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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 343 records · Page 19
All sourcesNASA NTRSDOE OSTI
NASA NTRS1989

Partial gravity habitat study: With application to lunar base design

Comprehensive design requirements associated with designing habitats for humans in a partial gravity environment were investigated and then applied to a lunar base design. Other potential sites for application include planetary surfaces such as Mars, variable gravity research facilities, or a rotating spacecraft. Design requirements for partial gravity environments include: (1) locomotion changes in less than normal Earth gravity; (2) facility design issues, such as interior configuration, module diameter and geometry; and (3) volumetric requirements based on the previous as well as psychological issues involved in prolonged isolation. For application to a Lunar Base, it was necessary to study the exterior architecture and configuration to insure optimum circulation patterns while providing dual egress. Radiation protection issues were addressed to provide a safe and healthy environment for the crew, and finally, the overall site was studied to locate all associated facilities in context with the habitat. Mission planning was not the purpose of this study; therefore, a Lockheed scenario was used as an outline for the Lunar Base application, which was then modified to meet the project needs.

Capps, Stephen↗
NASA NTRS2017

Parametric Study of an Ablative TPS and Hot Structure Heatshield for a Mars Entry Capsule Vehicle

The National Aeronautics and Space Administration is planning to send humans to Mars. As part of the Evolvable Mars Campaign, different en- try vehicle configurations are being designed and considered for delivering larger payloads than have been previously sent to the surface of Mars. Mass and packing volume are driving factors in the vehicle design, and the thermal protection for planetary entry is an area in which advances in technology can offer potential mass and volume savings. The feasibility and potential benefits of a carbon-carbon hot structure concept for a Mars entry vehicle is explored in this paper. The windward heat shield of a capsule design is assessed for the hot structure concept as well as an ablative thermal protection system (TPS) attached to a honeycomb sandwich structure. Independent thermal and structural analyses are performed to determine the minimum mass design. The analyses are repeated for a range of design parameters, which include the trajectory, vehicle size, and payload. Polynomial response functions are created from the analysis results to study the capsule mass with respect to the design parameters. Results from the polynomial response functions created from the thermal and structural analyses indicate that the mass of the capsule was higher for the hot structure concept as compared to the ablative TPS for the parameter space considered in this study.

Langston, Sarah L.↗
NASA NTRS2021

Thermal Analysis of Landers using Radioisotope Power Systems on Ice Worlds

The surfaces of Ice Worlds record evidence of interior processes, chemical potential, habitability, and potentially life within the interior. Volatile and organic chemistry at the surface is critical in determining habitability and detecting the presence of past or extant life. Radioisotope Power Systems (RPS) could be an enabling technology for in situ missions to ice worlds, providing both power and heat for long durations where solar power would not be feasible. However, it is necessary to understand the potential impact of RPS upon the local environment, to ensure that the rejected heat from RPS does not compromise science measurements or planetary protection requirements. To address these concerns, an RPS Ice World Lander Study was carried out in 2019 to investigate possible requirements on RPS surface mission concepts and approaches to excess heat management. The study focused on two destinations that are representative of the range of potential environments: Europa and Enceladus.Initial analysis showed that, due to the very low pressures on the surfaces of most ice world targets, surface melting does not occur because the water ice does not meet the triple-point. A 4 kW heat source suspended above the surface of Europa or Enceladus would not cause any melting, only sublimation.The study used a surface sublimation limit of 10 cm over a two-year period (the baseline for the recent Europa Lander study). To stay within this limit, Europa, with its relatively warm surface, could tolerate only 10 W/m2 of surface heat flux. Enceladus, with its relatively cold pure ice composition, could tolerate up to 100 W/m2.Various lander and heat shield configurations were analyzed for their heat flux radiated from the RPS to the surface. For a given heat shield configuration, the study team determined the minimum height of the RPS above the surface for which the heat flux would be within the accepted parameters for Europa and for Enceladus. Based on these thermal analyses, such RPS-powered landers could remain compliant with science investigation and planetary protection requirements with only modest mass allocated to spacecraft thermal accommodations.

Perl, Scott↗
NASA NTRS1975

Planetary magnetospheres

Space-probe observations of planetary magnetospheres are discussed. Three different categories of planetary magnetospheres are identified (intrinsic slowly rotating, intrinsic rapidly rotating, and induced), and the characteristics of each type are outlined. The structure and physical processes of the magnetospheres of Mercury, Mars, and Jupiter are described, and possible configurations are presented for the Martian and Jovian ones. Expected magnetic moments are derived for Saturn, Uranus, and Neptune. Models are constructed for possible induced magnetospheres of the moon, Mercury, Venus, Mars, and Io.

