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NASA NTRS2009

Development of Life on Early Mars

Exploration of Mars has begun to unveil the history of the planet. Combinations of remote sensing, in situ compositional measurements and photographic observations have shown Mars had a dynamic and active geologic evolution. Mars geologic evolution encompassed conditions that were suitable for supporting life. A habitable planet must have water, carbon and energy sources along with a dynamic geologic past. Mars meets all of these requirements. The first 600 My of Martian history were ripe for life to develop because of the abundance of (i) Water- as shown by carved canyons and oceans or lakes with the early presence of near surface water shown by precipitated carbonates in ALH84001, well-dated at ~3.9 Gy, (ii) Energy from the original accretional processes, a molten core which generated a strong magnetic field leaving a permanent record in the early crust, active volcanism continuing throughout Martian history, and continuing impact processes, (iii) Carbon, water and a likely thicker atmosphere from extensive volcanic outgassing (i.e. H20, CO2, CH4, CO, O2, N2, H2S, SO2, etc.) and (iv) crustal tectonics as revealed by faulting and possible plate movement reflected by the magnetic pattern in the crust [1]. The question arises: "Why would life not develop from these favorable conditions on Mars in its first 600 My?" During this period, environmental near-surface conditions on Mars were more favorable to life than at any later time. Standing bodies of water, precipitation and flowing surface water, and possibly abundant hydrothermal energy would favor the formation of early life. (Even if life developed elsewhere on Earth, Venus, or on other bodies-it was transported to Mars where surface conditions were suitable for life to evolve). The commonly stated requirement that life would need hundreds of millions of year to get started is only an assumption; we know of no evidence that requires such a long interval for the development of life, if the proper habitable conditions are meet. Perhaps it could start in a very short interval during the first tens of millions of years after crustal formation. Even with impact-driven extinction events, such a short start-up time would allow life to restart multiple times until it persevered. If panspermia is considered, life could be introduced as soon as liquid surface water was present and could instantly thrive and spread.

Gibson, Everett K.↗
NASA NTRS2009

Relative Shock Effects in Mixed Powders of Calcite, Gypsum, and Quartz: A Calibration Scheme from Shock Experiments

The shock behavior of calcite and gypsum is important in understanding the Cretaceous/Tertiary event and other terrestrial impacts that contain evaporite sediments in their targets. Most interest focuses on issues of devolatilization to quantify the production of CO2 or SO2 to better understand their role in generating a temporary atmosphere and its effects on climate and biota [e.g., papers in 1,2,3,4]. Devolatilization of carbonate is also important because the dispersion and fragmentation of ejecta is strongly controlled by the expansion of large volumes of gas during the impact process as well [5,6]. Shock recovery experiments for calcite yield seemingly conflicting results: early experimental devolatilization studies [7,8,9] suggested that calcite was substantially outgassed at 30 GPa (> 50%). However, the recent petrographic work of [10,11,12] presented evidence that essentially intact calcite is recovered from 60 GPa experiments. [13] reported results of shock experiments on anhydrite, gypsum, and mixtures of those phases with silica. Their observations indicate little or no devolatilization of anhydrite shocked to 42 GPa and that the fraction of sulfur, by mass, that degassed is approx.10(exp -2) of theoretical prediction. In another (preliminary) report of shock experiments on calcite, anhydrite, and gypsum, [14] observe calcite recrystallization when shock loaded at 61 GPa, only intensive plastic deformation in anhydrite shock loaded at 63 GPa, and gypsum converted to anhydrite when shock loaded at 56 GPa. [15] shock loaded anhydrite and quartz to a peak pressure of 60 GPa. All of the quartz grains were trans-formed to glass and the platy anhydrite grains were completely pseudomorphed by small crystallized anhydrite grains. However, no evidence of interaction between the two phases could be observed and they suggest that recrystallization of anhydrite grains is the result of a solid state transformation. [16] reanalyzed the calcite and anhydrite shock wave experiments of [17] using improved equations of state of porous materials and vaporized products. They determined the pressures for incipient and complete vaporization to be 32.5 and 122 GPa for anhydrite and 17.8 and 54.1 GPa for calcite, respectively, a factor of 2 to 3 lower than reported earlier by [17].

