The Experts below are selected from a list of 33033 Experts worldwide ranked by ideXlab platform
Siebo Reershemius - One of the best experts on this subject based on the ideXlab platform.
-
improving the slippage resistance of successors of the Mars instrument heat flow property package instrument hp3 using bekker s spaced linked track
International Journal of Aerospace Engineering, 2020Co-Authors: Siebo ReershemiusAbstract:The “Heat Flow Property Package Instrument” (HP3) is part of NASA’s current Mars Mission “InSight”, which was launched in 2018 and currently operates on the surface of Mars. The instrument needs to remain at its initial position and orientation during operation. Although the landing site can have significant tilt and can be covered with low cohesion soil, any mechanical excitation might make the instrument slip. Therefore, the instrument is using a tailored feet design, which can withstand lateral loads. Future instruments might require higher resistance against slip. This can be due to stronger tilted landing sites or due to higher shocks emitted from stronger penetration probes. This paper introduces a novel design for those instruments based on the idea of the “spaced-link track” of Bekker to further minimize slippage. This design concept is originally used on tracks of heavy machinery. It is presented how the major design feature can be incorporated into the current design. A newly developed analytical-numerical model is utilized to estimate the track force of the new design. The paper closes with a design study at which the new design and the current design are compared to each other for different sized feet.
-
design and verification of the feet design used for the heat flow property package instrument hp3 on board the Mars Mission insight
Advances in Space Research, 2020Co-Authors: Siebo Reershemius, T L HudsonAbstract:Abstract The HP3 instrument measures the thermal flux through the Martian crust using a penetration probe. Launched on the InSight Mission in 2018, HP3 was deployed for penetration activities in the beginning of 2019. During initial operation, the instrument is vulnerable to slip, due to a combination of low system mass (3.3 kg on Earth), shocks delivered by the penetration probe’s action, and the possibility of an inclined attitude on the surface. An uncontrolled position change of the instrument on the surface can reduce the scientific output and even lead to a loss of the experiment if the probe’s supporting structure moves laterally. Naturally, the design of the feet has major impact on the total amount of slippage. A new design for the feet with a high slippage resistance capability at a low level of complexity and mass was developed for this instrument’s supporting structure. The design provides sufficient slippage resistance while fulfilling the challenging set of requirements for a Mars surface Mission. The design was verified by test campaigns which emulate launch environments and operational behavior on Mars. This paper gives a detailed overview of the HP3 instrument itself, the relevant requirements, the complex different test campaigns and the final flight design.
-
design and analysis of the feet and it s configuration used for the heat flow property package instrument hp3 on board the Mars Mission insight
IEEE Aerospace Conference, 2020Co-Authors: Siebo ReershemiusAbstract:The HP3 instrument measures the thermal flux through the Martian crust using a penetration probe. Launched on the InSight Mission in 2018, HP3 was deployed for penetration activities in the beginning of 2019. This paper shortly introduces the HP3 instrument and shows the design and analysis process of the feet pattern and of each foot. The pattern of the feet is driven by the accommodation of the instrument on the lander and the need to ensure stability of the instrument on the surface. A four-feet design was chosen as it can be fitted very good into the available volume. During operation, the instrument is vulnerable to tipping as the landing site can be tilted and partially covered with rocks and depressions. Therefore it is shown analytically, that the instrument is stable, although it might be partially located on rocks or depression in combination with a tilted landing site. The new design of the feet is introduced and compared to a flat-plate foot. The capability of each design to produce slippage resistance is estimated analytically. The analytical estimations show, that the chosen flight-design generates more slippage resistance than the flat-plate approach. Even though the analytical estimations do not cover all effects generating slippage resistance.
