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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 253 records · Page 14

All sources NASA NTRS DOE OSTI

NASA NTRS1990

Identifying atmospheric monitoring needs for Space Station Freedom

The monitoring needs for Space Station Freedom were identified by examining: the experiences of past missions; ground based tests of proposed life support systems; a contaminant load model; metabolic production from an 8-person crew; and a fire scenario. Continuous monitoring is recommended for components critical for life support, and that intermittent analysis be provided for all agents that may exceed one-half the spacecraft maximum allowable concentration. The minimum monitoring effort recommended includes continuous monitoring for: N2, O2, CO2, CO, H2O, H2, CH4, nonmethane hydrocarbons, aromatic hydrocarbons, refrigerants, and halons. Information on over 70 compounds is presented on the rationale for monitoring the frequency of analysis, and concentration ranges.

Casserly, Dennis M.↗

NASA NTRS1987

Magnetic suspension and balance systems (MSBSs)

The problems of wind tunnel testing are outlined, with attention given to the problems caused by mechanical support systems, such as support interference, dynamic-testing restrictions, and low productivity. The basic principles of magnetic suspension are highlighted, along with the history of magnetic suspension and balance systems. Roll control, size limitations, high angle of attack, reliability, position sensing, and calibration are discussed among the problems and limitations of the existing magnetic suspension and balance systems. Examples of the existing systems are presented, and design studies for future systems are outlined. Problems specific to large-scale magnetic suspension and balance systems, such as high model loads, requirements for high-power electromagnets, high-capacity power supplies, highly sophisticated control systems and position sensors, and high costs are assessed.

Britcher, Colin P.↗

NASA NTRS1991

Computational simulation of the creep-rupture process in filamentary composite materials

A computational simulation of the internal damage accumulation which causes the creep-rupture phenomenon in filamentary composite materials is developed. The creep-rupture process involves complex interactions between several damage mechanisms. A statistically-based computational simulation using a time-differencing approach is employed to model these progressive interactions. The finite element method is used to calculate the internal stresses. The fibers are modeled as a series of bar elements which are connected transversely by matrix elements. Flaws are distributed randomly throughout the elements in the model. Load is applied, and the properties of the individual elements are updated at the end of each time step as a function of the stress history. The simulation is continued until failure occurs. Several cases, with different initial flaw dispersions, are run to establish a statistical distribution of the time-to-failure. The calculations are performed on a supercomputer. The simulation results compare favorably with the results of creep-rupture experiments conducted at the Lawrence Livermore National Laboratory.

Slattery, Kerry T.↗

NASA NTRS1992

Energy loss analysis of an integrated space power distribution system

The results of studies related to conceptual topologies of an integrated utility-like space power system are described. The system topologies are comparatively analyzed by considering their transmission energy losses as functions of mainly distribution voltage level and load composition. The analysis is expedited by use of a Distribution System Analysis and Simulation (DSAS) software. This recently developed computer program by the Electric Power Research Institute (EPRI) uses improved load models to solve the power flow within the system. However, present shortcomings of the software with regard to space applications, and incompletely defined characteristics of a space power system make the results applicable to only the fundamental trends of energy losses of the topologies studied. Accountability, such as included, for the effects of the various parameters on the system performance can constitute part of a planning tool for a space power distribution system.

Kankam, M. David↗

NASA NTRS1992

Energy loss analysis of an integrated space power distribution system

Kankam, M. D.↗

NASA NTRS1994

A comparison of eastern North American seismic strain-rates to glacial rebound strain-rates

Glacial rebound strain-rates computed using a simple Laurentide glacial loading model are of the order of 10(exp -9) per year within the region of glaciation and extending several hundred kilometers beyond. The horizontal strain-rates receive approximately equal contributions from horizontal and vertical velocities, a consequence of the spherical geometry adopted for the Earth model. In the eastern United States and southeastern Canada the computed strain-rates are 1-3 orders of magnitude greater than an estimate of the average seismic strain-rate (Anderson, 1986) and approximately 1 order of magnitude greater than predicted erosional strain-rates. The predicted glacial rebound strain-rates are not, in general, oriented in such a way as to augment the observed state of deviatoric stress, possibly explaining why the seismic strain-rates are much smaller than the glacial rebound strain-rates. An exception to this may be seismically active regions in the St. Lawrence valley.

