Robyn L. Carrasquillo

Status of the Node 3 Regenerative ECLSS Water Recovery and Oxygen Generation Systems

NASAs Marshall Space Flight Center is providing three racks containing regenerative water recovery and oxygen generation systems (WRS and OGS) for flight on the International Space Stations (ISS) Node 3 element. The major assemblies included in these racks are the Water Processor Assembly (WPA), Urine Processor Assembly (UPA), Oxygen Generation Assembly (OGA), and the Power Supply Module (PSM) supporting the OGA. The WPA and OGA are provided by Hamilton Sundstrand Space Systems International (HSSSI), while the UPA and PSM are being designed and manufactured in-house by MSFC. The assemblies are completing the manufacturing phase and are in various stages of ORU and system level testing, to be followed by integration into the flight racks. This paper gives a current status, along with technical challenges encountered and lessons learned.

Trade Spaces in Crewed Spacecraft Atmosphere Revitalization System Development

Developing the technological response to realizing an efficient atmosphere revitalization system for future crewed spacecraft and space habitats requires identifying and describing functional trade spaces. Mission concepts and requirements dictate the necessary functions; however, the combination and sequence of those functions possess significant flexibility. Us-ing a closed loop environmental control and life support (ECLS) system architecture as a starting basis, a functional unit operations approach is developed to identify trade spaces. Generalized technological responses to each trade space are discussed. Key performance parameters that apply to functional areas are described.

Sabatier Methanation Reactor for Space Exploration

The Sabatier Methanation Reactor technology is of vital importance to the success of the human and robotic exploration program. In order to achieve an affordable program, the logistics supply to support the mission must be minimized to the fullest extent possible. One area of potential reduction with high return on investment is the closure of life support loops, particularly oxygen and water. The Sabatier system accomplishes this by utilizing hydrogen and carbon dioxide, waste products from the life support system, to produce water and methane. The recovered water is then recycled back into the life support system to provide oxygen; while the methane can be used for propulsion, or can be broken down further to recover the hydrogen. This technology is applicable not only to transit phases of exploration, but surface habitats as well as in-situ propellant production. The Sabatier Reactor system has been developed for ground based demonstration experiments extensively over the past 30 years. Over the past three years, NASA has funded development of the Sabatier Carbon Dioxide Reduction Assembly (CRA) for use on the ISS. Currently this system is at TRL 5 and it is expected that the system will be flown on the ISS as a flight experiment, The purpose of the flight experiment is to integrate the Sabatier CRA into a synchronized system with the oxygen generation system and the carbon dioxide concentrator. The flight experiment will verify the integration of the different systems working together plus it will verify the capability of the system to operate, and effectively separate its products in a micro-gravity environment. Subsequent to design validation, the flight experiment can remain onboard the ISS providing valuable water to offset logistics re-supply requirements. Some of the challenges facing the development of the Sabatier system include handling vibration induced particulates, microgravity phase separation and containment of hazardous gases. Plans for adequately addressing these issues will be presented. The Sabatier carbon dioxide reduction process will greatly benefit any of the extended duration human exploration missions because of the tremendous savings of consumables realized. Any of these mission scenarios, be they transit or surface based, must consider closing the life support loops in order to make the mission achievable, let alone affordable. Carbon dioxide reduction technology will be necessary for future outpost habitats, and the technology needs to be proven viable in a space application. The Sabatier methanation reaction is also a desirable method for producing propellant from the Mars atmosphere. The common system could be designed to accept carbon dioxide from an indoor air revitalization loop concentrator, or from an outdoor atmosphere compressor. Carbon dioxide reduction validation is but one step in the spiral development of the in-situ propellant production system desired for future planetary exploration.

National Aeronautics and Space Administration (NASA) Environmental Control and Life Support (ECLS) Integrated Roadmap Development

At present, NASA has considered a number of future human space exploration mission concepts . Yet, detailed mission requirements and vehicle architectures remain mostly undefined, making technology investment strategies difficult to develop and sustain without a top-level roadmap to serve as a guide. This paper documents a roadmap for development of Environmental Control and Life Support Systems (ECLSS) capabilities required to enhance the long-term operation of the International Space Station (ISS) as well as enable beyond-Low Earth Orbit (LEO) human exploration missions. Three generic mission types were defined to serve as a basis for developing a prioritized list of needed capabilities and technologies. Those are 1) a short duration micro gravity mission; 2) a long duration transit microgravity mission; and 3) a long duration surface exploration mission. To organize the effort, ECLSS was categorized into three major functional groups (atmosphere, water, and solid waste management) with each broken down into sub-functions. The ability of existing state-of-the-art (SOA) technologies to meet the functional needs of each of the three mission types was then assessed by NASA subject matter experts. When SOA capabilities were deemed to fall short of meeting the needs of one or more mission types, those gaps were prioritized in terms of whether or not the corresponding capabilities enable or enhance each of the mission types. The result was a list of enabling and enhancing capabilities needs that can be used to guide future ECLSS development, as well as a list of existing hardware that is ready to go for exploration-class missions. A strategy to fulfill those needs over time was then developed in the form of a roadmap. Through execution of this roadmap, the hardware and technologies intended to meet exploration needs will, in many cases, directly benefit the ISS operational capability, benefit the Multi-Purpose Crew Vehicle (MPCV), and guide long-term technology investments for longer duration missions The final product of this paper is an agreed-to ECLSS roadmap detailing ground and flight testing to support the three mission scenarios previously mentioned. This information will also be used to develop the integrated NASA budget submit in January 2012.