-
structure development of the hp3 instrument support system for the Mars Mission insight
Acta Astronautica, 2019Co-Authors: Siebo Reershemius, T L Hudson, Marco Scharringhausen, Mark Fittock, Kaname Sasaki, Tilman Spohn, Tom Sprowitz, Torben WippermannAbstract:Abstract On May 05, 2018 NASA JPL launched its Mission to Mars called “InSight”. Main objective of this Mission is to gain more knowledge of the evolution of terrestrial planets. Beside a number of different scientific instruments onboard the lander there are two instruments that will perform measurements on the Martian ground. One of the instruments is HP3 (Heat Flow and Physical Properties Package), which was developed by the German Aerospace Center (DLR) to measure the heat flow of the Martian outer crust. Main elements of this instrument are the heat flow probe, the Backend Electronic and the Support System. With this paper the authors give a detailed insight of the function of the Support System within the instrument and its development. The Support System enables the operation of the heat flow probe on the surface. The mechanical design of the Support System is mainly driven by a unique set of requirements derived from the working environment on Mars, the deployment from the lander deck, and the mechanically separated operation on the surface. The paper will give an overview of the development and the qualification of the structure of the Support System. It will focus on the mechanical design and the analysis of the structural dynamics, and on the testing which includes standard environmental testing but also numerous development tests that are very Mission specific.
T L Hudson - One of the best experts on this subject based on the ideXlab platform.
-
design and verification of the feet design used for the heat flow property package instrument hp3 on board the Mars Mission insight
Advances in Space Research, 2020Co-Authors: Siebo Reershemius, T L HudsonAbstract:Abstract The HP3 instrument measures the thermal flux through the Martian crust using a penetration probe. Launched on the InSight Mission in 2018, HP3 was deployed for penetration activities in the beginning of 2019. During initial operation, the instrument is vulnerable to slip, due to a combination of low system mass (3.3 kg on Earth), shocks delivered by the penetration probe’s action, and the possibility of an inclined attitude on the surface. An uncontrolled position change of the instrument on the surface can reduce the scientific output and even lead to a loss of the experiment if the probe’s supporting structure moves laterally. Naturally, the design of the feet has major impact on the total amount of slippage. A new design for the feet with a high slippage resistance capability at a low level of complexity and mass was developed for this instrument’s supporting structure. The design provides sufficient slippage resistance while fulfilling the challenging set of requirements for a Mars surface Mission. The design was verified by test campaigns which emulate launch environments and operational behavior on Mars. This paper gives a detailed overview of the HP3 instrument itself, the relevant requirements, the complex different test campaigns and the final flight design.
-
penetration and performance testing of the hp mole for the insight Mars Mission
Planetary and Space Science, 2020Co-Authors: Torben Wippermann, T L Hudson, T Spohn, Lars Witte, Marco Scharringhausen, Georgios Tsakyridis, Mark Fittock, Olaf Kromer, S Hense, M GrottAbstract:Abstract During the development and the qualification of the Heat Flow Physical Properties Package (HP³) instrument (developed by the German Aerospace Center), which is part of the NASA Mars Mission InSight, its self-propelling subsurface probe, the HP³ Mole was used in several penetration tests. Here, the performance of the Mole to reach the target depth, to avoid or overcome obstacles on its path, and its directional stability in the subsurface is elaborated. The different test beds and set ups are described and the results are presented. The deep penetration tests (DPT), with the purpose to reach the target depth, are the most important performance tests and therefore the results are investigated in more detail in section 2. Full functional tests (FFT), which showed the performance and degradation of the mechanism inside the Mole, are presented in section 3. Additional penetration and life cycle tests are described in section 4. The testing has demonstrated that the HP³ Mole meets all of its penetration requirements with margin.
-
structure development of the hp3 instrument support system for the Mars Mission insight
Acta Astronautica, 2019Co-Authors: Siebo Reershemius, T L Hudson, Marco Scharringhausen, Mark Fittock, Kaname Sasaki, Tilman Spohn, Tom Sprowitz, Torben WippermannAbstract:Abstract On May 05, 2018 NASA JPL launched its Mission to Mars called “InSight”. Main objective of this Mission is to gain more knowledge of the evolution of terrestrial planets. Beside a number of different scientific instruments onboard the lander there are two instruments that will perform measurements on the Martian ground. One of the instruments is HP3 (Heat Flow and Physical Properties Package), which was developed by the German Aerospace Center (DLR) to measure the heat flow of the Martian outer crust. Main elements of this instrument are the heat flow probe, the Backend Electronic and the Support System. With this paper the authors give a detailed insight of the function of the Support System within the instrument and its development. The Support System enables the operation of the heat flow probe on the surface. The mechanical design of the Support System is mainly driven by a unique set of requirements derived from the working environment on Mars, the deployment from the lander deck, and the mechanically separated operation on the surface. The paper will give an overview of the development and the qualification of the structure of the Support System. It will focus on the mechanical design and the analysis of the structural dynamics, and on the testing which includes standard environmental testing but also numerous development tests that are very Mission specific.
