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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 379 records · Page 21
All sourcesNASA NTRSDOE OSTI
NASA NTRS2025

Beamed Energy and Communications Optical Node (BEACON) Demonstrator

Due to long shadow periods (2 weeks or greater) on the south pole, concepts to raise solar arrays to a sufficient height at specific locations have shown the capability to provide power to surface users for much longer periods. Such a tower can also provide a 3rd Generation Partnership Project (3GPP) service for users up to 10 km away, dependent on terrain. An option to deliver power, albeit with low efficiency, using a laser beam coupled with the tower height could provide mobile and fixed users power during darkness, reducing their battery requirements. A demonstration of these technologies in the lunar environment is crucial to support future Artemis campaigns as well as potential emerging lunar infrastructures. A demonstrator design of a 15 m deployed boomon the south pole has been shown to enable both the gathering of kilowatts of power and the provision of 3GPP relay and backhaul given an appropriate lunar location. Using a laser to send power to a photovoltaic receiver has been proposed to transmit electrical power on the moon, particularly for applications such as powering a rover in near-polar permanently shadowed regions (PSR) where solar power is not available. In this work, the Compass team performed a conceptual engineering design study of a near-term laser surface-to-surface power beaming and relay station using a tower to simultaneously carry the power source (Vertical Solar Array Technologies (VSAT)[1]), the 3GPP relay antenna, and the laser telescope.

Deployable solar array tower laser beamed power 3G↗
NASA NTRSDate not supplied

Beamed Energy and Communications Optical Node (BEACON) Demonstrator

Due to long shadow periods (2 weeks or greater) on the south pole, concepts to raise solar arrays to a sufficient height at specific locations have shown the capability to provide power to surface users for much longer periods. Such a tower can also provide a 3rd Generation Partnership Project (3GPP) service for users up to 10 km away, dependent on terrain. An option to deliver power, albeit with low efficiency, using a laser beam coupled with the tower height could provide mobile and fixed users power during darkness, reducing their battery requirements. A demonstration of these technologies in the lunar environment is crucial to support future Artemis campaigns as well as potential emerging lunar infrastructures. A demonstrator design of a 15 m deployed boomon the south pole has been shown to enable both the gathering of kilowatts of power and the provision of 3GPP relay and backhaul given an appropriate lunar location. Using a laser to send power to a photovoltaic receiver has been proposed to transmit electrical power on the moon, particularly for applications such as powering a rover in near-polar permanently shadowed regions (PSR) where solar power is not available. In this work, the Compass team performed a conceptual engineering design study of a near-term laser surface-to-surface power beaming and relay station using a tower to simultaneously carry the power source (Vertical Solar Array Technologies (VSAT)[1]), the 3GPP relay antenna, and the laser telescope.

Lunar Relay↗
NASA NTRS1990

Thermal interaction between an impinging hot jet and a conducting solid surface

Powered-lift aircraft may produce severe high-temperature environments which are potentially damaging to a landing surface or the aircraft. The interaction betweean the high temperature flow field and a nonadiabatic landing surface is analyzed with a coupled computational fluid dynamics/solid thermal conduction computer code, HOTJET. The HOTJET code couples time-accurate, implicit, factored solution schemes for the governing fluid dynamics equations (Reynolds-averaged Navier-Stokes equations) to the unsteady thermal conduction equation, which governs heat flux within a solid. HOTJET is validated against exact solutions to the thermal conduction and Navier-Stokes equations. First-of-a-kind results are included which show the impact of surface material properties on the fluid physics and the coupled fluid/material thermal fields.

