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Cinda Chullen

Publications and source records attributed to Cinda Chullen.

30 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRSDate not supplied

Rapid Cycle Amine 4.0 System Development

Carbon dioxide (CO2) and humidity control is a key function of the spacesuit Portable Life Support Subsystem (PLSS). The latest spacesuit design utilizes a pressure swing bed containing a solid amine sorbent to scrub CO2 and humidity produced by the crewmember from the ventilation loop. The solid amine sorbent removes CO2 and humidity from the ventilation loop through a chemisorption mechanism. Simultaneously, CO2 and humidity are desorbed to vacuum via the two-bed pressure swing system during operation. This continuous regeneration allows for longer Extravehicular Activity (EVA) times while minimizing maintenance, consumables, and power usage. This concept has been in development for over 20 years, during which many prototypes and design iterations have been fabricated and evaluated. This paper discusses the recent Rapid Cycle Amine (RCA) design, development, and testing that has been done to advance the technology. The most recent fabrication is the RCA 3.0. It was delivered to NASA Johnson Space Center in 2015 and has since been tested at the component level and at the integrated PLSS level. The purpose of the component level testing was to understand CO2 removal capacity, end-of-life performance, and establish a baseline performance prior to integrated testing. The RCA 3.0 was integrated into the Exploration Extravehicular Mobility Unit (xEMU) PLSS for a comprehensive Design Verification Test (DVT) series. The integrated testing provided the benefit of characterizing the impact performance degradation has on the system. Many of the RCA requirements were developed through analysis, based on the limitations of the PLSS and, in some cases, assumptions about the system and flow behavior. Integrated testing was an opportunity to validate those requirements and assumptions. While the RCA 3.0 was being tested, the next design iteration, RCA 4.0, was under development. The RCA 4.0 preliminary design phase began in late-2019 and shortly after the Preliminary Design Review, the critical design phase began in 2021. The design work has concluded with the completion of a Pre-Manufacturing Review in 2022. This paper provides an overview of the RCA 4.0 system design, summarizes the results of integrated RCA 3.0 testing, and discusses the pertinence of driving requirements such as mass, volume, and power consumption.

Kelsey Bloom↗
NASA NTRSDate not supplied

Gas Related Problems Related to Spacesuits

Dr. Jonathan B. Clark is an adjunct Associate Professor of Neurology and Space Medicine at Baylor College of Medicine. From 1997 to 2005, he worked at NASA as a six-time Space Shuttle crew surgeon and was chief of the Medical Operations Branch at the Johnson Space Center. During this event, Dr. Clark discussed the hazards of low oxygen partial pressure (hypoxia) and high CO2 concentration (hypercarbia). This is one event of a medical series delivered to the SKC Program by Dr. Clark. This series focuses on spacesuit medical lessons learned and medical safety aspects of the suit.

Jonathan B. Clark↗
NASA NTRSDate not supplied

Ammonia-Removal Efficiency By Full-Scale Carbon-Based Trace-Contaminant Sorbent Monoliths Integrated With the Rapid-Cycle Amine (RCA) Swing Bed

Results are presented on full-scale performance testing of vacuum-regenerable, carbon based sorbent monoliths for trace-contaminant (TC) removal integrated with the Rapid-Cycle Amine (RCA) swing bed for use in the Portable Life Support System (PLSS) during Extravehicular Activities (EVAs). The current state-of-art in TC-control technology involves the use of a packed bed of acid-impregnated granular charcoal, which is difficult to regenerate. The carbon-based sorbent under development in this project can be regenerated by exposure to vacuum at room temperature. Data on cyclic sorption-desorption of ammonia, which is a major TC of concern, were collected in a simulated PLSS ventilation loop which involved the RCA placed upstream of the Trace Contaminant Control System (TCCS). Results of testing involving pressure-swing operation of the integrated TCCS/RCA system indicate ammonia-removal efficiency exceeding 80% throughout multiple sorption-desorption cycles. This paper presents an overview of the TCCS research, the favorable results obtained, and provides insight into future work needed to further the technology development.

