International Conference on Environmental Systems

Permanent URI for this collection

The International Conference on Environmental Systems, or ICES (known prior to 1990 as the Intersociety Conference on Environmental Systems), is an annual technical conference focusing on human spaceflight technology and space human factors. Session topics include: Environmental Control and Life Support Systems (ECLSS), thermal control, life sciences, extra-vehicular activity (EVA) systems (including space suit design and human-robot interaction), space architecture, and mission planning for exploration. The conference has taken place annually since 1971.

If you find the ThinkTech digital repository useful, please tell us! Share how open access to scholarship benefits you. Your story matters to us.


Recent Submissions

Now showing 1 - 20 of 2525
  • Item
    An Experimental Study on Low Pressure Frost Formation for Lunar Polar Water Capture
    (2023 International Conference on Environmental Systems, 2023-07-16) Compton, Beau; Krause, Timothy; Struchen Deans, Leah
    In-situ resource utilization (ISRU) is a vital component of NASA's mission to the Moon and beyond, as the extraction of resources from the environment can reduce payload weight and the frequency of resupply missions. Since the discovery of water in the regolith of the permanently shadowed regions (PSR) of the Moon, its extraction and transport has become an area of increasing interest for NASA. One proposed method is heating icy regolith to free the water before desublimating and transporting it as ice in a tanker. However, little is known regarding the dynamics of frost growth at low pressures, and an understanding of the heat transfer process is required to properly size the heat exchanger for the tanker. To investigate this phenomenon, a cold plate was placed in a vacuum chamber with water vapor directed at its surface. The chamber pressure (300 and 500 Pa) and cold plate temperature (-18 to -5 °C) were kept below the triple point and varied throughout the experiment to examine their impact on frost layer heat transfer. As water flowed into the chamber and deposited on the cold plate surface, the heat flux and temperature were measured along with the frost layer thickness and/or mass. Density calculated at the conclusion of each test suggests the frost layer is denser than that of frost grown at atmospheric pressure. The results demonstrate unexpected density and heat transfer characteristics and require development of a new model of frost growth for lunar conditions.
  • Item
    Artemis-I - Development and Testing of Radiation Mitigation Strategies for Crewed Missions
    (2023 International Conference on Environmental Systems, 2023-07-16) Barzilla, Janet; Gaza, Ramona; Stoffle, Nicholas
    The Space Radiation Analysis Group (SRAG) at Johnson Space Center developed a variety of radiation monitoring devices, space weather tools and crew exposure tracking products that were successfully tested during Artemis-I. These include vehicle area monitoring using the Hybrid Electronic Radiation Assessor (HERA) as the prime environment monitor for flight operations on Orion; Crew Active Dosimeter (CAD) as a precursor for crew worn dosimeters and tested during Artemis-I Science Payloads research (e.g., Commander Moonikin Campos, BioExpt-1 and the international collaboration Matroshka AstroRad Radiation Experiment - MARE); space weather Scoreboard interface hosting prediction model outputs (collaboration with Moon to Mars Space Weather Analysis Office and Community Coordinated Modeling Center at Goddard Space Flight Center); Acute Radiation Risk Tool (ARRT) predicting biological impacts during an energetic solar particle event using as input onboard radiation instrumentation; Mission operation tools to monitor real-time telemetered data and allow efficient 24/7 console operations support in preparation for the first crewed lunar mission (including daily communications with the Flight Control Team (FCT), internal and external collaborators). The current paper will present an overview of the Artemis-I radiation protection technology and tools, radiation measurements and data using the International Space Station (ISS) as testbed for these technologies, and preliminary Artemis-I data.
  • Item
    DAVINCI EDU Descent Sphere Thermal Insulation Test Results and Model Correlation
    (2023 International Conference on Environmental Systems, 2023-07-16) Zara, Rommel; Alexander, Evan
    The Deep Atmosphere Venus Investigation of Noble gases, Chemistry, and Imaging (DAVINCI) Mission will send an approximately 1-meter diameter probe into Venus to take detailed measurements of the Venus atmosphere and surface to answer questions about terrestrial planet formation and evolution, including the role (if any) of oceans. This probe, called the Descent Sphere, contains five science instruments and avionics that, as a system, must survive and operate thru the extremely challenging environment of the Venus atmosphere with pressures and temperatures reaching 90 bars and 465°C respectively. To mitigate the influence of this environment, the Descent Sphere design utilizes passive thermal control methods that include a 1-inch thick, high temperature MLI, and a 2-inch thick mat insulation to minimize the internal radiative and convective heat leaks from the very hot outer shell. To characterize the performance of the MLI and mat insulations, an engineering development unit (EDU) Descent Sphere was fabricated and tested at an industrial furnace where the predicted transient temperatures were simulated (up to 465°C), data collected, and subsequently a thermal model was correlated. The resulting correlated thermal model reduced uncertainties in the MLI and mat insulation performance and provided increased confidence in the flight predictions and design margins.