Hill, T. W.↗
NASA NTRS1982

A study of the selection of microcomputer architectures to automate planetary spacecraft power systems

Performance and reliability models of alternate microcomputer architectures as a methodology for optimizing system design were examined. A methodology for selecting an optimum microcomputer architecture for autonomous operation of planetary spacecraft power systems was developed. Various microcomputer system architectures are analyzed to determine their application to spacecraft power systems. It is suggested that no standardization formula or common set of guidelines exists which provides an optimum configuration for a given set of specifications.

Nauda, A.↗
NASA NTRS1993

Electron impact emission cross sections needed in modeling UV observations of the upper atmospheres of the planets

In recognition of the need for accurate collision cross-sections suitable for modeling spectroscopic observations of the planetary systems and calibrate flight instruments, NASA-JPL has determined the laboratory emission cross-sections of H, H2, N2, SO2, etc. Resonance excitation, predissociation, and non-Franck-Condon band intensity systems are determined by configuration interaction and must be taken into account in analyses of spacecraft observations. Attention is given to the application of the cross-sectional data obtained to both electron energy loss codes and models of Voyager, IUE, Galileo, and HST observations of the solar system.

Ajello, J. M.↗
NASA NTRS2003

Callisto: A World in Its Own Right

This paper presents a discussion on the planetary structure, evolution and composition of the Gallilean Satellite, Callisto. The Jupiter Icy Moons Orbiter (JIMO) mission is currently planned to first orbit Callisto then its two icy sisters Ganymede and Europa to investigate Callisto's actual configuration. The JIMO mission consists of three globally complete mapping sets of Callisto along with spectrographic measurements to answer remaining outstanding questions about the geomorphology of Callisto.

Moore, Jeffrey M.↗
NASA NTRS1968

Performance of a 19.7 Meter Diameter Disk-Gap-Band Parachute in a Simulated Martian Environment

Inflation and drag characteristics of a 64.7-foot (19.7-meter) nominal-diameter disk-gap-band parachute deployed at a Mach number of 1.59 and a dynamic pressure of 11.6 psf (555 newtons per m(exp 2)) were obtained from the second balloon-launched flight test of the Planetary Entry Parachute Program. In addition, parachute stability characteristics during the subsonic descent portion of the test are presented. After deployment, the parachute rapidly inflated to a full condition, partially collapsed, and then reinflated to a stable configuration. After reinflation, an average drag coefficient of about 0.55 based on nominal surface area was obtained. The parachute exhibited good stability characteristics during descent. The only major damage to the parachute during the test was the tearing of two canopy panels; a loss of less than 0.5 percent of nominal surface area resulted.

TESTS↗
NASA NTRS2010

Overview of the James Webb Space Telescope

The James Webb Space Telescope (JWST) is ulxve uperk/rc (6.5 meter), cryogenic space telescope with a suite of near and mid-infrared instruments covering the wavelength range of 0.6 prnio 28 pn). JWS7 s primaryacicoce goal is k) detect and characterize the first galaxies. U will also study the uascrob|y of galaxies, uiur bzcrou1ion, and the formation of evolution of planetary systems. Recent progress in hardware development for the observatory will he presented, including a discussion of the status of JWST's optical system and Beryllium mirror fabrication, progress with sunshield prototypes, and the integration and test configuration. We also review the expected scientific performance of the observatory for observations of exosolar planets by means of transit imaging and spectroscopy. We will review the science goals, the capabilities of each science instrument, and the design and operation of the telescope.

Champin, Mark↗
NASA NTRS2013

Radial Internal Material Handling System (RIMS) for Circular Habitat Volumes

On planetary surfaces, pressurized human habitable volumes will require a means to carry equipment around within the volume of the habitat, regardless of the partial gravity (Earth, Moon, Mars, etc.). On the NASA Habitat Demonstration Unit (HDU), a vertical cylindrical volume, it was determined that a variety of heavy items would need to be carried back and forth from deployed locations to the General Maintenance Work Station (GMWS) when in need of repair, and other equipment may need to be carried inside for repairs, such as rover parts and other external equipment. The vertical cylindrical volume of the HDU lent itself to a circular overhead track and hoist system that allows lifting of heavy objects from anywhere in the habitat to any other point in the habitat interior. In addition, the system is able to hand-off lifted items to other material handling systems through the side hatches, such as through an airlock. The overhead system consists of two concentric circle tracks that have a movable beam between them. The beam has a hoist carriage that can move back and forth on the beam. Therefore, the entire system acts like a bridge crane curved around to meet itself in a circle. The novelty of the system is in its configuration, and how it interfaces with the volume of the HDU habitat. Similar to how a bridge crane allows coverage for an entire rectangular volume, the RIMS system covers a circular volume. The RIMS system is the first generation of what may be applied to future planetary surface vertical cylinder habitats on the Moon or on Mars.