Bell, Mary S.↗
NASA NTRS2008

25th Space Simulation Conference. Environmental Testing: The Earth-Space Connection

Topics covered include: Methods of Helium Injection and Removal for Heat Transfer Augmentation; The ESA Large Space Simulator Mechanical Ground Support Equipment for Spacecraft Testing; Temperature Stability and Control Requirements for Thermal Vacuum/Thermal Balance Testing of the Aquarius Radiometer; The Liquid Nitrogen System for Chamber A: A Change from Original Forced Flow Design to a Natural Flow (Thermo Siphon) System; Return to Mercury: A Comparison of Solar Simulation and Flight Data for the MESSENGER Spacecraft; Floating Pressure Conversion and Equipment Upgrades of Two 3.5kw, 20k, Helium Refrigerators; Affect of Air Leakage into a Thermal-Vacuum Chamber on Helium Refrigeration Heat Load; Special ISO Class 6 Cleanroom for the Lunar Reconnaissance Orbiter (LRO) Project; A State-of-the-Art Contamination Effects Research and Test Facility Martian Dust Simulator; Cleanroom Design Practices and Their Influence on Particle Counts; Extra Terrestrial Environmental Chamber Design; Contamination Sources Effects Analysis (CSEA) - A Tool to Balance Cost/Schedule While Managing Facility Availability; SES and Acoustics at GSFC; HST Super Lightweight Interchangeable Carrier (SLIC) Static Test; Virtual Shaker Testing: Simulation Technology Improves Vibration Test Performance; Estimating Shock Spectra: Extensions beyond GEVS; Structural Dynamic Analysis of a Spacecraft Multi-DOF Shaker Table; Direct Field Acoustic Testing; Manufacture of Cryoshroud Surfaces for Space Simulation Chambers; The New LOTIS Test Facility; Thermal Vacuum Control Systems Options for Test Facilities; Extremely High Vacuum Chamber for Low Outgassing Processing at NASA Goddard; Precision Cleaning - Path to Premier; The New Anechoic Shielded Chambers Designed for Space and Commercial Applications at LIT; Extraction of Thermal Performance Values from Samples in the Lunar Dust Adhesion Bell Jar; Thermal (Silicon Diode) Data Acquisition System; Aquarius's Instrument Science Data System (ISDS) Automated to Acquire, Process, Trend Data and Produce Radiometric System Assessment Reports; Exhaustive Thresholds and Resistance Checkpoints; Reconfigurable HIL Testing of Earth Satellites; FPGA Control System for the Automated Test of MicroShutters; Ongoing Capabilities and Developments of Re-Entry Plasma Ground Tests at EADS-ASTRIUM; Operationally Responsive Space Standard Bus Battery Thermal Balance Testing and Heat Dissipation Analysis; Galileo - The Serial-Production AIT Challenge; The Space Systems Environmental Test Facility Database (SSETFD), Website Development Status; Simulated Reentry Heating by Torching; Micro-Vibration Measurements on Thermally Loaded Multi-Layer Insulation Samples in Vacuum; High Temperature Life Testing of 80Ni-20Cr Wire in a Simulated Mars Atmosphere for the Sample Analysis at Mars (SAM) Instrument Suit Gas Processing System (GPS) Carbon Dioxide Scrubber; The Planning and Implementation of Test Facility Improvements; and Development of a Silicon Carbide Molecular Beam Nozzle for Simulation Planetary Flybys and Low-Earth Orbit.

Packard, Edward↗
NASA NTRS2007

Mars Reconnaissance Orbiter Interplanetary Navigation

This viewgraph presentation reviews the Mars Reconnaissance Orbiter (MRO) interplanetary navigation. An interplanetary overview including dynamic models of outgassing, small force calibration and trending, solar radiation pressure and trajectory correction maneuvers are also described.