  • Item
    SWIM: Progress Report on the Organics Detection from Water
    (2023 International Conference on Environmental Systems, 2023-07-16) Nikolic, Dragan; Madzunkov, Stojan; Simcic, Jurij
    Jet Propulsion Laboratory (JPL) is developing a Quadrupole Ion Trap Mass Spectrometer (QIT-MS) suited for detecting ppm and ppb levels of organics within the liquid sample. The QIT-MS sensor is of the same heritage as one used in Spacecraft Atmosphere Monitor (S.A.M.). However, the pumping system, introduction of the sample, and operational architecture and procedures are different. We present our progress in this new instrument development and illustrate its ruggedized design by injecting 98% concentrated sulfuric acid that has the potential as a solvent for biochemistry. Using ruggedized QIT-MS to detect organic species dissolvable in water is straightforward and directly supports Spacecraft Water Impurity Monitor (SWIM) technology development.
  • Item
    Cyclone Sub-Micron Particulate Separator
    (2023 International Conference on Environmental Systems, 2023-07-16) Haggerty, Matthew; Emmons, Matthew; Wagner, Andrew; Cutbirth, Michael
    A hygienic environment for deep space exploration vehicles is vital to the health and functionality of crew members and the hardware. Previous missions have shown the pervasive problem of fine particulate including obscuring optical systems, scratching surfaces, and potential long-term health impacts. The current International Space Station (ISS) Environmental Control and Life Support (ECLS) system architecture employs traditional High-Efficiency Particulate Air (HEPA) filters to combat sub-micron particles, but these require frequent cleaning and ultimate replacement as particles embed within the filters and are unable to be removed. As missions return to planetary bodies, particulate becomes an even larger challenge as frequent migration of crew members to and from the vehicle will cause sub-micron lunar regolith particles to permeate throughout the pressurized cabin. Mainstream Engineering has been developing a cyclone-based system for sub-micron particulate capture that integrates with the central HVAC system. In this work, we present our computational fluid dynamics (CFD) model development, rapid prototyping process, and validated system design to achieve an in-place regenerable system with high-efficiency sub-micron particle collection and a comparable pressure drop to HEPA filters. The results of this work can aid in the reduction of consumable filtration devices and provide a longer service life than the filters that are currently in use on deep space exploration vehicles.
  • Item
    Development of ARGOS Offloading Assessments and Methodology for Lunar EVA Simulations
    (2023 International Conference on Environmental Systems, 2023-07-16) Jarvis, Sarah; Vu, Linh; Gupta, Garima; Benson, Elizabeth; Kim, Han; Rhodes, Richard; Rajulu, Sudhakar
    The Active Response Gravity Offload System (ARGOS) at NASA Johnson Space Center (JSC) is an analog environment that can offload pressurized suited subjects at various gravity levels. The suit is suspended from a robotic overhead crane by a cable connected to the suit via a gimbal with an adjustable pivot point. There has been increased interest in providing lunar pressurized suited training at ARGOS in preparation for lunar missions. Determination of the appropriate gimbal pivot point location for a given subject is vital for a high-fidelity and functional lunar simulation. Interactions between the pivot point location and center of gravity (CG) can result in righting moments that may lead to artificially stable or unrealistically challenging configurations. Changing the pivot point location is time consuming and repeated adjustment can result in significant loss of valuable pressurized suited time. This paper aims to share the knowledge obtained from the offloading characterization efforts during pressurized suited testing at ARGOS and document the ongoing process to define an appropriate pivot point location through iterative quantitative and qualitative assessments. The human-spacesuit CG locations for the ARGOS lunar simulation were estimated using a 3D body scan and density model combined with spacesuit hardware CAD and specifications. Early pilot testing of the gimbal revealed that setting the pivot point coincident with the modeled CG location was not always possible due to the current gimbal design, and small shifts forward and aft had noticeable effects on subject stability. Fifteen subjects performed a series of CG-related tasks in the xEMU spacesuit to assess simulation acceptability. Through iterative testing, this task list evolved to streamline the process needed to efficiently identify a suitable pivot point for a given subject. The developed methodology will be critical to determine pivot point selection for astronaut training in the xEMU ARGOS environment.