Howe, Alan S.↗
NASA NTRS2024

The CARMENES Search for Exoplanets Around M Dwarfs: Revisiting the GJ 581 Multi-Planetary System With New Doppler Measurements From CARMENES, HARPS, and HIRES

Context.GJ 581 is a nearby M dwarf known to host a packed multiple planet system composed of two super-Earths and a Neptune-mass planet. We present new orbital analyses of the GJ 581 system, utilizing recent radial velocity (RV) data obtained from the CARMENES spectrograph combined with newly reprocessed archival data from the HARPS and HIRES spectrographs. Aims.Our aim was to analyze the post-discovery spectroscopic data of GJ 581, which were obtained with CARMENES. In addition, we used publicly available HIRES and HARPS spectroscopic data to seek evidence of the known and disputed exoplanets in this system. We aimed to investigate the stellar activity of GJ 581 and update the planetary system’s orbital parameters using state-of-the-art numerical models and techniques. Methods.We performed a periodogram analysis of the available precise CARMENES, HIRES, and HARPS RVs and of stellar activity indicators. We conducted detailed orbital analyses by testing various orbital configurations consistent with the RV data. We studied the posterior probability distribution of the parameters fit to the data and we explored the long-term stability and overall orbital dynamics of the GJ 581 system. Results. We refined the orbital parameters of the GJ 581 system using the most precise and complete set of Doppler data available. Consistent with the existing literature, our analysis confirms that the system is unequivocally composed of only three planets detectable in the present data, dismissing the putative planet GJ 581 d as an artifact of stellar activity. Our N-body fit reveals that the system’s inclination is i=47.0+14.6−13.0deg, which implies that the planets could be up to 30% more massive than their previously reported minimum masses. Furthermore, we report that the GJ 581 system exhibits long-term stability, as indicated by the posterior probability distribution, characterized by secular dynamical interactions without the involvement of mean motion resonances.

Satellites↗
DOE OSTI2021

TOI-1749: an M dwarf with a Trio of Planets including a Near-resonant Pair

We report the discovery of one super-Earth- (TOI-1749b) and two sub-Neptune-sized planets (TOI-1749c and TOI-1749d) transiting an early M dwarf at a distance of 100 pc, which were first identified as planetary candidates using data from the TESS photometric survey. We have followed up this system from the ground by means of multiband transit photometry, adaptive optics imaging, and low-resolution spectroscopy, from which we have validated the planetary nature of the candidates. We find that TOI-1749b, c, and d have orbital periods of 2.39, 4.49, and 9.05 days, and radii of 1.4, 2.1, and 2.5 R {sub ⊕}, respectively. We also place 95% confidence upper limits on the masses of 57, 14, and 15 M {sub ⊕} for TOI-1749b, c, and d, respectively, from transit timing variations. The periods, sizes, and tentative masses of these planets are in line with a scenario in which all three planets initially had a hydrogen envelope on top of a rocky core, and only the envelope of the innermost planet has been stripped away by photoevaporation and/or core-powered mass-loss mechanisms. These planets are similar to other planetary trios found around M dwarfs, such as TOI-175b,c,d and TOI-270b,c,d, in the sense that the outer pair has a period ratio within 1% of 2. Such a characteristic orbital configuration, in which an additional planet is located interior to a near 2:1 period-ratio pair, is relatively rare around FGK dwarfs.

47 OTHER INSTRUMENTATION↗
NASA NTRS1980

Design integration of aerocapture and aeromaneuver vehicles for a Mars sample return mission

The concept of using an aerocapture vehicle for Mars and other planetary missions is a technology that yields significant fuel savings. This concept uses the planet's atmosphere to dissipate excess velocity of the entry vehicle allowing it to go into orbit. A conceptual design integration study of two configurations of aerocapture vehicles which can make an aerodynamically controlled entry has been made. The first configuration contains the existing Viking type Lander and an Orbiter. The second spacecraft is more general in payload and could be used to place an Orbiter and a Lander on other planets with a single aeroshell.

