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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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All sourcesNASA NTRSDOE OSTI
NASA NTRS2001

Space Power Architectures for NASA Missions: The Applicability and Benefits of Advanced Power and Electric Propulsion

The relative importance of electrical power systems as compared with other spacecraft bus systems is examined. The quantified benefits of advanced space power architectures for NASA Earth Science, Space Science, and Human Exploration and Development of Space (HEDS) missions is then presented. Advanced space power technologies highlighted include high specific power solar arrays, regenerative fuel cells, Stirling radioisotope power sources, flywheel energy storage and attitude control, lithium ion polymer energy storage and advanced power management and distribution.

Hoffman, David J.↗
NASA NTRS2016

Solar vs. Fission Surface Power for Mars

A multi-discipline team of experts from the National Aeronautics and Space Administration (NASA) developed Mars surface power system point design solutions for two conceptual missions. The primary goal of this study was to compare the relative merits of solar- versus fission-powered versions of each surface mission. First, the team compared three different solar power options against a fission power system concept for a sub-scale, uncrewed demonstration mission. The 4.5 meter (m) diameter pathfinder lander's primary mission would be to demonstrate Mars entry, descent, and landing techniques. Once on the Martian surface, the lander's In Situ Resource Utilization (ISRU) payload would demonstrate liquid oxygen propellant production using atmospheric resources. For the purpose of this exercise, location was assumed to be at the Martian equator. The three solar concepts considered included a system that only operated during daylight hours (at roughly half the daily propellant production rate of a round-the-clock fission design), a battery-augmented system that operated through the night (matching the fission concept's propellant production rate), and a system that operated only during daylight, but at a higher rate (again, matching the fission concept's propellant production rate). Including 30% mass growth allowance, total payload masses for the three solar concepts ranged from 1,116 to 2,396 kg, versus the 2,686 kg fission power scheme. However, solar power masses are expected to approach or exceed the fission payload mass at landing sites further from the equator, making landing site selection a key driver in the final power system decision. The team also noted that detailed reliability analysis should be performed on daytime-only solar power schemes to assess potential issues with frequent ISRU system on/off cycling. Next, the team developed a solar-powered point design solution for a conceptual four-crew, 500-day surface mission consisting of up to four landers per crewed expedition mission. Unlike the demonstration mission, a lengthy power outage due to the global dust storms that are known to occur on Mars would pose a safety hazard to a crewed mission. A similar fission versus solar power trade study performed by NASA in 2007 concluded that fission power was more reliable-with a much lower mass penalty-than solar power for this application. However, recent advances in solar cell and energy storage technologies and changes in operational assumptions prompted NASA to revisit the analysis. For the purpose of this exercise a particular landing site at Jezero Crater, located at 18o north latitude, was assumed. A fission power system consisting of four each 10 kW Kilopower fission reactors was compared to a distributed network of Orion-derived Ultraflex solar arrays and Lithium ion batteries mounted on every lander. The team found that a solar power system mass of about 9,800 kg would provide the 22 kilowatts (kW) keep-alive power needed to survive a dust storm lasting up to 120-days at average optical depth of 5, and 35 kW peak power for normal operations under clear skies. Although this is less than half the mass estimated during the 2007 work (which assumed latitudes up to 30o) it is still more than the 7,000 kg mass of the fission system which provides full power regardless of dust storm conditions.