James, Thomas S.↗

NASA NTRS1999

Recent Advances in Mars Tectonics

Since the publication of the "Stress and Tectonics on Mars" chapter in the Mars book (the last comprehensive summary of our knowledge on the topic) considerable advances have been made in certain areas of Martian tectonics and significant advances are expected with the return of Mars Global Surveyor data. This abstract will summarize the advances in our knowledge of tectonic features and processes on Mars since the Mars book and point towards new areas of research that can be expected from the Mars Global Surveyor data. Two out of three areas of study that were discussed as future directions of work in the Mars chapter have had significant work directed towards them. One area is the field of structural mapping and understanding the timing of tectonic activity on Mars in the framework of the global stratigraphy. Although the general development and relative timing of the development of the Tharsis province on Mars had been understood for some time, actual placement of mapped tectonic features in a global stratigraphic framework has only recently been completed. The second area of study mentioned in the Mars chapter was the impact of improved topography and gravity on modeling loads and deriving stresses in the Martian lithosphere. Mars Global Surveyor is on the brink of returning vastly improved topographic and gravity fields and these newer data sets can be used to better define the size and shape of Tharsis and to quantify loads and derived stresses in the Martian lithosphere. Additional information is contained in the original extended abstract.

Golombek, M. P.↗

NASA NTRS2007

Risk Assessment of Bone Fracture During Space Exploration Missions to the Moon and Mars

The possibility of a traumatic bone fracture in space is a concern due to the observed decrease in astronaut bone mineral density (BMD) during spaceflight and because of the physical demands of the mission. The Bone Fracture Risk Module (BFxRM) was developed to quantify the probability of fracture at the femoral neck and lumbar spine during space exploration missions. The BFxRM is scenario-based, providing predictions for specific activities or events during a particular space mission. The key elements of the BFxRM are the mission parameters, the biomechanical loading models, the bone loss and fracture models and the incidence rate of the activity or event. Uncertainties in the model parameters arise due to variations within the population and unknowns associated with the effects of the space environment. Consequently, parameter distributions were used in Monte Carlo simulations to obtain an estimate of fracture probability under real mission scenarios. The model predicts an increase in the probability of fracture as the mission length increases and fracture is more likely in the higher gravitational field of Mars than on the moon. The resulting probability predictions and sensitivity analyses of the BFxRM can be used as an engineering tool for mission operation and resource planning in order to mitigate the risk of bone fracture in space.

Lewandowski, Beth E.↗

NASA NTRS2008

Risk Assessment of Bone Fracture During Space Exploration Missions to the Moon and Mars

Lewandowski, Beth E.↗

NASA NTRS2009

NASA #837 Tribute The Jet with a Thousand Faces

This slide presentation reviews the TF-1 (later designated as an F-15B) aircraft, which was delivered as an F-15 trainer. The aircraft was used as a test aircraft for various programs. The aircraft was later renamed to NASA 837 in 2001. Prior to its retirement it was used to test various features and concepts. Some of these tests were: (1) Canopy Off Testing, (2) STOL and Maneuvering Technology Demonstrator (S/MTD), (3) 2D Nozzles (4) Autonomous landing guidance, (5) Advanced Control Technology for Integrated Vehicles (ACTIVE), (6) Intelligent Flight Control System (IFCS), (7) Structural Loads Model Validation (SLMV), (8) Enhanced Communication and Navigation System (ECANS), (9) QuietSpike Probing, and (10) Lift and Nozzle Effects on Tail Shocks (LaNCETS)