  • Item
    Calibration and Performance of the Spacecraft Atmosphere Monitor, an Air Constituent Monitor for Human Spaceflight
    (2023 International Conference on Environmental Systems, 2023-07-16) Darrach, Murray; Bae, Byunghoon; Fu, Dejian; Garkanian, Vachik; Homer, Margie; Kidd, Richard; Jung-Kubiak, Cecile; Kraus, Hannes; Maiwald, Frank; Madzunkov, Stojan; Malone, Charles; Nikolic, Dragan; Rais-Zadeh, Mina; Simcic, Jurij; Tillmans, Tina; Zhong, Fang
    The Spacecraft Atmosphere Monitor (S.A.M.) is a miniaturized gas chromatograph mass spectrometer (GC/MS) instrument for monitoring the cabin atmosphere for human spaceflight missions. The first Technology Demonstration Unit (TDU1) operated successfully aboard the International Space Station (ISS) from August 2019 to July 2021. The second unit, TDU2, will be delivered to ISS in 2023. While on-station, TDU2 will continuously monitor the major atmospheric constituents and, on command, perform analysis of the cabin atmosphere for trace organic volatiles. The S.A.M. TDU2 uses the same quadrupole ion trap mass spectrometer (QITMS) sensor as in TDU1, but includes a MEMS preconcentrator, gas chromatograph, and microvalve system. Its miniature, ruggedized form factor allows the S.A.M. to be aisle-deployed to monitor the cabin in different locations and during activities such as exercise and sleep.
  • Item
    Development and Testing of Crew Interfaces for an Advanced Unpressurized Exploration Rover
    (2023 International Conference on Environmental Systems, 2023-07-16) Hanner, Charles; Bolatto, Nicolas; Gribok, Daniil; Quizon, Spencer; Quintero, Rowan; Welfeld, Ian; Akin, David
    Although revolutionary in its impact on lunar exploration, the Apollo Lunar Roving Vehicle (LRV) had only rudimentary navigation capabilities, and crew controls were essentially limited to go/stop and turn right/turn left. After more than five decades, rovers supporting the Artemis program will have vastly increased capabilities, and a corresponding need for more detailed and complex crew interfaces. The VERTEX rover has been developed at the University of Maryland as an field test analogue of concepts such as the Lunar Terrain Vehicle, and incorporates advanced capabilities such as active suspension, variable deck height and angle, reconfigurable payload interfaces with multipurpose electronic interfaces, and advanced controls including teleoperation and autonomous driving modes. This paper details the development and human factors evaluation of controls, displays, and restraint systems for the VERTEX rover, based on both laboratory and field testing. While advanced robotic systems are often controlled from graphical user interfaces including touch screens, the extremes of lighting on the lunar surface and effects of regolith on pressure suit gloves drive designers to greater use of discrete and dedicated control interfaces and single-function displays easy to read in both bright sunshine and darkness. Extensive human factors testing was performed to examine potential layouts for the comparatively large number of discrete displays and controls, without impacting rover ingress/egress in spacesuits. Display and control layouts are also inherently impacted by crew seating and restraints, and a focused effort was made to move beyond the unsatisfactory simple seat belts of the Apollo LRV to restraint systems which are easier to engage and release in a spacesuit. The seat design itself is strongly driven by the portable life support system, and the VERTEX seat system was optimized to accommodate a number of different backpack designs and sizes to support external test objectives.
  • Item
    Check Valve Anomaly Investigation for the Mars 2020 Spacecraft
    (2023 International Conference on Environmental Systems, 2023-07-16) Miller, Jennifer; Bhandari, Pradeep; Novak, Keith; Kandilian, Razmig; Singh, Kaustabh; Karlmann, Paul; Abid, Mohamed; Lyra, Jacqueline
    Following launch of the Mars 2020 spacecraft July 30, 2020, a fault response safely re-configured the operational pumps for the cruise heat rejection system as a result of a larger-than-expected system temperature gradient. Further analysis and investigation determined the cause to be a stuck open check valve downstream of one of three pumps, allowing re-circulation through the pump itself and a reduced system flow rate. An in-flight characterization test confirmed the cause and cleared the check valve issue, returning the system to its as-designed flow rate. This investigation described here documents performance with and without re-circulation, possible causes for the check valve issue, characterization results, and improvements for future missions. Note: This abstract previously submitted by Jackie Lyra and withdrawn. Being resubmitted for publication for 2023 conference.