Rucker, Michelle A.↗
NASA NTRSDate not supplied

Cathode Modeling of Solid-State Batteries

The search for safe, reliable, and compact high-capacity energy storage devices has led to increased interest in all-solid-state battery research. The use of solid electrolytes provides enhanced safety and durability due to their reduced flammability and increased mechanical strength compared to organic liquid electrolytes. Still, the use of solid electrolytes remains challenging. Computational modeling plays a substantial role in addressing these challenges. A particle dynamics electromechanical model for simulating electrochemical processes in a solid-state battery cathode will be presented. The model presents cathode microstructure at the particle level as a mixture of ionically conductive solid electrolyte particles, electrically conductive carbon additives, and cathodic reactant particles. After densification, the particle connectivity is analyzed to reconstruct the complex electric network connecting reactant particles with an anodic and cathodic current collectors through the electrolyte and carbon particles. The Kirchhoff’s matrix equation describing this electric network, is solved to obtain values of various critical parameters, such as the overall conductivity of the cathode for lithium ions and electrons, cathodic reactant material utilization, and the distribution of the electric current and voltages within the cathode. In addition, by representing the reactant particles as electrolyte or galvanic microcells governed by the Butler-Volmer electrochemical equation, the overall performance of battery cells during charge or discharge processes, respectively, can be predicted for a given cathodic powder composition. The presented model, executed on a high-performance computing architecture, essentially provides a valuable guidance in designing and developing future solid-state batteries.

solid-state battery↗
NASA NTRS2008

Desert Research and Technology Studies (RATS) 2007 Field Campaign Objectives and Results

Desert "RATS" (Research and Technology Studies) is a combined, multi-discipline group of inter-NASA center scientists and engineers, net-working and collaborating with representatives of industry and academia, for the purpose of conducting planetary surface exploration-focused remote field exercises. These integrated testing exercises conducted under representative analog Lunar and Mars surface terrain conditions, provide NASA the capability to validate experimental prototype hardware and software systems as well as to evaluate and develop mission operational techniques in order to identify and establish technical requirements and identify potential technology "gaps" applicable for future planetary human exploration. The 2007 D-RATS field campaign test activities were initiated based on the major themes and objectives of a notional 5-year plan developed for conducting relative analog test activities in support of the engineering evaluation and assessment of various system architectural requirements, conceptual prototype support equipment and selected technologies necessary for the establishment of a lunar outpost. Specifically, the major objectives included measuring task efficiency during robot, human, and human-robot interactive tasks associated with lunar outpost site surveying and reconnaissance activities and deployment of a representative solar panel power and distribution system. In addition, technology demonstrations were conducted with a new Lithium-ion battery and autonomous software to coordinate multiple robot activities. Secondary objectives were evaluating airlock concept mockups and prototype removable space suit over-garment elements for dust mitigation, and upgrades to the prototype extravehicular activities (EVA) communication and information system. Dry run test activities, prior to testing at a designated remote field site location, were initially conducted at the Johnson Space Center (JSC) Remote Field Demonstration Test Site. This is a multi-acre external test site located at JSC and has detailed representative terrain features simulating both Lunar and Mars surface characteristics. Both the local JSC and remote field test sites have terrain conditions that are representative and characteristic of both the Moon and Mars, such as strewn rock and volcanic ash fields, craters, rolling plains, hills, gullies, slopes, and outcrops. The D-RATS 2007 field campaign, representing the completion of its tenth year of analog testing, was conducted at the large Cinder Lake volcanic ash bed area adjacent to Flagstaff, Arizona.