Mars Reconnaissance Orbiter (MRO)↗
NASA NTRS2009

Light-Curing Adhesive Repair Tapes

Adhesive tapes, the adhesive resins of which can be cured (and thereby rigidized) by exposure to ultraviolet and/or visible light, are being developed as repair patch materials. The tapes, including their resin components, consist entirely of solid, low-outgassing, nonhazardous or minimally hazardous materials. They can be used in air or in vacuum and can be cured rapidly, even at temperatures as low as -20 C. Although these tapes were originally intended for use in repairing structures in outer space, they can also be used on Earth for quickly repairing a wide variety of structures. They can be expected to be especially useful in situations in which it is necessary to rigidize tapes after wrapping them around or pressing them onto the parts to be repaired.

Allred, Ronald↗
NASA NTRS2009

Contamination Examples and Lessons from Low Earth Orbit Experiments and Operational Hardware

Flight experiments flown on the Space Shuttle, the International Space Station, Mir, Skylab, and free flyers such as the Long Duration Exposure Facility, the European Retrievable Carrier, and the EFFU, provide multiple opportunities for the investigation of molecular contamination effects. Retrieved hardware from the Solar Maximum Mission satellite, Mir, and the Hubble Space Telescope has also provided the means gaining insight into contamination processes. Images from the above mentioned hardware show contamination effects due to materials processing, hardware storage, pre-flight cleaning, as well as on-orbit events such as outgassing, mechanical failure of hardware in close proximity, impacts from man-made debris, and changes due to natural environment factors.. Contamination effects include significant changes to thermal and electrical properties of thermal control surfaces, optics, and power systems. Data from several flights has been used to develop a rudimentary estimate of asymptotic values for absorptance changes due to long-term solar exposure (4000-6000 Equivalent Sun Hours) of silicone-based molecular contamination deposits of varying thickness. Recommendations and suggestions for processing changes and constraints based on the on-orbit observed results will be presented.

Pippin, Gary↗
NASA NTRS2009

Integrated Modeling of Spacecraft Touch-and-Go Sampling

An integrated modeling tool has been developed to include multi-body dynamics, orbital dynamics, and touch-and-go dynamics for spacecraft covering three types of end-effectors: a sticky pad, a brush-wheel sampler, and a pellet gun. Several multi-body models of a free-flying spacecraft with a multi-link manipulator driving these end-effectors have been tested with typical contact conditions arising when the manipulator arm is to sample the surface of an asteroidal body. The test data have been infused directly into the dynamics formulation including such information as the mass collected as a function of end-effector longitudinal speed for the brush-wheel and sticky-pad samplers, and the mass collected as a function of projectile speed for the pellet gun sampler. These data represent the realistic behavior of the end effector while in contact with a surface, and represent a low-order model of more complex contact conditions that otherwise would have to be simulated. Numerical results demonstrate the adequacy of these multibody models for spacecraft and manipulator- arm control design. The work contributes to the development of a touch-and-go testbed for small body exploration, denoted as the GREX Testbed (GN&C for Rendezvous-based EXploration). The GREX testbed addresses the key issues involved in landing on an asteroidal body or comet; namely, a complex, low-gravity field; partially known terrain properties; possible comet outgassing; dust ejection; and navigating to a safe and scientifically desirable zone.

Quadrelli, Marco↗
NASA NTRS2010

WFC3: In-Flight Performance Highlights

Wide Field Camera 3 (WFC3), a powerful new imager for the Hubble Space Telescope (HST), was successfully installed in the telescope in May 2009 during the first dramatic spacewalk of space shuttle flight STS-125, also known as HST Servicing Mission 4. This new camera offers unique observing capabilities in two channels spanning a broad wavelength range from the near ultraviolet to the near infrared (200-1000nm in the UV/Visible [UVIS] channel; 850-1700nm in the IR channel). After an initial outgassing period, WFC3 was cooled to its observing configuration in June. In the following months, a highly successful Servicing Mission Observatory Verification (SMOV4) program was executed, which has confirmed the exciting scientific potential of the instrument. Detailed performance results from the SMOV 4 program are presented in a number of papers in this session. In this paper, we highlight some top-level performance assessments (throughput, limiting magnitudes, survey speeds) for WFC3, which is now actively engaged in the execution of forefront astronomical observing programs.

