sign in sign up
<<
Home , European Service Module, Lunar Gateway, Orion (spacecraft)

ICES-2020-432

Integrating and Initial Environmental Control and Life Support Systems

Heather Mera1, Joel A. Kirkland2, Ryan E. Wall3, Timothy Cichan4 Space, 12257 S. Wadsworth Blvd, Littleton, CO 80127

The Gateway is a next generation platform that will enable a sustained human, robotic, and commercial exploration of deep space. Leveraging Orion’s capabilities, including the Environmental Control and Life Support System (ECLSS), to augment Gateway operations in an integrated, evolutionary approach will reduce Gateway complexity and provide a low- mass, reliable solution for a human-rated system. This paper explores the capabilities of the Orion ECLSS to support the initial Gateway buildup and an approach to integrate the systems for human-rated redundancy as the Gateway evolves to independence.

Nomenclature ATCO = Ambient Temperature Catalyst Oxidizer ARS = Air Revitalization System CHC = CO2 and Humidity Control CM = Crew Module (Orion) CO = Carbon Monoxide CO2 = Carbon Dioxide ECLSS = Environmental Control and Life Support Systems ESM = European (Orion) HALO = Habitation and Logistics Outpost HEOMD = Human Exploration and Operations Mission Directorate IMV = Inter-Module Ventilation ISS = International LEO = Low Orbit LM = Lockheed Martin NASA = National Aeronautics and Space Administration NextSTEP = Next Space Technologies for Exploration Partnerships PCS = Pressure Control System PPE = Power and Propulsion Element ppCO2 = Partial Pressure of Carbon Dioxide ppO2 = Partial Pressure of Oxygen PWS = Potable Water System SLS = SMAC = Maximum Allowable Concentration TBD = To Be Determined TCCS = Trace Contaminant Control System

1 Mechanical Engineer Staff, Advanced Programs, Bldg: 730 Glenn L Martin Boulevard Bldg Code: CO/730 Floor: 1 Room: 150 MailDrop: H3005 2 Systems Engineer Staff, Advanced Programs, Bldg: 730 Glenn L Martin Boulevard Bldg Code: CO/730 Floor: 1 Room: 150B MailDrop: H3005 3 Systems Engineer Associate, Advanced Programs, Bldg: 730 Glenn L Martin Boulevard Bldg Code: CO/730 Floor: 1 Room: 150D MailDrop: H3005 4 Architect, Advanced Programs, Bldg: 730 Glenn L Martin Boulevard Bldg Code: CO/730 Floor: 1 Room: 132B MailDrop: H3005

Copyright © 2020 I. Introduction ational Aeronautics and Space Administration’s (NASA) Human Exploration and Operations Mission N Directorate (HEOMD) has outlined a strategic vision for the Gateway guided by principles including fiscal realism, technology pull and push, gradual capability build-up, and architecture openness and resilience1. The Gateway is envisioned to be a small orbital platform for supporting short duration crewed missions initially to demonstrate proving ground technologies and act as a staging point for lunar and exploration missions. The build-up of the early Gateway will occur over a series of Support Missions via commercial, Space Launch System (SLS), and Orion elements during the 2020s2. Under NASA’s Next Space Technologies for Exploration Partnerships (NextSTEP) public private partnership, Lockheed Martin is conducting studies to determine the best architecture approach to the Gateway build-up that optimally utilizes contributions from domestic, international, commercial, and government partners; addresses key policy and scientific objectives; and, is realistically achievable within desired fiscal and schedule constraints. While the specific results of these studies vary, they establish common themes of flexibility, adaptability, evolvability, and robustness. Across these themes, a consistent finding aligned with HEOMD principles was the value of leveraging existing capabilities to achieve toward overall human exploration goals while specific program architecture and objectives are still evolving. As the first spacecraft to transport humans beyond (LEO) since , Orion has many of the design capabilities needed to safely support humans in deep space on the Gateway. Leveraging Orion’s capabilities, particularly in the early Gateway assembly, offers an agnostic flexible path to conduct early demonstrative crewed missions, regardless of the ultimate architecture or program objectives3. Current HEOMD plans consist of an initial Phase 1 Gateway with the minimum systems required to support the 2024 human lunar landing mission, including the Power & Propulsion Element (PPE), the Habitation and Logistics Outpost (HALO), and logistics delivery services 4. The HALO is planned to be a functional pressurized volume with avionics, power storage, thermal control, and limited life support systems significantly reliant on Orion’s life support and crew systems4; and, it will serve as a docking hub for crew and logistics transfer to the Human Landing System (HLS) while providing additional living and work space for the crewmembers on the Gateway for up to 30 days. Orion can also support any other early habitation modules that require in-flight outfitting due to constraints. As such, this paper explores Orion’s general capabilities to provide integrated life support for an early Gateway assuming a generic habitation module rather than a specific configuration. The Orion Environmental Control and Life Support System (ECLSS) can provide many of the habitable functions required to support these crewed missions, requiring only minimal initial capabilities on the early Gateway or exploration elements5. As the Gateway is built and missions evolve in capability and complexity, the Gateway will transition to the primary provider of ECLSS functions, potentially evolving from an open system to a closed loop system6. However, Orion ECLSS capability extends to the fully built Gateway configuration, enabling Orion to serve as a reliable secondary provider of critical ECLSS functions and offers an integrated human-rated system that utilizes existing capabilities. This integrated approach reduces overall Gateway complexity, frees resources for new objectives, and achieves the principles outlined in HEOMD’s strategic vision for the flexible utilization of the Gateway.

