Pioneering Space Through the Evolvable Mars Campaign

Craig, Douglas A.; Troutman, Patrick A.; Herrmann, Nicole

doi:10.2514/6.2015-4409

Cited by 41 publications

(24 citation statements)

References 12 publications

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“…The data are presented in modified Arrhenius form for the forward reactions with the backward reactions determined via the equilibrium constant, as per Equations (1)- (2). The kinetic data set used for LAURA is detailed in Ref.…”

Section: B Kinetic Modelsmentioning

confidence: 99%

Blunt-Body Heating and Pressure Database from High-Enthalpy, CO₂ Testing in an Expansion Tunnel

Hollis

Prabhu

MacLean

2016

46th AIAA Thermophysics Conference

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An extensive database of heating, pressure, and flow field measurements on a 70-deg sphere-cone blunt body geometry in high-enthalpy, CO 2 flow has been generated through testing in an expansion tunnel. This database is intended to support development and validation of computational tools and methods to be employed in the design of future Mars missions. The test was conducted in an expansion tunnel in order to avoid uncertainties in the definition of free stream conditions noted in previous studies performed in reflected shock tunnels. Data were obtained across a wide range of test velocity/density conditions that produced various physical phenomena of interest, including laminar and transitional/turbulent boundary layers, non-reacting to completely dissociated post-shock gas composition and shock-layer radiation. Flow field computations were performed at the test conditions and comparisons were made with the experimental data. Based on these comparisons, it is recommended that computational uncertainties on surface heating and pressure for laminar, reacting-gas environments can be reduced to ±10% and ±5%, respectively. However, for flows with turbulence and shock-layer radiation, sufficient validation-quality data were not obtained in this study to make any conclusions with respect to uncertainties for those phenomena, which highlights the need for further research in these areas. NomenclatureA f,j = rate coefficient for forward reaction j (m 3 /kmol.s) D f,j = characteristic temperature of forward reaction j (K) H 0 = total enthalpy (J/kg) H w = wall enthalpy (J/kg) K c = equilibrium constant (-) or (kmol/m 3 ) k b,j = backward rate for reaction j (m 3 /kmol.s) or (m 6 /kmol 2 .s) k f,j = forward rate for reaction j (m 3 /kmol.s) M ∞ = free stream Mach number P ∞ = free stream pressure (Pa) P 0,2 = post-shock pitot pressure (Pa) q w = heat-transfer rate at the wall (W/m 2 ) Re ∞,D = free stream Reynolds Number based on diameter -ρ ∞ U ∞ D/μ ∞ Reθ = momentum thickness Reynolds Number -ρ e U e θ/μ e T a,j = controlling temperature for forward reaction j (K) T ∞ = free stream temperature (K) T w = wall temperature (K) U ∞ = free stream velocity (m/s) * Associate Fellow AIAA, Senior Technical Lead, Aerothermodynamics Branch, Research Directorate † Associate Fellow AIAA, Senior Scientist ‡ Senior Member AIAA, Senior Research Scientist Downloaded by PURDUE UNIVERSITY on June 25, 2016 | http://arc.aiaa.org |

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Section: B Kinetic Modelsmentioning

confidence: 99%

Blunt-Body Heating and Pressure Database from High-Enthalpy, CO₂ Testing in an Expansion Tunnel

Hollis

Prabhu

MacLean

2016

46th AIAA Thermophysics Conference

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“…As an example, destinations such as the Mars surface would introduce communication latencies with Earth from 4-22 minutes in each direction, depending on planetary alignments. The NEEMO mission discussed in this paper simulated concepts for human exploration of Mars systems aligned with NASA's Evolvable Mars Campaign (EMC) [1][2][3][4]. NEEMO 21 also evaluated science operations that informed the development of NASA's exploration EVA operations concepts.…”

