Results for “Energy use model” — Page 38

NASA NTRS1977

A nickel-cadmium battery reconditioning circuit

The circuit presented is simple and small enough to be included in a typical battery charge/power control assembly, yet provides the advantage of a complete ground-type battery reconditioning discharge. Test results on the circuit when used to recondition two 24 cell, 20 A-h nickel-cadmium batteries are given. These results show that a battery reconditioned with this circuit returns to greater than 90 percent of its original capacity (greater than nameplate capacity) and follows a typical new battery degradation curve even after over 20,000 simulated orbital cycles for a 4 year period. Applications of the circuit are considered along with recommendations relative to its use. Its application in low voltage (22 to 36 Vdc) power systems and in high voltage (100 to 150 Vdc) power systems is discussed. The implications are that the high voltage systems have a greater need for battery reconditioning than their low voltage counterparts, and that using these circuit techniques, the expected life of a battery in low Earth orbit can be up to 5 years.

Lanier, R.↗

NASA NTRS2014

Crewed Space Vehicle Battery Safety Requirements

This requirements document is applicable to all batteries on crewed spacecraft, including vehicle, payload, and crew equipment batteries. It defines the specific provisions required to design a battery that is safe for ground personnel and crew members to handle and/or operate during all applicable phases of crewed missions, safe for use in the enclosed environment of a crewed space vehicle, and safe for use in launch vehicles, as well as in unpressurized spaces adjacent to the habitable portion of a space vehicle. The required provisions encompass hazard controls, design evaluation, and verification. The extent of the hazard controls and verification required depends on the applicability and credibility of the hazard to the specific battery design and applicable missions under review. Evaluation of the design and verification program results shall be completed prior to certification for flight and ground operations. This requirements document is geared toward the designers of battery systems to be used in crewed vehicles, crew equipment, crew suits, or batteries to be used in crewed vehicle systems and payloads (or experiments). This requirements document also applies to ground handling and testing of flight batteries. Specific design and verification requirements for a battery are dependent upon the battery chemistry, capacity, complexity, charging, environment, and application. The variety of battery chemistries available, combined with the variety of battery-powered applications, results in each battery application having specific, unique requirements pertinent to the specific battery application. However, there are basic requirements for all battery designs and applications, which are listed in section 4. Section 5 includes a description of hazards and controls and also includes requirements.

Jeevarajan, Judith A.↗

NASA NTRSDate not supplied

Evaluation of Particle Degradation of a Ytterbium Disilicate Gas Turbine Coating in a Combustion Environment

Ytterbium disilicate (Yb2Si2O7) is a state-of-the-art topcoat material used in environmental barrier coatings (EBCs) to protect SiC-SiC composites from water vapor corrosion in gas turbine engines. However, it’s degradation by thermochemical and thermomechanical particle interactions may limit its use in next generation engine systems. Several static furnace tests have been performed on Yb2Si2O7 to elucidate methods of degradation, although dynamic testing in an engine-relevant environment has not been carried out. Ultimately, testing and evaluation of materials that incorporates all environmental damage modes will allow for an accurate assessment of long-term durability and operating lifetime. This work details the investigation of particle-induced erosion and corrosion of Yb2Si2O7 in NASA Glenn’s Erosion Burner Rig Facility. Coating durability was investigated as a function of test temperature, particle size, and deposition rate. Thermal cycling was also incorporated into testing to determine the interplay of heating/cooling cycles with particle degradation. Overall, these analyses will be used to determine coating robustness in an engine relevant environment.

Jamesa L Stokes↗

NASA NTRSDate not supplied

Evaluation of Particle Degradation of a Ytterbium Disilicate Gas Turbine Coating in a Combustion Environment

Ytterbium disilicate (Yb2Si2O7) is a state-of-the-art topcoat material used in environmental barrier coatings (EBCs) to protect SiC-SiC composites from water vapor corrosion in gas turbine engines. However, it’s degradation by thermochemical and thermomechanical particle interactions may limit its use in next generation engine systems. Several static furnace tests have been performed on Yb2Si2O7 to elucidate methods of degradation, although dynamic testing in an engine-relevant environment has not been carried out. Ultimately, testing and evaluation of materials that incorporates all environmental damage modes will allow for an accurate assessment of long-term durability and operating lifetime. This work details the investigation of particle-induced erosion and corrosion of Yb2Si2O7 in NASA Glenn’s Erosion Burner Rig Facility. Coating durability was investigated as a function of test temperature, particle size, and deposition rate. Thermal cycling was also incorporated into testing to determine the interplay of heating/cooling cycles with particle degradation. Overall, these analyses will be used to determine coating robustness in an engine relevant environment.

