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Water recovery is essential for long-duration space exploration transit and outpost missions. Primary stage wastewater recovery systems partially satisfy this need, and generate concentrated wastewater brines that are unusable without further processing. The Enhanced Brine Dewatering System (EBDS) is being developed to allow nearly complete recovery of water from Lunar Outpost wastewater brines. This paper describes the operation of the EBDS and discusses the development and testing of the major functional materials, components, and subsystems, including the wastewater brine ersatz formulations that are used in subsystem testing. The assembly progress of the EBDS full system prototype is also discussed, as well as plans for testing the prototype hardware.

A modular and scalable Dense Medium Plasma Water Purification Reactor was developed, which uses atmospheric-pressure electrical discharges under water to generate highly reactive species to break down organic contaminants and microorganisms. Key benefits of this novel technology include: (i) extremely high efficiency in both decontamination and disinfection; (ii) operating continuously at ambient temperature and pressure; (iii) reducing demands on the containment vessel; and (iv) requiring no consumables. This plasma based technology was developed to replace the catalytic reactor being used in the planned International Space Station Water Processor Assembly.

Humidity control within confined spaces is of great importance for existing NASA environmental control systems and Exploration applications. The Engineered Multifunction Surfaces (MFS) developed in this STTR Phase II form the foundation for a modular and scalable Distributed Humidity Control System (DHCS) while minimizing power, size and mass requirements. Key innovations of the MFS-based DHCS include passive humidity collection, control, and phase separation without moving parts, durable surface properties without particulate generation and accumulation, and the ability to scale up, or network in a distributed manner, a compact, modular device for Exploration applications including space suits, CEV, Rovers, Small and Transit Habitats and Large Habitats.

A prototype packed bed convective dryer has been studied for use in an energy-efficient closed air-loop heat-pump drying system for astronaut cabin waste. This paper presents a transient continuum model for the heat and mass transfer between the air and wet ersatz trash in the cylindrical drying vessel. The model is based on conservation equations for energy and moisture applied to the air and solid phases and its formulation includes the unique waste characteristic of having both dry and wet solids. It incorporates heat and mass transfer coefficients for the system measured on an ersatz trash in the dryer vessel, and experimentally determined moisture sorption equilibrium relationship for the wet material. The resulting system of differential equations is solved by the finite-volume method as implemented by the commercial software COMSOL. The validated model will be used in the optimization of the entire closed-loop system consisting of dryer, condenser, and heat-recovery modules.

A Plasma Air Decontamination System (PADS) is being developed by ORBITEC for trace contaminant control in spacecraft cabin air, based on non-thermal, atmospheric pressure plasma discharges that generate various highly reactive species that can react with and break down trace air contaminants. It uses a simple and modular design, and may be scaled up or down to meet the requirements of different applications. The prototype PADS reactor has successfully demonstrated removal of ammonia and other selected volatile organic carbons from air, including acetone, ethylbenzene, methane, and methylene chloride. It has the potential to replace the existing high-temperature catalytic oxidizers.

The High Efficiency Solid State Lighting with Integrated Adaptive Control (HELIAC) system was developed to independently detect the presence of green plant tissue and to direct light only to those locations. During testing of the HELIAC system, a major factor interfering with effective tissue detection was reflectance of sensed wavebands from the walls and ceiling causing false positives. Since it is desirable to have reflective surfaces to maintain higher light levels with less power, selective reflection systems that absorb some wavebands but reflected others were tested. A test device was fabricated to measure the reflection of red, green, and blue light from a variety of colored mirrors. It was observed that both pink and purple tinted mirrors reduced the reflection of green wavebands more than red and blue wavebands. This effect could also be obtained by using colored films attached to a silvered mirrored surface.

Orbital Technologies Corporation (ORBITEC) utilizes a variety of in-house testing capabilities (vibration, shock, acoustic loads, space vacuum, temperature cycling, humidity, burn-in, etc.) for qualification and screening of flight components. A lunar dust chamber was designed and constructed to include exposure to lunar regolith and dust simulants. A full factorial design of experiment (DOE) was used to investigate the failure modes of electric fans when exposed to airborne JSC-1AF lunar regolith simulant. This type of testing provides valuable insight into reliability predictions, planned maintenance of a system, and component design improvements to mitigate the effects of lunar dust. Incorporating lunar dust exposure testing at an early stage in the design process will help ensure proper system performance and reliability.