Marek A Wójtowicz↗
NASA NTRSDate not supplied

Advancing xEMU Lunar Dust Mitigation Devices

Fine, electrically charged, glass like dust particles caused significant damage to the Apollo EMU9 during lunar EVAs, identified as one of the greatest challenges to future exploration. Passive Lunar Dust Mitigation Devices (LDMD) were developed, within a SBIR Phase II, to prohibit this dust from interrupting venting space suit component operation. A Computational Fluid-Dynamics and Discrete Element Method (CFD-DEM) Simulation Tool was developed at the University of Colorado, Boulder to predict venting gas flow ability to self-clean adhered dust particles from LDMD surfaces. Lunar dust properties (i.e., adhesion and cohesion strengths) required to complete Simulation Tool analysis are relatively unknown due to considerable differences between the Earth and the Moon (i.e., gravity, humidity) and due to an absence of dust particles in their native state. Analytically determining gas flow velocity, density and direction within the fluid Boundary Layer, microns from LDMD surfaces presented a second challenge. Dusty Plasma Chamber testing is being performed at Auburn University, Auburn to observe electrostatically charged dust behavior as it adheres to LDMD prototypes and specific geometry and is then blown away by metered gas flow. Test articles were developed to offer insight into the impact of different flow geometries, surface roughness and dust removal within the gas Boundary-Layer. Observed dust behavior is currently being developed to support the CFD-DEM analysis. Many Simulation Tool analytical cases have been processed to support the intention of completing sensitivity studies to assess how different dust adherence values and Boundary Layer fluid properties impact LDMD self-cleaning effectivity.

Thomas J Stapleton↗
NASA NTRSDate not supplied

Trace Contaminant Control Test Bed for Evaluation of TCC Prototypes with Vacuum Regenerable and Non-Regenerable Sorbents

A new Space Suit Exploration Portable Life Support System (xPLSS) is being designed, built, integrated, and tested into the Extra-Vehicular Mobility Unit (xEMU). The Trace Contaminant Control (TCC) system is a component in the oxygen ventilation loop of xPLSS that removes contaminants generated by the crewmembers’ metabolic processes. The primary trace contaminants that must be removed include ammonia (NH3), carbon monoxide (CO), formaldehyde (CH2O), and methyl mercaptan (CH3SH). The current state-of-the-art TCC sorbent is non-regenerable activated carbon. As a non-regenerable sorbent, its use negatively impacts the logistics for future missions. Thus, an ideal solution can be a vacuum-regenerable sorbent integrated with the xPLSS CO2/H2O removal system. To test new designs and sorbents, XploSafe has constructed a recirculating test bed that mimics the environment within the xPLSS by providing concentrations of the trace contaminant analytes generated at the operating temperature, humidity, pressure, and flow rates of the xPLSS. This system can perform regeneration or desorption by exposing the sorbent to a pressure swing from 4.3 psia to <1 torr over approximately 2 minutes. Using this test system, XploSafe evaluated various TCC prototypes constructed using rapid prototyping techniques and identified a process that allows vacuum regenerative TCC designs to be quickly examined for flow, pressure drop, and performance. By using toluene as a segregate for volatile organics, this test system was evaluated using both vacuum regenerable and non-regenerable sorbents to demonstrate the operational effectiveness of these sorbents in maintaining the concentrations of the trace contaminant analytes below the 7-day Spacecraft Maximum Allowable Concentrations.

Nicholas Materer↗
NASA NTRSDate not supplied

NASA Extravehicular Activity Technology Roadmaps for Exploration

The National Aeronautics and Space Administration (NASA) has developed and matured many technologies over the decades to advance extravehicular activity (EVA) systems. Over the last 15 years, major steps were taken to advance the technology with the Exploration Extravehicular Mobility Unit (xEMU) government reference design at the Johnson Space Center (JSC) in Houston, Texas. The xEMU builds on the lessons learned of the Apollo, Space Shuttle, and International Space Station (ISS) EMUs, evolving the technology to increase performance for extreme environments. As NASA sets its goals toward Earth’s Moon and Mars, a spacesuit design tolerable of gravity and dust will be needed for these adverse environments. NASA has used roadmaps as the means of documenting actionable plans for strategizing technology developments needed to meet NASA’s mission and goals. To help reach and create a sustained presence on the Moon, NASA procured EVA services from industry through the Exploration EVA Services (xEVAS) contract. These services include certified contractor-provided spacesuits, tools, equipment, vehicle interfaces, and support to training and real-time operations. NASA will now focus on a mission to Mars. NASA leadership has set goals and objectives related to the Agency’s vision and a Moon to Mars (M2M) strategy. This paper presents an organizational framework to provide insight into how NASA’s vision is realized. Additionally, this paper covers the maturation and development of the spacesuit technology and reveals the EVA technology roadmaps for the M2M Program. These EVA roadmaps visualize an actionable path to EVA capabilities needed for Mars exploration.

Cinda Chullen↗
NASA NTRSDate not supplied

Transitioning Sixty Years of NASA Spacesuit Knowledge Capture Lessons Learned to Searchable Knowledge Transfer Databases

Sixty years of spacesuit knowledge capture and lessons learned by spacesuit subject matter experts are documented on videos and presentations and archived with the NASA Engineering and Safety Center (NESC) Academy. The NESC Academy is a web-based platform that hosts online courses by technical experts. A process is underway to transition these decades of lessons learned from the U.S. Spacesuit Knowledge Capture Program Library into more quicky searchable databases and to proactively provide this information to those working on spacesuit projects. Hundreds of lessons learned from Project Mercury, Gemini, Apollo, Apollo- Soyuz Test Project, Skylab, Space Shuttle, International Space Station, and Artemis have been captured in a format that can be quickly searched, enabling users to find information directly applicable to their needs. Transitioning this information to a NASA wiki page will further enhance search and retrieval of data immediately useful to users. This paper provides information about how the lessons learned were determined and how to access them.

