Browsing by Author "Ortega, Stephania"
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Item Advanced Passive Thermal eXperiment (APTx) for Warm Reservior Hybrid Wick Variable Conductance Heat Pipes on the International Space Station(48th International Conference on Environmental Systems, 2018-07-08) Tarau, Calin; Ababneh, Mohammed; Anderson, William; Alvarez-Hernandez, Angel; Ortega, Stephania; Farmer, Jeff; Hawkins, RobertAs NASA prepares to further expand human and robotic presence in space, it is well known that spacecraft architectures will be impacted by unprecedented power requirements and thermal environments in deep space. In addition, there is a need to extend the duration of the missions in both cold and hot environments, including cis-lunar and planetary surface excursions. The heat rejection turn–down ratio of the increased thermal loads in the above-mentioned conditions is crucial for minimizing vehicle power needs. Therefore, future exploration activities will have the need of thermal management systems that can provide higher reliability and performance, and power and mass reduction. In an effort to start addressing the current technical gaps in thermal management systems, novel new passive thermal technologies have been selected and tested on the board of the International Space Station (ISS). This testing was performed under the Advanced Passive Thermal eXperiment (APTx) project that is a collaboration between the Johnson Space Center (JSC), Marshall Space Flight Center (MSFC), University of Texas, and Advanced Cooling Technologies, Inc. (ACT) with funding from ISS Technology Demonstration Office at JSC as well as NASA’s Small Business Innovative Research Program. A hybrid-wick copper-Monel-water Variable Conductance Heat Pipe (VCHP) with warm reservoir design that consists of a copper evaporator (with sintered wick), a monel adiabatic section and a condenser both with grooved wick inside was developed and tested successfully on ground. The VCHP worked on the board of the ISS, but at higher temperatures than expected. Hence, a new flight VCHP design is currently under development to mitigate the shortcomings encountered in microgravity. The final paper will include some results and conclusions from the original flight testing and the ground test results for the improved VCHP.Item Advanced Passive Thermal Experiment for Hybrid Variable Conductance Heat Pipes and HiK™ Plates on the International Space Station(47th International Conference on Environmental Systems, 2017-07-16) Ababneh, Mohammed T.; Tarau, Calin; Anderson, William G.; Farmer, Jeffery T.; Alvarez-Hernandez, Angel R.; Ortega, StephaniaAs NASA prepares to further expand human and robotic presence in space, it is well known that spacecraft architectures will be challenged with unprecedented thermal environments in deep space. In addition, there is a need to extend the duration of the missions in both cold and hot environments, including cis-lunar and planetary surface excursions. The heat rejection turn–down ratio of the increased thermal loads in the above-mentioned conditions is crucial for minimizing vehicle resources (e.g. power). Therefore, future exploration activities will have the need of thermal management systems that can provide higher reliability and performance, and power and mass reduction. In an effort to start addressing the current technical gaps in thermal management systems, novel new passive thermal technologies have been selected to be included as part of suite of experiments to be tested on the board of the International Space Station (ISS), tentatively in 2017. Advanced Cooling Technologies, Inc. (ACT), together with NASA Marshall Space Flight Center and NASA Johnson Space Center, are working to test and validate hybrid wick VCHP with warm reservoir and HiK™ plates on the ISS under the Advanced Passive Thermal experiment (APTx) project. The APTx consists of two separate payloads that will be tested sequentially: • Payload 1 contains a VCHP/HiK™ plate assembly: a hybrid-wick copper-Monel-water VCHP design consists of a copper evaporator (with sintered wick inside), a monel adiabatic section and a condenser both with grooved wick inside and a NCG reservoir thermally and physically attached to the evaporator. In turn, the VCHP evaporator is mounted on an aluminum HiK™ plate. • Payload 2 contains a HiK™ plate and the ElectroWetting Heat Pipe (EWHP) experiment, developed by the University of Texas at Austin. This paper will cover the results to date for the flight test, which is planned for 2017.Item Demonstration of Copper-Water Heat Pipes Embedded in High Conductivity (HiK™) Plates in the Advanced Passive Thermal eXperiment (APTx) on the International Space Station(48th International Conference on Environmental Systems, 2018-07-08) Ababneh, Mohammed; Tarau, Calin; Anderson, William; Alvarez-Hernandez, Angel; Ortega, Stephania; Farmer, Jeffrey; Hawkins, RobertCopper-water heat pipes are commonly used for thermal management of electronics systems on earth and aircraft, but have not been used in spacecraft thermal control applications to date, due to the satellite industry’s requirement that any device or system be successfully tested in a microgravity environment prior to adoption. Recently, Advanced Cooling Technologies Inc., (ACT), in coordination with engineers from NASA’s Marshall Space Flight Center (MSFC) and Johnson Space Center (JSC) demonstrated successful flight operation of these heat pipes in low-Earth orbit. The testing was conducted aboard the International Space Station (ISS) under the Advanced Passive Thermal eXperiment (APTx) project, a project to test a suite of passive thermal control devices funded by the ISS Technology Demonstration Office at NASA JSC. The heat pipes were embedded in a high conductivity (HiK™) aluminum base plate and subject to a variety of thermal tests over a temperature range of -10 to 38 ºC for a ten-day period. Results showed excellent agreement with both predictions and ground tests. The HiK™ plate underwent 15 freeze-thaw cycles between -30 and 70 ºC during ground testing, and an additional 14 freeze-thaw cycles during the ISS testing. The following was demonstrated during 10 days of testing on the ISS: 1. Successful operation of the copper-water heat pipes and HiK™ plate 2. Ability of the copper-water heat pipes and HiK™ plate to survive multiple freeze/thaw cycles 3. As-designed heat transport via Copper-water heat pipes. 4. Reliable, repeatable start up of Copper-water heat pipes and HiK™ plate from a frozen state. This paper describes the test hardware, ground and flight test campaign, and discusses the results and conclusions of the testing.Item Design Analysis and Performance testing of a Novel Passive Thermal Management System for Future Exploration Missions(48th International Conference on Environmental Systems, 2018-07-08) Alvarez, Angel; Ortega, Stephania; Farmer, Jeff; Breeding, Shawn; Tarau, Calin; Ababneh, Mohammed; Anderson, WilliamIn response to an announcement of opportunity from the NASA’s Science Mission Directorate (SMD) Discovery Program, the Southwest Research Institute in collaboration with the Aerospace Corporation and the NASA Johnson Space Center (JSC) proposed a lunar lander science mission. The Moon Age and Regolith Explorer (MARE) would use a lunar lander to reach a young, nearside lunar lava flow for the collection and analysis of the lunar soil. This would be used for the determination of the impact history of the inner solar system and the evolution and differentiation of the interiors of one-plate planets. The lunar lander proposed was based on the NASA JSC Morpheus lander vehicle. The thermal environments for the proposed mission were both challenging and unprecedented, since survival of multiple lunar day/night cycles at the south-west region of the Aristarchus plateau were required. Other thermal design challenges included the need of a low mass, simple, robust and reliable thermal management system that would assure the success of the proposed mission. As part of the proposal effort, and leveraging on existing NASA Small Business Innovative Research (SBIR), a completely passive thermal control system concept was used to meet mission requirements. The thermal management system proposed uses a novel type of hybrid grooved and sintered wick variable conductance heat pipe and a high conductivity heat spreader; the thermal management systems tested wer developed by Advanced Cooling Technologies, Inc. (ACT) in Landcaster, Pennsylvania. This publication will present the design, analysis and prototype component and system level performance testing done at NASA JSC.