Kimble, Randy A.↗
NASA NTRS2010

Early Mars: A Warm Wet Niche for Life

Exploration of Mars has begun to unveil the history of the planet. Combinations of remote sensing, in situ compositional measurements and photographic observations have shown Mars had a dynamic and active geologic evolution. Mars geologic evolution had conditions that were suitable for supporting life. A habitable planet must have water, carbon and energy sources along with a dynamic geologic past. Mars meets all of these requirements. The first 600 Ma of Martian history were ripe for life to develop because of the abundance of: (i) Water-as shown by carved canyons and oceans or lakes with the early presence of near surface water shown by precipitated carbonates in ALH84001, well-dated at approx.3.9 Ga, (ii) Energy from the original accretional processes, a molten core which generated a strong magnetic field leaving a permanent record in the early crust, active volcanism continuing throughout Martian history, and continuing impact processes, (iii) Carbon, water and a likely thicker atmosphere from extensive volcanic outgassing (i.e. H2O, CO2, CH4, CO, O2, N2, H2S, SO2, etc.) and (iv) crustal tectonics as revealed by faulting and possible plate movement reflected by the magnetic patterns in the crust [1]. The question arises: "Why would life not develop from these favorable conditions on Mars in its first 600 Ma?" During this period, environmental near-surface conditions on Mars were more favorable to life than at any later time. Standing bodies of water, precipitation and flowing surface water, and possibly abundant hydrothermal energy would favor the formation of early life. (Even if life developed elsewhere on Earth, Venus, or on other bodies-it was transported to Mars where surface conditions were suitable for life to evolve)

Gibson, Everett K.↗
NASA NTRS2006

Stable Satellite Orbits for Global Coverage of the Moon

A document proposes a constellation of spacecraft to be placed in orbit around the Moon to provide navigation and communication services with global coverage required for exploration of the Moon. There would be six spacecraft in inclined elliptical orbits: three in each of two orthogonal orbital planes, suggestive of a linked-chain configuration. The orbits have been chosen to (1) provide 99.999-percent global coverage for ten years and (2) to be stable under perturbation by Earth gravitation and solar-radiation pressure, so that no deterministic firing of thrusters would be needed to maintain the orbits. However, a minor amount of orbit control might be needed to correct for such unmodeled effects as outgassing of the spacecraft.

Ely, Todd↗
NASA NTRS2010

MoS2-Filled PEEK Composite as a Self-Lubricating Material for Aerospace Applications

At BAM, several projects were conducted in the past years dealing with the tribological properties of friction couples at cryogenic temperature and in vacuum environment. Promising candidates for vacuum application are MoS2-filled PEEK/PTFE composites, which showed a friction coefficient as low as 0.03 in high vacuum. To complete the tribological profile of these composites, further tests were performed in ultra-high vacuum (UHV) at room temperature. In this paper, friction and stick slip behavior, as well as outgassing characteristics during the test are presented.

Theiler, Geraldine↗
NASA NTRS2010

Material Properties of Three Candidate Elastomers for Space Seals Applications

A next-generation docking system is being developed by the National Aeronautics and Space Administration (NASA) to support Constellation Space Exploration Missions to low Earth orbit (LEO), to the Moon, and to Mars. A number of investigations were carried out to quantify the properties of candidate elastomer materials for use in the main interface seal of the Low Impact Docking System (LIDS). This seal forms the gas pressure seal between two mating spacecraft. Three candidate silicone elastomer compounds were examined: Esterline ELA-SA-401, Parker Hannifin S0383-70, and Parker Hannifin S0899-50. All three materials were characterized as low-outgassing compounds, per ASTM E595, so as to minimize the contamination of optical and solar array systems. Important seal properties such as outgas levels, durometer, tensile strength, elongation to failure, glass transition temperature, permeability, compression set, Yeoh strain energy coefficients, coefficients of friction, coefficients of thermal expansion, thermal conductivity and diffusivity were measured and are reported herein.