Section: Introductionmentioning

confidence: 99%

Integration of an Earth-based science team during human exploration of Mars

Chappell

Beaton

Newton

et al. 2017

2017 IEEE Aerospace Conference

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NASA Extreme Environment Mission Operations (NEEMO) is an underwater spaceflight analog that allows a true mission-like operational environment and uses buoyancy effects and added weight to simulate different gravity levels. A mission was undertaken in 2016, NEEMO 21, at the Aquarius undersea research habitat. During the mission, the effects of varied operations concepts with representative communication latencies associated with Mars missions were studied. Six subjects were weighed out to simulate partial gravity and evaluated different operations concepts for integration and management of a simulated Earth-based science team (ST) who provided input and direction during exploration activities. Exploration traverses were planned in advance based on precursor data collected. Subjects completed science-related tasks including presampling surveys and marine-science-based sampling during saturation dives up to 4 hours in duration that simulated extravehicular activity (EVA) on Mars. A communication latency of 15 minutes in each direction between space and ground was simulated throughout the EVAs. Objective data included task completion times, total EVA time, crew idle time, translation time, ST assimilation time (defined as time available for the science team to discuss, to review and act upon data/imagery after they have been collected and transmitted to the ground). Subjective data included acceptability, simulation quality, capability assessment ratings, and comments. In addition, comments from both the crew and the ST were captured during the post-mission debrief. Here, we focus on the acceptability of the operations concepts studied and the capabilities most enhancing or enabling in the operations concept. The importance and challenges of designing EVA timelines to account for the length of the task, level of interaction with the ground that is required/desired, and communication latency, are discussed.

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“…The National Aeronautics and Space Administration's Evolvable Mars Campaign (EMC) [1] is an ongoing series of architectural trade analyses to define the capabilities and elements needed for a sustainable human presence on the surface of Mars.…”

Section: Introductionmentioning

confidence: 99%

Mars surface tunnel element concept

Rucker

Jefferies

Mary

et al. 2016

2016 IEEE Aerospace Conference

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When the first human visitors on Mars prepare to return to Earth, they will have to comply with stringent planetary protection requirements. Apollo Program experience warns that opening an EVA hatch directly to the surface will bring dust into the ascent vehicle. To prevent inadvertent return of potential Martian contaminants to Earth, careful consideration must be given to the way in which crew ingress their Mars Ascent Vehicle (MAV). For architectures involving more than one surface elementsuch as an ascent vehicle and a pressurized rover or surface habitat-a retractable tunnel that eliminates extravehicular activity (EVA) ingress is an attractive solution. Beyond addressing the immediate MAV access issue, a reusable tunnel may be useful for other surface applications, such as rover to habitat transfer, once its primary mission is complete. A National Aeronautics and Space Administration (NASA) team is studying the optimal balance between surface tunnel functionality, mass, and stowed volume as part of the Evolvable Mars Campaign (EMC). The study team began by identifying the minimum set of functional requirements needed for the tunnel to perform its primary mission, as this would presumably be the simplest design, with the lowest mass and volume. This Minimum Functional Tunnel then becomes a baseline against which various tunnel design concepts and potential alternatives can be traded, and aids in assessing the mass penalty of increased functionality. Preliminary analysis indicates that the mass of a single-mission tunnel is about 237 kg, not including mass growth allowance.

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Pioneering Space Through the Evolvable Mars Campaign

Cited by 41 publications

References 12 publications

Blunt-Body Heating and Pressure Database from High-Enthalpy, CO₂ Testing in an Expansion Tunnel

Blunt-Body Heating and Pressure Database from High-Enthalpy, CO₂ Testing in an Expansion Tunnel

Integration of an Earth-based science team during human exploration of Mars

Mars surface tunnel element concept

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Pioneering Space Through the Evolvable Mars Campaign

Cited by 41 publications

References 12 publications

Blunt-Body Heating and Pressure Database from High-Enthalpy, CO2 Testing in an Expansion Tunnel

Blunt-Body Heating and Pressure Database from High-Enthalpy, CO2 Testing in an Expansion Tunnel

Integration of an Earth-based science team during human exploration of Mars

Mars surface tunnel element concept

Contact Info

Product

Resources

About

Blunt-Body Heating and Pressure Database from High-Enthalpy, CO₂ Testing in an Expansion Tunnel

Blunt-Body Heating and Pressure Database from High-Enthalpy, CO₂ Testing in an Expansion Tunnel