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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 865 records · Page 48
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NASA NTRS2012

Scientific Value of a Saturn Atmospheric Probe Mission

Atmospheric entry probe mISSions to the giant planets can uniquely discriminate between competing theories of solar system formation and the origin and evolution of the giant planets and their atmospheres. This provides for important comparative studies of the gas and ice giants, and to provide a laboratory for studying the atmospheric chemistries, dynamics, and interiors of all the planets including Earth. The giant planets also represent a valuable link to extrasolar planetary systems. As outlined in the recent Planetary Decadal Survey, a Saturn Probe mission - with a shallow probe - ranks as a high priority for a New Frontiers class mission [1].

Simon-Miller, A. A.↗
NASA NTRS1977

The design and reconstruction of the Viking Lander descent trajectories

The success of the Viking Mission is truly a major milestone in this country's planetary exploration program. This paper deals with the trajectory characteristics of the Viking Lander descent trajectories, beginning with the imposed requirements and constraints, the final preflight design based on the final hardware and operational capability, and ending with the actual performance achieved. A comparison between the predicted and actual trajectory characteristics is made to indicate the achieved accuracy and modeling fidelity. Also, estimates of the Martian environment derived from the entry-trajectory reconstruction process are presented.

Euler, E. A.↗
NASA NTRS2011

Mars Ascent Vehicle Test Requirements and Terrestrial Validation

The Mars robotic sample return mission has been a potential flagship mission for NASA s science mission directorate for decades. The Mars Exploration Program and the planetary science decadal survey have highlighted both the science return of the Mars Sample Return mission, but also the need for risk reduction through technology development. One of the critical elements of the MSR mission is the Mars Ascent Vehicle, which must launch the sample from the surface of Mars and place it into low Mars orbit. The MAV has significant challenges to overcome due to the Martian environments and the Entry Descent and Landing system constraints. Launch vehicles typically have a relatively low success probability for early flights, and a thorough system level validation is warranted. The MAV flight environments are challenging and in some cases impossible to replicate terrestrially. The expected MAV environments have been evaluated and a first look of potential system test options has been explored. The terrestrial flight requirements and potential validation options are presented herein.

Dankanich, John W.↗
NASA NTRS2011

Stratospheric Collection of Dust from Comet 73P/Schwassmann-Wachmann 3

Interplanetary dust particles (IDPs) collected in the stratosphere are unique materials that are compositionally distinct from meteorites. Astronomical observations and dynamical models indicate that both asteroids and short-period comets are significant sources of IDPs. IDPs having fragile, porous structures, unequilibrated, anhydrous mineralogy, and high atmospheric entry velocities are thought to derive from comets, whereas asteroidal IDPs are identified by their compact structure, hydrated mineralogy and low atmospheric entry velocities. Uncertainty remains in the classification of asteroidal and cometary IDPs owing to our limited sampling of comets and the asteroid belt and the complex dynamical histories of most IDPs in space. Most IDPs spend thousands of years in space prior to being accreted by the Earth. During this time, dust particles undergo orbital evolution, including gradual reduction in their perihelion and eccentricity as a result of Poynting-Robertson drag. Planetary encounters may also significantly change their orbital parameters. Consequently, it is generally not possible to identify the specific parent body of a given IDP. However, it has been proposed that it is possible to identify dust from comets that have formed Earth-crossing dust trails. In this case, the dust particles have been in space for such a short period of time (a few decades or less) that their orbits have not significantly changed. Furthermore, these fresh IDPs could be identified in the laboratory from their short space-exposure histories (low solar noble gas abundance and lack of solar flare tracks). NASA flew several dedicated IDP collection missions attempting to collect dust from comet 26P/Grigg-Skjellerup, the best candidate identified. Remarkably, many particles from those collectors exhibit unusual properties, including low abundances of solar noble gases and high abundances of presolar grains. These observations are consistent with the dust particles originating from comet Grigg-Skjellerup (hereafter G-S). This study considers the prospects for collection of dust from comet 73P/Schwassmann-Wachmann 3 (hereafter SW3). SW3 is a small (2 km diameter) Jupiter family comet whose perihelion is close to and just inside the Earth's orbit. The orbit of SW3 is suitable for producing a low-velocity Earth-crossing dust stream and is the likely parent of the Tau Herculid meteor stream. This study complements a previously published model of the SW3 meteor stream that predicted a very low level of activity for grains 100 micron -- 100 mm in size.

