limits Due to Photon-Detector Jitter; System for Removing Pollutants from Incinerator Exhaust; Sealing and External Sterilization of a Sample Container; Converting EOS Data from HDF-EOS to netCDF; HDF-EOS 2 and HDF-EOS 5 Compatibility Library; HDF-EOS Web Server; HDF-EOS 5 Validator; XML DTD and Schemas for HDF-EOS; Converting from XML to HDF-EOS; Simulating Attitudes and Trajectories of Multiple Spacecraft; Specialized Color Function for Display of Signed Data; Delivering Alert Messages to Members of a Work Force; Delivering Images for Mars Rover Science Planning; Oxide Fiber Cathode Materials for Rechargeable Lithium Cells; Electrocatalytic Reduction of Carbon Dioxide to Methane; Heterogeneous Superconducting Low-Noise Sensing Coils; Progress toward Making Epoxy/Carbon-Nanotube Composites; Predicting Properties of Unidirectional-Nanofiber Composites; Deployable Crew Quarters; Nonventing, Regenerable, Lightweight Heat Absorber; Miniature High-Force, Long-Stroke SMA Linear Actuators; "Bootstrap" Configuration for Multistage Pulse-Tube Coolers; Reducing Liquid Loss during Ullage Venting in Microgravity; Ka-Band Transponder for Deep-Space Radio Science; Replication of Space-Shuttle Computers in FPGAs and ASICs; Demisable Reaction-Wheel Assembly; Spatial and Temporal Low-Dimensional Models for Fluid Flow; Advanced Land Imager Assessment System; Range Imaging without Moving Parts.

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NASA NTRS2008

Evaluation of Sulfur 'Concrete' for Use as a Construction Material on the Lunar Surface

Combining molten sulfur with any number of aggregate materials forms, when solid, a mixture having attributes similar, if not better, to conventional water-based concrete. As a result the use of sulfur "concrete" on Earth is well established, particularly in corrosive environments. Consequently, discovery of troilite (FeS) on the lunar surface prompted numerous scenarios about its reduction to elemental sulfur for use, in combination with lunar regolith, as a potential construction material; not requiring water, a precious resource, for its manufacture is an obvious advantage. However, little is known about the viability of sulfur concrete in an environment typified by extreme temperatures and essentially no atmosphere. The experimental work presented here evaluates the response of pure sulfur and sulfur concrete subjected to laboratory conditions that approach those expected on the lunar surface, the results suggesting a narrow window of application.

Grugel, R. N.↗
NASA NTRS2008

Radiation-Insensitive Inverse Majority Gates

To help satisfy a need for high-density logic circuits insensitive to radiation, it has been proposed to realize inverse majority gates as microscopic vacuum electronic devices. In comparison with solid-state electronic devices ordinarily used in logic circuits, vacuum electronic devices are inherently much less adversely affected by radiation and extreme temperatures. The proposed development would involve state-of-the-art micromachining and recent advances in the fabrication of carbon-nanotube-based field emitters. A representative three-input inverse majority gate would be a monolithic, integrated structure that would include three gate electrodes, six bundles of carbon nanotubes (serving as electron emitters) at suitable positions between the gate electrodes, and an overhanging anode. The bundles of carbon nanotubes would be grown on degenerately doped silicon substrates that would be parts of the monolithic structure. The gate electrodes would be fabricated as parts of the monolithic structure by means of a double-silicon-on-insulator process developed at NASA's Jet Propulsion Laboratory. The tops of the bundles of carbon nanotubes would lie below the plane of the tops of the gate electrodes. The particular choice of shapes, dimensions, and relative positions of the electrodes and bundles of carbon nanotubes would provide for both field emission of electrons from the bundles of carbon nanotubes and control of the electron current to obtain the inverse majority function, which is described in the paper.

Manohara, Harish↗
NASA NTRS2007

Capabilities and History of NASA Marshall Space Flight Center's Hydrogen Test Facility

The Hydrogen Test Facility (HTF) has conducted mechanical testing for aerospace materials at NASA's Marshall Space Flight Center for many years. One of the first facilities of its kind to run high-pressure cryogenic permeability tests in liquid hydrogen, HTF is now characterized as a unique national resource capable of overcoming hazardous conditions to perform tests directly in various hydrogen environments. At HTF, custom test systems are operated in eight structurally reinforced test cells from 0 to 68,948 kPa (0 to 10,000 psi) at -253 to 982 C (--423 to 1800 F) in hydrogen, air, helium, and nitrogen, with other environments available upon request. Standard mechanical procedures include compression, fatigue crack growth rate, four-point bend, high/low cycle fatigue, fracture toughness, shear, strain-to-crack, and tensile testing. Cryogenic permeability and thermal conductivity and gaseous creep testing are offered, as well as simulated service under different combinations of operating environment(s), stress, pressure, and ambient-to-extreme temperatures. Advanced tests are routinely developed upon demand, and special component testing is also available. Current efforts include the renovation of two high-pressure gaseous test cells to generate data for a J-2X engine designed for Constellation's Ares I and V vehicles. In the past, HTF has supported other critical NASA programs, such as Apollo, Space Shuttle, and Next Generation Launch Technologies. During the 1990's, hundreds of tests were conducted in liquid hydrogen and liquid nitrogen during development of the Space Shuttle's super lightweight tank, which provided the thrust required to achieve low Earth orbit for the International Space Station. This facility was designed and built in 1963. Originally called the Low Temperature Test Facility, it became known as the Cryogenic Test Facility in the late 1980's and HTF in the early 1990's.

Malone, T. W.↗