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Hypothermia is a well documented problem for surgical patients and is historically addressed by the use of a variety of warming aids and devices applied to the patient before, during, and after surgery. Their effectiveness is limited in many surgeries by practical constraints of surgical access, and hypothermia remains a significant concern. Increasing the temperature of the operating room has been proposed as an alternative solution. However, operating room temperatures must be cool enough to limit thermal stress on the surgical team despite the heat transport barriers imposed by protective sterile garments. Space technology in the form of the liquid cooling garment worn by EVA astronauts answers this need. Hamilton Sundstrand Space Systems International (HSSSI) has been working with Hartford Hospital to adapt liquid cooling garment technology for use by surgical teams in order to allow them to work comfortably in warmer operating room environments.

The demands of future NASA exploration and scientific missions in space force the reevaluation of some of the basic assumptions and approaches that underlie current extravehicular activity (EVA) systems. Developing designs that can simultaneously achieve the advanced capabilities and the reductions in system mass and mission expendables targeted by NASA has proven to be a formidable challenge. The constraints of human needs, space environments, and current EVA system architectures demand technical capabilities beyond current expectations to achieve system goals. Under NASA Institute for Advanced Concepts (NIAC) sponsorship, Hamilton Sundstrand has been studying a new system paradigm to achieve the EVA system goals. The Chameleon Suit concept employs an active pressure suit that directly interacts between human systems and space environments.

Catalytic oxidation is an effective means of controlling the build up of ammonia and other trace gas contaminants within closed spaces. However, it sometimes leads to the formation of noxious gases that need to be removed in post-treatment systems. In addition, ammonia removal is an issue when regeneration of water from wastewater is considered since ammonia is a byproduct of urea decomposition. For example, the VPCAR (Vapor Phase Catalytic Ammonia Reduction) advanced water processor system includes an oxidation reactor for the destruction of ammonia and of other volatile organics that are not separated out in the evaporator due to their volatility. The oxidation of ammonia may produce nitrogen, nitrogen oxides (NO and NO2), nitrous oxide (N2O) and water vapor. The Spacecraft Maximum Allowable Concentration (SMAC) for NO and NO2 are respectively 4.5 and 0.5 ppm whereas the Threshold Limit Value (TLV) for N2O is 25 ppm.

The purification of waste water is a critical element of any long-duration space mission. The Vapor Phase Catalytic Ammonia Removal (VPCAR) system offers the promise of a technology requiring low quantities of expendable material that is suitable for exploration missions. NASA has funded an effort to produce an engineering development unit specifically targeted for integration into the NASA Johnson Space Center's Integrated Human Exploration Mission Simulation Facility (INTEGRITY) formally known in part as the Bioregenerative Planetary Life Support Test Complex (Bio-Plex) and the Advanced Water Recovery System Development Facility. The system includes a Wiped-Film Rotating-Disk (WFRD) evaporator redesigned with micro-gravity operation enhancements, which evaporates wastewater and produces water vapor with only volatile components as contaminants. Volatile contaminants, including organics and ammonia, are oxidized in a catalytic reactor while they are in the vapor phase.

The Conductivity Sensor designed for use in the Node 3 Water Processor Assembly (WPA) was based on the existing Space Shuttle application for the fuel cell water system. However, engineering analysis has determined that this sensor design is potentially sensitive to two- phase fluid flow (gas/liquid) in microgravity. The source for this sensitivity is the fact that free gas will become lodged between the sensor probe and the wall of the housing without the aid of buoyancy in 1-g. Once gas becomes lodged in the housing, the measured conductivity will be offset based on the volume of occluded gas. A development conductivity sensor was flown on the NASA Microgravity Plane (KC-135) to measure the offset, which was determined to range between 0 and 50%. This range approximates the offset experienced in 1-g gas sensitivity testing.

Hamilton Sundstrand Space Systems International, Inc. (HSSSI) is under contract to NASA Marshall Space Flight Center (MSFC) to develop a Water Processor Assembly (WPA) and Oxygen Generation Assembly (OGA) for the international Space Station (ISS). The WPA produces potable quality water from humidity condensate, carbon dioxide reduction water, water obtained from fuel cells, reclaimed urine distillate, hand wash and oral hygiene waste waters. The Oxygen Generation Assembly (OGA) electrolyzes potable water from the Water Recovery System (WRS) to provide gaseous oxygen to the Space Station module atmosphere. The OGA produces oxygen for metabolic consumption by crew and biological specimens. The OGA also replenishes oxygen lost by experiment ingestion, airlock depressurization, CO2 venting, and leakage. As a byproduct, gaseous hydrogen is generated. The hydrogen will be supplied at a specified pressure range to support future utilization.

