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In a near future, telecommunication satellites should be characterized by more and more dissipative payloads and platform. The heat dissipation of the only communication module (CM) could be more than three times higher than the current large satellite payloads. At the same time, the strong restricted requirements to mass and power budget of satellite subsystems lead to choice of mainly passive thermal control system, specifically with heat pipe integration. In such a context, the investigations of existing high performance grooved heat pipes, which are commonly used nowadays for thermal control of telecommunication and scientific satellites, as well as the ways of improve its heat dissipation performance are strongly relevant. This paper is devoted to the R&D of advanced design of grooved heat pipes (GHPs) with thin porous layer (TPL) on its inner surface.

Performance tests and analysis of a new flexible Variable Conductance Heat Pipe (VCHP) design are reported. The unit features a single liquid passage through most of the length and incorporates flexible sections to reduce transverse bending stiffness to less than 175 N/m. A feedthru plate is accommodated to enable installation of the heat pipe in a dual environment. The unit accepts a high heat flux heat input of more than 50 W/cm2 and has a demonstrated thermal conductance of ∼50 W/°C (at 14 W per cm of evaporator length). The demonstrated room temperature heat transport limit is approximately 150 W-m for this 1 cm OD design as configured. The unit was first tested as a Constant Conductance Heat Pipe (CCHP) to validate ammonia charge quantity and heat transport. It was then reworked to include a gas reservoir, and the performance was again validated. The test data was then compared with the thermohydraulic model predictions and shown to be in excellent agreement.

The Terrapin Undergraduate Rover for Terrestrial Lunar Exploration (TURTLE) system was developed as part of a senior design course at the University of Maryland; it has since become a test bed for habitability and life support studies. The design requirements for the project dictated a 2,500 kg pressurized lunar rover to sustain two crew members for eight days with a range of 100 km. Part of the design effort included a full-scale mock-up populated with volumetric representations of interior elements. This research proposes a solution to the life support requirements for spacecraft as well as design requirements for other habitat elements. An analysis of relevant technologies and their application to small rovers is presented. Habitability issues (with respect to interior layout of life support hardware) are also considered. Testing was done with the full-scale TURTLE mockup to determine suitable configuration of life support equipment.

A long-term lunar outpost will require sustainable life support technologies that are capable of functioning for years with minimum resupply and maintenance. While life support resources such as water and air will remain in short supply, the availability of gravity, energy, and natural resources on the lunar surface allow for innovation in the design of outpost technologies, potentially including the adoption of terrestrial technologies previously not feasible for short duration microgravity flight. One technology with potential for such innovation is the water recovery system. Current spacecraft water recovery systems rely on oxidizing pretreatment chemicals to stabilize wastewater, as microgravity compatible distillation or filtration systems are prone to fouling and failure.

A regenerative Air Revitalization system has been developed by JAXA. Its major assemblies are a CO2 concentration assembly which contains membrane dryers to remove humidity and zeolite to remove CO2, a CO2 reduction assembly, and a water electrolysis assembly to which water is supplied in the vapor phase through molecule-size pores in a NAFION membrane rather than as liquid to solve the problem of gas-liquid separation in microgravity conditions. A small satellite mission using a subscale air revitalization system (for 1/10 person) is planned as an orbital demonstration of solving microgravity-related problems, interface problems between assembly, compaction problems and saving energy design. A small satellite is used because it has a greater chance of being selected for flight than ISS experiments, and it will be useful for mission assurance to perform small satellite experiments before an ISS manned mission.

The Closed-Loop Air REvitalisation System ARES is a regenerative life support system for closed habitats. With regenerative processes the ARES covers the life support functions: 1. Removal of carbon dioxide from the spacecraft atmosphere via a regenerative adsorption/desorption process, 2. Supply of breathable oxygen via electrolysis of water, 3. Catalytic conversion of carbon dioxide with hydrogen to water and methane. ARES will be accommodated in a double ISPR Rack which will contain all main and support functions like power and data handling and process water management. It is foreseen to be installed onboard the International Space Station (ISS) in the Columbus Module in 2013. After an initial technology demonstration phase ARES shall continue to operate thus enhancing the capabilities of the ISS Life Support System as acknowledged by NASA [5]. Due to its regenerative processes ARES will allow a significant reduction of water upload to the ISS.

