Search NASA⌕ Search

SEARCH · Search NASA

Results for “Planetary environments”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 721 records · Page 40
All sourcesNASA NTRSDOE OSTI
NASA NTRS1992

A unique high Mn/Fe microgabbro in the Parnallee (LL3) ordinary chondrite - Nebular mixture or planetary differentiate from a previously unrecognized planetary body?

We studied a unique microgabbro fragment from the Parnallee (LL3) unequilibrated ordinary chondrite. The fragment, which was originally identified by its ophitic to sub-ophitic texture, exhibits features characteristic of lunar and terrestrial tholeiitic basalts (i.e., extreme compositional zoning in clinopyroxene (Wo10En65Fs25 to Wo15En2FS83), a multiply saturated major element composition similar to mid-ocean ridge basalt with 3.1 wt pct Na2O and 0.15 wt pct K2O, and uniformly enriched rare earth elements (c. 10 x C1). A high bulk MnO/FeO ratio (0.064) distinguishes the microgabbro from other basaltic rocks and suggests the precursor material formed or reached equilibrium in a reducing environment. However, the absence of Fe metal and the extreme enrichment of FeO (up to 40 wt pct), in late crystallizing pyroxferroite, requires the last crystallization event to have occurred in a relatively oxidizing environment. We suggest the microgabbro formed by partial melting in a planetary body after removal of metallic Fe.

Kennedy, A. K.↗
NASA NTRS1997

Ultraviolet radiation from F and K stars and implications for planetary habitability

Now that extrasolar planets have been found, it is timely to ask whether some of them might be suitable for life. Climatic constraints on planetary habitability indicate that a reasonably wide habitable zone exists around main sequence stars with spectral types in the early-F to mid-K range. However, it has not been demonstrated that planets orbiting such stars would be habitable when biologically-damaging energetic radiation is also considered. The large amounts of UV radiation emitted by early-type stars have been suggested to pose a problem for evolving life in their vicinity. But one might also argue that the real problem lies with late-type stars, which emit proportionally less radiation at the short wavelengths (lambda < 200 nm) required to split O2 and initiate ozone formation. We show here that neither of these concerns is necessarily fatal to the evolution of advanced life: Earth-like planets orbiting F and K stars may well receive less harmful UV radiation at their surfaces than does the Earth itself.

NASA Discipline Exobiology↗
NASA NTRS2010

GeoLab in NASA's Pressurized Excursion Module: First Results from the 2010 Field Trials

Before humans explore other planets, NASA must develop advanced techniques for collection, preservation and return of unique extraterrestrial samples. To help evaluate hardware requirements and operational concepts for future sample-return missions, we designed and built GeoLab our first generation lab for geological samples into NASA s Habitat Demonstration Unit in the Pressurized Excursion Module (HDU1-PEM). The center of GeoLab is a glovebox for the examination of samples in a shirt-sleeve environment. As part of a deployable habitat, GeoLab can participate in NASA s analog missions that simulate planetary exploration activities and support the testing of relevant technologies for collecting and handling geological samples. Over time, these tests will evaluate sample handling environments (field and lab), sampling tools and analytical instruments, and different scenarios involving both robotic and human procedures. The GeoLab design supports evolving tests and configurations. The glovebox is mounted on the habitat bulkhead, with three sample pass-though chambers that allow for direct sample transfer into the glovebox from the outside. The glovebox design and construction (low-particle shedding, minimally off-gassing materials) provides a clean environment to reduce sample contamination; in the future, we will integrate a positive pressure, enriched nitrogen atmosphere. The glovebox is equipped with configurable instrument ports. The 2010 test included a mass balance, a stereomicroscope with a HD camera for detailed imaging of samples, and a handheld XRF analyzer for preliminary geochemical characterization of samples. Network cameras provided context imagery and sample handling activities. We present early results from the initial field trial of GeoLab during the 2010 Desert Research and Technology Studies (D-RATS) planetary analog test near Flagstaff AZ. The 2010 D-RATS mission involved two rovers, the habitat with GeoLab, four crew members, and a team of scientists and flight controllers. The crewed rovers conducted geological traverses and collected samples on the planetary surface. Selected samples were transferred into GeoLab for detailed examination and initial analysis, providing critical data to the science team for evaluation and prioritization of samples.