Rhoades, Carrie M.↗

NASA NTRS2009

Stability and Control Analysis of the F-15B Quiet SpikeTM Aircraft

The primary purpose of the Quiet Spike(TradeMark) flight research program was to analyze the aerodynamic, structural, and mechanical proof-of-concept of a large multi-stage telescoping nose spike installed on the National Aeronautics and Space Administration Dryden Flight Research Center (Edwards, California) F-15B airplane. This report describes the preflight stability and control analysis performed to assess the effect of the spike on the stability, controllability, and handling qualities of the airplane; and to develop an envelope expansion approach to maintain safety of flight. The overall flight test objective was to collect flight data to validate the spike structural dynamics and loads model up to Mach 1.8. Other objectives included validating the mechanical feasibility of a morphing fuselage at operational conditions and determining the near-field shock wave characterization. The two main issues relevant to the stability and control objectives were the effects of the spike-influenced aerodynamics on the F-15B airplane flight dynamics, and the air data and angle-of-attack sensors. The analysis covered the sensitivity of the stability margins, and the handling qualities due to aerodynamic variation and the maneuvering limitations of the F-15B Quiet Spike configuration. The results of the analysis and the implications for the flight test program are also presented.

McWherter, Shaun C.↗

NASA NTRS2016

The Effect of Golden Pothos in Reducing the Level of Volatile Organic Compounds in a Simulated Spacecraft Cabin

The impact of Golden Pothos on indoor air quality was studied against a simulated spacecraft trace contaminant load model, consistent with the International Space Station (ISS), containing volatile organic compounds (VOCs) and formaldehyde. Previous research provides inconclusive results on the efficacy of plant VOC removal which this projects seeks to rectify through a better experimental design. This work develops a passive system for removing common VOC's from spacecraft and household indoor air and decreasing the necessity for active cabin trace contaminant removal systems.

Ursprung, Matthew↗

NASA NTRS2019

A Study of the Individual Contributions of Heat Generated by a XRISM/Resolve ADR Stage Magnet and Its Magnetic Shielding

A typical Adiabatic Demagnetization Refrigerator (ADR) has modest cooling power, on the order of a few microwatts. Thus, understanding heat loads going into and generated within the ADR is vital to its efficiency as well as the efficiency of the total cryogenic system of a spacecraft. One of the many sources of heat that effects the total cryogenic system is the parasitic heat due to AC loss in the ADR magnet and hysteretic loss in its magnetic shielding during a ramp. Although the sum of the heat from both of these sources can be measured during the operation of the ADR, the individual contributions are not easily obtainable in situ. Therefore, a study is being conducted to experimentally measure the contributions of the parasitic heat produced during ramping from the magnet only and from the magnet-shield combo. This study will give better inputs to the heat load model of the total cryogenic system being built for the X-Ray Imaging and Spectroscopy Mission (XRISM) slated to launch in 2022.

AC Loss↗

NASA NTRSDate not supplied

Impedance Measurements of Motor Drives and Supplies in NASA NEAT Facility

Many electrified aircraft configurations consist of a number of power components operating on the same shared electrical bus. Understanding the impedance performance of electrical loads and sources is key to understanding, and designing for, acceptable overall vehicle power quality and power system stability. This paper discusses impedance measurements made on the NASA Electric Aircraft Testbed (NEAT) Electrical Power System (EPS) at NASA Glenn Research Center. First, an overall discussion of the NEAT facility configuration during testing is presented. Then, details of the impedance measurement approach and the various testing configurations are discussed. Next, input impedance measurements at NEAT, including sources (DC supplies) and loads (multiple motor drives, electric machines, and resistive load banks, with long interconnecting cable leads), are performed under a number of conditions, and results, including load model comparisons and stability analysis, are presented and discussed.

electrified aircraft propulsion↗

NASA NTRSDate not supplied

Impedance Measurements of Motor Drives and Supplies in NASA NEAT Facility

Many electrified aircraft configurations consist of a number of power components operating on the same shared electrical bus. Understanding the impedance performance of electrical loads and sources is key to understanding, and designing for, acceptable overall vehicle power quality and power system stability. This paper discusses impedance measurements made on the NASA Electric Aircraft Testbed (NEAT) Electrical Power System (EPS) at NASA Glenn Research Center. First, an overall discussion of the NEAT facility configuration during testing is presented; then details of the impedance measurement approach and the various testing configurations are discussed. Next, input impedance measurements at NEAT, including sources (DC supplies) and loads (multiple motor drives, electric machines, and resistive load banks, with long interconnecting cable leads), are performed under a number of conditions, and results, including load model comparisons and stability analysis, are presented and discussed.