This report describes proof-of-concept testing of a commercial-off-the-shelf deep ultraviolet LED for future application as a point-of-use or residual disinfection device for spacecraft potable water systems. The electro-optical performance and disinfection efficacy of a 0.5 mW 265nm UV-C LED (UVTOP, Sensor Electronic Technology, Inc., Columbia, SC) was measured in both static and flow environments against five challenge microorganisms inoculated into potable water at an initial concentration ≥ 108 cells per milliliter. The germicidal irradiation from a single UV-C LED array was sufficient to effect > 4-log kill (> 99.99%) of the challenge bacterial population in < 60 minutes contact time.

Dynamic modeling and simulation of recycling space life support is necessary to determine processing rates, buffer sizes, controls, and other aspects of systems design. A common approach is to develop an overall inclusive model that reflects nominal system operation. A full dynamic simulation of space life support represents many system elements in an inclusive model, but it cannot and should not include everything possible. A model is a simplified, partial, mathematical representation of reality. Including unnecessary elements makes the model complex, costly, and confusing. Models are built to help understand a system and to make predictions and decisions about it. The best and most useful models are developed to answer specific important questions. There are many possible questions about life support design and performance. Different questions are best answered by different models. Static spreadsheet analysis is a good starting point.

Environmental control and life support systems are usually associated with high demands for performance robustness and cost efficiency. However, considering the complexity of such systems, determining the balance between those two design factors is nontrivial for even the simplest space missions. Redundant design is considered as a design optimization dilemma since it usually means higher system reliability as well as system cost. Two coupled fundamental questions need to be answered. First, to achieve certain level of system reliability, what is the corresponding system cost? Secondly, given a budget to improve system reliability, what is the most efficient design for component or subsystem redundancy? The proposed analysis will continue from previous work performed on series systems by expanding the scope of the analysis and testing parallel systems. Namely, the online and offline redundancy designs for a Lunar Outpost Mission are under consideration.

Two detailed numerical models for flame growth and spread over solid surfaces are solved. For the three-dimensional model of steady spread over thin solids, the computations have included the variations of pressure, oxygen percentage and gravity in buoyant flows and pressure, oxygen percentage and flow velocity in purely forced flow in zero gravity. The overall comparisons of spread rates with experiments are reasonable but there is not enough data to perform a thorough comparison on the extinction limits. The computed results provide detailed flame structures in these different conditions that also reveal the difference between flames in a buoyant flow and in a forced flow. The ignition and flame growth processes along a thick solid surface are studied by a two-dimensional transient model which has a quasi-steady gas phase and an unsteady solid phase.

Space is characterized by many uncertainties, natural and human induced, for manned missions in hostile environments. Therefore, human operations in space require reliable Life Support Systems (LSS) capable to maintain functionality for long durations. However, the ultimate theoretical analysis of LSS reliability for space applications is very difficult due to many unknown and possibly undiscovered factors which might affect system functional performance. In this work the conceptual approach for a complex LSS reliability analysis is reviewed. Methodology based on Fokker-Planck statistical equation is proposed and investigated. According to these preliminary considerations, a few critical variables are identified and determined: 1) average rate of material recirculation in LSS; 2) LSS and environment uncertainty level (level of material circulation rate fluctuations); and 3) human control level and its limitations.

The objective of this paper is to detail the development of the DL/H-1 full pressure suit, which was developed by De Leon Technologies LLC, with the assistance of the University of North Dakota. The DL/H-1 was specifically developed to fulfill the needs for a full pressure suit for private spaceflight in case of decompression or in the need of bailout of the spacecraft. This work also details the objectives, basis for design, problems encountered by the designers, final development of the DL/H-1 full pressure suit and testing in the high altitude chamber at the School of Aerospace Sciences at the University of North Dakota. The authors believe that during experimental flights of private spaceflight, orbital or suborbital a full pressure suit will be required to augment safety during all flight phases where in the case of cabin pressure loss, without personal protection, the loss of crew and vehicle could result.

Field of view has always been a design feature paramount to helmets, and in particular space suits, where the helmet must provide an adequate field of view for a large range of activities, environments, and body positions. For Constellation Project, a different approach to helmet requirement maturation was utilized; one that was less a direct function of body position and suit pressure and more a function of the mission segment in which the field of view will be required. Through taxonimization of various parameters that affect suited field of view, as well as consideration for possible nominal and contingency operations during that mission segment, a reduction process was employed to condense the large number of possible outcomes to only six unique field of view angle requirements that still captured all necessary variables while sacrificing minimal fidelity.