-
a revised calibration function and results for the phoenix Mission tecp relative humidity sensor
Journal of Geophysical Research, 2016Co-Authors: Aaron P Zent, T L Hudson, M H Hecht, Stephen E Wood, V F ChevrierAbstract:A new calibration function for the humidity sensor in the Thermal and Electrical Conductivity Probe (TECP) on the Phoenix (PHX) Mars Mission has been developed. Two changes are incorporated: (1) it is now cast in terms of frost point (Tf) rather than relative humidity (RH), and (2) flight data, taken when the atmosphere is independently known to be saturated, are included in the calibration data set. Daytime (6:00 h–19:00 h) frost points ranged from 194 K to 209 K; the nighttime frost point ranged from 179 K to 206 K. The response of the sensor was smooth and continuous throughout. Daytime humidity exhibited large, high-frequency variance driven by turbulence, whereas nighttime humidity varied smoothly with the temperature of the atmosphere. Nighttime saturation of the atmosphere begins at Ls 101°, (Martian solar day (sol) 55), which is earlier than reported by either Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) or solid-state imager (SSI). Early mornings are the most humid part of the sol after Ls 113° (sol 80), due to sublimation of surface ice that precipitates overnight. H2O is removed from the atmosphere into the regolith, mostly during the late afternoon, although this continues into the evening. The ground ice exposed by Phoenix operations masks the naturally occurring process in the early evening and may cause the atmosphere immediately around the lander to saturate somewhat earlier in the evening than it otherwise would have. The average H2O vapor density is close to the summertime value expected for equilibrium with ground ice. A discrepancy between the H2O column calculated from TECP data and the column measured by CRISM and SSI is likely due to comparable timescales between turbulent mixing through the planetary boundary layer and adsorptive drawdown of H2O. We find that RH is mostly 95% (nighttime), and the transition between the two extremes is extremely rapid.
Jean-pierre Barriot - One of the best experts on this subject based on the ideXlab platform.
-
Assessment of Phobos gravity field determination from both near polar and near equatorial orbital flyby data
Monthly Notices of the Royal Astronomical Society, 2018Co-Authors: J. Yan, X. Yan, M Andert, J Jin, Jean-pierre BarriotAbstract:The C20 and C22 coefficients of the Phobos gravity field are key parameters to constrain the internal structure of the Martian moon, but reliable observed values of these parameters are still missing. In this paper, we demonstrate, through a combination of forward and inverse modelling of simulated Doppler spacecraft tracking data collected from the Earth, that a Phobos flyby along a near polar Mars orbit is optimal when determining the C20 coefficient, and further, that a near equatorial flyby Mars orbit is optimal for determination of the C22 coefficient. Therefore, the combination of a near polar and a near equatorial orbit is an effective way to determine the Phobos C20 and C22 gravity field coefficients. This work provides a reference for a future Chinese Mars Mission.
Darlene S S Lim - One of the best experts on this subject based on the ideXlab platform.
-
the basalt research program designing and developing Mission elements in support of human scientific exploration of Mars
Astrobiology, 2019Co-Authors: Darlene S S Lim, Andrew F J Abercromby, Shannon Kobs E Nawotniak, David Lees, Michael J Miller, A L Brady, Zara Mirmalek, Alexander SehlkeAbstract:The articles associated with this Special Collection focus on the NASA BASALT (Biologic Analog Science Associated with Lava Terrains) Research Program, which aims at answering the question, "How do we support and enable scientific exploration during human Mars Missions?" To answer this the BASALT team conducted scientific field studies under simulated Mars Mission conditions to both broaden our understanding of the habitability potential of basalt-rich terrains on Mars and examine the effects of science on current Mars Mission concepts of operations. This article provides an overview of the BASALT research project, from the science, to the operational concepts that were tested and developed, to the technical capabilities that supported all elements of the team's research. Further, this article introduces the 12 articles that are included in this Special Collection.