Maturity of the Bosch CO2 reduction technology for Space Station application

The Bosch process, which catalytically reduces CO2 with H2 to solid carbon and water, is a promising technique for the reduction of the CO2 removed from the Space Station atmosphere and the subsequent water formation for O2 recovery. A Bosch engineering subsystem prototype CO2 reduction unit was developed to demonstrate the feasibility of the Bosch process as a viable technology for Space Station application. A man-rated prototype unit is then described as part of the ECLSS Technology Demonstrator Program. The goal was to develop a Bosch subsystem that not only meets the performance requirements of two 60 person-day carbon cartridge capacities, but also satisfies inherent man-rated requirements such as offgassing characteristics, fail-safe operation, and ease of maintainability. It is concluded that the technology is at a state of maturity directly applicable to flight status for the NASA Space Station program.

The Space Station Air Revitalization Subsystem Design Concept

The current status of the Space Station (SS) Environmental Control and Life Support System (ECLSS) Air Revitalization Subsystem (ARS) design is outlined. ARS performance requirements are provided, along with subsystem options for each ARS function and selected evaluations of the relative merits of each subsystem. Detailed computer models that have been developed to analyze individual subsystem performance capabilities are also discussed. A summary of ARS subsystem level testing planned and completed by NASA Marshall Space Flight Center (MSFC) is given.

Evolution of the Baseline ISS ECLSS Technologies-The Next Logical Steps

The baseline Environmental Control and Life Support Systems which are currently deployed on the International Space Station or planned to be launched in Node 3 are based on technologies selected in the early 1990s. While they are generally meeting or exceeding requirements for supporting the ISS crew, lessons learned from years of on orbit and ground testing, new advances in technology state of the art, and requirements for future manned missions prompt consideration of the next logical step to enhance these systems to increase performance, robustness, reliability, and reduce on-orbit and logistical resource requirements. This paper discusses the current state of the art in ISS ECLSS technologies, and possible areas for enhancement/improvement. Potential utilization of the ISS as a testbed for on-orbit checkout of selected technology improvements is also addressed.

ECLSS Design for the International Space Station Nodes 2 and 3

The International Space Station (ISS) modules Nodes 2 and 3 are currently under development by Alenia Spazio and the Marshall Space Flight Center (MSFC). The design of the Environmental Control and Life Support Systems (ECLSS) for these two modules have some similarities but many differences. The Node 2 ECLSS provides inter- and intramodule ventilation, temperature and humidity control, fire detection and suppression, and distribution of atmosphere samples, low pressure and recharge oxygen and nitrogen, fuel cell water and wastewater. Design Review 1 was held in March 1998. Fabrication of the ducting, tubing, and support structure is ongoing with Design Review 2 planned for December 1999. In addition to providing the same functions as Node 2, the ECLSS for Node 3 includes carbon dioxide removal, trace contaminant control, atmosphere monitoring, atmosphere pressure control, oxygen generation, urine and potable water processing, waste management, and potable water distribution to support the habitability functions relocated from the U.S. Hab module. Scarring for future incorporation of carbon dioxide reduction is also included. Design Review 1 is planned for July 1999. An overview of each Nodes system design as well as issues and challenges are discussed.

Environmental Control and Life Support (ECLS) Hardware Commonality for Exploration Vehicles

In August 2011, the Environmental Control and Life Support Systems (ECLSS) technical community, along with associated stakeholders, held a workshop to review NASA s plans for Exploration missions and vehicles with two objectives: revisit the Exploration Atmospheres Working Group (EAWG) findings from 2006, and discuss preliminary ECLSS architecture concepts and technology choices for Exploration vehicles, identifying areas for potential common hardware or technologies to be utilized. Key considerations for selection of vehicle design total pressure and percent oxygen include operational concepts for extravehicular activity (EVA) and prebreathe protocols, materials flammability, and controllability within pressure and oxygen ranges. New data for these areas since the 2006 study were presented and discussed, and the community reached consensus on conclusions and recommendations for target design pressures for each Exploration vehicle concept. For the commonality study, the workshop identified many areas of potential commonality across the Exploration vehicles as well as with heritage International Space Station (ISS) and Shuttle hardware. Of the 36 ECLSS functions reviewed, 16 were considered to have strong potential for commonality, 13 were considered to have some potential commonality, and 7 were considered to have limited potential for commonality due to unique requirements or lack of sufficient heritage hardware. These findings, which will be utilized in architecture studies and budget exercises going forward, are presented in detail.

Atmosphere Revitalization Technology Development for Crewed Space Exploration

As space exploration objectives extend human presence beyond low Earth orbit, the solutions to technological challenges presented by supporting human life in the hostile space environment must build upon experience gained during past and present crewed space exploration programs. These programs and the cabin atmosphere revitalization process technologies and systems developed for them represent the National Aeronautics and Space Administration’s (NASA) past and present operational knowledge base for maintaining a safe, comfortable environment for the crew. The contributions of these programs to the NASA’s technological and operational working knowledge base as well as key strengths and weaknesses to be overcome are discussed. Areas for technological development to address challenges inherent with the Vision for Space Exploration (VSE) are presented and a plan for their development employing unit operations principles is summarized. I. Introduction VER the course of the United States’ space exploration program, the National Aeronautics and Space Administration (NASA) has developed and operated a variety of environmental control and life support (ECLS) systems to achieve a range of space exploration objectives. Beginning with Project Mercury and continuing through the International Space Station (ISS) program, the technological solutions to safely support human life in the hostile space environment have evolved from those required to support a single astronaut for minutes or hours to those supporting for crews of three or more for months and ultimately years. The Vision for Space Exploration (VSE) presents new challenges and performance standards that build on and extend the NASA’s experience and working knowledge of ECLS systems. Objectives specified by the VSE are the following: 1