Jamesa L Stokes↗

NASA NTRS1997

Fullerenes, PAH, Carbon Nanostructures, and Soot in Low Pressure Diffusion Flames

The formation of fullerenes C 60 and C 7O is known to occur in premixed laminar benzene/oxygen/argon flames operated at reduced pressures. High resolution transmission electron microscopy (HRTEM) images of material collected from these flames has identified a variety of multishelled nanotubes and fullerene 'onions' as well as some trigonous structures. These fullerenes and nanostructures resemble the material that results from commercial fullerene production systems using graphite vaporization. As a result, combustion is an interesting method for fullerenes synthesis. If commercial scale operation is to be considered, the use of diffusion flames might be safer and less cumbersome than premixed flames. However, it is not known whether diffusion flames produce the types and yields of fullerenes obtained from premixed benzene/oxygen flames. Therefore, the formation of fullerenes and carbon nanostructures, as well as polycyclic aromatic hydrocarbons (PAH) and soot, in acetylene and benzene diffusion flames is being studied using high performance liquid chromatography (HPLC) and high resolution transmission electron microscopy (HRTEM).

William J Grieco↗

NASA NTRS2026

Recommended Practices in Laser-Induced Fluorescence (LIF) Diagnostics for Electric Propulsion

Laser-induced fluorescence (LIF) spectroscopy uses Doppler-shifted laser photons to excite a bound electron transition in an atom or ion, with subsequent fluorescence emission detected in order to measure the local velocity distribution function (VDF) and/or particle density. Due to its non-invasive nature, high spatial resolution, and acceptable difficulty of implementation, LIF has become a favored diagnostic for electric propulsion (EP) plasmas, particularly in the study of Hall thrusters. This paper presents recommended best practices for LIF measurements in electric thrusters, drawn from over three decades of implementation heritage in the EP community. Focusing on both single-photon LIF (typically used to measure VDFs) and two-photon LIF (TALIF, typically used to determine densities), the paper covers selection of atomic transitions to target, experimental setups, and interpretation of data. A number of special topics and advanced applications are discussed, including uncertainty analysis, techniques for high-speed measurements, and applications to a variety of propellants.

plasma plume↗

NASA NTRS1971

The 20 kW battery study program

Six battery configurations were selected for detailed study and these are described. A computer program was modified for use in estimation of the weights, costs, and reliabilities of each of the configurations, as a function of several important independent variables, such as system voltage, battery voltage ratio (battery voltage/bus voltage), and the number of parallel units into which each of the components of the power subsystem was divided. The computer program was used to develop the relationship between the independent variables alone and in combination, and the dependent variables: weight, cost, and availability. Parametric data, including power loss curves, are given.

Source record↗

NASA NTRS2000

Implementation of Self-Align Local Poly Interconnection on 0.25 Micron Flash Memory

For ETOX Flash technology. the self-aligned source module plays a critical role in minimizing cell size. For advanced Flash technology using the shallow-trench isolation (STI) scheme, however, it is difficult to form a stable source line. The Flash process in this experiment features an ETOX structure and with SIN spacer. Poly-Si (implanted poly) is used as the local interconnection material connecting the source line and was successfully implemented in the ETOX flash array in this paper.

C H Lee↗

NASA NTRS2026

Computational Materials for Qualification and Certification (CM4QC) Strategy Document: Maturation of Computational Materials Methods for Aviation-Focused Qualification and Certification of Metal Additive Manufacturing (as an Example of Process-Intensive Materials)

Although considerable scientific and technological advances have been made in recent years in additive manufacturing (AM) processes, these advances have not translated into significant market penetration of AM parts within the aviation industry. It is broadly acknowledged that using traditional qualification and certification (Q&C) approaches for AM components is one of the most significant barriers to broader adoption of AM, resulting in high costs, long product development and certification timelines, and complex design iterations during the product development cycle. A new approach is urgently needed. This document lays out a vision for a new Q&C paradigm with increased use of computational materials (CM) methods aimed at decreasing the time and cost of Q&C of process-intensive material (PIM) approaches in the aviation industry, with AM as the immediate use case. This vision was developed with substantial input from industry, regulatory agencies, government research organizations, and academia.