-
developing intra eva science support team practices for a human Mission to Mars
Astrobiology, 2019Co-Authors: Samuel J Payler, Shannon Kobs E Nawotniak, A L Brady, Zara Mirmalek, S S Hughes, Adam R H Stevens, Charles S Cockell, Darlene S S LimAbstract:During the BASALT research program, real (nonsimulated) geological and biological science was accomplished through a series of extravehicular activities (EVAs) under simulated Mars Mission conditions. These EVAs were supported by a Mission Support Center (MSC) that included an on-site, colocated Science Support Team (SST). The SST was composed of scientists from a variety of disciplines and operations researchers who provided scientific and technical expertise to the crew while each EVA was being conducted (intra-EVA). SST management and organization developed under operational conditions that included Mars-like communication latencies, bandwidth constraints, and EVA plans that were infused with Mars analog field science objectives. This paper focuses on the SST workspace considerations such as science team roles, physical layout, communication interactions, operational techniques, and work support technology. Over the course of BASALT field deployments to Idaho and Hawai'i, the SST team made several changes of note to increase both productivity and efficiency. For example, new roles were added for more effective management of technical discussions, and the layout of the SST workspace evolved multiple times during the deployments. SST members' reflexive adjustments resulted in a layout that prioritized face-to-face discussions over face-to-data displays, highlighting the importance of interpersonal communication during SST decision-making. In tandem with these workspace adjustments, a range of operational techniques were developed to help the SST manage discussions and information flow under time pressure.
Francis A Cucinotta - One of the best experts on this subject based on the ideXlab platform.
-
Non-Targeted Effects Models Predict Significantly Higher Mars Mission Cancer Risk than Targeted Effects Models
Scientific Reports, 2017Co-Authors: Francis A Cucinotta, Eliedonna CacaoAbstract:Cancer risk is an important concern for galactic cosmic ray (GCR) exposures, which consist of a wide-energy range of protons, heavy ions and secondary radiation produced in shielding and tissues. Relative biological effectiveness (RBE) factors for surrogate cancer endpoints in cell culture models and tumor induction in mice vary considerable, including significant variations for different tissues and mouse strains. Many studies suggest non-targeted effects (NTE) occur for low doses of high linear energy transfer (LET) radiation, leading to deviation from the linear dose response model used in radiation protection. Using the mouse Harderian gland tumor experiment, the only extensive data-set for dose response modelling with a variety of particle types (>4), for the first-time a particle track structure model of tumor prevalence is used to investigate the effects of NTEs in predictions of chronic GCR exposure risk. The NTE model led to a predicted risk 2-fold higher compared to a targeted effects model. The scarcity of data with animal models for tissues that dominate human radiation cancer risk, including lung, colon, breast, liver, and stomach, suggest that studies of NTEs in other tissues are urgently needed prior to long-term space Missions outside the protection of the Earth’s geomagnetic sphere.
-
How Safe Is Safe Enough? Radiation Risk for a Human Mission to Mars
PLoS ONE, 2013Co-Authors: Francis A Cucinotta, Myung Hee Y. Kim, Lori J. Chappell, Janice L. HuffAbstract:Astronauts on a Mission to Mars would be exposed for up to 3 years to galactic cosmic rays (GCR)--made up of high-energy protons and high charge (Z) and energy (E) (HZE) nuclei. GCR exposure rate increases about three times as spacecraft venture out of Earth orbit into deep space where protection of the Earth's magnetosphere and solid body are lost. NASA's radiation standard limits astronaut exposures to a 3% risk of exposure induced death (REID) at the upper 95% confidence interval (CI) of the risk estimate. Fatal cancer risk has been considered the dominant risk for GCR, however recent epidemiological analysis of radiation risks for circulatory diseases allow for predictions of REID for circulatory diseases to be included with cancer risk predictions for space Missions. Using NASA's models of risks and uncertainties, we predicted that central estimates for radiation induced mortality and morbidity could exceed 5% and 10% with upper 95% CI near 10% and 20%, respectively for a Mars Mission. Additional risks to the central nervous system (CNS) and qualitative differences in the biological effects of GCR compared to terrestrial radiation may significantly increase these estimates, and will require new knowledge to evaluate.