electrified aircraft propulsion↗

NASA NTRS2024

MSFC-TVC | TB-03: Derivation of Thrust Vector Control (TVC) Actuator-Force / Gimbal-Torque Transformation Matrix

Thrust vector control (TVC) systems for rocket engine propulsion traditionally use a simple linear relationship to convert between actuator forces and torques about the engine gimbal’s center-of-rotation (COR). As shown in Equation (1), the torque about the gimbal COR is proportional to the applied actuator force and the TVC moment arm (MA)—the perpendicular distance between the TVC actuator’s line-of-action (LOA) and the engine gimbal’s COR. While this fundamental relationship remains valid and accurate in a two-dimensional (2D), one-degree-of-freedom (1-DOF) context—particularly in its non-linear formulation as described in the ER63 Technical Bulletin TB-02 (Derivation of Thrust Vector Control (TVC) Engine-Gimbal / Actuator Moment-Arm Geometry)—it becomes limited when extended to three-dimensional (3D), two-degree-of-freedom (2-DOF) analyses. In 3D, out-of-plane angular displacements can arise, causing the gimbaled engine plane-of-motion to become non-coplanar with the respective actuator plane-of-motion. Such misalignments occur due to the rod-end (RE) and/or tail-stock (TE) mounting geometry of individual TVC actuators. These geometric complexities lead to inaccuracies in calculating engine torques and corresponding actuator forces if only the traditional TVC MA relationship is employed. For higher gimbal angular displacements (e.g., greater than 5 degrees), these inaccuracies become more pronounced, necessitating a more robust mathematical framework. This document presents a comprehensive 3D (2-DOF) derivation of a transformation matrix that accurately converts between gimbaled engine torques and TVC actuator forces. By incorporating the necessary geometric and rotational considerations, this new approach corrects the limitations of the traditional TVC MA method. Subsequent sections compare the newly formulated approach to the traditional method, demonstrating its enhanced accuracy and reliability for a broad range of gimbaled engine conditions.

Thrust Vector Control↗

NASA NTRS2024

Updates to NASA’S Break-in-Prebreathe Flight Rules Due to Type II Decompression Sickness Risk Considerations

Investigation of a central neurological decompression sickness (DCS) case during hypobaric ground testing at Johnson Space Center (JSC) identified a ~3 min break-in-prebreathe (BiP) late in the prebreathe (13 min prior to depressurization) as the leading credible cause for the DCS case. This occurred despite applicable prebreathe payback rules being followed. Applicable NASA rules, for ground and flight, directed 2:1 payback of breaks up to 10 min in duration, regardless of when a break occurs relative to depress. Breaks lasting longer than 10 min require a complete restart of the prebreathe protocol. The adequacy of NASA’s BiP rules was evaluated prior to resuming any hypobaric ground testing or International Space Station (ISS) extravehicular activity (EVA). Of particular interest to the authors was the timing of the BiP in relation to the overall prebreathe timeline. Although there exists no agreed-upon definition, a ‘late’ BiP means towards the end of the prebreathe period, and in particular, the last hour prior to depressurization. The following information sources were reviewed prior to formulating recommendations: i) the type II DCS case report and findings from the investigation; ii) documented rationale for existing flight rules, iii) consultations with subject matter experts involved in definition of existing flight rules (several of whom had since left NASA); iv) relevant published literature; v) tissue gas loading model estimates; and vi) NASA’s operational experience with late breaks in prebreathe.

Andrew F J Abercromby↗

DOE OSTI2025

Demand response of loads having thermal reserves

Systems and methods are described herein that improve grid performance by smoothing demand using thermal reserves. The smoothed demand can reduce peak loads as well as the ramp rate of demand that will otherwise require the use of inefficient, expensive generation sources. These improvements are tied to the selective switching on or off electrical loads that are coupled to thermal reserves, effectively using the thermal reserves as an energy storage mechanism. Historical data of past usage can be used to create load model and ensure that effects on customer comfort are minimized while still accomplishing the beneficial effects for the overall grid, which enables grid owners to both reduce their operational cost by avoiding expensive generation and improve system reliability by achieving more predictable power demand.

Ren, Wei↗