II. ECLSS Integration Overview LM NextSTEP architecture trade study results showed that early reliance on Orion ECLSS optimized the value of the initial mission of a habitation module by enabling more launch mass and volume allocation towards unique habitation features or utilization. Increasing Gateway ECLSS independence lowered overall value by adding cost, increasing schedule risk to the critical path, and detracting from utilization objectives. Therefore, the recommended initial architecture is the use of Orion’s core ECLSS for atmosphere revitalization and waste management while the Gateway habitation module ECLSS provides the minimal systems or infrastructure required for utilization activities and evolution to an independent system. Additionally, the habitat and/or logistics element provides consumables for the extended mission duration to conserve for Orion’s safe haven contingency capabilities and Earth-return transit period. While Orion’s consumable storage capability is limited, the hardware can support missions of much long durations. On subsequent missions, Orion ECLSS continues to provide primary support until systems are installed in the habitat to build up integrated Gateway capabilities and redundancy as needed to achieve campaign objectives. By incorporating lessons learned from International Space Station (ISS) module design and crew installation activities, the habitation module and ECLSS systems can be designed in a modular fashion to minimize flight crew time impacts. One example concept of a plug-and-play ECLSS studied through NextSTEP partnerships included not only core 2 International Conference on Environmental Systems

Table 1. Gateway and Orion Functional Allocation. Orion systems such as atmosphere revitalization but initially provides core ECLSS functions and Gateway provides also an upgrade path to add in regenerative 7 commodity-based systems and permanent infrastructure. Orion systems for loop closure . Addition of transitions to backup redundancy as Gateway adds capability. regenerative systems into the Gateway, if appropriately scarred for in the initial habitat Early Evolved infrastructure design, could reduce logistics Function Configuration Configuration costs, enable longer duration stays beyond 30 Orion Gateway Orion Gateway days at the Gateway, and provide early Mars- CO2 Removal Prime n/a Backup Prime class systems testing; however, the addition of Humidity Removal Prime n/a Backup Prime these systems significantly reduces valuable Trace Contaminant Prime n/a or Backup Prime habitation volume for utilization activities and Removal Shared may not be necessary in the final Gateway configuration. Regardless of the ultimate Particulate Removal Shared Shared Backup Prime Gateway ECLSS design, once the Gateway Air Monitoring Shared Shared Backup Prime achieves independent core ECLSS functionality, Cabin Ventilation Shared Shared Backup Prime Orion will then transition to serving as a Inter-module Ventilation n/a Prime n/a Prime redundant backup. Table 1 provides a summary Temperature Control Shared Shared Backup Prime of proposed functional allocation and Avionics Cooling Shared Shared Shared Shared redundancy over time. Fire Detection Shared Shared Backup Prime A. Air Revitalization Fire Suppression Backup Prime Backup Prime The Orion Air Revitalization System (ARS), Emergency Equipment Backup Prime Backup Prime see Figure 1 for a simplified block diagram, is Waste Management Prime n/a Backup Prime responsible for providing adequate ventilation Water Storage Backup Prime Backup Prime for the crew, maintaining carbon dioxide, Water Distribution Backup Prime Backup Prime humidity, particulates, and trace contaminant Water Monitoring n/a n/a n/a Prime concentrations at comfortable and safe levels, Pressure Control Backup Prime Backup Prime and maintaining the temperature at the desired crew selected set point. It consists of a high- Gas Storage Backup Prime Backup Prime flow, low-pressure drop cabin loop and a low- Gas Recharge n/a n/a n/a Prime flow, high-pressure drop suit loop. During EVA Support n/a n/a n/a Prime nominal crewed operations, the two loops are Vacuum Service n/a n/a n/a Prime integrated to maintain the shirt-sleeve cabin Optional – Regen ECLSS environment. Water Processing n/a n/a n/a Prime The system accommodates for both low Urine/Brine Processing n/a n/a n/a Prime (sleep) and highly active (exercise) periods for two to four crewmembers. As such, many of O2 Generation n/a n/a n/a Prime these components are already sized to handle the CO2 Reduction n/a n/a n/a Prime Gateway crew as-is, though there are some unique considerations regarding the extended volume and mission requirements. For example, mission durations greater than 30 days (launch to landing) may necessitate an enhanced exercise protocol beyond Orion’s nominal 30-minute protocol8. Depending on the integrated configuration and crew operations, Orion may be able to accommodate the increased metabolic loading without any additional augmentation on the Gateway. Another consideration is trace contaminants generated over potentially long uncrewed Gateway periods between missions and whether a dedicated system is needed to ensure a safe environment prior to crew arrival. The Orion CO2 and Humidity Control (CHC) system is a regenerative amine dual bed system that simultaneously adsorbs CO2 and humidity from the air in one bed while desorbing the second bed via vacuum; a series of valves cycles between the two beds for continuous removal and regeneration9. The technology enables Orion to support an extended integrated mission without the need for additional consumables or complicated humidity capture systems on the Gateway as those may be difficult to maintain during uncrewed dormancy periods.