Abeloff, P. A.↗
NASA NTRS2006

A Comparison of Fission Power System Options for Lunar and Mars Surface Applications

This paper presents a comparison of reactor and power conversion design options for 50 kWe class lunar and Mars surface power applications with scaling from 25 to 200 kWe. Design concepts and integration approaches are provided for three reactor-converter combinations: gas-cooled Brayton, liquid-metal Stirling, and liquid-metal thermoelectric. The study examines the mass and performance of low temperature, stainless steel based reactors and higher temperature refractory reactors. The preferred system implementation approach uses crew-assisted assembly and in-situ radiation shielding via installation of the reactor in an excavated hole. As an alternative, self-deployable system concepts that use earth-delivered, on-board radiation shielding are evaluated. The analyses indicate that among the 50 kWe stainless steel reactor options, the liquid-metal Stirling system provides the lowest mass at about 5300 kg followed by the gas-cooled Brayton at 5700 kg and the liquid-metal thermoelectric at 8400 kg. The use of a higher temperature, refractory reactor favors the gas-cooled Brayton option with a system mass of about 4200 kg as compared to the Stirling and thermoelectric options at 4700 and 5600 kg, respectively. The self-deployed concepts with on-board shielding result in a factor of two system mass increase as compared to the in-situ shielded concepts.

Mason, Lee S.↗
DOE OSTI2020

Tailoring electrode microstructure via ink content to enable improved rated power performance for platinum cobalt/high surface area carbon based polymer electrolyte fuel cells

Improvements in polymer electrolyte fuel cell (PEFC) electrode performance have primarily focused on catalyst and ionomer developments, marginalizing the importance of catalyst ink formulation. In this study, the effect of ink formulation is examined across a series of cathodes comprised of PtCo supported on high surface area carbon (PtCo/ HSC ) and Nafion ionomer using an array of in situ electrochemical and ex situ characterization techniques. In contrast to prior work on Pt/Vu systems, ink water content had little effect on the electrochemically determined ionomer coverage for the PtCo/HSC electrocatalyst examined here. Characterization using nano-scale resolution X-ray computed tomography (nano-CT) demonstrated that water-rich ink formulations lead to a reduction in aggregate size (ionomer + PtCo/HSC), improving local O 2 transport. This understanding, combined with the use of a commercially-available electrocatalyst was used to produced state-of-the-art membrane electrode assemblies with Pt loadings of 0.03/0.08 mg Pt /cm 2 on the anode and cathode respectively, having; i) > 1 A/mg Pt (0.9 V iR-free , 150 kPa, 80 °C, 100% RH, H 2 /O 2 ), ii) 320 mA/cm 2 at 0.8 V, 150 kPa, 80 ° C, 100% RH, H 2 /Air), and iii) > 1 W/cm 2 elec at rated power (0.67 V, 250 kPa, 94 °C, 65% RH, H 2 /Air) or < 0.11 g Pt /kW rated .

25 ENERGY STORAGE↗
NASA NTRS1990

Megawatt solar power systems for lunar surface operations

The work presented here shows that a solar power system can provide power on the order of one megawatt to a lunar base with a fairly high specific power. The main drawback to using solar power is still the high mass, and therefore, cost of supplying energy storage through the solar night. The use of cryogenic reactant storage in a fuel cell system, however, greatly reduces the total system mass over conventional energy storage schemes.

Adams, B.↗
NASA NTRS1961

Transonic and Supersonic Flutter Investigation of 1/2-Size Models of All-Movable Canard Surface of an Expendable Powered Target

A transonic and a supersonic flutter investigation of 1/2-size models of the all-movable canard surface of an expendable powered target has been conducted in the Langley transonic blowdown tunnel and in the Langley 9- by 18-inch supersonic aeroelasticity tunnel, respectively. The transonic investigation covered a Mach number range from 0.7 to 1.3, and the supersonic investigation was made at Mach numbers 1.3, 2.O, and 2.55. The effects on the flutter characteristics of the models of different levels of stiffness and of free play in the pitch control linkage were examined. The semispan models, which were tested at an angle of attack of 0 deg, had pitch springs with the scaled design and 1/2 the scaled design pitch stiffness and total free play in pitch ranging from 0 to 1 deg. An additional model configuration which had a pitch spring 1/4 the scaled design pitch stiffness and no free play in pitch was included in the supersonic tests. All model configurations investigated were flutter free up to dynamic pressures 32 percent greater than those required for flight throughout the Mach number range. Several model configurations were tested to considerably higher dynamic pressures without obtaining flutter at both transonic and supersonic speeds.

