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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 703 records · Page 39
All sourcesNASA NTRSDOE OSTI
NASA NTRS2011

Entry Guidance for the 2011 Mars Science Laboratory Mission

The 2011 Mars Science Laboratory will be the first Mars mission to attempt a guided entry to safely deliver the rover to a touchdown ellipse of 25 km x 20 km. The Entry Terminal Point Controller guidance algorithm is derived from the final phase Apollo Command Module guidance and, like Apollo, modulates the bank angle to control the range flown. For application to Mars landers which must make use of the tenuous Martian atmosphere, it is critical to balance the lift of the vehicle to minimize the range error while still ensuring a safe deploy altitude. An overview of the process to generate optimized guidance settings is presented, discussing improvements made over the last nine years. Key dispersions driving deploy ellipse and altitude performance are identified. Performance sensitivities including attitude initialization error and the velocity of transition from range control to heading alignment are presented.

Mendeck, Gavin F.↗
NASA NTRS2020

Saponite Dissolution Experiments and Implications for Mars

Phyllosilicates detected throughout the Noachian terrains of Mars provide ample evidence of water-rock interactions in its geologic past, and characterizing their formation would elucidate past environmental conditions on the martian surface. Previous work suggests that ferric smectite may have been deposited in the Noachian as ferroan (Fe2+) smectite and then subsequently oxidized after formation. This is further supported by the detection of trioctahedral saponite at the base of the stratigraphic section in Gale crater by CheMin and the gradual transition to dioctahedral ferric smectite up section. A better understanding of the dissolution behavior of saponites would therefore help us better interpret past water-rock interactions at Gale crater. However, smectite structures and compositions are variable and complex, and very few saponite dissolution rates exist in the literature. To further understand past water-rock interactions at Gale crater, we are reporting our results to date from dissolution experiments of Fe- and Mg- saponites under a range of conditions.

Luu, N. C.↗
NASA NTRSDate not supplied

Exploring rock-regolith interfaces in Jezero crater with Mars 2020 SHERLOC

The Perseverance rover successfully landed in Jezero crater, Mars in February 2021 at the Octavia E. Butler landing site and began its mission to explore and sample an ancient crater lake basin. Principal goals of the Mars 2020 mission include characterizing the geology of Mars and seeking signs of ancient microbial life via the spacecraft cameras and spectroscopic instruments onboard. The Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals (SHERLOC) instrument is a deep UV Raman spectrometer that utilizes a 248.6nm pulsed laser. Part of SHERLOC is a color camera known as the Wide Angle Topographic Sensor for Operations and eNgineering (WATSON). The SHERLOC suite provides coordinated, spectroscopic and imaging capabilities at high spatial resolution, to detect minerals and organic molecules in microtextural context. By pairing high spatial resolution (~100 μm) resonance Raman and native fluorescence spectroscopy with microscopic imaging in a novel spacecraft capability, SHERLOC enables texture-specific molecular composition measurements of rock and regolith targets on Mars. Coordinated rock-regolith observations illuminate unique insights into weathering processes and thereby to primary properties of rocks in Jezero crater. This work describes the potential of rock-regolith interfaces to preserve unique records of geological processes in Jezero crater and can powerfully supplement observations of the more general rock record on Mars. Linking observations of local rock texture with associated regolith reveals important lithologic information based on the interrelationship between differential weathering behavior and mineralogy, grain size, and cement chemistry. Preliminary observations indicate that the polygonally fractured lithotype common near the Octavia E. Butler landing site may weather by granular disintegration and/or surface creep, a relation that can be uniquely observed at the rock-regolith interface. SHERLOC -specific observations of microtextural and elemental composition transitions presented here trace rock-regolith boundaries at multiple indurated surfaces adjacent to regolith. At these locales, grain-scale based examinations suggest chemical weathering could be related to a variably distributed coating or rind on dark rock targets that may be mafic in composition. Granule deposits overlying widely distributed fine-grained material are also observable. Mineral identifications of each phase are presented, with cross-scale comparisons to the remote insights gained by the SuperCam instrument.

Emily L. Cardarelli↗
NASA NTRS1990

Observational evidence of crystalline iron oxides on Mars

A series of new spectral observations of Mars was obtained at Mauna Kea Observatory in the 0.4-1.0-micron wavelength range during the extremely favorable 1988 opposition, which yielded new spectral reflectance and relative reflectance data for a number of distinct spots on the Martian surface at 500-600 km spatial resolution. The new spectra revealed absorptions at 0.62-0.72 micron and at 0.81-0.94 micron, both seen clearly for the first time. These absorption features are interpreted as Fe(3+) electronic transition bands that indicate the presence of crystalline ferric oxide or hydroxide minerals on the Martian surface.

