Browsing by Author "Sepka, Steven"
Now showing 1 - 7 of 7
- Results Per Page
- Sort Options
Item Advancements in Logistics Reduction for Exploration Missions(2023 International Conference on Environmental Systems, 2023-07-16) McKinley, Melissa; Ewert, Michael; Borrego, Melissa; Orndoff, Evelyn; Fink, Patrick; Sepka, Steven; Richardson, Justine; Hill, CurtisManagement of logistics on exploration missions includes both looking for ways to minimize the quantities, mass and volume of various consumables, supplies, spares and equipment as well as ways to minimize the crew time needed for locating and handling those items. Also included are ways to minimize the waste, handling and resultant products from the processes of maintaining a crew on these missions. The Logistics Reduction project encompasses technologies for management of waste, trash, autonomous logistics, and clothing. This paper provides a status of work in these areas including recent accomplishments and challenges encountered. Future objectives will also be covered along with the work currently in progress. Specifically, the paper will cover technologies in waste management, namely, the Universal Waste Management System (UWMS) or exploration toilet and work on an alternative waste collection container, the Alternate Fecal Canister. Trash management technologies work on the Trash Compaction and Processing System (TCPS) and Trash to Gas (TtG) is summarized with progress to date as well as information on how Jettison as an option is related. Progress and summary of recent accomplishment on the RFID (Radio Frequency ID) Enabled Autonomous Logistics Management (REALM) and the Autonomous Logistics (AL) technologies is detailed. Advanced Clothing System (ACS) and work in the area of Systems Engineering and Integration (SE&I) is also included. Status of the technologies, accomplishments and how the focus areas inform program decisions will be addressed.Item Considerations For Waste-to-Base Future Research Paths(2023 International Conference on Environmental Systems, 2023-07-16) Sepka, Steven; Shapiro, Andrew; Ewert, Michael; Lee, JeffreyDeveloping innovative technologies to reprocess low value waste into high value base products will enable a new “Waste-to-Base” (WtB) capability leading to innovative approaches to space mission design. Systems engineers and mission architects will work together under a new paradigm in logistics planning. Equipment, components, packaging,storage, and structures will be understood not only by functional requirements, but also in terms of useful lifetimes and materials of construction. The advent of a new technical discipline- reprocess engineering - will grow from the intersection between chemical, mechanical, and systems engineering, mission design, and logistics planning. A crowdsourcing approach was employed to gather low Technology Readiness Level (TRL) concepts into workable solutions for issues in trash management, CO2 processing, foam reprocessing, and fecal processing. The results of the crowdsourcing activities are summarized along with a discussion for future technology development work.Item Ground Testing of Full-Scale Direct Contact Ultrasonic Human Solid Waste Dryer with Water Extraction System(2024 International Conference on Environmnetal Systems, 2024-07-21) Momen, Ayyoub; Shelander, Connor; Bigelow, Jon; Chertkovsky, Dennis; Richardson, Tra-My Justine; Martin, Kevin; Sepka, StevenIn this study, we will report on the development and ground testing results of the novel ultrasonic human solid waste dryer at scale and its water extraction performance. Unlike conventional thermal drying methods, direct contact ultrasonic drying technology does not require substantial heat for water evaporation. Therefore, it is not constrained by the high energy input needed for water vaporization. This innovative drying method removes water by rapidly shaking the object (on a micron-scale) utilizing piezoelectric transducers. By partially bypassing the evaporation process, the technology demonstrates significantly higher efficiency and drying speed for bagged human solid waste. Previously, the performance of this platform technology for human fecal drying has been shown in the laboratory and at the benchtop scale. The team also demonstrated a lab-scale system performance under zero Gravity conditions and parabolic flights. In this paper, we will report on the full-size machine design and development process and the ground testing results of the ultrasonic drying performance of simulated feces and its water capture potential. This study will also report our team's effort to make the process as automated as possible for flight crew members' ease of use. The results of this study serve as the cornerstone for developing the first human solid waste dryer system for ISS, Moon, Mars, and other space applications.Item Logistics Reduction Advancements and Future Plans for NASA’s Exploration Missions(2024 International Conference on Environmnetal Systems, 2024-07-21) McKinley, Melissa K.; Ewert, Michael K.; Borrego, Melissa A.; Fink, Patrick; Sepka, Steven; Richardson, Tra-My Justine; Pitts, Ray; Meier,Anne; Hill,CurtisManagement of logistics on exploration missions includes both looking for ways to minimize the quantities, mass and volume of various consumables, supplies, spares, and equipment as well as ways to minimize the crew time needed for locating and handling those items. Also included are ways to minimize the waste, handling, and resultant products from the processes of maintaining a crew on these missions. The Logistics Reduction project encompasses technologies for management of waste, trash, autonomous logistics, and clothing. This paper provides a status of work from 2023 in these areas including recent accomplishments and challenges encountered. Future objectives and plans for 