Kosmo, Joseph↗
NASA NTRS2012

Ground and Airborne Methane Measurements using Optical Parametric Amplifiers

We report on an initial airborne demonstration of atmospheric methane column measurements at 1.65 micrometers using a widely tunable, seeded optical parametric amplifier (OPA) lidar and a photon counting detector. Methane is an important greenhouse gas and accurate knowledge of its sources and sinks is needed for climate modeling. Our lidar system uses 20 pulses at increasing wavelengths and integrated path differential absorption (IPDA) to map a methane line at 1650.9 nanometers. The wavelengths are generated by using a Nd:YAG pump laser at 1064.5 nanometers and distributed feedback diode laser at 1650.9 nanometers and a periodically-poled lithium niobate (PPLN) crystal. The pulse width was 3 nanoseconds and the pulse repetition rate was 6.28 KHz. The outgoing energy was approximately 13 microJoules/pulse. A commercial 20 nanometer diameter fiber-coupled telescope with a photon counting detector operated in analog mode with a 0.8 nanometer bandpass filter was used as the lidar receiver. The lidar system was integrated on NASA's DC-8 flying laboratory, based at Dryden Airborne operations Facility (DAOF) in Palmdale CA. Three flights were performed in the central valley of California. Each flight lasted about 2.5 hours and it consisted of several flight segments at constant altitudes at approximately 3, 4.5, 6, 7.6, 9.1, 10.6 km (l0, 15, 20, 25, 30, 35 kft). An in-situ cavity ring down spectrometer made by Picarro Inc. was flown along with the lidar instrument provided us with the "truth" i.e. the local CH4, CO2 and H2O concentrations at the constant flight altitude segments. Using the aircraft's altitude, GPS, and meteorological data we calculated the theoretical differential optical depth of the methane absorption at increasing altitudes. Our results showed good agreement between the experimentally derived optical depth measurements from the lidar instrument and theoretical calculations as the flight altitude was increased from 3 to 10.6 kilometers, assuming a constant methane mixing ratio of 1.8 parts per million. The in-situ spectrometer did not show any significant deviations from the ambient concentrations. Further analysis using meteorological data from the Global Modeling and Assimilation Office (http://gmao.gsfc.nasa.gov/) to derive the theoretical optical depth also showed good agreement with the experimentally derived values. The OPA lidar system with slight modifications has also been used to measure CO2, water vapor, and CO in the near and mid-infrared spectral regions on the ground.

Riris, Haris↗
NASA NTRS2005

Electric Power System Technology Options for Lunar Surface Missions

In 2004, the President announced a 'Vision for Space Exploration' that is bold and forward-thinking, yet practical and responsible. The vision explores answers to longstanding questions of importance to science and society and will develop revolutionary technologies and capabilities for the future, while maintaining good stewardship of taxpayer dollars. One crucial technology area enabling all space exploration is electric power systems. In this paper, the author evaluates surface power technology options in order to identify leading candidate technologies that will accomplish lunar design reference mission three (LDRM-3). LDRM-3 mission consists of multiple, 90-day missions to the lunar South Pole with 4-person crews starting in the year 2020. Top-level power requirements included a nominal 50 kW continuous habitat power over a 5-year lifetime with back-up or redundant emergency power provisions and a nominal 2-kW, 2-person unpressurized rover. To help direct NASA's technology investment strategy, this lunar surface power technology evaluation assessed many figures of merit including: current technology readiness levels (TRLs), potential to advance to TRL 6 by 2014, effectiveness of the technology to meet the mission requirements in the specified time, mass, stowed volume, deployed area, complexity, required special ground facilities, safety, reliability/redundancy, strength of industrial base, applicability to other LDRM-3 elements, extensibility to Mars missions, costs, and risks. For the 50-kW habitat module, dozens of nuclear, radioisotope and solar power technologies were down-selected to a nuclear fission heat source with Brayton, Stirling or thermoelectric power conversion options. Preferred energy storage technologies included lithium-ion battery and Proton Exchange Membrane (PEM) Regenerative Fuel Cells (RFC). Several AC and DC power management and distribution architectures and component technologies were defined consistent with the preferred habitat power generation technology option and the overall lunar surface mission. For rover power, more than 20 technology options were down-selected to radioisotope Stirling, liquid lithium-ion battery, PEM RFC, or primary fuel cell options. The author discusses various conclusions that can be drawn from the findings of this surface power technologies evaluation.

Kerslake, Thomas W.↗
NASA NTRS1985

A measurement of the efficiency of lithium vapor production in high altitude releases

The masses of lithium vapor produced in two sounding rocket chemical releases were determined by comparing ground measurements of the irradiance and the brightness distribution of the sunlit releases with the results from a model calculation. The yields of the two releases, which had different compositions, were found to be approximately 5 and 15 percent of the available lithium.