Evans, Cynthia A.↗
NASA NTRS1993

Plasma, magnetic, and electromagnetic measurements at nonmagnetic bodies

The need to explore the magnetospheres of the Earth and the giant planets is widely recognized and is an integral part of our planetary exploration program. The equal need to explore the plasma, magnetic, and electromagnetic environments of the nonmagnetic bodies is not so widely appreciated. The previous, albeit incomplete, magnetic and electric field measurements at Venus, Mars, and comets have proven critical to our understanding of their atmospheres and ionospheres in areas ranging from planetary lightning to solar wind scavenging and accretion. In the cases of Venus and Mars, the ionospheres can provide communication paths over the horizon for low-altitude probes and landers, but we know little about their lower boundaries. The expected varying magnetic fields below these planetary ionospheres penetrates the planetary crusts and can be used to sound the electrical conductivity and the thermal profiles of the interiors. However, we have no knowledge of the levels of such fields, let alone their morphology. Finally, we note that the absence of an atmosphere and an ionosphere does not make an object any less interesting for the purposes of electromagnetic exploration. Even weak remanent magnetism such as that found on the Moon during the Apollo program provides insight into the present and past states of planetary interiors. We have very intriguing data from our space probes during times of both close and distant passages of asteroids that suggest they may have coherent magnetization. If true, this observation will put important constraints on how the asteroids formed and have evolved. Our planetary exploration program must exploit its full range of exploration tools if it is to characterize the bodies of the solar system thoroughly. We should especially take advantage of those techniques that are proven and require low mass, low power, and low telemetry rates to undertake.

Russell, C. T.↗
NASA NTRSDate not supplied

The Chemical Evolution of Cosmic Dust: From Gas-Phase Precursors to Solid Grains - Laboratory Studies with the COSmIC Facility

Cosmic dust in in its gas phase and solid phase components plays an essential role in the chemical and physical evolution of the universe. Our understanding of cosmic dust properties relies on a combination of astronomical observations, astrophysical modeling and laboratory studies of realistic analogs of cosmic dust being gas-phase molecules and/or solid grains. The COSmIC facility was developed at NASA Ames to study the evolution of cosmic carbon from circumstellar outflows to interstellar clouds to planetary atmospheres in the laboratory [1]. COSmIC stands for “Cosmic Simulation Chamber” and is dedicated to the study of neutral and ionized molecules and grain particles under the low temperature and density conditions that are required to simulate space environments. It integrates a variety of instruments that allow generating, processing, and monitoring simulated space conditions in the laboratory. It is composed of a Pulsed Discharge Nozzle (PDN) expansion that generates a plasma in a free supersonic jet expansion, coupled to high-sensitivity, complementary in situ diagnostic tools used for the detection and characterization of the species present in the expansion: Cavity Ring Down Spectroscopy (CRDS) and fluorescence spectroscopy systems for photonic detection and an orthogonal Reflectron Time-Of-Flight Mass Spectrometer (oReTOF-MS) for mass detection. Recent advances achieved using COSmIC’s laboratory data in synergy with observational data will be presented. These results include the formation of dust grains and aerosols from gas-phase molecular precursors in environments as varied as circumstellar outflows of late AGB stars [2, 3] and planetary atmospheres [4] and the evolution of our understanding of the diffuse interstellar bands (DIBs) with applications to the ESO Diffuse Interstellar Bands Large Exploration Survey (EDIBLES [5, 6]). Plans for future laboratory developments and techniques to study the evolution of cosmic carbon molecules and grains (including NIR-MIR CRDS, laser induced fluorescence (LIF) and incandescence (LII)) will also be addressed as well as their astronomical applications.

Planetary↗
NASA NTRSDate not supplied

Performance of Doppler Lidar Velocity and Range Sensor Operating in Highly Dynamic Environments

The operation of a coherent Doppler lidar, developed by NASA for missions to planetary bodies, is analyzed and its projected performance is described. The lidar transmits three laser beams at different but fixed directions and measures line-of-sight range and velocity along each beam. The three line-of-sight measurements are then combined in order to determine the three components of the vehicle velocity vector and its altitude relative to the ground. Operating from over five kilometers altitude, the NDL provides velocity and range data with a few cm/sec and a few meters precision, respectively, depending on the vehicle dynamics. This paper explains the sources of measurements error and analyzes the impacts of vehicle dynamics on the lidar performance.

