12 research outputs found
Prototype Backscatter Moessbauer Spectrometer for Measurement of Martian Surface Mineralogy
We have designed and successfully tested a prototype of a backscatter Moessbauer spectrometer (BaMS) targeted for use on the Martian surface to (1) determine oxidation states of iron, and (2) identify and determine relative abundances of iron-bearing mineralogies. No sample preparation is required to perform measurements; it is only necessary to bring sample and instrument into physical contact. The prototype meets our projected specification for a flight instrument in terms of mass, power, and volume. A Moessbauer spectrometer on the Martian surface would provide wide variety of information about the current state of the Martian surface, and this information is described
Moessbauer Spectroscopy for Lunar Resource Assessment: Measurement of Mineralogy and Soil Maturity
First-order assessment of lunar soil as a resource includes measurement of its mineralogy and maturity. Soils in which the mineral ilmenite is present in high concentrations are desirable feedstock for the production of oxygen at a lunar base. The maturity of lunar soils is a measure of their relative residence time in the upper 1 mm of the lunar surface. Increasing maturity implies increasing load of solar wind species (e.g., N, H, and He-3), decreasing mean grain size, and increasing glass content. All these physicochemical properties that vary in a regular way with maturity are important parameters for assessing lunar soil as a resource. For example, He-3 can be extracted and potentially used for nuclear fusion. A commonly used index for lunar soil maturity is I(sub s)/FeO, which is the concentration of fine-grained metal determined by ferromagnetic resonance (I(sub s)) normalized to the total iron content (as FeO). I(sub s)/FeO has been measured for virtually every soil returned by the Apollo and Luna missions to the Moon. Because the technique is sensitive to both oxidation state and mineralogy, iron Moessbauer spectroscopy (FeMS) is a viable technique for in situ lunar resource assessment. Its utility for mineralogy is apparent from examination of published FeMS data for lunar samples. From the data published, it can be inferred that FeMS data can also be used to determine soil maturity. The use of FeMS to determine mineralogy and maturity and progress on development of a FeMS instrument for lunar surface use are discussed
Backscatter Mossbauer Spectrometer (BaMS) for extraterrestrial applications
Mossbauer spectroscopy is a nuclear gamma resonance technique particularly well suited to the study of materials that contain iron (Fe-57). It can provide information on the oxidation state of iron as well as the type and proportion of iron-containing mineral species in a sample of interest. Iron Mossbauer spectroscopy (FeMS) has been applied to samples believed to have come from Mars (SNC meteorites) and has been helpful in refining the choice among putative Martian surface materials by suggesting a likely nanophase component of the Martian regolity. FeMS spectrum of a Martial analogue material (Hawaiian palagonite) is shown; it is dominated by ferric-bearing phases and shows evidence of a nanophase component. FeMS has also been applied to lunar materials. It can be used to measure the maturity of lunar surface material and has been proposed as a prospector for lunar ilmenite, an oxygen resource mineral. Several years ago we suggested a backscatter Mossbauer spectrometer (BaMS) for a Mars rover mission. Backscatter design was selected as most appropriate for in-situ application because no sample preparation is required. Since that time, we have continued to develop the BaMS instrument in anticipation that it would eventually find a home on a NASA planetary mission. Gooding proposed BaMS as a geochemistry instrument on MESUR. More recently, an LPI workshop has recommended that BaMS be included in a three-instrument payload on the next (1996?) lunar lander
Analytic Shielding Optimization to Reduce Crew Exposure to Ionizing Radiation Inside Space Vehicles
A sustainable lunar architecture provides capabilities for leveraging out-of-service components for alternate uses. Discarded architecture elements may be used to provide ionizing radiation shielding to the crew habitat in case of a Solar Particle Event. The specific location relative to the vehicle where the additional shielding mass is placed, as corroborated with particularities of the vehicle design, has a large influence on protection gain. This effect is caused by the exponential- like decrease of radiation exposure with shielding mass thickness, which in turn determines that the most benefit from a given amount of shielding mass is obtained by placing it so that it preferentially augments protection in under-shielded areas of the vehicle exposed to the radiation environment. A novel analytic technique to derive an optimal shielding configuration was developed by Lockheed Martin during Design Analysis Cycle 3 (DAC-3) of the Orion Crew Exploration Vehicle (CEV). [1] Based on a detailed Computer Aided Design (CAD) model of the vehicle including a specific crew positioning scenario, a set of under-shielded vehicle regions can be identified as candidates for placement of additional shielding. Analytic tools are available to allow capturing an idealized supplemental shielding distribution in the CAD environment, which in turn is used as a reference for deriving a realistic shielding configuration from available vehicle components. While the analysis referenced in this communication applies particularly to the Orion vehicle, the general method can be applied to a large range of space exploration vehicles, including but not limited to lunar and Mars architecture components. In addition, the method can be immediately applied for optimization of radiation shielding provided to sensitive electronic components
Orion EM-1 Internal Environment Characterization: The Matroshka AstroRad Radiation Experiment