Ledley, B. G.↗
NASA NTRS2016

Lithium Inventory of 2 Solar Mass Red Clump Stars in Open Clusters: A Test of the Helium Flash Mechanism

The temperature distribution of field Li-rich red giants suggests the presence of a population of Li-rich red clump (RC) stars. One proposed explanation for this population is that all stars with masses near 2 solar mass experience a shortlived phase of Li-richness at the onset of core He-burning. Many of these stars have low C-12/C-13, a signature of deep mixing that is presumably associated with the Li regeneration. To test this purported mechanism of Li enrichment, we measured abundances in 38 RC stars and 6 red giant branch (RGB) stars in four open clusters selected to have RC masses near 2 solar mass. We find six Li-rich stars (A(Li) greater than or equal to 1.50 dex) of which only two may be RC stars. None of the RC stars have Li exceeding the levels observed in the RGB stars, but given the brevity of the suggested Li-rich phase and the modest sample size, it is probable that stars with larger Li-enrichments were missed simply by chance. However, we find very few stars in our sample with low C-12/C-13. Such low C-12/C-13, seen in many field Li-rich stars, should persist even after lithium has returned to normal low levels. Thus, if Li synthesis during the He flash occurs, it is a rare, but potentially long-lived occurrence rather than a short-lived phase for all stars. We estimate a conservative upper limit of the fraction of stars going through a Li-rich phase to be less than 47%, based on stars that have low C-12/C-13 for their observed A(Li).

Li-rich red giants↗
NASA NTRS1985

The stopping of deuterons in lithium

The interaction of 52 MeV deuterons with lithium was investigated, in view of the optimization of a lithium target for an intense neutron source based on the d-Li stripping reaction. The experimental results are compared with theoretical calculations obtained from an updated version of the Bragg code. This code describes in detail the interaction of charged particles with matter. Within the experimental uncertainties the theoretical results are well reproduced by the experiments.

NASA Program Space Medicine↗
NASA NTRSDate not supplied

Cryogenically-Operable Electronics for Surviving the Lunar Night

Current solar-powered robotic lunar landers and rovers have not demonstrated survivability of the extreme cold temperatures seen during the 354-hour lunar night. To address this capability gap, we have been investigating the feasibility of a passive hibernation approach to enable low-cost solar- and battery-powered missions to operate over multiple lunar cycles. This strategy relies on isolating the batteries from the main bus during the lunar night and allowing cells to freeze as temperatures descend as low as 50K. The entire power architecture remains in a hibernation state with no electrical activity until lunar dawn. When the sun returns over the horizon, the now-illuminated solar arrays begin generating power. In order to manage the array power, architecture consisting of cryogenically-operable COTS electronics must be utilized. This architecture will distribute and control power to subsystems - importantly controlling heaters to bring the frozen lithium-ion battery cells to normal operating conditions. This alternative approach to lunar operations will enable low-cost commercial lunar landers and payloads to passively survive the night and continue to operate over multiple lunar cycles without a significant impact to cost or payload mass. Research last year focused on creating a power supply that was capable of operation at cryogenic temperatures. At the end of FY23, our team successfully designed and manufactured a Sequential Switching Shunt Regulator (S3R) that is operational in a cryogenic vacuum chamber. It is capable of full operation down to the coldest lunar night temperatures (~50K). Our presentation will provide an overview of the Lunar Hibernation strategy but will focus mainly on the technical details of this cryogenically-operable shunt regulator and test results.

Cryogenic↗
NASA NTRS1983

Transmission electron microscopy characterization of microstructural features of Al-Li-Cu alloys

A transmission electron microscopy (TEM) examination of aluminum-lithium-copper alloys was conducted. The principal purpose is to characterize the nature, size, and distribution of stringer particles which result from the powder metallurgy (P/M) processing of these alloys. Microstructural features associated with the stringer particles are reported that help explain the stress corrosion susceptibility of the powder metallurgy-processed Al-Li-Cu alloys. In addition, matrix precipitation events are documented for a variety of heat treatments and process variations. Hot rolling is observed to significant alter the nature of matrix precipitation, and the observations are correlated with concomitant mechanical property variations.