Hamilton Sundstrand Space Systems International, Inc. (HSSSI) is under contract to NASA Marshall Space Flight Center (MSFC) to develop a Water Processor Assembly (WPA) and Oxygen Generation Assembly (OGA) for the International Space Station (ISS). The WPA produces potable quality water from humidity condensate, carbon dioxide reduction water, water obtained from fuel cells, reclaimed urine distillate, shower, handwash and oral hygiene waste waters. The Oxygen Generation Assembly (OGA) electrolyzes potable water from the Water Recovery System (WRS) to provide gaseous oxygen to the Space Station module atmosphere. The OGA produces oxygen for metabolic consumption by crew and biological specimens. The OGA also replenishes oxygen lost by experiment ingestion, airlock depressurization, CO2 venting, and leakage. As a byproduct, gaseous hydrogen is generated. The hydrogen will be supplied at a specified pressure range to support future utilization.

The Water Processor developed for the International Space Station includes a high temperature catalytic reactor that utilizes oxygen gas to oxidize dissolved chemicals. The effluent from the reactor is a mixture of gases (O2, CO2, N2) and hot water. Since the crew has requested that drinking water does not contain any free gas at body temperature (37.8 °C or 100 °F), a phase separator operating at elevated temperatures is required downstream of the catalytic reactor. For this application, Hamilton Sundstrand Space Systems International (HSSSI) has developed a passive Gas Liquid Separator (GLS) that relies on a positive barrier - a membrane - to extract the free gas from the inlet two-phase mixture. The membrane selected is a hollow fiber hydrophobic asymmetric membrane with pore size in the ultra-filtration range. This paper outlines the challenges in both design and operation that were overcome during the development of this device.

A Low Pressure Electrolyzer (LPE) is being developed to provide metabolic oxygen aboard US nuclear submarines. The system is derived from a more complex system already developed for the Virginia Class of attack submarines. The LPE generates up to 250 standard cubic feet per hour (SCFH) of oxygen at ambient pressure through electrolysis of water utilizing SPE® (Solid Polymer Electrolyte) technology. The hydrogen is generated at pressures suitable for disposal overboard. The system operates unattended which minimizes crew workload, and can safely shut down without crew intervention. Generating oxygen at ambient pressure significantly reduces risk to personnel and greatly simplifies the system. Reliability, maintainability, safety, and ease of operation are major system design drivers.

Designing an EVA system for Mars’s exploration will require a thorough understanding of the mission. Data are available from NASA mission studies, preliminary EVA requirements document, and Apollo program experience. However, additional relevant field experience is required to complete the picture. NASA has addressed this through field tests using prototype EVA equipment and field science programs like the Haughton Mars Project on Devon Island. There, a group of scientists conducts scientific exploration in and around an impact crater in a polar desert similar to expected exploration sites on Mars. Hamilton Sundstrand Space Systems Intl. (HSSSI) EVA system engineers participated in the summer 2000 field research program to gain firsthand knowledge of field science activities. By using a Mars EVA system mockup, they were also able to conduct experiments on EVA system impacts on field science tasks. This field experience and some of its results are described in this paper.

Enhancements to the Regenerable Carbon Dioxide Removal System (RCRS) have undergone full-scale, pre-prototype development and testing to demonstrate a redundant system within the volume allotted for the RCRS on the Space Shuttle Orbiter. The concept for a Redundant Regenerable Carbon Dioxide Removal System (RRCRS) utilizes the existing canister of the RCRS, but partitions it into two, independent, two-bed systems. This partitioning allows for two, fully capable RCRS units to be packaged within the original volume, thus reducing stowage volume and launch weight when compared to the flight RCRS plus the backup LiOH system. This paper presents the results of development and testing of a full-scale, pre-prototype RRCRS and includes an overview of the design concept for a redundant system that can be packaged within the existing envelope.

The TIMES system was evaluated to determine its ability to process reverse osmosis (RO) brine as one of the Advanced Water Processor steps. Since preliminary testing performed in 1998 showed that the membrane typically used in the process (Nafion 117) offered a very poor ammonia rejection, a search for an alternate membrane exhibiting high ammonia rejection capability was initiated under NASA-JSC funding. This investigation has resulted in the selection of a PolyVinylAlcohol (PVA) composite membrane as a replacement. When processing RO brine and untreated human urine as feeds, the Pervap 2201 membrane showed a 96% ammonia rejection over a large range of ammonia concentration. The water permeation rates in both laboratory-scale and pilot scale testings were also similar to the Nafion. The water permeance of the Pervap 2201 was approximately 7.5 kg/h/m2/atm (1.1 lb/h/m2/psi).

Carbon dioxide reduction in a closed loop life support system recovers water from otherwise waste carbon dioxide and hydrogen. Incorporation of a carbon dioxide reduction assembly (CRA) into the International Space Station life support system frees up thousands of pounds of payload capacity in the supporting Space Shuttle that would otherwise be required to transport water. Achievement of this water recovery goal requires coordination of the CRA design to work within the existing framework of the interface systems that are either already on orbit or well advanced in their development; namely, the Oxygen Generator Assembly (OGA), Carbon Dioxide Removal Assembly (CDRA) and Water Processor Assembly (WPA). The Oxygen Generation System (OGS) rack is in its final design phase and is scarred to accept later installation of the CRA.