Bastrzyk, Marta B.↗
NASA NTRS2010

Ionization-Assisted Getter Pumping for Ultra-Stable Trapped Ion Frequency Standards

A method eliminates (or recovers from) residual methane buildup in getter-pumped atomic frequency standard systems by applying ionizing assistance. Ultra-high stability trapped ion frequency standards for applications requiring very high reliability, and/or low power and mass (both for ground-based and space-based platforms) benefit from using sealed vacuum systems. These systems require careful material selection and system processing (cleaning and high-temperature bake-out). Even under the most careful preparation, residual hydrogen outgassing from vacuum chamber walls typically limits the base pressure. Non-evaporable getter pumps (NEGs) provide a convenient pumping option for sealed systems because of low mass and volume, and no power once activated. An ion gauge in conjunction with a NEG can be used to provide a low mass, low-power method for avoiding the deleterious effects of methane buildup in high-performance frequency standard vacuum systems.

Tjoelker, Robert L.↗
NASA NTRS2009

Old Faithful Model for Radiolytic Gas-Driven Cryovolcanism at Enceladus

A new model is presented on how chemically driven cryovolcanism might contribute to episodic outgassing at the icy moon Enceladus and potentially elsewhere including Europa and Kuiper Belt Objects. Exposed water ices can become oxidized from radiolytic chemical alteration of near-surface water ice by space environment irradiation. In contact with primordially abundant reductants such as NH3, CH4, and other hydrocarbons, the product oxidants can react exothermically to produce volatile gases driving cryovolcanism via gas-piston forces on any subsurface liquid reservoirs. Radiolytic oxidants such as H2O2 and O2 can continuously accumulate deep in icy regoliths and be conveyed by rheological flows to subsurface chemical reaction zones over million-year time scales indicated by cratering ages for active regions of Enceladus and Europa. Surface blanketing with cryovolcanic plume ejecta would further accelerate regolith burial of radiolytic oxidants. Episodic heating from transient gravitational tides, radioisotope decay, impacts, or other geologic events might occasionally accelerate chemical reaction rates and ignite the exothermic release of cumulative radiolytic oxidant energy. The time history for the suggested "Old Faithful" model of radiolytic gas-driven cryovolcanism at Enceladus and elsewhere therefore consists of long periods of chemical energy accumulation punctuated by much briefer episodes of cryovolcanic activity. The most probable sequence for detection of activity in the current epoch is a long evolutionary phase of slow but continuous oxidant accumulation over billions of years followed by continuous but variable high activity over the past 10(exp 7)-10(exp 8) years. Detectable cryovolcanic activity could then later decline due to near-total oxidation of the rheologically accessible ice crust and depletion the accessible reductant abundances, as may have already occurred for Europa in the more intense radiation environment of Jupiter's magnetosphere. Astrobiological potential of Enceladus could correspondingly be higher than at Europa due to a less extreme state of oxidation and greater residual abundance of organics.

Cooper, John F.↗
NASA NTRS2000

Mir Contamination Observations and Implications to the International Space Station

A series of external contamination measurements were made on the Russian Mir Space Station. The Mir external contamination observations summarized in this paper were essential in assessing the system level impact of Russian Segment induced contamination on the International Space Station (ISS). Mir contamination observations include results from a series of flight experiments: CNES Comes-Aragatz, retrieved NASA camera bracket, Euro-Mir '95 ICA, retrieved NASA Trek blanket, Russian Astra-II, Mir Solar Array Return Experiment (SARE), etc. Results from these experiments were studied in detail to characterize Mir induced contamination. In conjunction with Mir contamination observations, Russian materials samples were tested for condensable outgassing rates in the U.S. These test results were essential in the characterization of Mir contamination sources. Once Mir contamination sources were identified and characterized, activities to assess the implications to ISS were implemented. As a result, modifications in Russian materials selection and/or usage were implemented to control contamination and mitigate risk to ISS.