Bell, James F., III↗
NASA NTRS1989

Spectral mineralogy of terrestrial planets - Scanning their surfaces remotely

Information on the surface mineralogy, chemical composition, and lithology of terrestrial planets, as well as on their atmospheres, that can be obtained by earth-based from visible and NIR spectra of light reflected from planetary surfaces is discussed. Such reflectance spectra may have absorption bands in the 1- and 2-micron wavelength regions which originate from crystal field transitions within Fe(2+) ions. Since pyroxenes with Fe(2+) in M2 positions usually dominate the spectra, the resulting 1-micron vs 2-micron spectral determinative curves can be used to identify compositions and structural types of pyroxenes on the surface of a planet or an asteroid. Future spececraft missions to solar system objects will concentrate on remote-sensing experiments using visible and NIR reflectance spectra. These include the Galileo mission to Jupiter; the Mars Orbiter mission to Phoebus; the Comet Rendezvous Asteroid Flyby mission; the Cassini mission to Saturn; the Lunar Geoscience Observer; and the Mars Rover/Sample Return mission.

Burns, Roger G.↗
NASA NTRS2006

DSMC Simulations of Apollo Capsule Aerodynamics for Hypersonic Rarefied Conditions

Direct simulation Monte Carlo DSMC simulations are performed for the Apollo capsule in the hypersonic low density transitional flow regime. The focus is on ow conditions similar to that experienced by the Apollo Command Module during the high altitude portion of its reentry Results for aerodynamic forces and moments are presented that demonstrate their sensitivity to rarefaction that is for free molecular to continuum conditions. Also aerodynamic data are presented that shows their sensitivity to a range of reentry velocity encompasing conditions that include reentry from low Earth orbit lunar return and Mars return velocities to km/s. The rarefied results are anchored in the continuum regime with data from Navier Stokes simulations

Moss, James N.↗
NASA NTRS1988

Polygenic eruptions on Alba Patera, Mars

A new model for the evolution of the martian volcano Alba Patera is constructed. Numerous digitate channel networks on the flanks of the volcano are interpreted to be carved by sapping due to the release of nonjuvenile water from unconsolidated flank deposits. The particle size of these deposits is estimated to be 3-10 microns, which, together with theoretical modelling of the disperison of explosively derived volcanic materials, leads to the conclusion that the flank deposits on Alba Patera are low-relief pyroclastic flows. The recognition of numerous late-stage summit and subterminal lava flows thus makes Alba Patera a unique martian volcano that is transitional between the older pyroclastic-dominated highland paterae and the more recent effusive central-vent volcanoes such as the Tharsis Montes.

Mouginis-Mark, P. J.↗
NASA NTRS1977

UBV photometry of small and distant asteroids

Photoelectric magnitudes and colors on the ultraviolet (UBV) system are presented for 65 minor planets, including four Mars crossers, six Trojans, and main-belt objects down to 6 km in diameter. The Trojans all have very similar colors not characteristic of the main-belt population. A paucity of S-type asteroids at the smallest diameters, predicted from trends seen at larger sizes, is not observed. The newly available color data for small objects ranging from 1.0 to 5.2 astronomic units in heliocentric distance show the main belt to be a transition zone between predominantly silicate and carbonaceous compositions.

Zellner, B.↗
NASA NTRS1989

Enabling human exploration of space - A life sciences overview

In the transition from the short-duration missions of the Space Shuttle era to long-duration exploration missions, the health and safety of crewmembers must be ensured. The body undergoes many complex physiological changes as a result of its adaptation to a microgravity environment and U.S. and Soviet experiences have shown that time is required for readaptation to gravity. The consequences of these changes for the extended exploration missions envisioned for the future are unknown. A Mars mission may require crewmembers to spend many months in microgravity, and then work effectively in a one-third gravity environment. Other problems may arise when returning crewmembers must readapt to earth's gravity. Life Sciences activities are being planned to systematically address the physiological issues involved with long-term manned exploration missions, through ground-based studies and flight investigations on the Shuttle and Space Station Freedom. The areas of focus are artificial gravity, radiation, health care, and space human factors.