Doppler Lidar↗
NASA NTRS2024

Key Perseverance Sampling Locations for the Ancient Martian Crust and Implications for Mars Science

Since Feb 2021, the Perseverance rover has collected samples in the Jezero crater. The plan baselined at the 2018 landing site selection, subsequently further developed by the Mars-2020 team, and presented to the Decadal Survey included the exploration and sampling of the Jezero crater rim and the Nili Planum area, a rock record that is important to preserving the science return of the endeavor. Specifically, the science team identified the following prioritized science objectives aligned with community objectives that are not covered by the current sample cache: 1) Investigate the habitable environments with potential biosignatures from a more ancient time interval and from a diverse set of geological environments (incl. exposed subsurface) than the Jezero crater sedimentary deposits (Fig. 2). (2) Determine radioisotopic ages for well-defined craterretaining surfaces and/or the Isidis basin impact event. (3) Characterize ancient aqueous environments to study climate, environmental transitions, and habitability on ancient Mars. (4) Investigate planetary accretion, crustal evolution, and dynamo activity through analysis and sampling of igneous lithologies. (5) Study the geology of basin-forming impacts. In addition, for the Jezero rim and any Jezero ejecta: (6) Analyze Jezero impactites for potentially habitable hydrothermal environments and radioisotopic dating of the Jezero crater formation. From 2018 to now, we used a combination of High Resolution Imaging Experiment (HiRISE) and Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) data to further characterize Jezero rim and Nili Planum, culminating in our prioritized sample location recommendations: (1) Monument Valley and (2) Northwest Jezero rim.

Mars sample return↗
NASA NTRS1984

Exploration of the Solar System by Airborne Astronomy

The contributions of airborne astronomy to the knowledge of our solar system are reviewed, beginning in 1967 when planetary observations became a vigorous part of NASA's airborne astronomy initiatives using aircraft outfitted with 30 cm diameter telescopes for infrared observations at altitudes between 12 and 15 km. These early facilities and their successor, the Kuiper airborne observatory (KAO), profoundly influenced many areas of planetary science by providing optimized platforms for the conduct of certain types of remote sensing experiments that were incompatible with both ground-based and spacecraft environments. Specific topics reviewed include energy balance in the outer planets, the composition and structure of planetary atmospheres, and planetary ring systems.

Larson, H. P.↗
NASA NTRS2018

Magnetour: Surfing Planetary Systems on Electromagnetic and Multi-Body Gravity Fields

In this NIAC Phase One study, we propose a new mission concept, named Magnetour, to facilitate the exploration of outer planet systems and address both power and propulsion challenges. Our approach would enable a single spacecraft to orbit and travel between multiple moons of an outer planet, with no propellant required. Our approach would enable a single spacecraft to orbit and travel between multiple moons of an outer planet, with no propellant nor onboard power source required. To achieve this free-lunch _Grand Tour', we exploit the unexplored combination of magnetic and multi-body gravitational fields of planetary systems, with a unique focus on using a bare tether for power and propulsion. The main objective of the study is to develop this conceptually novel mission architecture, explore its design space, and investigate its feasibility and applicability to enhance the exploration of planetary systems within a 10-year timeframe. Propellantless propulsion technology offers enormous potential to transform the way NASA conducts outer planet missions. We hope to demonstrate that our free-lunch tour concept can replace heavy, costly, traditional chemical-based missions and can open up a new variety of trajectories around outer planets. Leveraging the powerful magnetic and multi-body gravity fields of planetary systems to travel freely among planetary moons would allow for long-term missions and provide unique scientific capabilities and flagship-class science for a fraction of the mass and cost of traditional concepts. New mission design techniques are needed to fully exploit the potential of this new concept.This final report contains the results and findings of the Phase One study, and is organized as follows. First, an overview of the Magnetour mission concept is presented. Then, the research methodology adopted for this Phase One study is described, followed by a brief outline of the main findings and their correspondence with the original Phase One task plan. Next, an overview of the environment of outer planets is provided, including magnetosphere, radiation belt and planetary moons. Then performance of electrodynamic tethers is assessed, as well as other electromagnetic systems. A method to exploit multi-body dynamics is given next. These analyses allow us to carry out a Jovian mission design to gain insight in the benefits of Magnetour. In addition, a spacecraft configuration is presented that fully incorporates the tether in the design. Finally technology roadmap considerations are discussed.