3 International Conference on Environmental Systems

Figure 1. Orion ARS Block Diagram. The Orion ARS contains a redundant CHC system, which removes both CO2 and humidity, a trace contaminant control system, air cooling, and particulate filters.

An integrated analysis performed by Lockheed Martin using modified Orion models showed that Orion can independently provide CO2 and humidity removal for both Orion and a Gateway habitable volume over a variety of operational scenarios. A Gateway volume of 45 m3 (1600 ft3) and an Intermodule-Ventilation (IMV) rate of 3.5-4.2 m3/min (125-150 cfm) were assumed for analysis purposes. A series of cases was evaluated with varying crew location between Orion and the Gateway volume (all four in either module or split between), exercise protocols (Orion’s 30 minute or an assumed 90 minute enhanced protocol), and Orion CHC operational parameters. Metabolic rates for the assumed enhanced protocol were generated by extending the peak rate in the Orion protocol out to 90 min, which may be more conservative than the rates subsequently published by NASA8, and may alter the resulting conditions and constraints described herein. Analysis results showed that the CO2 and humidity remained within requirements of 533 Pa (4 mmHg) and 25- 75% 8,10, respectively, in both nominal and off-nominal (faulted) situations in all cases where the Orion exercise protocol was performed or all four crewmembers were not collocated in the Gateway habitat volume while performing the enhanced exercise protocol. Further, the CO2 was below the limits and closer to the exploration goal of 2 mmHg; The relative humidity was 4-9% dryer than the minimum 40% desired by Gateway standards11; however, there are indications that the typical 25%-75% range continue to be acceptable for short duration missions12. The challenging case for Orion control occurred with the longer enhanced exercise protocol and crew congregation in the Gateway due to the IMV limitation, showing a dewpoint in excess of 15.6°C (60°F) without additional IMV or augmented control on the Gateway. Example plots of CO2 and dewpoint in the Gateway are shown below in Figure 2.

4 International Conference on Environmental Systems

Gateway Daily ppCO2 and Dew Point Gateway Daily ppCO2 and Dew Point Enhanced Exercise, 2 Crew Gateway, 2 Crew Orion Enhanced Exercise, 4 Crew Gateway 600 18 600 18

Max DP 15.4 °C, RH 59% Max DP 16.1 °C, RH 62% C

500 15 500 15 C ° ppCO2: 261-386 Pa ppCO2: 279-404 Pa ° 400 (2.0-2.9 mmHg) 12 400 (2.1-3.0 mmHg) 12

300 9 300 9

200 6 200 6 Cabin ppCO2, ppCO2, Cabin Pa Cabin ppCO2, ppCO2, Cabin Pa ppCO2 [Pa] ppCO2 [Pa]