Presentation Outline: Orion Multipurpose Crew Vehicle (MPCV); Radiation Vest for Astronauts - AstroRad; ISS (International Space Station) Matroshka; Matroshka AstroRad Radiation Experiment (MARE) on Exploration Mission 1 (EM-1)
Operational Aspects of Space Radiation Analysis
Minimizing astronaut's short and long-term medical risks arising from exposure to ionizing radiation during space missions is a major concern for NASA's manned spaceflight program, particularly exploration missions. For ethical and legal reasons, NASA follows the "as low as reasonably achievable" (ALARA) principal in managing astronaut's radiation exposures. One implementation of ALARA is the response to space weather events. Of particular concern are energetic solar particle events, and in low Earth orbit (LEO), electron belt enhancements. To properly respond to these events, NASA's Space Radiation Analysis Group (SRAG), in partnership with the NOAA Space Environment Center (SEC), provides continuous flight support during U.S. manned missions. In this partnership, SEC compiles space weather data from numerous ground and space based assets and makes it available in near real-time to SRAG (along with alerts and forecasts), who in turn uses these data as input to models to calculate estimates of the resulting exposure to astronauts. These calculations and vehicle instrument data form the basis for real-time recommendations to flight management. It is also important to implement ALARA during the design phase. In order to appropriately weigh the risks associated with various shielding and vehicle configuration concepts, the expected environment must be adequately characterized for nominal and worst case scenarios for that portion of the solar cycle and point in space. Even with the best shielding concepts and materials in place (unlikely), there will be numerous occasions where the crew is at greater risk due to being in a lower shielded environment (short term transit or lower shielded vehicles, EVAs), so that accurate space weather forecasts and nowcasts, of particles at the relevant energies, will be crucial to protecting crew health and safety
MATROSHKA ASTRORAD RADIATION EXPERIMENT (MARE) ON THE ORION EM-1 FLIGHT: HOW TO TACKLE THE HAZARD OF RADIATION FOR EXPLORATION MISSIONS
NASA鈥檚 Human Research Program has organized and summarized five classifications of hazards for long
duration human exploration missions beyond Low Earth Orbit (LEO). These five hazards are 1) radiation, 2)
isolation, 3) distance, 4) gravity fields and 5) the hostile/close environment inside the spacecraft. Leaving LEO
and traveling in free space will expose the astronauts to a much harsher radiation environment than currently on
board the International Space Station (ISS). The relevant radiation risks for these upcoming exploration
missions, to the Moon, near Earth Asteroids and in the end to Mars need to be identified and dealt with to enable
safe and secure human exploration. Within this context Orion, being NASA麓s next generation spacecraft
designed for human exploration of the solar systems will be the home of the next generation of astronauts. The
upcoming Orion Exploration Mission 1 (EM-1), being an unmanned test flight scheduled for 2020 venturing
beyond LEO and into cislunar space offers the unique opportunity to house a variety of secondary research
payloads to tackle the problem of radiation and radiation protection. One of these payloads is the Matroshka
AstroRad Radiation Experiment (MARE), a science payload proposed by the German Aerospace Center (DLR)
and the Israel Space Agency (ISA) and approved by NASA and manifested for flight aboard EM-1 in 2017.
MARE will consist of two anthropomorphic female phantoms (torsos), named Helga and Zohar, located inside
the Orion cabin at seat positions 3 and 4. Each of the phantoms will be equipped with a variety of active and
passive radiation detectors to determine the skin and organ doses during this first flight beyond LEO since
almost 50 years. In addition one of the phantoms (Zohar) will be equipped with a novel radiation protection vest
(AstroRad) developed in cooperation between StemRad Ltd, Israel and Lockheed Martin. An ergonomic
evaluation of AstroRad is planned onboard ISS as early as 2019. With this flight configuration Helga will act as
the reference phantom while the protection properties of the AstroRad vest will be tested with Zohar. MARE is
designed to provide a comprehensive picture of the radiation environment beyond Earth orbit specific to the Orion
vehicle and internal to human body analogs. This data set will inform about expected exposures, enable better
planning by validating the operational toolsets used to predict crew radiation exposure risk on future Orion
missions, and evaluate a potential countermeasure. MARE leverages the expertise and international collaboration
heritage of the ISS Matroshka experiments, and expands it further by adding the mitigation component of the
AstroRad shield. MARE represents a demonstration of science research opportunities aboard NASA鈥檚 next
generation space exploration vehicle. The presentation will provide an overview of the current status of the
experiment hardware design, presenting the first data on the special developed new active radiation detectors
included in MARE and provide insights in the international team working together to ensure safe human travels
for exploration missions
MARE International Payload aboard Orion EM-1: Status Update for 23rd WRMISS
The natural ionizing radiation environment present in space poses risks to human
exploration that require mitigation.Spacecraft designed for Exploration beyond Earth orbit
(BEO) do not benefit from the Earth鈥檚 magnetosphere protection and are subject to stricter
radiation design requirements than their low Earth orbit (LEO) counterparts. Orion is NASA鈥檚
nextgeneration crewed spacecraft, developed specifically for Exploration missions. [...