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The Waste Collection Systems (WCS) for space vehicles have utilized a variety of hardware for collecting human metabolic wastes. It has typically required multiple missions to resolve crew usability and hardware performance issues that are difficult to duplicate on the ground. New space vehicles should leverage off past WCS systems. Past WCS hardware designs are substantially different and unique for each vehicle. However, each WCS can be analyzed and compared as a subset of ‘technologies’ which encompass fecal collection, urine collection, air systems, and urine pretreatment systems. Technology components from the WCS of various vehicles can then be combined to reduce hardware mass and volume while maximizing use of previous technology and proven human-equipment interfaces. Analysis of past US and Russian WCS are compared and extrapolated to Constellation missions.

The National Aeronautics and Space Administration's (NASA) planned future missions set stringent demands on the design of the Portable Life Support System (PLSS), requiring dramatic reductions in weight, decreased reliance on supplies and greater flexibility for Extravehicular Activity (EVA) duration and objectives. Use of regenerable systems that reduce weight and volume of the space suit life support system is of critical importance to NASA, both for low orbit operations and for long duration manned missions. The carbon dioxide and humidity control unit in the existing PLSS design is relatively large, since it has to remove and store eight hours worth of carbon dioxide (CO2). If the sorbent regeneration can be carried out during the EVA with a relatively high regeneration frequency, the size of the sorbent canister and weight can be significantly reduced.

Extended manned missions to the lunar and martian surfaces pose new challenges for active thermal control systems (ATCS's). Moderate-temperature heat rejection becomes a problem during the lunar day, when the effective sink temperature exceeds that of the heat-rejection system. The martian atmosphere poses unique problems for rejecting moderate-temperature waste heat because of the presence of carbon dioxide and dust. During a recent study, several ATCS options including heat pumps, radiator shading devices, and single-phase flow loops were considered. The ATCS chosen for both lunar and martian habitats consists of a heat pump integral with a nontoxic fluid acquisition and transport loop, and vertically oriented modular reflux-boiler radiators. The heat pump operates only during the lunar day. The lunar and martian transfer vehicles have an internal single-phase water-acquisition loop and an external two-phase ammonia rejection system with rotating inflatable radiators.

A new waste collection system (WCS) is undergoing development for use in the extended duration orbiter (EDO). Requirements for missions up to 18 days and the capability for missions up to 30 days necessitate the development of a new WCS that will have the appropriate capacity. The new system incorporates design features from both Skylab and Space Shuttle Orbiter WCSs. For urine collection, airflow is used to entrain the fluid and transport it to the phase separator where it is separated from the airflow and pumped to the waste water tank. For fecal collection, airflow is used to transport the waste into a collection bag. After use, a plastic lid is installed on the bag, and the bag and contents are compacted. The system for EDO utilizes redundant fans and urine separators. Plans call for the new WCS to be implemented for OV-105 (Endeavor) as well as for EDO. This paper describes the design and development status of the new WCS.

The International Space Station (ISS) Russian Segment currently provides potable water dispensing capability for crewmember food and beverage rehydration. All ISS crewmembers rehydrate Russian and U.S. style food packages from this location. A new United States On-orbit Segment (USOS) Potable Water Dispenser (PWD) is under development. This unit will provide additional potable water dispensing capability to support an on-orbit crew of six. The PWD is designed to provide incremental quantities of hot and ambient temperature potable water to U.S. style food packages. It will receive iodinated water from the Fuel Cell Water Bus in the U.S. Laboratory element. The unit will provide potable-quality water, including active removal of biocidal iodine prior to dispensing. A heater assembly contained within the unit will be able to supply up to 2.0 liters of hot water (65 to 93°C) every thirty minutes.

The Urine Receptacle Assembly (URA) initially was developed for Apollo as a primary means of urine collection. The aluminum housing with stainless steel honeycomb insert provided all male crewmembers with a non-invasive means of micturating into a urine capturing device and then venting to space. The performance of the URA was a substantial improvement over previous devices but its performance was not well understood. The Crew Exploration Vehicle (CEV) program is exploring the URA as a contingency liquid waste management system for the vehicle. URA improvements are required to meet CEV requirements, including consumables minimization, flow performance, acceptable hygiene standards, crew comfort, and female crewmember capability. This paper presents the results of a historical review of URA performance during the Apollo program, recent URA performance tests on the reduced gravity aircraft under varying flow conditions, and a proposed development plan for the URA to meet CEV needs.