Soares, Carlos↗
NASA NTRS2003

Space Environment Factors Affecting the Performance of International Space Station Materials: The First Two Years of Flight Operations

In this paper, the natural and induced space environment factors affecting materials performance on ISS are described in some detail. The emphasis will be on ISS flight experience and the more significant design and development issues of the last two years. The intent is to identify and document the set of space environment factors, affecting materials, that are producing the largest impacts on the ISS flight hardware verification and acceptance process and on ISS flight operations. Orbital inclination (S1.6 ) and altitude (nominal3S0 km to 400 km altitude) determine the set of natural environment factors affecting the functional life of materials and subsystems on ISS. ISS operates in the F2 region of Earth's ionosphere in well-defined fluxes of atomic oxygen, other ionospheric plasma species, and solar UV, VUV, and x-ray radiation, as well as galactic cosmic rays, trapped radiation, and solar cosmic rays (1,2). The high latitude orbital environment also exposes external surfaces to significantly less well-defined or predictable fluxes of higher energy trapped electrons and auroral electrons (3 ,4). The micrometeoroid and orbital debris environment is an important determinant of spacecraft design and operations in any orbital inclination. Environment factors induced by ISS flight operations include ram-wake effects, magnetic induction voltages arising from flight through Earth's magnetic field, hypergolic thruster plume impingement from proximity operations of visiting vehicles, materials outgassing, venting and dumping of fluids, ISS thruster operations, as well as specific electrical power system interactions with the ionospheric plasma (S-7). ISS must fly in a very limited number of approved flight attitudes leading to location specific environmental exposures and extreme local thermal environments (8). ISS is a large vehicle and produces a deep wake structure from which both ionospheric plasma and neutrals (atomic oxygen) are largely excluded (9-11). At high latitude, the ISS wake may produce a spacecraft charging environment similar to that experienced by the DMSP and Freja satellites (800 to 100 km altitude polar orbits), especially during geo-magnetic disturbances (12-14). ISS is also subject to magnetic induction voltages (VxB L) on conducting structure, a result of high velocity flight through Earth's magnetic field. The magnitude of the magnetic induction voltage varies with location on ISS, as well as the relative orientation of the vehicle velocity vector and planetary magnetic field vector, leading to maximum induction voltages at high latitude (15). The space environment factors, natural and induced, that have had the largest impact on pre-launch ISS flight hardware verification and flight operations during the first two years of ISS flight operations are listed below and grouped according to the physical and chemical processes driving their interaction with ISS materials.

Koontz, Steven L.↗
NASA NTRS2010

The Interaction of the Solar Wind with Solar Probe Plus - 3D Hybrid Simulation: The Study for the Distance 4.5Rs - Report 1

Our report devotes a 3D numerical hybrid model of the interaction of the solar wind with the Solar Probe spacecraft. The SPP model includes 3 main parts, namely, a non-conducting heat shield, a support system, and cylindrical section or spacecraft bus that contains the particle analysis devices and antenna. One observes an excitation of the low frequency Alfven and whistler type wave directed by the magnetic field with an amplitude of about (0.06-0.6) V/m. The compression waves and the jumps in an electric field with an amplitude of about (0.15-0.7) V/m were also observed. The wave amplitudes are comparable to or greater than previously estimated max wave amplitudes that SPP is expected to measure. The results of our hybrid simulation will be useful for understanding the plasma environment near the SPP spacecraft at the distance 4.5 Rs. Future simulation will take into account the charging of the spacecraft, the charge separation effects, an outgassing from heat shield, a photoionization and an electron impact ionization effects near the spacecraft.

Lipatov, Alexander S.↗
NASA NTRS2010

The Interaction of the Solar Wind with Solar Probe Plus - 3D Hybrid Simulation: The Study for the Distance 4.5Rs - Report 1

Our report devotes a 3D numerical hybrid model of the interaction of the solar wind with the Solar Probe spacecraft. The Solar Probe Plus (SPP) model includes 3 main parts, namely, a non-conducting heat shield, a support system, and cylindrical section or spacecraft bus that contains the particle analysis devices and antenna. One observes an excitation of the low frequency Alfven and whistler type wave directed by the magnetic field with an amplitude of about (0.06-0.6) V/m. The compression waves and the jumps in an electric field with an amplitude of about (0.15-0.7) V/m were also observed. The wave amplitudes are comparable to or greater than previously estimated max wave amplitudes that SPP is expected to measure. The results of our hybrid simulation will be useful for understanding the plasma environment near the SPP spacecraft at the distance 4.5 Rs. Future simulation will take into account the charging of the spacecraft, the charge separation effects, an outgassing from heat shield, a photoionization and an electron impact ionization effects near the spacecraft.

Lipatov, Alexander S.↗