2024 will also be covered along with the work currently in progress. Specifically, the paper will cover technologies in waste management, namely, the Universal Waste Management System (UWMS) or exploration toilet and work on an alternative waste collection container, the Alternate Fecal Canister. Trash management technologies work on the Trash Compaction Processing System (TCPS) and Trash to Gas (TtG) is summarized with progress to date as well as information on how Jettison as an option is related. Progress and summary of recent accomplishment on the RFID (Radio Frequency ID) Enabled Autonomous Logistics Management (REALM) and the Autonomous Logistics (AL) technologies is detailed. Advanced Clothing System (ACS) and work in the area of Systems Engineering and Integration (SE&I) is also included. Status of the technologies, accomplishments and how the focus areas inform program decisions will be addressed.Item A Review of Existing Policies Affecting the Jettison of Waste in Low Earth Orbit and Deep Space(50th International Conference on Environmental Systems, 7/12/2021) Parodi, Jurek; Ewert, Michael; Trieu, Serena; Young, Janine; Pace, Greg; Martin, Kevin; Richardson, Tra-My Justine; Lee, Jeffrey; Sepka, StevenThe management of waste generated onboard spacecraft during future long-duration deep-space missions will require different solutions from those currently implemented on the International Space Station which consist exclusively of collecting, storing, and returning the waste to Earth. Alternative options for managing spacecraft waste are to process it for recycling and recovery of resources, and to jettison it overboard in a solid form (such as a comapcted tile) or in agaseous form after torifaction. The waste generated during a deep-space mission is derived mainly from spacecraft logistics supplies, food and beverage residues, personal or scientific items used by the crew, human metabolic waste, and unused spare components. Uncontained and unprocessed trash is a potential health hazard and a habitat volume liability, which makes onboard long-term storage an inefficient and non-optimal option. However, the jettison of solid, processed waste appears to be an effective solution for crewed deep-space missions, leading not only to volume reduction and habitat safening, but also to considerable mass savings in the spacecraft�s propulsion system. However, the disposal of trash overboard also creates a navigation hazard for spacecraft and the potential risk of contamination of planetary bodies, interfering with the search for life. This paper investigates the requirements covered by existing policies that could affect the jettison concept of operations (ConOps) and system design.Item Updated Effluent Analysis of the Heat Melt Compactor: Water Quality and Dewpoint Simulation of Gas Effluent(50th International Conference on Environmental Systems, 7/12/2021) Young, Janine; Parodi, Jurek; Trieu, Serena; Richardson, Tra-My Justine; Sepka, Steven; Lee, Jeffrey; Martin, Kevin; Pace, Gregory; Nadeau, Mary LouThe Trash Compaction and Processing System (TCPS) processes astronaut trash through volume reduction, biological safening, trash stabilization, effluent management, and resource recovery. TCPS development for the International Space Station (ISS) and risk reduction activities are supported by testing the Heat Melt Compactor (HMC) at NASA Ames Research Center (ARC). Processing trash extracts water vapor that can be recovered and releases volatile gases that must be managed. Part of the effluent is condensed and collected for analysis. The evaluation of the liquid effluent includes total organic carbon (TOC) concentrations, which provide a general indication of overall water quality, other defining characteristics such as pH and conductivity, and identified chemical components. On the other hand, the gas effluent may be recovered through a contaminant control system and vented to ISS cabin or vented overboard into space through the ISS Vacuum Exhaust System (VES). In the latter venting scenario, a constraint is the dewpoint of the gases disposed into the VES must be less than 15.5 oC. With simulations using Aspen Plus� and the HMC gas effluent results, flash calculations were conducted in the modeling study to calculate feed temperature and dewpoint at fixed pressures. Saturated vapor curves were also produced and provide a preliminary result on optimal feed conditions that satisfy the dewpoint and vapor-phase only requirements upon venting to VES. This paper serves as an update on the ongoing liquid and gas effluent analysis of the HMC/TCPS.Item Waste Container Filtration To Minimize Microbial Escape During Long-Term Storage On Mars(2024 International Conference on Environmnetal Systems, 2024-07-21) Sepka, Steven; Pace, Greg S.; Spry, J. AndyIn the search for life on Mars, keeping its surface pristine and free of microbes due to human presence is of utmost importance. Astronauts will use emptied logistics containers during their Martian stay to store waste. These containers will be left on the planet�s surface and are a potential source of microbial contamination. It is desired for these containers to be free from leaks for a minimum of 50 years. If leaks do occur a likely location will be at the port. At this location the mating surfaces will be sealed using a flexible gasket material like a thin metal or a polymer. Eventually these seals will fail. To mitigate these effects, a particulate filter can be employed to equilibrate the pressure between the Martin environment and inside the container. To meet planetary protection requirements, the filter can only allow particulates smaller than 0.2 um diameter to pass. This paper discusses why a particulate filter may be needed and how such a filter would be tested to survive and operate in the harsh Martian environment.