Ruhlin, Charles L.↗
NASA NTRS1990

Future NASA mission applications of space nuclear power

Recent studies sponsored by NASA show a continuing need for space nuclear power. A recently completed study considered missions (such as a Jovian grand tour, a Uranus or Neptune orbiter and probe, and a Pluto flyby) that can only be done with nuclear power. There are also studies for missions beyond the outer boundaries of the solar system at distances of 100 to 1000 astronomical units. The NASA 90-day study on the Space Exploration Initiative identified a need for nuclear reactors to power lunar surface bases and radioisotope power sources for use in lunar or Martian rovers, as well as considering options for advanced, nuclear propulsion systems for human missions to Mars.

Bennett, Gary L.↗
NASA NTRS2024

Lunar Dust Considerations for Vertical Solar Arrays Volume 1: Lunar Environment and Dust Interactions

Lunar dust can complicate nearly every aspect of operations on the lunar surface. Jagged surface asperities, electrostatic charge, chemical reactivity, and interactions resulting in high-velocity motion enable a myriad of potential interaction pathways for lunar dust to adversely affect any exposed surface. Optimization of solar array energy collection efficiency, which will be important for a sustained lunar presence, will require overcoming many challenges presented by lunar dust. In this work, the fundamental properties of lunar dust, natural aspects of the lunar environment that influence the properties of lunar dust, and lunar exploration activities that will contribute to problems associated with lunar dust exposure are discussed. Aspects of the lunar environment that could contribute to reducing the operational efficiency of vertical solar arrays, which will be required for the lunar south pole region, are also identified.

vertical solar array technology↗
NASA NTRS2014

Radioisotope Stirling Engine Powered Airship for Atmospheric and Surface Exploration of Titan

The feasibility of an advanced Stirling radioisotope generator (ASRG) powered airship for the near surface exploration of Titan was evaluated. The analysis did not consider the complete mission only the operation of the airship within the atmosphere of Titan. The baseline airship utilized two ASRG systems with a total of four general-purpose heat source (GPHS) blocks. Hydrogen gas was used to provide lift. The ASRG systems, airship electronics and controls and the science payload were contained in a payload enclosure. This enclosure was separated into two sections, one for the ASRG systems and the other for the electronics and payload. Each section operated at atmospheric pressure but at different temperatures. The propulsion system consisted of an electric motor driving a propeller. An analysis was set up to size the airship that could operate near the surface of Titan based on the available power from the ASRGs. The atmospheric conditions on Titan were modeled and used in the analysis. The analysis was an iterative process between sizing the airship to carry a specified payload and the power required to operate the electronics, payload and cooling system as well as provide power to the propulsion system to overcome the drag on the airship. A baseline configuration was determined that could meet the power requirements and operate near the Titan surface. From this baseline design additional trades were made to see how other factors affected the design such as the flight altitude and payload mass and volume.

Titan↗
NASA NTRSDate not supplied

Power Hibernation for Low-Cost Solar Powered Lunar Missions

Lunar Surface temperatures can span from equatorial highs near 400K and polar lows of 50K. The extreme cold combined with the 354-hour duration of the lunar night is particularly challenging for small robotic lander missions. NASA’s Commercial Lunar Payload Services (CLPS) missions involve robotic landers intended to provide low-cost access to the lunar surface. Current CLPS Missions are solar powered and are only intended to survive a single lunar day. The ability to survive the night and continue operations over many lunar cycles would provide a dramatic increase in science productivity. The Power Hibernation approach relies on battery cells that can tolerate the extreme cold night and recover once temperatures return to normal. System recovery from hibernation depends on power electronics that can “cold start” at lunar dawn and operate on solar array output alone. Once battery and avionics systems are restored the spacecraft resumes daytime operations. The challenge is to achieve this capability with minimum impact to the spacecraft design and payload capacity. This talk will describe recent and ongoing investigations in battery and electronics technologies that will enable power hibernation and recovery.