Gravity Fields↗
NASA NTRS2019

Laboratory Astrophysics Studies of the Evolution of Organic Matter with the COSmIC Facility.

Understanding the origin of organic matter in astrophysical environments ranging from circumstellar (CS) outflows to diffuse and dense interstellar (IS) clouds to protoplanetary disks and planetary bodies has become a central objective in astrophysics. Experimental facilities dedicated to the formation and characterization of laboratory analogs generated under conditions relevant to the targeted environments have been developed in the past recent years. Recent advances achieved in laboratory astrophysics using COSmIC’s laboratory data in synergy with observational data will be presented. These results include the use of laboratory spectra to search for IS organic molecules and ions in astronomical spectra, the formation of laboratory analogs of CS and IS dust grains and planetary atmospheres aerosols from molecular precursors.

Salama, Farid↗
NASA NTRS1979

Dust-magnetospheric interactions

The important processes controlling the electrical potentials of dust grains in planetary magnetospheres are considered, and the quasi-equilibrium electric potentials acquired by them in the different plasma and radiative environments encountered are evaluated. The orbital dynamics of such charged grains is discussed, and their interaction with satellites within the planetary magnetospheres is considered. The possibility of magneto-gravitational capture of these gains by magnetospheres, to form dust rings around the planets, is also discussed. Finally, the possible break-up of grains charged to large electrical potentials and its consequences are briefly addressed.

Mendis, D. A.↗
NASA NTRS1983

The young sun and the atmosphere and photochemistry of the early earth

The origin and evolution of the earth's early atmosphere depend crucially on the dissipation time of the primitive solar nebula (SN). Using different theories of turbulence, the dissipation time of an SN of 0.1 solar mass is estimated as 2.5-8.3 Myr. Because accretion times are usually much longer, it is concluded that most planetary accretion must have occurred in a gas-free environment. Using new IUE data, a wavelength-dependent UV flux is constructed for the young sun which is then used to study the photochemistry and concentrations of O, O2, O3, OH, H, HCO and formaldehyde H2CO in the earth's early prebiological atmosphere.

Canuto, V. M.↗
NASA NTRS1985

Clustered impacts - Experiments and implications

The characteristics of impact by clusters of projectiles are experimentally studied by launching grouped projectiles of aluminum shot, steel shot, iron filings, and sand. Cratering efficiency is considered as a function of a dimensionless parameter related to projectile size and impact velocity. The effects of different target and projectile densities on cratering efficiency are examined. Crater morphology is addressed by considering a typical example, reviewing the systematics between cluster dispersion and crater morphology for vertical impacts, and examining oblique angle impacts which have relevance for planetary secondary cratering processes. These results are compared with impacts by single bodies with different strengths. The evolution of the ejecta plume for clustered impacts is compared to that for single-body impacts for vertical and oblique impacts from 1.3 to 1.8 km/s. The experimental results are discussed in the context of planetary surface processes, emphasizing processes in an atmosphere-free environment and secondary impact cratering.

Schultz, P. H.↗
NASA NTRS1985

Strategies for a permanent lunar base

One or more of three possible objectives, encompassing scientific research, lunar resource exploitation for space infrastructure construction, and lunar environment self-sufficiency refinement with a view to future planetary habitation, may be the purpose of manned lunar base activities. Attention is presently given to the possibility that the early phases of all three lunar base orientations may be developed in such a way as to share the greatest number of common elements. An evaluation is made of the cost and complexity of the lunar base, and the Space Transportation System used in conjunction with it, as functions of long term base use strategy.