The Biomass Production System (BPS) was flown on the ISS for 73 days as part of the Increment 4 mission. To obtain maximum benefit from the long mission duration, numerous manual crew procedures were incorporated into the BPS experiments. These procedures included gas sampling, root module priming, harvesting, pollination, filter cleaning, water refill, and water sampling. On-orbit crew assessments were filled out for each of these procedures to evaluate the ability of BPS to accommodate them. The assessment asked questions about each phase of an activity and solicited recommendations for improvements. Further analysis of most procedures was provided by detailed video made on-orbit and multiple post-flight crew debriefs. Most assessments indicated no need for improvements, but a number of crew suggestions will be incorporated into hardware and procedure updates.

The Biomass Production System, recently flown on the ISS for 73 days, demonstrated significant advancements in functional performance over previous systems for conducting plant science in microgravity. The Biomass Production System (BPS) was the first flight of a system with multiple, independently controlled, plant growth chambers. Each of four chambers was controlled separately with respect to temperature, humidity, light level, nutrient level, and CO2, and all were housed in a double Middeck locker-sized payload. During the mission, each of the subsystems performed within specification. This paper focuses on how the performance of the BPS hardware allowed successful completion of the preflight objectives.

Based upon the development experience and flight heritage of the Biomass Production System, the Plant Research Unit embodies the next generation in the evolution of on-orbit plant research systems. The design focuses on providing the finest scientific instrument possible, as well as providing a sound platform to support future capabilities and enhancements. Performance advancements, modularity and robustness characterize the design. This new system will provide a field ready, highly reliable research tool.

The longest BPS ground test to-date was the BPS Mission Verification Test done to provide a high fidelity end-to-end system test of BPS hardware and operations. This test took place at Kennedy Space Center from 4/9/01 to 6/21/01. The BPS temperature and humidity control, atmospheric control, lighting, and nutrient delivery systems performed within specifications. Ambient temperature conditions for the test ranged from 22°C to 28°C. Temperature systems performed well over the full range of ambient conditions and temperature setpoints were maintained throughout the test. Humidity setpoints were maintained within specification under nominal conditions; however, drift in humidity was observed during high ambient temperatures with large plant load conditions, and during CO2 drawdowns. CO2 levels in the wheat chambers were within ± 10% of setpoint under nominal conditions. Several automated CO2 drawdowns and CO2 cylinder changeouts were successfully completed.

As space hardware continues to grow in complexity, the demands on crews expected to be able to operate and maintain this equipment continue to grow. In terms of the International Space Station, the demands on the crew have been further increased by the reduction in crew capacity from the originally planned seven members down to three. This situation has prompted the need to find new ways of training that can meet these demands. In particular, just-in-time training techniques promise to enable crew members to correctly execute procedures that they have never performed before on equipment that they are only marginally familiar with or perhaps have never even seen before. To enable crews to work with unfamiliar procedures or equipment, we believe that it is necessary to employ a highly visual approach to convey the complex spatial information that is often involved.

The Plant Research Unit (PRU) is the Space Station Biological Research Program plant growth facility being developed for the International Space Station. The plant habitat is designed for experiments in near-zero gravity or it can be rotated by the ISS Centrifuge for experiments at any gravity level from microgravity to twice Earth's gravity. Plant experimentation will be possible in multiple Plant Research Units at one time, isolating the effect of gravity on the biological specimens. The PRU will provide and control all aspects of a plant's needs in a nearly closed system. In other words, the shoot and root environments will not be open to the astronaut's environment except for experiment maintenance such as planting, harvesting and plant sampling. This also means that all lighting, temperature and humidity control, nutrient delivery, and air filtering and cleaning must be done in a very small volume, with very little mass and power usage and with minimal crew time.

The Advanced Animal Habitat (AAH) represents the next generation of Space Station based animal research facilities. Building upon previously developed flight hardware and experience, the AAH offers greatly enhanced system capabilities and performance. The design focuses upon the creation of a robust and flexible platform capable of supporting present and future experimental needs. A modular packaging and distributed control architecture leads to increased system adaptability and expandability. The baseline configuration includes group housing capability for up to six rats with automated food and water delivery as well as waste collection. Animals are continuously monitored with three cameras during both day and night cycles. The animals can be accessed while on-orbit through the Life Sciences Glovebox to perform a wide variety of experimental protocols.