  • Item
    A Constellation of Dreamers: Advancing Space Exploration through Democratization
    (2023 International Conference on Environmental Systems, 2023-07-16) Ngarambe, Daniella; Grubbs, Patrick; Trepos, Anatole; Bourlette, Florent; Ben Slimane, Tarek; Fleischer, Louise
    The New Space industry gives us an opportunity to prioritize a new generation of space exploration, driven less by military and state needs and more by commercial and private interests. Despite progress, space remains inaccessible to many, with only six nations sending astronauts to space in 2021. To prevent underrepresented demographics from being excluded, the Spring Institute aims to democratize space creating opportunities for engagement for individuals from diverse nationalities and disciplines - and to do it in such a way that enables them to return their knowledge and experience to their homes. We do so by creating and collaborating on projects, proposals, and grants; as well as hosting events like hackathon challenges with local organizations, universities, and governments to encourage action in communities. Some of The Spring Institute's goals being to generate usable data for citizen science initiatives, leveraging their network and skills imparted by these collaborations. By championing the strength and resilience afforded by a diverse community of scientists, engineers, artists, and dreamers, The Spring Institute for Forests on the Moon will accomplish its objective of building a functional ecosystem in a lunar environment. We hope to inspire generations to continue looking towards the stars that are our shared cultural heritage.
  • Item
    Successful Testing of Advanced Space Habitat
    (2023 International Conference on Environmental Systems, 2023-07-16) Morgan, Matthew; Schaepe, Elizabeth; Lin, John; Valle, Gerard; Buckley, Shawn; Kirwan, James
    Commercial Space is an ecosystem which is rapidly evolving with advanced space habitats and broad interest in habitation development opportunities. Addressing this growing space economy requires the on-orbit presence of multi-use environments, similar to the International Space Station. One of these advancements is maximizing the livable volume of the space habitat without the burden of multiple launches or heavy lift capabilities, which is addressed by use of softgoods. Softgoods provide the benefit of an expandable volume once on orbit but minimal packed-size while launched, creating a significantly better volume-to-weight ratio. This enables support functions for diverse payload, governmental and civilian human visitors, on orbit in various scenarios including robotic, human tended, and autonomous/remote operations. In order to support a variety of user case functions in the manner in which customer bases are accustomed, the ecosystem of services should be scalable. The ability to scale and evolve on orbit habitation is a key discriminator in the advancement of space exploration. ILC Dover and Sierra Space have successfully tested multiple Ultimate Burst Pressure (UBP) subscale softgoods space habitats, a significant milestone towards manned flight qualification. The UBP tests verify the structural integrity of the system at or above a 4.0 factor of safety requirement at maximum operating pressure (15.2 psi) and demonstrates repeatability in the design across test units with both units exceeding the required 182.4 psig (operating pressure x 4 = 60.8 x 3 = 182.4 taking into account the 1:3 sub-scale factor) , averaging 198 psig internal pressure before failure. This paper discusses the system architecture, concept of operations, rationale for testing approach, and test results gathered.
  • Item
    Ionic Liquid Parameter Prediction Leveraging Quantum Structure Property Relationships
    (2023 International Conference on Environmental Systems, 2023-07-16) Woolever, Mitchell; Nabity, James; Cook, Ronald; Fox, Eric
    U.S. Space Exploration Policy denotes the critical importance of establishing an outpost on the Moon to provide the foundation for human missions beyond cislunar space. However, launching spare components and systems from Earth will likely be cost prohibitive, so the single most important development that is required for enhancing, and in some cases enabling, sustained human presence on the Lunar surface is having the capability to extract metals, oxygen, and water from the Lunar regolith. Ionic Liquids (ILs) are noteworthy for their host of unique chemical properties: a relatively large temperature range in the liquid phase, negligible vapor pressures, thermal and chemical stability, wide voltage window, and many have low toxicity. Furthermore, their coupled organic and ionic nature make them excellent solvents for a wide range of materials. In particular, acidic ionic liquids show the potential to enhance oxygen and metals production from regolith via dissolution and electrolysis. Furthermore, given their organic composition, the physical and chemical properties of ILs can be fine-tuned by modifying their ion structures and combination. Relative abundance changes with sample location, but the principal metals of interest for In Situ Resource Utilization (ISRU) in the Lunar regolith are iron, aluminum, magnesium, calcium, and titanium. However, an IL has yet to be identified that reliably dissolves titanium dioxide or silicon dioxide. Manufacturing and testing even a relatively small subset of the million theoretically stable IL anion/cation combinations for mineral digestion performance analysis is time and cost prohibitive. This paper will discuss a software process pipeline and corresponding analysis setpoints for a method to determine quantum structure property relationships (QSPR), which relate IL molecular structure to chemical function. Using QSPR, hundreds or even thousands of ILs could be assessed for efficacy in regolith ISRU and beyond.