The Orion Crew Exploration Vehicle Module (CM) is being designed to operate in an atmosphere of up to 30% oxygen at a pressure of 10.2 psia for lunar missions. Spacecraft materials selection is based on a normal gravity upward flammability test conducted in a closed chamber under the worst expected conditions of pressure and oxygen concentration. Material flammability depends on both oxygen concentration and pressure, but since oxygen concentration is the primary driver, all materials are certified in the 30% oxygen, 10.2 psia environment. Extensive data exist from the Shuttle Program at this condition, which used essentially the same test methodology as the Constellation Program is currently using. Raising the partial pressure of oxygen in the Orion CM immediately before reentry, while maintaining the total cabin pressure at 14.7 psia, has been proposed to maximize the time the crew is able to breathe cabin air after splashdown.

Fire detection, post fire atmospheric monitoring, fire extinguishing, and post fire atmospheric cleaning are vital components of a spacecraft fire response system, Preliminary efforts focused on the technology evaluation of fire detection, post fire atmospheric monitoring and post fire cleanup systems under realistic conditions are described in this paper. While the primary objective of testing is to determine the performance of a smoke mitigation filter, supplemental evaluations measuring the smoke-filled chamber handheld Commercial Off The Shelf (COTS) atmospheric monitoring devices (combustion product monitors) are conducted. The test chamber consists of a 1.4 cubic meter (50 cu. ft.) volume containing a smoke generator.

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.

Increased nickel concentrations in the IATCS coolant prompted a study of the corrosion rates of nickel-brazed heat exchangers in the system. The testing has shown that corrosion is occurring in a silicon-rich intermetallic phase in the braze filler of coldplates and heat exchangers as the result of a decrease in the coolant pH brought about by cabin carbon dioxide permeation through polymeric flexhoses. Similar corrosion is occurring in the EMU de-ionized water loop. Certain heat exchangers and coldplates have more silicon-rich phase because of their manufacturing method, and those units produce more nickel corrosion product. Silver biocide additions did not induce pitting corrosion at silver precipitate sites.

The design requirements for the Orbiter thermal protection system (TPS), the various TPS materials that are used, the different design approaches associated with each of the materials, and the performance experienced during the flight test program are described. The first five flights of the Orbiter Columbia have provided the necessary data to verify the TPS thermal performance, structural integrity, and reusability. The flight performance characteristics of each TPS material are discussed. This discussion is based on postflight inspections and postflight interpretation of the flight instrumentation data. The flights to date indicate that the thermal and structural design requirements for the Orbiter TPS have been met and that the overall performance has been outstanding.

This paper describes the Orbiter silica tile thermal protection system (TPS); the inherent moisture, absorption problems associated with low-density, highly porous insulation systems; and methods used to minimize and/or prevent water ingestion into the TPS tile. The test programs associated with developing water repellent agents for the tiles, application technique development, flight test program results, and material improvements are discussed.

With the advent of manned spacecraft opportunities requiring routine and complex extravehicular activities (EVA) a new concept for heat rejection is mandatory in order to realize maximum crewmember productivity. An optimum extravehicular mobility unit (EMU) thermal control system must be capable of successful operation without requiring expendables and without introducing contaminants into the environment, and be readily regenerable. This paper presents a regenerable non-venting thermal control subsystem requirements specification generated for a Shuttle-related EMU, identifies candidate concepts capable of fulfilling the requirements for each thermal control subsystem application, evaluates each candidate concept with respect to the subsystem requirements, and selects the best approach for each requirement.

A device has been developed (by others) which senses and displays forces and torques generated at the end of a manipulator arm. This device was integrated and evaluated in the one-g version of the Space Transportation System Canadian remote manipulator system arm at the NASA Lyndon B. Johnson Space Center. Evaluations of astronaut performance and preference under varying task conditions and using alternative display formats were performed. Findings indicate that providing visual graphic feedback of force and torque information affects both the time taken to do manipulator tasks and the size of forces generated during these tasks. Also, the format of graphics used affects operator reaction time.