spacesuit↗
NASA NTRSDate not supplied

Exploring the Moon: Preserving the Legacy Through Spacesuit Knowledge Capture and Strategic Communication

NASA is returning to the Moon to stay. To establish a sustained lunar presence, astronauts will pack spacesuits, surface-mobility tools, rovers, and decades’ worth of knowledge. The U.S. Spacesuit Knowledge Capture (SKC) and Strategic Communications (Strat Comm) team is specialized in capturing, preserving, and sharing space-related knowledge with NASA scientists, technicians, engineers, vendors, and the public to support space exploration. Since the SKC Program’s 2007 inception, its focus has been to capture and share valuable spacesuit-related knowledge with the NASA community. As the program evolved, its notoriety, funding, scope, and staffing expanded from a one-person, part-time, unfunded operation to a small-team, funded entity. Currently, this team has been formulated with a diverse skillset to meet the requirements of its stakeholders. The SKC and Strat Comm team has used its skills to produce over 260 recorded knowledge captures of subject-matter experts (SMEs) and photoshoots. These knowledge captures are in the form of photographs, lectures, workshops, vignettes, videos, and interviews containing essential space-related knowledge. To help educate the space community and public, this trove of information (e.g., videos of world-class facilities, photographs, and SME lectures), produced inside NASA Johnson Space Center, can be obtained through various sources. During Fiscal Year 2024, the SKC and Strat Comm team will focus on several initiatives. Examples of initiatives include the following: 1) share lessons learned during NASA’s internal venues such as Safety & Health Day and Day of Remembrance; 2) share knowledge with the public, educators, and students through a media production titled Exploring the Moon; and 3) highlight NASA’s unique capabilities and expertise in a video series titled What’s Behind This Door? This paper discusses the team's approach, unique capture capability, initiatives, and much more.

Cinda Chullen↗
NASA NTRSDate not supplied

NASA Extravehicular Activity Technology Roadmaps for Exploration

The National Aeronautics and Space Administration (NASA) has developed and matured many technologies over the decades to advance extravehicular activity (EVA) systems. Over the last 15 years, major steps were taken to advance the technology with the Exploration Extravehicular Mobility Unit (xEMU) government reference design at the Johnson Space Center (JSC) in Houston, Texas. The xEMU builds on the lessons learned of the Apollo, Space Shuttle, and International Space Station (ISS) EMUs, evolving the technology to increase performance for extreme environments. As NASA sets its goals toward Earth’s Moon and Mars, a spacesuit design tolerable of gravity and dust will be needed for these adverse environments. NASA has used roadmaps as the means of documenting actionable plans for strategizing technology developments needed to meet NASA’s mission and goals. To help reach and create a sustained presence on the Moon, NASA procured EVA services from industry through the Exploration EVA Services (xEVAS) contract. These services include certified contractor-provided spacesuits, tools, equipment, vehicle interfaces, and support to training and real-time operations. NASA will now focus on a mission to Mars. NASA leadership has set goals and objectives related to the Agency’s vision and a Moon to Mars (M2M) strategy. This paper presents an organizational framework to provide insight into how NASA’s vision is realized. Additionally, this paper covers the maturation and development of the spacesuit technology and reveals the EVA technology roadmaps for the M2M Program. These EVA roadmaps visualize an actionable path to EVA capabilities needed for Mars exploration.

Cinda Chullen↗
NASA NTRSDate not supplied

NASA's Development of Advanced Space Suits for Lunar Exploration

Significant work has been completed recently at NASA’s Johnson Space Center in the Space Suit and Crew Survival Systems Branch to design and mature an advanced exploration EVA (Extra-Vehicular Activity) architecture. This effort culminated in the xEMU (eXploration Extra-vehicular Mobility Unit) space suit, which was completed in 2022 and tested extensively through 2023, including human performance, cycle life performance and thermal vacuum testing. An overview of the xEMU design and test campaign is provided, as well as its value as the government reference design supporting the transition to EVA commercial services for the Artemis program. Lastly, a development roadmap is discussed which outlines NASA’s identified strategy to enable the next generation of exploration EVA hardware for sustaining-class Lunar and Mars missions.

Shane M McFarland↗
NASA NTRSDate not supplied

Extravehicular Activity (EVA) Roadmaps Pressure Garment System (PGS)

As NASA focuses on the Moon to Mars (M2M) efforts, an environment-tolerable spacesuit design will be needed. NASA has traditionally used Roadmaps to strategize technology development and lay the foundation for the Exploration EMU (xEMU) spacesuit prototype. The Roadmaps visualize an actionable plan to realize EVA capabilities needed for Mars exploration.

Cinda Chullen↗