Avalos-Borja, M.↗
NASA NTRS1984

Transmission electron microscopy characterization of microstructural features in aluminum-lithium-copper alloys

A transmission electron microscopy (TEM) examination of aluminum-lithium-copper alloys was conducted. The principal purpose is to characterize the nature, size, and distribution of stringer particles which result from the powder metallurgy (P/M) processing of these alloys. Microstructural features associated with the stringer particles are reported that help explain the stress corrosion susceptibility of the powder metallurgy-processed Al-Li-Cu alloys. In addition, matrix precipitaton events are documented for a variety of heat treatments and process variations. Hot rolling is observed to significantly alter the nature of matrix precipitation, and the observations are correlated with concomitant mechanical property variations.

Avalos-Borja, M.↗
NASA NTRS1997

Lithium Abundances in the Young Open Cluster IC 2602

We have obtained high-resolution spectra for 28 candidate late-type stars in the 30 Myr old cluster IC 2602. NLTE Li abundances have been derived from measured equivalent widths. The log n(Li) - T(sub eff) and log n(Li) - mass distributions for our sample stars have been compared with those of the Pleiades and alpha Persei. Our data show that F stars in the three clusters have the same lithium content, which corresponds to the initial content for Pop. I stars. G and early-K IC 2602 stars are, on average, somewhat more Li-rich than their counterparts in the two slightly older clusters. Finally, the latest-type IC 2602 stars are heavily Li depleted, with their Li content being as low as the lowest measured among the Pleiades. As in the Pleiades and alpha Per, a star-to-star scatter in lithium is observed among 30 Myr old late-K/early-K dwarfs in IC 2602, indicating that this spread develops in the pre-main sequence phases.

Randich, S.↗
NASA NTRS2003

High-Energy Two-Stage Pulsed Plasma Thruster

A high-energy (28 kJ per pulse) two-stage pulsed plasma thruster (MSFC PPT-1) has been constructed and tested. The motivation of this project is to develop a high power (approximately 500 kW), high specific impulse (approximately 10000 s), highly efficient (greater than 50%) thruster for use as primary propulsion in a high power nuclear electric propulsion system. PPT-1 was designed to overcome four negative characteristics which have detracted from the utility of pulsed plasma thrusters: poor electrical efficiency, poor propellant utilization efficiency, electrode erosion, and reliability issues associated with the use of high speed gas valves and high current switches. Traditional PPTs have been plagued with poor efficiency because they have not been operated in a plasma regime that fully exploits the potential benefits of pulsed plasma acceleration by electromagnetic forces. PPTs have generally been used to accelerate low-density plasmas with long current pulses. Operation of thrusters in this plasma regime allows for the development of certain undesirable particle-kinetic effects, such as Hall effect-induced current sheet canting. PPT-1 was designed to propel a highly collisional, dense plasma that has more fluid-like properties and, hence, is more effectively pushed by a magnetic field. The high-density plasma loading into the second stage of the accelerator is achieved through the use of a dense plasma injector (first stage). The injector produces a thermal plasma, derived from a molten lithium propellant feed system, which is subsequently accelerated by the second stage using mega-amp level currents, which eject the plasma at a speed on the order of 100 kilometers per second. Traditional PPTs also suffer from dynamic efficiency losses associated with snowplow loading of distributed neutral propellant. The twostage scheme used in PPT-I allows the propellant to be loaded in a manner which more closely approximates the optimal slug loading. Lithium propellant was chosen to test whether or not the reduced electrode erosion found in the Lithium Lorentz Force Accelerator (LiLFA) could also be realized in a pulsed plasma thruster. The use of the molten lithium dense plasma injector also eliminates the need for a gas valve and electrical switch; the injector design fulfills both roles, and uses no moving parts to provide, in principle, a highly reliable propellant feed and electrical switching system. Experimental results reported in this paper include: second-stage current traces, high-speed photographic and holographic imaging of the thruster exit plume, and internal mapping of the discharge chamber magnetic field from B-dot probe data. The magnetic field data is used to create a two-dimensional description of the evolution of the current sheet inside the thruster.