Space Power↗
NASA NTRSDate not supplied

Power Hibernation for Low-Cost Solar Powered Lunar Missions

Lunar Surface temperatures can span from equatorial highs near 400K and polar lows of 50K. The extreme cold combined with the 354-hour duration of the lunar night is particularly challenging for small robotic lander missions. NASA’s Commercial Lunar Payload Services (CLPS) missions involve robotic landers intended to provide low-cost access to the lunar surface. Current CLPS Missions are solar powered and are only intended to survive a single lunar day. The ability to survive the night and continue operations over many lunar cycles would provide a dramatic increase in science productivity. The Power Hibernation approach relies on battery cells that can tolerate the extreme cold night and recover once temperatures return to normal. System recovery from hibernation depends on power electronics that can “cold start” at lunar dawn and operate on solar array output alone. Once battery and avionics systems are restored the spacecraft resumes daytime operations. The challenge is to achieve this capability with minimum impact to the spacecraft design and payload capacity. This talk will describe recent and ongoing investigations in battery and electronics technologies that will enable power hibernation and recovery.

Space Power↗
DOE OSTI2021

Design of High Power Density 100 kW Surface Permanent Magnet Machine with No Heavy Rare Earth Material Using Current Source Inverter for Traction Application

Surface permanent magnet (SPM) machines are appealing candidates for traction applications because of high power density and high efficiency. Rare-earth magnets deliver high performance but raise concerns about material supply dependability, particularly if they use heavy rare-earth materials. This paper presents the design of a high-performance SPM machine without any heavy rare-earth material that is optimized specifically for a current-source inverter (CSI) traction drive. This machine is designed for a constant-power speed ratio (CPSR) of 3. A genetic algorithm has been performed to achieve a target of 50 kW/L active power density at speeds up to 20,000 rpm. Operation at a peak line-to-line voltage of 800 V can be achieved using 1200 V power devices with a safety margin. The predicted electromagnetic and rotor structural performance characteristics are presented using both analytical and finite element analysis (FEA) results.

(CPSR)↗
NASA NTRS1987

Small reactor power systems for manned planetary surface bases

A preliminary feasibility study of the potential application of small nuclear reactor space power systems to manned planetary surface base missions was conducted. The purpose of the study was to identify and assess the technology, performance, and safety issues associated with integration of reactor power systems with an evolutionary manned planetary surface exploration scenario. The requirements and characteristics of a variety of human-rated modular reactor power system configurations selected for a range of power levels from 25 kWe to hundreds of kilowatts is described. Trade-off analyses for reactor power systems utilizing both man-made and indigenous shielding materials are provided to examine performance, installation and operational safety feasibility issues. The results of this study have confirmed the preliminary feasibility of a wide variety of small reactor power plant configurations for growth oriented manned planetary surface exploration missions. The capability for power level growth with increasing manned presence, while maintaining safe radiation levels, was favorably assessed for nominal 25 to 100 kWe modular configurations. No feasibility limitations or technical barriers were identified and the use of both distance and indigenous planetary soil material for human rated radiation shielding were shown to be viable and attractive options.

Bloomfield, Harvey S.↗
NASA NTRS1992

A dynamic isotope power system for Space Exploration Initiative surface transport systems

The Dynamic Isotope Power System (DIPS) Demonstration Program, sponsored by the U.S. Department of Energy with support funding from NASA, is currently focused on the development of a standardized 2.5-kWe portable generator for multiple applications on the lunar or Martian surface. A variety of remote and mobile potential applications have been identified by NASA, including surface rovers for both short- and extended-duration missions, remote power to science packages, and backup to central base power. Recent work focused on refining the 2.5-kWe design and emphasizing the compatibility of the system with potential surface transport systems. Work included an evaluation of the design to ensure compatibility with the Martian atmosphere while imposing only a minor mass penalty on lunar operations. Additional work included a study performed to compare the DIPS with regenerative fuel cell systems for lunar mobile and remote power systems. Power requirements were reviewed and a modular system chosen for the comparison.

Hunt, Maribeth E.↗