The Advanced Animal Habitat (AAH) and Plant Research Unit (PRU) are two major components of the Space Station Biological Research Project (SSBRP). These two habitats are currently under development by Orbital Technologies Corporation (ORBITEC). Science Evaluation Units (SEUs) have been developed for each of these habitats to allow investigators to plan and test flight experiments on the ground using hardware that is functionally similar to the flight versions of the AAH and PRU. The SEUs also contain key functionality that makes them excellent science tools for general laboratory experiments that are not related to flight experiments.

The VEGGIE unit is a deployable, low-resource plant growth system that can provide a source of fresh food and crew recreation on long duration space missions. VEGGIE can be stowed in 10% of its deployed volume; a single middeck locker equivalent can stow 1.0m2 of growing area. To reduce complexity, VEGGIE utilizes the ambient environment for temperature control and as a source of CO2. The lighting subsystem uses LEDs that provide a minimum light level of 300 µmol m−2s−1, spectral quality control, and a long operating life in a low profile package. The root zone is a compressible fabric mat. Each VEGGIE module has 0.17 m2 of growing area and can be varied in height from 5 to 45 cm. The mass, including the lighting subsystem and root mat, is 4.7 kg. On the ISS, VEGGIE can mount in the aisle, or in an EXPRESS rack.

The ECLSS (Environmentally Controlled Life Support System) project goals are to identify key requirements and guidelines for a Life Support System (LSS) for surface missions based on the Exploration Spirals, to review the various technology options and candidates to fulfill the life support functionality, and to conduct initial trades and assessments at a high level. With the completion of the first six month phase of the project, ORBITEC has generated and shown that for each Exploration Spiral, different LSS architectures are optimal, but when an entire mission model is considered, hybrid systems become more attractive. Also, we can easily show that future spiral requirements should and will influence the technologies and level of closure for earlier spiral developments to reduce overall development and implementation costs, and to increase commonality across the Constellation systems.

Orbital Technologies Corporation (ORBITEC) and the University of Wisconsin (UW) have demonstrated the feasibility of utilizing plasma manufacturing methods to functionalize fluid handling surfaces. Performance of hydrophilic coatings generated with both oxygen plasma and dichlorosilane plasma on aluminum (SiH2Cl2) substrates was demonstrated. Both give similar results, significantly decreasing contact angles and improving wicking ability of machined capillary grooves. Deposition of silver nanoparticles using plasma was also demonstrated and tested. Silver concentrations of 2% were obtained on hydrophilic-coated samples. Testing indicated that the silver-coated samples were biocidal against Listeria monocytogenes. Oxide-coated aluminum substrates were also shown to exhibit biocidal action against L. monocytogenes and a variety of other microorganisms.

The Advanced Animal Habitat (AAH) represents the next generation of Space Station based animal research facilities. Care has been taken to protect the ISS crew from exposure to the hazardous biological materials contained within the AAH. These materials include rat feces, urine, dander, and odor. The approach to containing biological materials relies on collecting the solid and liquid waste, providing physical barriers between the waste and the crew environment, maintaining negative pressure within the specimen environment with respect to the crew environment, and providing odor filtration of air exchanged between the specimen and crew environments. These protections will be in place during all modes of AAH operation.

In-situ resource utilization (ISRU) is an important part of current mission architectures for both a return to the Moon and the eventual human exploration of Mars. ORBITEC has developed and demonstrated an innovative direct energy processing approach for carbon-reduction of lunar and Martian regolith that can operate in a nearly closed-loop manner. Carbon-reduction of regolith produces oxygen and a variety of other useful products, including silicon, iron and glass ceramic materials. In addition, various ISRU propulsion technologies that utilize lunar and Martian resources have been developed and demonstrated. Work is also being conducted with the USDA on techniques to use biomass and waste materials to manufacture items such as shelters, furniture, filters and paper. Atmospheric carbon dioxide on Mars would be used to support the production of biomass in excess of life support needs to be used as the raw material to manufacture useful products on-site.