Gaiser, Karen K.↗
NASA NTRS2013

The Single Habitat Module Concept for Exploration - Mission Planning and Mass Estimates

The Single Habitat Module (SHM) concept approach to the infrastructure and conduct of exploration missions combines many new promising technologies with a central concept of mission architectures that use a single habitat module for all phases of an exploration mission. Integrating mission elements near Earth and fully fueling them prior to departure of the vicinity of Earth provides the capability of using the single habitat both in transit to/from an exploration destination and while exploring the destination. The concept employs the capability to return the habitat and interplanetary propulsion system to Earth vicinity so that those elements can be reused on subsequent exploration missions. This paper provides an overview of the SHM concept and the advantages it provides. The paper also provides a summary of calculations of the mass of the Habitat Propulsion System (HPS) needed to get the habitat from low-Mars orbit (LMO) to the surface and back to LMO, and an overview of trajectory and mission mass assessments related to use of a high specific impulse space-based propulsion system. Those calculations led to the conclusion that the SHM concept results in low total mass required and streamlines mission operations to explore Mars (or other exploration destinations).

Chambliss, Joe↗
NASA NTRS2025

Potential Health Impacts, Treatments, and Countermeasures of Martian Dust on Future Human Space Exploration

The challenges of human space exploration produce some of humanity’s greatest technological and scientific advances, not excluding innovations in medicine. The microgravity environment causes a whole host of physiological changes, and exposure to dust on the Moon caused considerable pulmonary distress to astronauts during the Apollo missions. As the National Aeronautics and Space Administration (NASA)and other space organizations prepare for long duration exploration missions to Mars, the hazards and consequences of the Martian surface need to be accounted for. This review investigates how substances analogous to the hazardous components of Martian dust have caused disease in people on Earth. Because of the small grain size of Martian dust, dust on Mars is more likely to cause lung irritation, absorb into the bloodstream, and lead to diseases in astronauts. Toxic components of Martian dust to astronaut health include perchlorates, silica, nanophase iron oxides, and gypsum in addition to trace amounts of toxic metals whose abundances are debated: chromium, beryllium, arsenic, and cadmium. Predicted effects of dust exposure ranges from asymptomatic to life threatening, with many substances being carcinogenic and most damage impacting the pulmonary system. The longer transit time for astronauts to return home makes the operations of performing emergency medical treatment more difficult and increases both the likelihood and consequences of developing chronic disease. Exposure mitigation needs to be prioritized; however, supplements may be taken to prevent disease from breakthrough exposures and treatment regimens could lessen morbidity and mortality. Treatments and equipment need to be carefully thought out and transported with the astronauts to be prepared for all possible scenarios.

Justin L Wang↗
NASA NTRS2019

Laboratory-Based Thermal Shock Investigation of Heat Flux Sensors for the Mars 2020 Backshell

In 2012 during the entry, descent, and landing of the Mars Science Laboratory (MSL), the MSL Entry, Descent, and Landing Instrumentation (MEDLI) sensor suite was collecting in-flight heatshield pressure and temperature data. The data collected by the MEDLI instruments has since been used for reconstruction of vehicle aerodynamics, atmospheric conditions, aerothermal heating, and Thermal Protection System (TPS) performance as well as material response model validation and refinement. The Mars Entry, Descent, and Landing Instrumentation 2 (MEDLI2) sensor suite for the Mars 2020 heatshield and backshell is being designed to expand on the measurements and knowledge gained from MEDLI. Similar to MEDLI, MEDLI2 will measure the pressure and temperature of the heatshield. MEDLI2 will additionally measure the temperature, pressure, total heat flux, and radiative heat flux on the backshell.Since the backshell instrumentation is new to MEDLI2, Do No Harm (DNH) testing was conducted on instrumented backshell TPS (SLA-561V) panels. The panels consisted of four pressure port holes, one Mars Entry Atmospheric Data System (MEADS) pressure port plug, one MEDLI2 Integrated Sensor Plug (MISP) thermal plug, and one heat flux sensor. DNH testing was conducted to ensure the performance of the TPS was not degraded due to sensor integration and to characterize any TPS performance changes. The testing consisted of environmental testing— vibration, shock, thermal vacuum (TVAC) cycling— and bounding aerothermal (arc jet) testing. During arc jet testing, the heat flux sensors embedded in the SLA-561V panels exhibited an unexpected temporary reduction in the heat flux sensor temperature and response. After review of the test results, it was determined that this unexpected response was confined to the two heat flux sensors that experienced the greatest thermal shock condition. This condition consisted of a liquid nitrogen (LN2) bath that induced temperatures of approximately -190°C, and then a transition (thermal shock) to an arc jet test at a heat rate of approximately 21 W/cm2. Both heat flux sensors that were exposed to this thermal shock experienced a blister in the thermal coating during the arc jet test.Two heat flux sensor thermal shock test series were performed to investigate the cause of the blistering and subsequent energy release. In these tests, the heat flux sensor was first cold soaked in either a dry ice or LN2 bath to induce temperatures of approximately -78°C or -190°C, respectively. Then the sensors were thermally shocked using two propane torches with a heat rate of either approximately 8 W/cm2 or 21 W/cm2. The key findings indicated that there is a correlation between thermal shock and the blistering observed in the DNH test series, and that the cause appeared to be rooted in the heat flux sensor epoxy that encapsulates the sensor thermopile.Since the heat flux sensors are required to measure heat fluxes up to 15 W/cm2 during the Mars 2020 entry, a third test series was designed to determine if blistering is an issue at this maximum expected flight heat flux. Results from all three thermal shock test series and a discussion about whether or not blistering of the heat flux sensor thermal coating could be an issue for the Mars 2020 mission will be presented.