Markusic, Tom↗
NASA NTRSDate not supplied

Simulation Studies for an Urban Air Mobility Aircraft using Hardware-In-Loop Experiments

Urban Air Mobility seeks to transport passengers, deliver cargo, and provide emergency transportation in major metropolitan areas. This will be accomplished with distributed electric-powered vertical takeoff and landing aircraft. The low specific energy of the current generation lithium-ion battery packs limit the operational range of electric aircraft. Limited range impacts safety by reducing the time available for analyzing and responding to errors and failures, and limiting the ability to fly to an alternative landing area or return to base. It is therefore critical to understand flight operational and environmental conditions that impact the onboard lithium-ion polymer battery pack’s health. With this as the motivation, experimental procedure in a laboratory setting, and results of the experiments performed on battery packs subject to power draw corresponding to power required during the different phases of flight of a NASA conceptual quadrotor aircraft in simulation are described. The fully charged battery is allowed to discharge at specific C-rates based on the power draw profile and the current and voltages are recorded. Observed results under different operating conditions and mission profiles are discussed.

UAM↗
NASA NTRSDate not supplied

Simulation Studies for an Urban Air Mobility Aircraft using Hardware-In-Loop Experiments

Urban Air Mobility seeks to transport passengers, deliver cargo, and provide emergency medical transportation in major metropolitan areas. This will be accomplished with distributed electric powered vertical takeoff and landing aircraft vehicles. The low specific energy of the current generation lithium-ion battery packs limit the operational range of the electric aircraft. Limited range impacts safety by reducing the amount of time available for analyzing the potential impact of errors and failures and responding to them, and for flying to an alternative landing area or returning to the base. It is therefore critical to understand the impact of flight and environmental conditions on the onboard lithium-ion battery pack’s health. With this as the motivation, the procedure for evaluating the performance of battery packs in a laboratory setting and the results obtained using this procedure on battery packs subject to power draw characteristics of a simulated flight of a NASA conceptual quadrotor aircraft model are described. The fully charged battery is allowed to discharge at specific C-rates based on the power draw profile during the experiment, and the current and voltages are recorded as a function of time. Observed results under different operating conditions and mission profiles are discussed.

UAM↗
NASA NTRS1990

Measurements and mechanisms of localized aqueous corrosion in aluminum-lithium alloys

Like most heat treatable aluminum alloys, localized corrosion and stress corrosion of Al-Li-Cu alloys is strongly dependent on the nature and distribution of second phase particles. To develop a mechanistic understanding of the role of localized corrosion in the stress corrosion process, bulk samples of T(sub 1) (Al2CuLi) and a range of Al-Cu-Fe impurity phases were prepared for electrochemical experiments. Potentiodynamic polarization and galvanic couple experiments were performed in standard 0.6 M NaCl and in simulated crevice solutions to assess corrosion behavior of these particles with respect to the alpha-Al matrix. A comparison of time to failure versus applied potential using a constant load, smooth bar SCC test technique in Cl(-), Cl(-)/CrO4(2-), and Cl(-)/CO3(2-) environments shows that rapid failures are to be expected when applied potentials are more positive than the breakaway potential (E sub br) of T(sub 1) (crack tip) but less than E(sub br) of alpha-Al (crack walls). It is shown that this criterion is not satisfied in aerated Cl(-) solutions. Accordingly, SCC resistance is good. This criterion is satisfied, however, in an alkaline isolated fissure exposed to a CO2 containing atmosphere. Rapid failure induced by these fissures was recently termed preexposure embrittlement. Anodic polarization shows that the corrosion behavior of T(sub 1) is relatively unaffected in alkaline CO3(2-) environments but the alpha-Al phase is rapidly passivated. X ray diffraction of crevice walls from artificial crevices suggests that passivation of alpha-Al occurs as hydrotalcite-type compound (LiAl2(OH)6)2(+) - CO3(2-) - nH2O.

Buchheit, Rudolph G., Jr.↗