100 1 hr Ave. ppCO2 [Pa] 3 100 1 hr Ave. ppCO2 [Pa] 3 Cabin Air Dewpoint, Air CabinDewpoint, Min RH 30% 24 hr Ave. ppCO2 [Pa] Air CabinDewpoint, Min RH 33% 24 hr Ave. ppCO2 [Pa] Dewpoint [°C] Dewpoint [°C] 0 0 0 0 0 3 6 9 12 15 18 21 24 0 3 6 9 12 15 18 21 24 Time, hr Time, hr Figure 2. CO2 & Humidity Control of Gateway. On the left, daily CO2 and dewpoint profile for the Gateway habitable volume, with 2 crew members each in Orion and Gateway, and enhanced exercise protocol performed on Gateway. Average CO2 is ~300 Pa (2.3 mmHg) and RH ~39%, and dewpoint is under 15.6 °C (60 °F) limit without any augmented control. On the right, all 4 crew members are on the Gateway with the average CO2 ~320 Pa (2.4 mmHg) and RH ~41%, but the dewpoint exceeds the 15.6 °C (60 °F) limit.

The Orion Trace Contaminant Control System (TCCS) is a consumable-based design that utilizes charcoal media for removal of high molecular weight compounds and an Ambient Temperature Catalyst Oxidizer (ATCO) that removes CO and hydrogen. Passive venting and cabin leakage are utilized to control methane13. The TCCS is designed to maintain trace contaminants below 50% of the 180-day SMAC (Spacecraft Maximum Allowable Contamination) limits based on a load model determined by NASA8. Lockheed Martin performed an analysis utilizing a NASA validated model, TCCS-CP14, and showed that Orion TCCS can maintain trace contaminant levels below the 180-day ½ SMAC limits10 for a 30-day mission at the Gateway plus the 7-day transit and return trips. Furthermore, on the initial habitat launch mission, Orion can provide cleanup of any off-gassing that occurs in the pressurized volume between the final ground purge through crew arrival (8-month timeline assumed), provided that short excursions above required limits are allowed during initial ingress. Analysis showed that most contaminants did not exceed limits or were resolved within 1-2 hours; however, the challenging case proved to be CO removal via the ATCO. CO exceeded the 180-day ½ SMAC limit for 31 hours and the 7-day limit for 3 hours, which requires further evaluation by toxicologists for acceptance. Alternatively, a catalyst could be deployed on the Gateway for off-gassing cleanup prior to opening the hatch after docking. Lockheed Martin analyzed the performance of an ISS-like TCCS on the Gateway, finding that 17 hours of continuous removal would be required before CO would fall below limits and must be accounted for in operations planning. Further analysis and acceptance criteria are required to assess longer uncrewed durations between missions to determine the optimal integrated TCCS solution. Each vehicle’s cabin ventilation and Gateway-provided IMV ensures that the habitable volume air between connected elements is well mixed, avoiding locally higher or lower concentrations of any one breathing gas constituent. Air monitoring is recommended on each module for independent into each element as well as monitoring of the Gateway during uncrewed periods. The minimum parameters to monitor on the Gateway are temperature, pressure and oxygen levels; however, additional monitoring capability such as CO2 and humidity adds system robustness for operations and data trending.

B. Fire Detection and Suppression Fire detection is expected to occur in every habitation volume with active cabin ventilation; and is, therefore, a shared function initially. As the Gateway ECLSS transitions to independent control, it would become the prime provider and smoke detection in Orion will occur via IMV. Fire suppression during crewed periods should be performed with dedicated Gateway portable fire extinguishers15, reserving Orion’s for the return trip. Fire cleanup, including the removal of smoke particulates, carbon monoxide, and combustion gas products, may require the use of dedicated filters (or additional sparing) as a more efficient means than depress/repress as additional elements are added to the Gateway16. Emergency equipment will be provided on the Gateway with the Orion equipment available as a backup. The Orion equipment will not be relocated due to the risk of being left behind in an emergency evacuation to Orion. 5 International Conference on Environmental Systems