  • Item
    Developing an Integrated Logistics Infrastructure for Lunar Surface Habitats
    (2023 International Conference on Environmental Systems, 2023-07-16) Akin, David
    The Artemis program is building up to a return to human lunar exploration, with the goal of extended and eventually permanent human lunar surface habitation. While this effort builds on almost 25 years of permanent human habitation at the International Space Station, logistics resupply will be uniquely different on the lunar surface, due to both substantial gravity and the greater challenge of logistics transport. While ISS resupply is accomplished with 6-8 dedicated cargo missions per year for a cumulative annual cargo mass of approximately twenty metric tons, there is an open question of the optimum number and size of resupply missions for a lunar surface base. Logistics for human habitats will remain primarily focused on the use of pressurized modules to protect the resupply items from vacuum and temperature extremes, as well as to simplify the process of bringing the logistics into the habitat for use. This paper focuses on technologies for establishing a robust logistics infrastructure for upcoming surface habitats and bases. Following a review of potential lander vehicles with their associated payload mass and volume limits, it identifies a set of candidate scales for incoming logistics elements, from full habitat modules to dedicated ISS-type logistics modules to small multi-unit logistics elements capable of being manipulated by EVA astronauts or robotic systems. Tasks for the logistics system will include offloading landing vehicles, which may include elevated payload decks, transporting the logistics elements up to a kilometer from the landing site to the base, berthing the pressurized module to the habitat, and systems for offloading cargo from the module's interior and transporting it internally to designated storage sites. Developmental testing includes the use of underwater simulation of human and robotic logistics tasks ballasted to replicate lunar gravity conditions.
  • Item
    SCAMPI Project: Design of an Aquatic Closed Ecological System for Microgravity
    (2023 International Conference on Environmental Systems, 2023-07-16) Ben Slimane, Tarek; Torchia, Costanza; Grubbs, Patrick; Galvan Lobo, Jorge; Ropero, Alvaro; Alberto Rodriguez, Jorge; Smith, Joshua; Berger, Anatole; Roche, Solène
    Long-duration crewed space missions require bioregenerative life support solutions to improve mission sustainability and resiliency in the harsh environment of space. Understanding the impact of the space environment on Earth ecosystems is a critical next step in developing such solutions. This manuscript presents the experimental design of the SCAMPI Project (Saltwater Crustacean, Algae, and Microbe Population Investigation), a student mission to investigate the effect of microgravity and increased radiation on a multitrophic aquatic closed ecological system. The team is developing a custom payload, consisting of a sealed aquarium and instrumentation suite, to be integrated into the ICE Cubes facility onboard the International Space Station. Remote monitoring will collect data and imagery on the biotic and abiotic factors within the closed environment, informing a digital twin simulation that is being developed concurrently. This experiment will be the latest in a short list of ecosystem-scale experiments to fly in space, and address fundamental knowledge gaps including microbial community dynamics in microgravity. Ultimately, SCAMPI will provide data to inform the design of future closed ecological life support technologies by validating the hypothesis that Earth's ecosystems can function nominally in the space environment. The experiment is currently being built as a part of ESA's PETRI program and anticipates launching in early 2025.