Duke, M. B.↗
NASA NTRS1990

Exobiology and SETI from the lunar farside

Within the Life Sciences Division of NASA, the Exobiology Program seeks to understand the origin, evolution and distribution of life in the universe. There are two feasible methods of searching for life beyond the earth. The first is to return to Mars and systematically explore its surface and subsurface with instrumentation capable of identifying extinct as well as extant life. The second is to search for advanced forms of life in other planetary systems that have developed a technology capable of modifying their environment in ways that make it detectable across the vast interstellar distances. The Exobiology Program is currently pursuing both of these options. If NASA's SETI (search for extraterrestrial intelligence) Microwave Observing Project of the 1990s fails to detect evidence of radio signals generated by an extraterrestrial technology, what might be the next step? The establishment of a permanent lunar base early in the next century may enable the construction of large aperture radio telescopes that can extend both the sensitivity and the frequency range of SETI observations. A lunar base may also provide the opportunity for construction of optical and IR telescopes intended for the direct detection of extrasolar planetary systems.

Tarter, Jill C.↗
NASA NTRS1994

Evolution of protoplanetary disks with dynamo magnetic fields

The notion that planetary systems are formed within dusty disks is certainly not a new one; the modern planet formation paradigm is based on suggestions made by Laplace more than 200 years ago. More recently, the foundations of accretion disk theory where initially developed with this problem in mind, and in the last decade astronomical observations have indicated that many young stars have disks around them. Such observations support the generally accepted model of a viscous Keplerian accretion disk for the early stages of planetary system formation. However, one of the major uncertainties remaining in understanding the dynamical evolution of protoplanetary disks is the mechanism responsible for the transport of angular momentum and subsequent mass accretion through the disk. This is a fundamental piece of the planetary system genesis problem since such mechanisms will determine the environment in which planets are formed. Among the mechanisms suggested for this effect is the Maxwell stress associated with a magnetic field treading the disk. Due to the low internal temperatures through most of the disk, even the question of the existence of a magnetic field must be seriously studied before including magnetic effects in the disk dynamics. On the other hand, from meteoritic evidence it is believed that magnetic fields of significant magnitude existed in the earliest, PP-disk-like, stage of our own solar system's evolution. Hence, the hypothesis that PP disks are magnetized is not made solely on the basis of theory. Previous studies have addressed the problem of the existence of a magnetic field in a steady-state disk and have found that the low conductivity results in a fast diffusion of the magnetic field on timescales much shorter than the evolutionary timescale. Hence the only way for a magnetic field to exist in PP disks for a considerable portion of their lifetimes is for it to be continuously regenerated. In the present work, we present results on the self-consistent evolution of a turbulent PP disk including the effects of a dynamo-generated magnetic field.

Reyes-Ruiz, M.↗
NASA NTRS2000

On the origin of Titan's atmosphere

The present atmosphere of Titan exhibits evidence of extensive evolution, in the form of rapid photochemical destruction of methane and a large fractionation of the nitrogen and oxygen isotopes. Attempts to recover the initial inventory of volatiles lead toward a model in which nitrogen was originally supplied as NH3, essentially unmodified from its relative abundance in the outer solar nebula. Titan's atmospheric methane, in contrast, appears to have been formed from carbon and other carbon compounds, either by gas phase reactions in the subnebula or by accretional heating during the formation of Titan. These conclusions can be tested by further studies of abundances and isotope ratios in Titan's atmosphere, augmented by studies of comets. The possible similarity of carbon and nitrogen inventories on Titan to those on the inner planets makes this investigation particularly intriguing.

Non-NASA Center↗
NASA NTRS2003

Spectral behavior of hydrated sulfate salts: implications for Europa mission spectrometer design

Remote sensing of the surface of Europa with near-infrared instruments has suggested the presence of hydrated materials, including sulfate salts. Attention has been focused on these salts for the information they might yield regarding the evolution of a putative interior ocean, and the evaluation of its astrobiological potential. These materials exhibit distinct infrared absorption features due to bound water. The interactions of this water with the host molecules lead to fine structure that can be used to discriminate among these materials on the basis of their spectral behavior. This fine structure is even more pronounced at the low temperatures prevalent on icy satellites. Examination of hydrated sulfate salt spectra measured under cryogenic temperature conditions provides realistic constraints for future remote-sensing missions to Europa. In particular, it suggests that a spectrometer system capable of 2-5 nm spectral resolution or better, with a spatial resolution approaching 100 m, would be able to differentiate among proposed hydrated surface materials, if present, and constrain their distributions across the surface. Such information would provide valuable insights into the evolutionary history of Europa.

Astronomy↗