C. Pressure Control The Gateway and Orion Partial Pressure O2 and Limits Pressure Control Systems (PCS) 30.0 maintain the vehicle’s habitable volume oxygen partial pressure 27.0 (ppO2) and total pressure within desired set points while also 24.0 ensuring that oxygen concentration

levels do not exceed flammability kPa ppO2, 21.0 limits. The PCS utilizes pressure sensors, a network of control 18.0 valves, and control logic to periodically deliver O2 and N2 from 15.0 high pressure storage systems to 0 3 6 9 12 15 18 21 24 maintain these habitable volume Time, hr pressures. Nominally, these Orion ppO2, kPa Gateway ppO2, kPa systems control habitable volume Normoxic ppO2, kPa Flammability Limit, kPa total pressure between 65.5 and Min Nominal O2 Physiological, kPa Max Nominal O2 Physiological, kPa 103.4 kPa (9.5 and 15.0 psia) and O2 levels above the HSIR defined Figure 3. Combine Orion and Gateway Pressure Control. Daily plot of ppO2 normoxic O2 partial pressure and shows brief (~10 min), periodic excursions outside Orion’s control window for below the O2 flammability nominal physiological limits but quickly within range. concentration of 25.9% total pressure. Orion’s gas storage17 supports a crew of four for 21 days, provides nominal atmospheric makeup from (Orion) cabin leakage, and provides contingency support in the event of a toxic atmosphere or depressurized cabin. The addition of a Gateway volume could be supported for a short duration if the crew quantity is reduced; e.g. Orion could support a 3-crew mission for 15 days integrated and 14 days Orion transit. However, a reduced crew number is undesirable; therefore, the Gateway should provide gas storage and pressure control for all missions. Although likely to reduce Orion contingency reserves, Orion’s PCS could be used, if necessary. An analysis performed by Lockheed Martin showed that Orion could independently control total pressure and ppO2 for both Orion 3 3 and a Gateway habitable volume up to 45 m (1600 ft ), with temporary allowable ppO2 control setpoint exceedances of ~10 minutes. These short excursions outside the control band occur upon O2 injection into Orion, but they do not exceed flammability limits and atmospheric mixing between the volumes quickly disperses the gas to nominal levels as shown in Figure 3.

D. Water Management The Orion Potable Water System (PWS) is an open-loop consumable-based system consisting of pressurized water storage tanks on the (ESM)17 and a redundant distribution system to supply potable water to the water dispenser in the Crew Module (CM). Like gas commodities, the water tanks are sized for 84-crew days and could be used in the event of a contingency, short duration missions, or missions with fewer than 4 crew. Nominally, the Gateway should transition to the primary water provider upon docking to avoid using Orion consumables; however, extra Orion mission capacity could be offloaded to the Gateway by using the external connection on Orion’s water dispenser to fill empty Gateway water containers.

E. Waste Management The Orion Waste Management System (WMS) features a full commode in a private compartment to collect and safely store crew generated urine and fecal waste18. A solid waste collection device with a built-in urine separator allows for simultaneous waste collection in relative crew comfort. Fecal content and disposable wipes are stored in multi-use consumable canisters, while urine is vented from a storage tank multiple times per day19. For off-nominal situations, contingency hoses and bags are used for manual collection. Since early Gateway mission(s) may not be long enough to warrant the overhead associated with preparing such systems for dormancy, Orion can provide the primary WMS initially with the Gateway providing additional canisters and urine-pretreat consumables and accommodating Orion urine venting. Once a WMS is installed on the Gateway, the Orion WMS transitions to redundant capability; therefore, it is recommended the Gateway architecture and control 6 International Conference on Environmental Systems

system support contingency Orion venting. Figure 4 and Figure 5 show potential configurations for avoiding venting contamination.

Direct Direct Venting Venting Cone Cone

Figure 4. Orion and Final Gateway Waste Venting. Figure 5. Orion and Early Gateway Waste Venting. Strategic placement of additional permanent modules in the Orion clocking and strategic use of docking ports while final configuration enables contingency Orion venting crewed avoids venting contamination of PPE without direct contamination of any radially docked arrays and the Human Lander for the early elements. During contingencies, minor droplets occur Gateway. outside the direct cone during startup and shutdown.

III. Conclusion Trade studies and in-depth analysis shows that initially leveraging Orion’s ECLSS provides a realistic and feasible low-cost, low-mass, and flexible solution to a gradual buildup of the Gateway. Integrating Orion ECLSS capabilities into the architecture enables NASA to consider a multitude of early missions and architectures without requiring significant ECLSS capability on the Gateway, providing an adaptable, risk-mitigated approach to shifting objectives, schedules, budgets, and partner contribution plans. As the Gateway builds in capability, continuing to utilize Orion’s capabilities for human-rating redundancy minimizes the cost and complexity of the Gateway, freeing up resources for new systems.