Hassett, R. J.↗
NASA NTRS1983

The dynamics of elliptical rings

The paper investigates the evolution of eccentric rings under the influence of (1) differential precession due to the planetary quadrupole moment; (2) self-gravity; (3) viscous forces due to interparticle collisions; and (4) eccentricity excitation by shepherd satellites. The principal conclusions are that: (1) uniform precession can be enforced by self-gravity; the resulting configuration is both dynamically and secularly stable. (2) due to viscous forces the line of apsides at the inner ring edge is not exactly aligned with the line of apsides at the outer edge; the apse shift may be detectable in the alpha and beta rings of Uranus; (3) the mean eccentricity is determined by a balance between viscous damping and excitation by shepherds; (4) and the dimensionless eccentricity gradient is expected to be positive and of order unity in most eccentric rings, as observed.

Borderies, N.↗
NASA NTRS2006

Hydrogen-Oxygen PEM Regenerative Fuel Cell Development at NASA Glenn Research Center

The closed-cycle hydrogen-oxygen PEM regenerative fuel cell (RFC) at NASA Glenn Research Center has demonstrated multiple back to back contiguous cycles at rated power, and round trip efficiencies up to 52 percent. It is the first fully closed cycle regenerative fuel cell ever demonstrated (entire system is sealed: nothing enters or escapes the system other than electrical power and heat). During FY2006 the system has undergone numerous modifications and internal improvements aimed at reducing parasitic power, heat loss and noise signature, increasing its functionality as an unattended automated energy storage device, and in-service reliability. It also serves as testbed towards development of a 600 W-hr/kg flight configuration, through the successful demonstration of lightweight fuel cell and electrolyser stacks and supporting components. The RFC has demonstrated its potential as an energy storage device for aerospace solar power systems such as solar electric aircraft, lunar and planetary surface installations; any airless environment where minimum system weight is critical. Its development process continues on a path of risk reduction for the flight system NASA will eventually need for the manned lunar outpost.

Bents, David J.↗
NASA NTRS2026

Radiation-Conditioned Ti–hBN Coatings for Space Mechanisms: Bridging Tribology and Irradiation Effects from Laboratory to Low-Earth Orbit

The longevity of tribological components in extraterrestrial environments is challenged by abrasive regolith, extreme temperatures, and ionizing radiation. This study evaluates the performance of vacuum plasma sprayed (VPS) Ti-2vol.% hexagonal boron nitride (hBN) coatings applied to joint mechanisms such as rod and slot, ball and socket, and hinge assemblies, fabricated from Al6061 and Ti6Al4V for planetary structures. Coated and uncoated samples were tested under vacuum with lunar regolith simulant (JSC-1A), followed by environmental exposures including electron radiation and thermal cycling. Results show that coated samples consistently outperformed uncoated counterparts across all configurations. Wear depth in coated components was reduced by over 80%, as confirmed by 3D profilometry and surface imaging. SEM analysis revealed severe abrasion and localized plastic deformation in uncoated surfaces, while coated samples retained structural integrity due to synergy of hard protective phases formed during deposition and retained hBN providing solid lubrication in the sliding surface. Coated and exposed samples exhibited smoother actuation profiles and reduced friction, indicating a beneficial "conditioning" effect from environmental exposure. The coatings-maintained performance even on complex geometries with minimal delamination. These findings demonstrate the potential of VPS Ti-hBN coatings to extend the operational life of lunar mechanisms, bridging laboratory-scale tribology with flight-relevant mechanical applications.

tribology↗
NASA NTRS2020

Gateway Lunar Habitat Modules as the Basis for a Modular Mars Transit Habitat

This paper provides a summary of the results from a recent concept study of various configurations for a Mars Transit Habitat. The designs considered are composed of modules based on published contractor concepts proposed for the lunar Gateway through NASA’s NextSTEP program. Using these Gateway concepts as a starting point for the design of a Mars Transit Habitat has potential advantages. Both Gateway and Mars Transit Habitats will have similar requirements for long-term operations in deep space, autonomous and remote operations when the crew is not onboard, and similar requirements for transferring crew to and from a planetary surface—the Moon and Mars respectively. The contractor designs for Gateway were traded against a monolithic transit habitat previously proposed by NASA’s Mars Integration Group. In addition, these concepts were considered for a “shakedown” mission for the transit habitat hardware in cislunar space to build confidence in new systems, including the advanced environmental control and life support systems needed for Mars missions. The results presented include overall vehicle configurations, mass, and volume estimates for the selected design concepts. Two concepts using large expandable modules are identified as leading candidates for a Mars Transit Habitat and the remaining elements are identified as representative of the habitable pressure vessels needed for safe haven configurations, logistics modules, surface habitats, rovers, and descent and ascent crew cabins in the overall Mars Architecture.

Smitherman, David↗