Miller, R. A.↗
NASA NTRS2007

Mineralogical In-situ Investigation of Acid-Sulfate Samples from the Rio Tinto River, Spain, with a Portable XRD/XRF Instrument

A field campaign was organized in September 2006 by Centro de Astobiologica (Spain) and Washington University (St Louis, USA) for the geological study of the Rio Tinto river bed sediments using a suite of in-situ instruments comprising an ASD reflectance spectrometer, an emission spectrometer, panoramic and close-up color imaging cameras, a life detection system and NASA's CheMin 4 XRD/XRF prototype. The primary objectives of the field campaign were to study the geology of the site and test the potential of the instrument suite in an astrobiological investigation context for future Mars surface robotic missions. The results of the overall campaign will be presented elsewhere. This paper focuses on the results of the XRD/XRF instrument deployment. The specific objectives of the CheMin 4 prototype in Rio Tinto were to 1) characterize the mineralogy of efflorescent salts in their native environments; 2) analyze the mineralogy of salts and oxides from the modern environment to terraces formed earlier as part of the Rio Tinto evaporative system; and 3) map the transition from hematite-dominated terraces to the mixed goethite/salt-bearing terraces where biosignatures are best preserved.

Sarrazin, P.↗
DOE OSTI2023

Band structure, superconductivity, and polytypism in AuSn 4

The orthorhombic compound AuSn 4 is compositionally similar to the Dirac node arc semimetal PtSn 4 . AuSn 4 is, contrary to PtSn 4 , superconducting with a critical temperature of T c = 2.35 K. Recent measurements present indications for quasi-two-dimensional superconducting behavior in AuSn 4 . Here we present measurements of the superconducting density of states and the band structure of AuSn 4 through scanning tunneling microscopy and angular resolved photoemission spectroscopy (ARPES). The superconducting gap values in different portions of the Fermi surface are spread around Δ 0 = 0.4 meV, which is close to but somewhat larger than Δ = 1.76k B T c expected from BCS theory. We observe superconducting features in the tunneling conductance at the surface up to temperatures about 20% larger than bulk T c . The band structure calculated with density functional theory follows well the results of ARPES. The crystal structure presents two possible stackings of Sn layers, giving two nearly degenerate polytypes. This makes AuSn 4 a rather unique case with a three-dimensional electronic band structure but properties ressembling those of low-dimensional layered compounds.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
NASA NTRS2010

Hematite at Meridiani Planum, Mars, Investigated by Simultaneous Fitting of MER Mossbauer Spectra

The Mars Exploration Rover Opportunity encountered sedimentary outcrop rocks at its landing site. Spherules with diameters in the millimeter range were found to weather from the outcrop rocks. With Opportunity s miniaturised M ssbauer spectrometer MIMOS II, hematite was detected in spherules and in the outcrop matrix [1,2]. Figure 1 shows the target Berry Bowl, where brushed outcrop and an accumulation of spherules could be investigated on sols 46 and 48 of Opportunity s mission. Hematite undergoes a transition from a weakly ferromagnetic above to an antiferromagnetic state below the Morin temperature (T(sub M) approx.265 K for chemically pure, crystalline hematite). The magnetic hyperfine splitting (B(sub hf)) shows a general decrease with increasing temperature and a drop of approx.0.8 T at T(sub M). The quadrupole splitting ((Delta)EQ) changes its sign at T(sub M), with negative values above and positive values below the transition. Crystallinity and particle size influence the magnitude and temperature dependence of the magnetic splitting and the quadrupole splitting [3].