This paper presents the conceptual design of a life support system sustaining a crew of six in a piloted Mars sprint. The requirements and constraints of the system are discussed along with its baseline performance parameters. An integrated operation is achieved with air, water, and waste processing and supplemental food production. The design philosophy includes maximized reliability considerations, regenerative operations, reduced expendables, and fresh harvest capability. The life support system performance will be described with characteristics of the associated physical-chemical subsystems and a greenhouse. MANNED MISSIONS TO THE PLANET MARS are included in the present NASA plans for the first decade of the next century [1]*. The first step of human exploration and eventual settlement on Mars will probably be a series of fast missions (“sprints”), with a duration of just over one year, round trip [2].

The NASA-developed space-suit configurations for Project Mercury and the Gemini Program originated from high-altitude-aircraft full-pressure-suit technology. These early suits lacked sophisticated mobility systems, since the suit served primarily as a backup system against the loss of cabin pressure and required limited pressurized intravehicular mobility functions for a return capability. Beginning with the Gemini Program, enhanced mobility systems were developed to enable crewmembers to perform useful tasks outside the spacecraft. The zero-prebreathe Hark III (ZPS Mk III) model of a higher operating pressure (57.2 kN/m2 (8.3 psi)) space-suit assembly represents a significant phase in the evolutionary development of a candidate operational space-suit system for the Space Station Program. The various design features and planned testing activities for the ZPS Mk III 57.2-kN/m2 (8.3 psi) space suit are described and identified.

The paper gives an update on an advanced development effort carried out under NASA Johnson Space Center (NASA/JSC) NAS 9-17775 by Ergenics Power Systems, Inc. (EPSI). The work was initiated in April 1987 to design and build a Fuel Cell Energy Storage System (FCESS) bench-test unit for the Space Station Freedom Extravehicular Mobility Unit (EMU). Fueled by oxygen and hydride stored hydrogen, the FCESS is being considered as an alternative to the EMU zinc-silver oxide battery. Superior cycle life and quick recharge are its main attributes. Design and performance of a non-venting 28V, 34 Ahr system with 7 amp rating are discussed. The FCESS is comprised of a 32-cell proton exchange membrane (PEM) stack, a metal hydride storage vessel and a control subsystem. The stack design incorporates passive product-water removal and thermal integration with the hydride vessel. The hydride vessel stores enough fuel for 5 hours.

The Space Shuttle waste management system has undergone a variety of design changes to improve performance and man-machine interface. These design improvements have resulted in more reliable operation and hygienic usage. Design enhancements include individual urinals, increased urine collection airflows, increased solids storage capacity, easier access to personal hygiene items, and additional wet trash stowage. The development and flight evaluation of these improvements are described herein. The Space Shuttle Orbiter has proved to be an invaluable test bed for development and in-flight evaluation of life support and habitability concepts which involve transport or separation of solids, liquids, and gases in a zero-g environment.

Waste water pretreatment and recovered water posttreatment techniques are essential for Space Station life support in order to achieve the necessary quality required of recycled water. This paper identifies methods of pre- and post-treatment applicable to spacecraft water recovery by distillation. The results of laboratory investigations show that oxidizers, which typically have been components of urine pretreatment formulas, produce many volatile organic compounds that contaminate the distillate and must later be removed by posttreatment. Two new nonoxidizing urine pretreatment formulas have been tested which minimize the generation of volatile organics and thereby significantly reduce posttreatment requirements. Three posttreatment methods were identified from among the many candidates that look promising (either alone or in combination) for removing organic contaminants in recovered water to nondetectable or barely detectable levels.

The International Space Station (ISS) is gaining many new capabilities in 2008. The delivery of the United States Operation Segment (USOS) Regenerative Environmental Control and Life Support (ECLS) Systems allow for the ISS crew expansion from 3 to 6 members. The ability to process recovered condensate and produce oxygen from water has been available on the Russian Segment (RS) since the astronauts and cosmonauts have been living on the ISS. The U.S. systems introduce the ability to process urine in addition to condensate greatly reducing the amount of water needed from the ground each year while also reducing the amount of time astronauts need to spend maintaining the systems. However, the interconnectedness of these systems may create operational difficulties and cause the loss of otherwise recoverable water. This paper outlines the current and future USOS and Russian system architectures, system interdependencies and the inter-segment relationships.