This paper describes the results of Engineering Development Unit (EDU) testing of a graded-groove Variable Conductance Heat Pipe (VCHP). This EDU pipe contains all the essential design features of an end-item unit, including multiple bends, flex sections, stainless steel transport section and high heat flux evaporator. Testing covered a wide range of environments including hot and cold condenser temperatures, hot and cold reservoir sink temperatures, and varying evaporator powers. A control algorithm was also developed which was designed to minimize warm-up time of the evaporator, minimize overshoot of the evaporator temperature, and maintain a stable evaporator temperature after warm-up. Testing was performed to determine whether the VCHP reservoir needed to be cooled during testing in an ambient environment. Results of the model correlation are also presented.

Gloves are a critical element of the space suit used for extra-vehicular activity (EVA) since most work is done with the hands. The stiffness of the pressurized space suit limits the dexterity and flexibility of the astronauts' fingers, considerably depriving the fingertips of tactile sense of objects external to the glove. Providing tactile feedback to the fingertips may potentially improve the dexterity of the astronauts' gloves to better handle EVA tools. A complete glove-based tactile feedback system was developed to translate the sense of touch from the external fingertips of the glove to the fingertips within the glove.

Radiator stagnation is being explored to design single loop thermal control systems using Galden HT170 for heat rejection systems requiring large turn-down ratios. A previous Small Business Innovation Research (SBIR) Phase 1 studied sequential stagnation in a system of different length tubing. As part of a follow-on Phase 2, tests were performed to study the effects of adding a facesheet in a manner consistent with typical spacecraft radiator effectiveness. Onset of stagnation for different tubes was demonstrated for a given inlet temperature by lowering mass flow rate. Temperature and/or mass flow rate were increased to investigate stagnation recovery. A Thermal Desktop® model was built to simulate the test. Test results and modeling comparisons are presented.

This paper present a summary of the design studies for the suit port proof of concept. The Suit Port reduces the need for airlocks by docking the suits directly to a rover or habitat bulkhead. The benefits include reductions in cycle time and consumables traditionally used when transferring from a pressurized compartment to EVA and mitigation of planetary surface dust from entering into the cabin. The design focused on the development of an operational proof of concept evaluated against technical feasibility, level of confidence in design, robustness to environment and failure, and the manufacturability. A future paper will discuss the overall proof of concept and provide results from evaluation testing including gas leakage rates upon completion of the testing program.

Good performance of the Columbus water loop active control system has been demonstrated by several analyses, ground test and is further confirmed by the current flight data. Even so, a comprehensive description of the control within the classical theory is needed, in order to complete the system description, posing also the basis for similar applications to come. Thermal and hydraulic control loops are considered as two separate systems and linear control methods are applied. Loop stability and performance is discussed by computing stability regions of the PI control coefficients at different loop configurations and results compared with available test, flight and simulation data.

Currently there are no submarine atmosphere exposure limits set for endocrine disrupting contaminants. Previous house dust research suggests that worrying levels of these contaminants can be detected in dust particles within the household environment. Endocrine disrupting contaminants can interfere with reproductive and immune systems, imitate hormones and potentially cause cancer in a variety of living organisms. Dust acts as a suitable medium for the collection of a wide variety of contaminants as it acts as a reservoir detailing historical exposure faced by the environment in question. While the existence of these contaminants has been monitored to some extent in house dust, the impact that the contaminants may have within an enclosed breathable atmosphere has not yet been investigated. With this in mind, four endocrine disrupting chemical groups that were believed to exist within the submarine environment, were specifically targeted for analysis.

In the frame of the space food production research activities conducted in the Thales Alenia Space Italia (TAS-I) Advanced Life Support Research and Development laboratory (RecycLAB, [6]), and with the contribution of a degree thesis developed in collaboration with the Politecnico of Torino, a rack-like facility for ground research on Life Support Systems based on Plants has been designed, developed, integrated, verified and tested in TAS-I. The new facility, called EDEN EPISODE 2, is a significant evolution of a previous TAS-I project (EDEN EPISODE 1) and takes benefit from other lower size TAS-I demonstrators (CUBE). It aims at realizing a completely closed and controlled environment for crop production, while a mobile lighting panel allows to maximize the delivered light in each phase of the plant life cycle. Hydroponic and aeroponic techniques have been implemented in the project for nutrient delivery to the plant roots.