Messenger, Scott R.↗
NASA NTRS2011

Modeling the Entry of Micrometeoroids into the Atmospheres of Earth-like Planets

The temperature profiles of micrometeors entering the atmospheres of Earth-like planets are calculated to determine the altitude at which exogenous organic compounds may be released. Previous experiments have shown that flash-heated micrometeorite analogs release organic compounds at temperatures from roughly 500 to 1000 K [1]. The altitude of release is of great importance because it determines the fate of the compound. Organic compounds that are released deeper in the atmosphere are more likely to rapidly mix to lower altitudes where they can accumulate to higher abundances or form more complex molecules and/or aerosols. Variables that are explored here are particle size, entry angle, atmospheric density profiles, spectral type of the parent star, and planet mass. The problem reduces to these questions: (1) How much atmosphere does the particle pass through by the time it is heated to 500 K? (2) Is the atmosphere above sufficient to attenuate stellar UV such that the mixing timescale is shorter than the photochemical timescale for a particular compound? We present preliminary results that the effect of the planetary and particle parameters have on the altitude of organic release.

Pevyhouse, A. R.↗
NASA NTRS2008

Propulsive Maneuver Design for the 2007 Mars Phoenix Lander Mission

On May 25, 2008, the Mars Phoenix Lander (PHX) successfully landed in the northern planes of Mars in order to continue and complement NASA's "follow the water" theme as its predecessor Mars missions, such as Mars Odyssey (ODY) and Mars Exploration Rovers, have done in recent years. Instruments on the lander, through a robotic arm able to deliver soil samples to the deck, will perform in-situ and remote-sensing investigations to characterize the chemistry of materials at the local surface, subsurface, and atmosphere. Lander instruments will also identify the potential history of key indicator elements of significance to the biological potential of Mars, including potential organics within any accessible water ice. Precise trajectory control and targeting were necessary in order to achieve the accurate atmospheric entry conditions required for arriving at the desired landing site. The challenge for the trajectory control maneuver design was to meet or exceed these requirements in the presence of spacecraft limitations as well as other mission constraints. This paper describes the strategies used, including the specialized targeting specifically developed for PHX, in order to design and successfully execute the propulsive maneuvers that delivered the spacecraft to its targeted landing site while satisfying the planetary protection requirements in the presence of flight system constraints.

FPC↗
NASA NTRSDate not supplied

Case Study of Meteoroid Fluence on a Mars Sample Return Mission

The Mars Sample Return Campaign must satisfy a Back Planetary Protection requirement that limits the risk of biological contamination of the Earth by Martian microbes. The Earth Re-turn Orbiter (ERO), being developed by the European Space Agency (ESA), will carry a Capture, Containment and Return System (CCRS), which is being developed by NASA to retrieve orbiting samples (OS) from Mars orbit, surround them with two containment layers to create a Contained OS (COS), and transfer the COS to the Earth Entry System (EES), which will be re-leased by ERO to carry the samples through entry, descent and landing at the Utah Test and Training Range. Micrometeoroid impact damage to the Thermal Protection System (TPS) of the EES, which may occur at any time in the ERO mission, is recognized as a potential risk driver for loss of sample containment that needs to be rigorously assessed. A Micrometeoroid Protection System (MMPS) will be implemented to limit that risk. The MMPS consists of a shield covering the TPS called the Micrometeoroid Garage (MMG) and a system of cameras to inspect the TPS. An extensive study was performed by the CCRS Project in collaboration with the NASA Engineering and Safety Center (NESC)to assess the probability of damage to the MMG and TPS by meteoroids over the entire ERO mission. This included the computation of the meteoroid fluence on the MMG and directly on the TPS after EES separation, and assessment of damage to the MMG and TPS via hypervelocity impact tests, hydrocode simulations, and empirical damage prediction and ballistic limit equations (BLEs). The focus of this paper is the meteoroid fluence on the MMG.