References 1National Aeronautics and Space Administration. Human Exploration and Operations Strategic Principles for Sustainable Exploration, https://www.nasa.gov/sites/default/files/atoms/files/2018_strategic_principles.pdf [cited 17 February 2020]. 2Bowersox, Ken. “NASA Human Exploration and Operations Program Update”. NASA Advisory Council. 31 Oct. 2019. 3K. Timmons, K. Coderre, W. D. Pratt and T. Cichan, “The Orion spacecraft as a key element in a deep space gateway,” 2018 IEEE Aerospace Conference, Big Sky, MT, 2018, pp. 1-12. 4Lehnhardt, Emma, Zavrel, Christopher, Herrmann, Nicole. “Gateway Program Acquisition Strategy Overview”. 70th International Astronautical Congress (IAC), p.2, 21-25 Oct. 2019. 5Anderson, Molly S., and Imelda C. Stambaugh. “Exploring Life Support Architectures for Evolution of Deep Space Human Exploration.” 45th International Conference on Environmental Systems, 2015. 6Anderson, Molly S., Ariel V. Macatangay, Melissa K. McKinley, Miriam J. Sargusingh, Laura A. Shaw, Jay L. Perry, Walter F. Schneider, Nikzad Toomarian, and Robyn L. Gatens. “NASA environmental control and life support technology development and maturation for exploration: 2018 to 2019 overview.”, 49th International Conference on Environmental Systems, Boston, Massachusetts. 2019. 7O’Neill, Jonathan, Bowers, Jason Corallo, Roger, Torres, Miguel A. “Environmental Control and Life Support Module Architecture for Deployment across Deep Space Platforms” 49th International Conference on Environmental Systems, 7-11 July 2019. 8Anderson, Molly S., Ewert, Michael K., Keener, John F. “Life Support Baseline Values and Assumptions Document.” NASA/TP-2015-218570, Rev1. Jan. 2018, pp. 42-50, 54, 68. 9Papale, William, Timothy Nalette, Michael Heldmann, and Jorge Hidalgo. "An Advanced CO2 Removal System Using Regenerable Solid Amines." 46th International Conference on Environmental Systems, 2016. 10CxP 70024, “ Human-Systems Integration Requirements, Revision E”, National Aeronautics and Space Administration, November 19, 2010. 7 International Conference on Environmental Systems

11“International Environmental Control and Life Support System (ECLSS) Interoperability Standards (IECLSSIS) – Draft C” February 2018, URL: https://internationaldeepspacestandards.com/ 12HLS-RQMT-001, “HLS Requirements Document (SRD), Revision B”, National Aeronautics and Space Administration, October 22, 2019. 13Stapleton, Thomas, Michael Heldmann, Miguel Torres, Jonathan O'Neill, Tracy Scott-Parry, Roger Corallo, Kimberly White, and Scott Schneider. "Environmental control and life support system developed for deep space travel." 47th International Conference on Environmental Systems, 2017. 14Perry, J.L. NASA TM-108456. “A User’s Guide to the Trace Contaminant Control Simulation Computer Program.” National Aeronautics and Space Administration Marshall Space Flight Center, April 1994. 15Rodriguez, Branelle R. "Development of the International Space Station (ISS) fine water mist (FWM) portable fire extinguisher." In 43rd International Conference on Environmental Systems, p. 3413. 2013. 16Alptekin, Gokhan, Matthew Cates, Ambalavan Jayaraman, Steve Paglieri, and Andrew Hagen. "An Advanced Smoke-Eater and Ammonia Filter for Post-Fire Cabin Atmosphere Cleanup." 46th International Conference on Environmental Systems, 2016. 17Lamantea, M., Faure, O., Bouckaert, F., “The Orion MPCV-ESM Consumables Storage Subsystem”, 47th International Conference for Environmental Systems, Charleston, South Carolina, 16-20 July 2017. 18Borrego, Melissa Anne, Yadira Garcia Zaruba, James Lee Broyan Jr, Melissa K. McKinley, and Shelley Baccus. "Exploration Toilet Integration Challenges on the International Space Station." 49th International Conference on Environmental Systems, Boston, Massachusetts. 2019. 19D’Souza, C., Zanetti, R., “A First Look at the Navigation Design and Analysis for the Orion Exploration Mission 2” AAS/AIAA Astrodynamics Specialist Conference, Stevenson, WA, August 20-24, 2017.

8 International Conference on Environmental Systems