  • Item
    Space Hands-on Training at the University of Stuttgart: from Microalgae to Docking Maneuvers
    (2023 International Conference on Environmental Systems, 2023-07-16) Detrell, Gisela
    The University of Stuttgart places great value in providing the students a unique opportunity to put in practice the concepts taught in theoretical lectures. Therefore, research and teaching at the Institute of Space Systems (IRS) are highly linked. A practical training module, "Selected hands-on training for space", has been offered for nine years, and its content is always being adapted to the current institute research. The courses offered over the years are linked to life support and energy systems (use of microalgae for oxygen and food production, electrolyzers and fuel cells), mission analysis, use of Earth observation satellite data and the most demanded by our students, the spacecraft maneuvering. Here, the students have the opportunity to carry out docking maneuvers with a full-scale Soyuz simulator. The students participate in two of the offered courses over one semester and are evaluated through a report, presentation or exam. After successful completion, this allows them to obtain three ECTS (European Credit Transfer System) for the space specialization in the aerospace engineering Master. This module is very popular, and the places offered are filled in a matter of hours, as soon as registration opens. Unfortunately, the number of places is limited, due to the resources required, both in terms of material and tutoring staff. The university, the faculty of Aeronautics and Geodesy, and the institute itself provide the necessary means to offer this module. This paper presents the different training courses from our institute and their link to the current research. Student's feedback from the current semester (Winter 2022/23) is included.
  • Item
    Lunar SmartHab Mission Operations and Crew Day-In-The-Life
    (2023 International Conference on Environmental Systems, 2023-07-16) Pritchard, Kenneth; Vaccino, Luca; Liu, Xiaoyu; Whitaker, Dawn; Dyke, Shirley; Joyal, Brian
    Toward the goal of developing realistic models and conducting useful trade studies, researchers, including those in the Resilient ExtraTerrestrial Habitat Institute (RETHi), depend on a shared notional understanding of how a smart planetary habitat (SmartHab) might look and operate. Models must originate from a baseline reference architecture for all mission characteristics. This project qualifies some general assumptions made about the daily activities and objectives of a SmartHab's crew. It provides crew schedules to represent agent actions and availability through a day-in-the-life (DITL) but refrains from defining a concrete mission architecture that might infringe on simulation flexibility . Researchers and designers can use these DITL schedules and the content of this paper as a contextual reference point to inform future projects.
  • Item
    Ionic Liquid-based CO2 Control of Plant Growth Chamber Atmospheres
    (2023 International Conference on Environmental Systems, 2023-07-16) Nitschke, Felix; Nabity, James
    Control of carbon dioxide (CO2) remains important for human spaceflight. Long-term continuous exposure to elevated CO2 concentrations (> 2,000 ppm (0.2 kPa)) has been hypothesized to adversely affect crew performance and contribute to crew physiological issues (headaches, vision impairment, and intracranial pressure). Open plant chambers such as the Russian Lada and NASA's Veggie unit have utilized the cabin CO2 to sustain photosynthesis, however dynamic changes in CO2 levels can adversely affect gas exchange and plant growth as the plants adapt to the new CO2 levels. A closed plant growth chamber with independent control of CO2 can establish conditions ideal for photosynthesis and thereby reduce stress on the plants. In this paper, we describe a CO2 control system that uses an ionic liquid membrane contactor for selective transport of CO2. A blower circulates the plant growth chamber atmosphere through the contactor. Red, blue, and green light-emitting diodes illuminate plants which dynamically alter the CO2 level within the growth chamber; plants remove CO2 during the light cycle and respire CO2 when it's dark. When the plant growth chamber CO2 level is low, the control system scrubs CO2 from a simulated CO2-laden cabin atmosphere and delivers it to the plant growth chamber to maintain the desired set point. If the chamber CO2 level is higher than the set point, then the control system reverses the direction of transport by scrubbing CO2 from the plant growth chamber atmosphere and rejecting this CO2 to the cabin. A model was developed with the V-HAB virtual habitat modeling and simulation tool to characterize CO2 control over a broad range of operating conditions and demonstrate feasibility for control between 1,000 and 2,000 ppm (0.1 and 0.2 kPa).