Micrometeoroid↗
NASA NTRSDate not supplied

Case Study of Meteoroid Fluence on a Mars Sample Return Mission

The Mars Sample Return Campaign must satisfy a Back Planetary Protection requirement that limits the risk of biological contamination of the Earth by Martian microbes. The Earth Re-turn Orbiter (ERO), being developed by the European Space Agency (ESA), will carry a Capture, Containment and Return System (CCRS), which is being developed by NASA to retrieve orbiting samples (OS) from Mars orbit, surround them with two containment layers to create a Contained OS (COS), and transfer the COS to the Earth Entry System (EES), which will be re-leased by ERO to carry the samples through entry, descent and landing at the Utah Test and Training Range. Micrometeoroid impact damage to the Thermal Protection System (TPS) of the EES, which may occur at any time in the ERO mission, is recognized as a potential risk driver for loss of sample containment that needs to be rigorously assessed. A Micrometeoroid Protection System (MMPS) will be implemented to limit that risk. The MMPS consists of a shield covering the TPS called the Micrometeoroid Garage (MMG) and a system of cameras to inspect the TPS. An extensive study was performed by the CCRS Project in collaboration with the NASA Engineering and Safety Center (NESC)to assess the probability of damage to the MMG and TPS by meteoroids over the entire ERO mission. This included the computation of the meteoroid fluence on the MMG and directly on the TPS after EES separation, and assessment of damage to the MMG and TPS via hypervelocity impact tests, hydrocode simulations, and empirical damage prediction and ballistic limit equations (BLEs). The focus of this paper is the meteoroid fluence on the MMG.

micrometeoroid↗
NASA NTRS1983

A program for planetary exploration

A series of recommendations constituting a core program for planetary exploration, to last from the present to the year 2000, is the outcome of a two-year study undertaken by the NASA Solar System Exploration Committee. The missions envisioned by the core program must be insulated from costly changes and delays once they are approved. The present Committee has therefore restricted its recommendations to missions which do not require novel technologies, but rather continue the techniques of the flybys, orbiters and atmospheric entry probes that have been successful in the past. Recommendations are made for exploration of the inner planets, cometary and asteroid bodies, and the outer planets. Attention is given to the identification of key elements driving mission costs. It is noted that the Space Shuttle/Centaur upper stage combination brings within reach comet and asteroid rendezvous missions that were once thought to require costly new technology.

Morrison, D.↗
NASA NTRS1988

Meteorites on Mars

Four types of meteoritic material should be found on Mars: (1) micrometeorites, many of which will survive atmospheric entry unmelted, which should fall relatively uniformly over the planet's surface, (2) ablation products from larger meteorites which ablate, break up and burn up in the Mars atmosphere, (3) debris from large, crater forming objects, which, by analogy to terrestrial and lunar impact events, will be concentrated in the crater ejecta blankets (except for rare, large events, such as the proposed C-T event on earth, which can distribute debris on a planetary scale), and (4) debris from the early, intense bombardment, which, in many areas of the planet, may now be incorporated into rocks by geologic processes subsequent to the intense bombardment era. To estimate the extent of meteoritic addition to indigenous Martian material, the meteoritic flux on Mars must be known. It is estimated that the overall flux is twice that for the Moon and 1.33 that for Earth. For small particles, whose orbital evolution is dominated by Poynting Robertson drag, the flux at Mars can be estimated from the Earth flux. The smaller Martian gravitational enhancement as well as the decrease in the spatial density of interplanetary dust with increasing heliocentric distance should reduce the flux of small particles at Mars to about 0.33 times the flux at Earth. Because of the smaller planetary cross-section the total infalling mass at Mars is then estimated to be 0.09 time the infalling mass in the micrometeorite size range at Earth.