Hamilton Sundstrand Space Systems International (HSSSI) is currently under contract with NASA MSFC to design, fabricate and deliver the Water Processor Assembly (WPA) for the International Space Station (ISS). As part of this effort HSSSI has developed an oxidation catalyst for the catalytic reactor assembly in the WPA. This paper discusses full-scale development reactor testing and the status of the life testing of the oxidation catalyst used in the reactor.

Hamilton Sundstrand Space Systems International, Inc. (HSSSI) is under contract to NASA Marshall Space Flight Center (MSFC) to develop a Water Processor Assembly (WPA) for the International Space Station (ISS). The WPA produces potable quality water from humidity condensate, carbon dioxide reduction water, water obtained from fuel cells, reclaimed urine distillate, shower, handwash and oral hygiene wastewaters. All planned development testing has been completed and this paper provides the status of the development activities and results for the WPA.

Pyrolysis processing is one of several options for solid waste resource recovery in space. It has the advantage of being relatively simple and adaptable to a wide variety of feedstocks and it can produce several usable products from typical waste streams. The overall objective of this study was to produce a prototype mixed solid waste pyrolyzer for spacecraft applications. A two-stage reactor system was developed which can process a maximum of about 0.5 kg of waste per cycle. The reactor includes a pyrolysis chamber where the waste is heated to temperatures above 600 °C for primary pyrolysis. The volatile products (liquids, gases) are transported by a N2 purge gas to a second chamber which contains a catalyst bed for cracking the tars at temperatures of about 1000-1100 °C. The tars are cracked into carbon and additional gases. Most of the deposited carbon is subsequently gasified by oxygenated volatiles (CO2, H2O) from the first stage.

This project is a Phase III SBIR contract between NASA and Water Reuse Technology (WRT). It covers the redesign, modification, and construction of the Wiped-Film Rotating-Disk (WFRD) evaporator for use in microgravity and its integration into a Vapor Phase Catalytic Ammonia Removal (VPCAR) system. VPCAR is a water processor technology for long duration space exploration applications. The system is designed as an engineering development unit specifically aimed at being integrated into NASA Johnson Space Center's Bioregenerative Planetary Life Support Test Complex (BIO-Plex). The WFRD evaporator and the compressor are being designed and built by WRT. The balance of the VPCAR system and the integrated package are being designed and built by Hamilton Sundstrand Space Systems International, Inc. (HSSSI) under a subcontract with WRT. This paper provides a description of the VPCAR technology and the advances that are being incorporated into the unit.

Hamilton Sundstrand Space Systems International, Inc. (HSSSI) is under contract to NASA Marshall Space Flight Center (MSFC) to develop, an Oxygen Generation Assembly (OGA) for the International Space Station (ISS). The Oxygen Generation Assembly (OGA) electrolyzes potable water from the Water Recovery System (WRS) to provide gaseous oxygen to the Space Station module atmosphere. The OGA produces oxygen for metabolic consumption by crew and biological specimens. The OGA also replenishes oxygen lost by experiment ingestion, airlock depressurization, CO2 venting, and leakage. As a byproduct, gaseous hydrogen is generated. The hydrogen will be supplied at a specified pressure range to support future utilization. Initially, the hydrogen will be vented overboard to space vacuum. The OGA has been under development at HSSSI for 3 years. This paper will update last year's ICES paper on the design/development of the OGA.

The International Space Station Waste Collector Subsystem Risk Mitigation Experiment (ISS WCS RME) was flown as the primary (Shuttle) WCS on Space Shuttle flight STS-104 (ISS-7A) in July 2001, to validate new design enhancements. In general, the WCS is utilized for collecting, storing, and compacting fecal & associated personal hygiene waste, in a zero gravity environment. In addition, the WCS collects and transfers urine to the Shuttle waste storage tank. All functions are executed while controlling odors and providing crew comfort. The ISS WCS previously flew on three Shuttle flights as the Extended Duration Orbiter (EDO) WCS, as it was originally designed to support extended duration Space Shuttle flights up to 30 days in length. Soon after its third flight, the Space Shuttle Program decided to no longer require 30 day extended mission duration capability and provided the EDO WCS to the ISS Program.

A trade study conducted in 2001 selected a rotary disk separator as the best candidate to meet the requirements for an International Space Station (ISS) Carbon Dioxide Reduction Assembly (CRA). The selected technology must provide micro-gravity gas/liquid separation and pump the liquid from 69 kPa (10 psia) at the gas/liquid interface to 124 kPa (18 psia) at the wastewater bus storage tank. The rotary disk concept, which has pedigree in other systems currently being built for installation on the ISS, failed to achieve the required pumping head within the allotted power. The separator discussed in this paper is a new design that was tested to determine compliance with performance requirements in the CRA. The drum separator and pump (DSP) design is similar to the Oxygen Generator Assembly (OGA) Rotary Separator Accumulator (RSA) in that it has a rotating assembly inside a stationary housing driven by a integral internal motor[1].