Edward H Glaessgen↗

NASA NTRS1964

Dry tape battery

Battery system using dry tape continuous feed of magnesium fuel

MAGNESIUM COMPOUND↗

NASA NTRSDate not supplied

Evaluating Crystallinity in Thermoplastic composites

Polymer matrix composites (PMCs) offer many benefits for the aerospace industry due to their potential for weight reduction when compared to metal or ceramic based materials. Most PMCs currently in flight use thermoset matrices, however, thermoplastic resins are being explored as alternatives due to their ability to be remelted, which is of particular interest due to the potential for in-situ repair and manufacturing required in space. Most thermoplastic resins are semicrystalline polymers. The properties of semicrystalline thermoplastics are largely influenced by their crystallinity, which can vary due to many factors including thermal treatments, environmental conditions, and mechanical deformation. Monitoring the crystallinity of thermoplastic composites is key to ensuring these materials reliably meet the high demands required by space exploration. This talk discusses the use of multiple techniques such as Polarized Light Optical Microscopy and Fourier-Transform Infrared Spectroscopy to characterize the crystallinity in various thermoplastic composites, including carbon fiber reinforced PMCs and novel bio-based Martian and Lunar regolith composites designed for in-situ manufacturing. This work aims to provide the fundamental data necessary to understand the effects of crystallinity on thermoplastic PMCs, which is key to advancing their use in space applications.

Thermoplastics↗

NASA NTRS2026

A Review of Pump Package Assembly Anomalies and Demonstration to Gain Motor Controller Replacement Capability

The International Space Station (ISS) generates heat within the US modules from systems used to operate the station, maintain crew health, and conduct science experiments in the orbiting laboratory. The Internal Thermal Control System (ITCS) collects this heat in water loops and transfers it to the external ammonia system for rejection to space. The ITCS uses six Pump Package Assemblies (PPA) as the motive force to circulate the water within the Lab, Node 2, and Node 3 (Node 1 is parasitic to the Lab and Node 3 ITCS loops). In the life of ISS, 3 PPAs have had to be replaced and 2 PPAs are currently showing signs of degradation. The first PPA to fail in 2003 was due to early coolant chemistry issues; the remaining pump failures and current pump degradations are determined to be related to the Pump/Fan Motor Controller (PFMC), with their individual signatures all being unique to this point. The PFMC of one of the failed PPAs was returned and testing confirmed its sub-components to be the root cause of the PPA failure. Due to the relative size and weight of the standalone PFMC in comparison to the integrated assembly, it is desired, from a launch and on-orbit stowage perspective, to replace the PFMC component of the degraded PPA instead of the entire PPA. The PPA was not designed for this capability, so on the ground demonstrations are planned using crew tools to show that the PFMC can be replaced on-orbit while maintaining full functionality. This paper will focus on the signatures of the two most recent PPA failures and the two PPAs showing signs of degradation, in addition to presenting the findings from the PFMC demonstration effort.

Aaron Rodriguez↗

NASA NTRS2026

A Review of Pump Package Assembly Anomalies and Demonstration to Gain Motor Controller Replacement Capability

The International Space Station (ISS) generates heat within the US modules from systems used to operate the station, maintain crew health, and conduct science experiments in the orbiting laboratory. The Internal Thermal Control System (ITCS) collects this heat in water loops and transfers it to the external ammonia system for rejection to space. The ITCS uses six Pump Package Assemblies (PPA) as the motive force to circulate the water within the Lab, Node 2, and Node 3 (Node 1 is parasitic to the Lab and Node 3 ITCS loops). In the life of ISS, 3 PPAs have had to be replaced and 2 PPAs are currently showing signs of degradation. The first PPA to fail in 2003 was due to early coolant chemistry issues; the remaining pump failures and current pump degradations are determined to be related to the Pump/Fan Motor Controller (PFMC), with their individual signatures all being unique to this point. The PFMC of one of the failed PPAs was returned and testing confirmed its sub-components to be the root cause of the PPA failure. Due to the relative size and weight of the standalone PFMC in comparison to the integrated assembly, it is desired, from a launch and on-orbit stowage perspective, to replace the PFMC component of the degraded PPA instead of the entire PPA. The PPA was not designed for this capability, so on the ground demonstrations are planned using crew tools to show that the PFMC can be replaced on-orbit while maintaining full functionality. This paper will focus on the signatures of the two most recent PPA failures and the two PPAs showing signs of degradation, in addition to presenting the findings from the PFMC demonstration effort.