Flynn, G. J.↗
NASA NTRS2004

Full Text Searching and Customization in the NASA ADS Abstract Service

The NASA-ADS Abstract Service provides a sophisticated search capability for the literature in Astronomy, Planetary Sciences, Physics/Geophysics, and Space Instrumentation. The ADS is funded by NASA and access to the ADS services is free to anybody worldwide without restrictions. It allows the user to search the literature by author, title, and abstract text. The ADS database contains over 3.6 million references, with 965,000 in the Astronomy/Planetary Sciences database, and 1.6 million in the Physics/Geophysics database. 2/3 of the records have full abstracts, the rest are table of contents entries (titles and author lists only). The coverage for the Astronomy literature is better than 95% from 1975. Before that we cover all major journals and many smaller ones. Most of the journal literature is covered back to volume 1. We now get abstracts on a regular basis from most journals. Over the last year we have entered basically all conference proceedings tables of contents that are available at the Harvard Smithsonian Center for Astrophysics library. This has greatly increased the coverage of conference proceedings in the ADS. The ADS also covers the ArXiv Preprints. We download these preprints every night and index all the preprints. They can be searched either together with the other abstracts or separately. There are currently about 260,000 preprints in that database. In January 2004 we have introduced two new services, full text searching and a personal notification service called "myADS". As all other ADS services, these are free to use for anybody.

Eichhorn, G.↗
NASA NTRSDate not supplied

Boundary Layer Analysis of Shock Tube Flows

Shock tubes offer a controlled environment to reproduce kinetic and radiative phenomena characteristic of atmospheric entry flows under ground-test conditions. The boundary layer developing behind the incident shock wave determines the available test time, influences particle residence times important for similarity scaling, and can affect radiative energy transport. In this study, we couple a quasi-1D space marcher with the compressible boundary-layer equations to numerically compute the post-shock flow in a shock frame of reference for various test gas mixtures representative of different planetary atmospheres. The solvers are individually verified against CFD simulations and analytical correlations available in the literature. Coupled solutions are computed for a finite-rate chemistry in the boundary layer and a non-catalytic isothermal wall. Results yield refined estimates of the maximum separation distance, as well as insights into concentration profiles of relevant species within the boundary layer.

Andrea Fagnani↗
NASA NTRS2011

Products from NASA's In-Space Propulsion Technology Program Applicable to Low-Cost Planetary Missions

Since September 2001 NASA s In-Space Propulsion Technology (ISPT) program has been developing technologies for lowering the cost of planetary science missions. Recently completed is the high-temperature Advanced Material Bipropellant Rocket (AMBR) engine providing higher performance for lower cost. Two other cost saving technologies nearing completion are the NEXT ion thruster and the Aerocapture technology project. Also under development are several technologies for low cost sample return missions. These include a low cost Hall effect thruster (HIVHAC) which will be completed in 2011, light weight propellant tanks, and a Multi-Mission Earth Entry Vehicle (MMEEV). This paper will discuss the status of the technology development, the cost savings or performance benefits, and applicability of these in-space propulsion technologies to NASA s future Discovery, and New Frontiers missions, as well as their relevance for sample return missions.

Anderson, David J.↗
NASA NTRSDate not supplied

Introduction to Trajectories

Presentation prepared for the 10th International Planetary Probe Workshop in 2013. The presentation was approved in the old approval system back in 2013. I am being asked to re-submit it for approval because the record of approval is no longer available. The presentation is being re-used for student seminars.

Trajectories↗
NASA NTRS1971

Guidance and navigation requirements for unmanned flyby and swingby missions to the outer planets. Volume 4: High thrust mission, part 2, phase C

The guidance and navigation requirements for a set of impulsive thrust missions involving one or more outer planets or comets. Specific missions considered include two Jupiter entry missions of 800 and 1200 day duration, two multiple swingby missions with the sequences Jupiter-Uranus-Neptune and Jupiter-Saturn-Pluto, and two comets rendezvous missions involving the short period comets P/Tempel 2 and P/Tuttle-Giacobini-Kresak. Results show the relative utility of onboard and Earth-based DSN navigation. The effects of parametric variations in navigation accuracy, measurement rate, and miscellaneous constraints are determined. The utility of a TV type onboard navigation sensor - sighting on planetary satellites and comets - is examined. Velocity corrections required for the nominal and parametrically varied cases are tabulated.