Fleischer, I.↗
NASA NTRS2012

Time and Energy, Exploring Trajectory Options Between Nodes in Earth-Moon Space

The Global Exploration Roadmap (GER) was released by the International Space Exploration Coordination Group (ISECG) in September of 2011. It describes mission scenarios that begin with the International Space Station and utilize it to demonstrate necessary technologies and capabilities prior to deployment of systems into Earth-Moon space. Deployment of these systems is an intermediate step in preparation for more complex deep space missions to near-Earth asteroids and eventually Mars. In one of the scenarios described in the GER, "Asteroid Next", there are activities that occur in Earth-Moon space at one of the Earth-Moon Lagrange (libration) points. In this regard, the authors examine the possible role of an intermediate staging point in an effort to illuminate potential trajectory options for conducting missions in Earth-Moon space of increasing duration, ultimately leading to deep space missions. This paper will describe several options for transits between Low Earth Orbit (LEO) and the libration points, transits between libration points, and transits between the libration points and interplanetary trajectories. The solution space provided will be constrained by selected orbital mechanics design techniques and physical characteristics of hardware to be used in both crewed missions and uncrewed missions. The relationships between time and energy required to transfer hardware between these locations will provide a better understanding of the potential trade-offs mission planners could consider in the development of capabilities, individual missions, and mission series in the context of the ISECG GER.

Martinez, Roland↗
NASA NTRSDate not supplied

Nuclear Electric Propulsion (NEP) Developments for Human Mars Missions

Nuclear Electric Propulsion (NEP) has the potential to enable human missions to Mars and other ambitious missions throughout the solar system. This paper will discuss ongoing NEP research and development efforts and challenges to developing NEP systems for these missions. The baseline NEP vehicle design is comprised of multiple subsystems operating in concert. The major subsystems include a nuclear reactor, a dynamic power conversion system to generate electrical power, heat rejection/radiators, a power management and distribution system to deliver power to the electric propulsion (EP) system and to the crewed transit habitat, and the EP system. An additional chemical propulsion system is also included to execute higher-thrust maneuvers in the Earth and Martian gravity wells. Specific issues that will be addressed include mission trajectory design and optimization, concurrent subsystem technology advancement plans and maturation efforts, and systems-level modeling of the entire vehicle to permit the fast exploration of trade-offs that can occur with changes in operating conditions or through the use of different technologies.

Kurt A Polzin↗
NASA NTRSDate not supplied

BioNutrients: Microbial on-demand production of short shelf-life micronutrients in space

Long duration deep space missions pose a significant challenge when considering adequate nutrition for human spaceflight. Many micronutrients supplied in pre-packaged foods for low Earth orbit flights have a short shelf life and will degrade over multi-year missions. One strategy to mitigate the risk of micronutrient malnutrition is to grow fresh foods to supplement a pre-packaged diet. The BioNutrients project aims to develop systems for growing edible microorganisms that are genetically engineered to produce short shelf life micronutrients. BioNutrients-1 (BN-1) is a five-year spaceflight project currently underway on the International Space Station (ISS) that tests long-term storage and production of two carotenoids, β-carotene and zeaxanthin, in genetically engineered yeast strains. BN-1 on-orbit and ground control activities indicate that the nutrient production system will be stable for at least two years in ambient storage conditions. BN-1 is also testing the effects of long-term ISS storage on viability and gene expression using “stasis packs” containing a series of microorganisms useful in food and biomanufacturing processes. Stasis pack analysis is distinguishing microorganisms with full viability after two years of storage from other species that lose viability rapidly. In parallel, BioNutrients-2 (BN-2) is being developed as a six-month flight experiment that will expand the range of foods produced on ISS to include yogurt, kefir, and probiotic yeast. BN-2 will improve upon hardware design by transitioning from a hard-shell polycarbonate bioreactor to a flexible fluorinated ethylene propylene (FEP) bag. This change reduces the mass and volume required to store production packs. The long-term goal of BioNutrients is to develop the capability for rapid and safe delivery of multiple micronutrients in single-use production packs. We expect synthetic biology approaches similar to BioNutrients will play an important role for astronaut health in future NASA missions to the Moon and Mars.

Synthetic Biology↗