Aaron Rodriguez↗

NASA NTRS1985

Nondestructive Evaluation of Composites By Optical Time Domain Reflectometry

Results in the measurement of slowly varying mechanical loading functions on composites using optical time domain reflectometry (OTDR) in imbedded optical fiber during both simulated manufacture and use are reviewed. First, the basic theoretical and experimental principles of the OTDR system are described. Next, the mechanical system of the composite and the imbedded fiber is analyzed. Results of measurement obtained for various loading functions applied to material specimens are then described and system limitations on spatial resolution, strain amplitude sensitivity, and frequency response are explained in terms of the range and resolution limits of the OTDR system.

R O Claus↗

NASA NTRS2026

Updates and Modernization of NASA’s Chemical Equilibrium with Applications (CEA) Code

NASA’s Chemical Equilibrium with Applications (CEA) code is a foundational tool for propulsion system analysis. It provides equilibrium chemistry, rocket performance, shock, and detonation calculations used across NASA and the broader aerospace community. NASA Engineering and Safety Center (NESC) Activity TI-22-01730 modernized the legacy CEA2 Fortran code into CEA v3, a Fortran 2008, object-oriented software package with expanded interface support, updated thermochemical data, improved maintainability, and substantially improved workflow integration. The modernized code preserves backward compatibility with legacy CEA input workflows while enabling direct use from modern analysis environments, including Python, C, MATLAB, and automated design studies.

Mark K Leader↗

NASA NTRS2026

Evaluation of AMSOIL® -ANT PGW Coolant Formula Change and Super Space AMSOIL Development

AMSOIL ® Propylene Glycol Water (PGW), is the baselined internal thermal control fluid for multiple manned spacecraft including Gateway (HALO, IHAB, and ALM modules) and Orion. The use of AMSOIL-ANT PGW was originally validated through extensive NASA/Collins materials-compatibility testing (circa 2008–2015). However, in late 2019, AMSOIL implemented an unannounced change in its PG inhibitor package. Because of this reformulation, concerns around materials compatibility arose. Therefore, NASA initiated corrosion rate and coolant stability testing in 2024. Results showed that the reformulated AMSOIL PG produced substantially elevated corrosion rates in aluminum alloys (about two times when compared to the original AMSOIL PG formula) accompanied by visible surface degradation. Coolant stability testing indicated accelerated propylene-glycol breakdown as well, with glycolate levels about nine times higher than the original formulation. Based on these findings, NASA Materials & Processes and Thermal Control Systems groups have baselined the use of the original PGW chemistry for all spacecraft use. In response, AMSOIL produced a reformulated variant, “Super Space AMSOIL” (ANT-SSA), compliant with MPCV 70156.This paper documents the reformulation testing completed, details on the formulation change, and the development of Super Space AMSOIL.

Woody Beringer↗

NASA NTRSDate not supplied

Evaluation of AMSOIL ® -ANT PGW Coolant Formula Change and Super Space AMSOIL ® Development

AMSOIL ® Propylene Glycol Water (PGW), is the baselined internal thermal control fluid for multiple manned spacecraft including Gateway (HALO, IHAB, and ALM modules) and Orion. The use of AMSOIL-ANT PGW was originally validated through extensive NASA/Collins materials-compatibility testing (circa 2008–2015). However, in late 2019, AMSOIL implemented an unannounced change in its PG inhibitor package. Because of this reformulation, concerns around materials compatibility arose. Therefore, NASA initiated corrosion rate and coolant stability testing in 2024. Results showed that the reformulated AMSOIL PG produced substantially elevated corrosion rates in aluminum alloys (about two times when compared to the original AMSOIL PG formula) accompanied by visible surface degradation. Coolant stability testing indicated accelerated propylene-glycol breakdown as well, with glycolate levels about nine times higher than the original formulation. Based on these findings, NASA Materials & Processes and Thermal Control Systems groups have baselined the use of the original PGW chemistry for all spacecraft use. In response, AMSOIL produced a reformulated variant, “Super Space AMSOIL” (ANT-SSA), compliant with MPCV 70156.This paper documents the reformulation testing completed, details on the formulation change, and the development of Super Space AMSOIL.

David Brockett↗

NASA NTRS1964

Pressurized-Cell Experiment

Pressurized-cell detectors were developed and constructed at the Langley Research Center to obtain a direct measurement of the micrometeoroid puncture hazard to thin structural material. A total of 160 detectors were mounted around the periphery of the rocket motor used on the Explorer XIII satellite. (See fig. IX-1.) Material thicknesses of 0.001, 0.0015, 0.002, 0.0025, and 0.005 inch were used on the detectors. The exposed surface of the test material of each detector was 21.8 square inches and the total exposed surface of the 160 detectors was 24.2 square feet. The average weight of the detectors was 68 grams.

Micrometeoroid↗