Source record↗
NASA NTRS1992

Atmospheric effects on ejecta emplacement and crater formation on Venus from Magellan

Surface signatures of energy partitioning are used as a framework for testing extrapolations from laboratory experiments and other planetary settings to assess the effects of both gravity and an atmosphere on impact crater formation on Venus. The dense lower atmosphere of Venus is found to assume the role of a low-density target for bodies smaller than about 4 km in diameter. Air blasts created by cratering in the atmosphere produce distinctive surface signatures that allow the derivation of an independent assessment of impactor energy at the limit of break up. Dynamic pressures during entry of larger bodies will exceed their strength limit but may not prevent penetration of the atmosphere due to aerodynamic reshaping that minimizes the drag coefficient. This process may account for the formation of unusually small craters (1-3 km). The dense atmosphere of Venus preserves signatures of early time cratering processes on the surface that are typically lost on atmosphere-free surfaces.

Schultz, Peter H.↗
NASA NTRS2010

Evaluation of the NASA Arc Jet Capabilities to Support Mission Requirements

NASA accomplishes its strategic goals through human and robotic exploration missions. Many of these missions require launching and landing or returning spacecraft with human or return samples through Earth's and other planetary atmospheres. Spacecraft entering an atmosphere are subjected to extreme aerothermal loads. Protecting against these extreme loads is a critical element of spacecraft design. The safety and success of the planned mission is a prime concern for the Agency, and risk mitigation requires the knowledgeable use of thermal protection systems to successfully withstand the high-energy states imposed on the vehicle. Arc jets provide ground-based testing for development and flight validation of re-entry vehicle thermal protection materials and are a critical capability and core competency of NASA. The Agency's primary hypersonic thermal testing capability resides at the Ames Research Center and the Johnson Space Center and was developed and built in the 1960s and 1970s. This capability was critical to the success of Apollo, Shuttle, Pioneer, Galileo, Mars Pathfinder, and Orion. But the capability and the infrastructure are beyond their design lives. The complexes urgently need strategic attention and investment to meet the future needs of the Agency. The Office of Chief Engineer (OCE) chartered the Arc Jet Evaluation Working Group (AJEWG), a team of experienced individuals from across the Nation, to capture perspectives and requirements from the arc jet user community and from the community that operates and maintains this capability and capacity. This report offers the AJEWG's findings and conclusions that are intended to inform the discussion surrounding potential strategic technical and investment strategies. The AJEWG was directed to employ a 30-year Agency-level view so that near-term issues did not cloud the findings and conclusions and did not dominate or limit any of the strategic options.

Calomino, Anthony↗
NASA NTRSDate not supplied

Aerodynamic Implications of Aerocapture Systems for Uranus Orbiters

Exploration of the Ice Giants, Uranus in particular, has been indicated as the highest priority new flagship-class mission by the 2022 Planetary Science Decadal Survey. However, due to it’s location in the solar system, extensive travel time and resources are required for a mission to reach Uranus. Aerocapture offers shorter interplanetary transit times and reduced propellant requirements for such a mission when compared to a traditional propulsive-capture orbiter. Considerations for the aerodynamics of an aerocapture system enabling flagship-class science mission to Uranus are presented. The applicability of a low lift-to-drag entry vehicle aeroshell with flight heritage to a new planet and atmosphere is evaluated. A preliminary aerodatabase is formulated from low-fidelity methods and heritage flight mission data to provide initial estimates of trajectory space to be considered for inserting a spacecraft into orbit at Uranus using aerocapture. Computational fluid dynamics calculations in the free molecular, transitional, and continuum regimes using Direct Simulation Monte Carlo and Navier-Stokes solutions are used to assess the validity of this preliminary aerodatabase. The considered entry vehicle is found to varying levels of agreement with work done by previous flight missions when evaluated for flight in Uranus’ atmosphere. Implications for the aerodynamics of this vehicle as applied in an aerocapture system in flight at Uranus as found by the current work are discussed.

Eli R. Shellabarger↗