  • Item
    Simulation-Based Assessment of Hazardous States in a Deep Space Habitat
    (2023 International Conference on Environmental Systems, 2023-07-16) Vaccino, Luca; Pritchard, Kenneth; Azimi, Mohsen; Dyke, Shirley; Lund, Alana
    The progression of the Artemis missions is bringing us nearer to extraterrestrial surface habitation and the realization of a sustainable living environment in deep space. This requires that we improve our capability in the design and evaluation of a variety of protocols to mitigate and manage a variety of hazards. Given the near impossibility of in situ testing, computer simulation is a suitable tool for this task. The Resilient Extra-Terrestrial Habitats institute (RETHi) has developed a Modular Coupled Virtual Testbed (MCVT) to simulate measures to enhance resilience in an extraterrestrial smart habitat (SmartHab). MCVT is composed of several subsystems with damageable/repairable components, and is capable of modeling different disruption scenarios. Micrometeorite impact, fire, moonquakes, and nuclear leakage are included along with typical environmental disturbances such as dust accumulation and solar flux. For each of these disruption scenarios, the location, onset time, and intensity can be specified by the user. The order and the rate of the repair are also user-defined. Consequently, the effect of the damage propagates through different components and subsystems, potentially rendering the habitat unlivable. The goal of this paper is to investigate the use of the MCVT for studying a resilient SmartHab. By altering the initial conditions, certain input parameters, and repair prioritizations across several simulations for different disruption scenarios we demonstrate some scenarios in which simulation is an effective tool to support design. In the end, the lessons learned and the conditions that contribute to placing the SmartHab in an unsafe or unrecoverable state are identified, alongside with the best-practice emergency responses. These results form a framework for future studies into resilient SmartHab design via similar methods.
  • Item
    Design of an Actively Shuttered Dust-Resilient Radiator for Lunar Applications
    (2023 International Conference on Environmental Systems, 2023-07-16) Gibson, Andrew S.; Bailes-Brown, Dominic; Iglesias, Angel; Humphries, Martin; Barber, Simeon; Hager, Philipp
    The design of radiators for the lunar surface must consider detrimental effects of lunar dust in terms of thermal performance, as well to the reliability of the mechanism. Radiator function is influenced by extreme temperature variations, where thermal cases must consider IR heating from the surface during the Lunar day as well as heat losses during the Lunar night. The overall challenge for the development was to maximize the range of functionality across a wide variety of lunar locations, while focusing on polar scenarios. In early stages, a thermal analytical model was developed in Python to study thermal shutter performance of 2 variants according to lunar latitude and orientation of the radiator, as it was required to maximize the shutters' usefulness. The trade-off resulted in the selection of the thermal shutter approach versus a louvered radiator concept, with the shutter favoured for lower mass and higher field of view and reliability. The actively shuttered design enables closure of the radiator to minimize heat losses at night and is also intended to protect from contamination during radiator during events and phases of the day with high expected dust deposition, such as the passing of the day/night terminator, landing, or activities of astronauts, rovers or robotic equipment. The paper describes progress made following one year of development, focusing on status. Results of component level breadboarding and an overview of the design of an Engineering Model unit will be covered, highlighting thermal design choices, risk mitigation activities and thermal capabilities predicted for this device as well as the mounting approach. The mechanism design will be described demonstrating the dust-resilient approach, suitable for lunar landers (EL3), rovers and other longer duration lunar surface applications.
  • Item
    Design of Working Fluid Venting System for Mechanical Pumped Fluid Loop Heat Rejection System for Mars Missions
    (2023 International Conference on Environmental Systems, 2023-07-16) Bhandari, Pradeep
    In several Mars missions flown by JPL, a mechanically pumped loop utilizing Freon-11 as the working fluid is utilized for thermal control of the spacecraft components during cruise. The fluid loop controls temperatures of components within the cruise stage as well the entry vehicle's lander or rover. During entry into the Mars atmosphere, the cruise stage needs to be separated from the entry vehicle, which requires the tubing connecting the two stages to be severed. Just cutting the tubing, without venting the freon in a controlled manner, would lead to a random direction and speed of the effluent fluid. The impulse from this would create a significant and non-deterministic nutation of the entry vehicle, which could jeopardize its entry. To avoid that impact, the Freon is vented in a very carefully controlled direction and speed to ensure that the direction of the vent vector passes along the center of gravity of the entry vehicle or is canceled by opposing nozzles. An innovative scheme of using the pressurized gas to "piston out" the Freon was designed and implemented in these missions. Additional concerns with the vent nozzle not freezing up due to the sublimation of the liquid Freon while escaping into the vacuum of space were investigated and mitigated in this design. A detailed fluid-thermal-impulse model was created to predict the resultant thrust profile and total impulse imparted on the spacecraft. This paper will describe the basic design, the corresponding design & analysis to assess and predict its performance, the trade -off of design concepts, and its implementation for flight usage.