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This paper documents the progress of a conceptual packaging design effort for a Portable Life Support Subsystem (PLSS). The concept discussed is a flexible backpack intended for use on the Constellation Program (CxP) lunar suit, also known as the Constellation Space Suit Element (CSSE). The goal of this effort is to reduce the weight of the PLSS packaging while also meeting CxP goals to develop systems that are less costly, more adaptable to mission and technology changes, and have more performance capability than that of existing systems or previous lunar systems. This flexible backpack concept relies on a foam protection system to absorb, distribute, and dissipate the energy from falls on the lunar surface. The testing and analysis of the foam protection system concept that took place during this effort indicate that this method of system packaging is a viable solution.

This paper discusses the Portable Life Support Subsystem (PLSS) packaging design work done by the NASA and Hamilton Sundstrand in support of the 3 future space missions; Lunar, Mars and zero-g. The goal is to seek ways to reduce the weight of PLSS packaging, and at the same time, develop a packaging scheme that would make PLSS technology changes less costly than the current packaging methods. This study builds on the results of NASA's in-house 1998 study, which resulted in the “Flex PLSS” concept. For this study the present EMU schematic (low earth orbit) was used so that the work team could concentrate on the packaging. The Flex PLSS packaging is required to: protect, connect, and hold the PLSS and its components together internally and externally while providing access to PLSS components internally for maintenance and for technology change without extensive redesign impact. The goal of this study was two fold: 1.

Future National Aeronautics and Space Administration (NASA)-planned missions set stringent demands on the design of the Portable Life Support Systems (PLSS), requiring dramatic reductions in weight, decreased reliance on supplies and greater flexibility on the types of missions. Use of regenerable systems that reduce weight and volume of the Extravehicular Mobility Unit (EMU) is of critical importance to NASA, both for low orbit operations and for long duration manned missions. TDA Research, Inc. (TDA) is developing a high capacity, rapid cycling sorbent to control CO2 and humidity in the space suit ventilation loop. The sorbent can be regenerated using space vacuum during the EVA, eliminating all duration-limiting elements in the life support system. This paper summarizes the results of the sorbent development and testing, and evaluation efforts.

Metabolically produced carbon dioxide (CO2) removal in spacesuit applications has traditionally been accomplished utilizing non-regenerative Lithium Hydroxide (LiOH) canisters. In recent years, regenerative Metal Oxide (MetOx) has been developed to replace the Extravehicular Mobility Unity (EMU) LiOH canister for extravehicular activity (EVA) missions in micro-gravity, however, MetOx may carry a significant weight burden for potential use in future Lunar or planetary EVA exploration missions. Additionally, both of these methods of CO2 removal have a finite capacity sized for the particular mission profile. Metabolically produced water vapor removal in spacesuits has historically been accomplished by a condensing heat exchanger within the ventilation process loop of the suit life support system.

Technology developers understand the need to optimize technologies for human missions beyond Earth. Greater benefits are achievable when systems that share common interfaces are optimized as an integrated unit, including taking advantage of possible synergies or removing counterproductive efforts at the mission level. Life support, extravehicular activity (EVA), and habitability are three systems that have significant interfaces with the crew, and thus share many common interfaces with each other. Technologies and architectures developed for these systems need to account for the effect that design decisions will have on each of the other systems. Many of these impacts stem from the use of water by the crew and the way that the life support system provides and processes that water. Other resources, especially air-related, can have significant impacts as well.

NASA JSC has contracted with Hamilton Standard Space Systems International (HSSSI) to develop a combined CO2/H2O removal system for an advanced space suit. This system will operate with a novel solid amine sorbent that has demonstrated a large increase in capacity over previous solid amine sorbents. The concept will use two beds of the sorbent operating on a pressure swing removal process. This paper discusses the design, fabrication and testing of this prototype system. The overall system design consists of two sorbent beds, a spool valve for directing vacuum and process air, and a controller to monitor the overall process and switch the spool valve at the appropriate time. We will include a discussion of the quick-cast process used in the fabrication of major system components. Finally, we will present the results of testing the full-scale prototype at HSSSI, and its ability to remove CO2/H2O and be regenerated continuously.