Passive Thermal Flight Experiment (Passive Thermal Flight Experiment) - 07.19.17

Overview | Description | Applications | Operations | Results | Publications | Imagery

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Science Objectives for Everyone
The Advanced Passive Thermal eXperiment (APTx) tests three advanced thermal management technologies. It demonstrates the in-space performance of each, an important step toward improving these technologies for use on future space exploration missions. This investigation leverages the fluid cooling capabilities of another space station experiment, the Phase Change Heat eXchanger (PCHX).
Science Results for Everyone
Information Pending

The following content was provided by Angel Alvarez-Hernandez, M.S., and is maintained in a database by the ISS Program Science Office.
Experiment Details

OpNom: Passive Thermal Testbed

Principal Investigator(s)
Angel Alvarez-Hernandez, M.S., NASA Johnson Space Center, Houston, TX, United States

Co-Investigator(s)/Collaborator(s)
Jeffery Farmer, Ph.D., NASA Marshall Space Flight Center, Huntsville, AL, United States

Developer(s)
NASA Johnson Space Center, Houston, TX, United States

Sponsoring Space Agency
National Aeronautics and Space Administration (NASA)

Sponsoring Organization
Technology Demonstration Office (TDO)

Research Benefits
Earth Benefits, Space Exploration

ISS Expedition Duration
April 2017 - September 2017

Expeditions Assigned
51/52

Previous Missions
Information Pending

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Experiment Description

Research Overview

  • The Advanced Passive Thermal eXperiment (APTx) is a suite of three advanced heat pipe based technologies devices: (1) a new hybrid wick, warm biased integrated reservoir, variable conductance heat pipe that can passively adjust to changing thermal conditions allowing efficient energy transport in warm conditions and power conservation in cold conditions; (2) a high conductivity plate (HiK™) for heat acquisition and heat sharing; and (3) an early concept of an electro-wetting heat pipe that may potentially increase heat transport by orders of magnitude over existing heat pipes.
  • The purpose of testing these devices in a micro-gravity environment is to improve design, performance, and understanding, and demonstrate in-space performance and increase the Technology Readiness Level (TRL) improving the likelihood of implementation and successful use in future applicable space exploration missions.
  • The use of these technologies can reduce system mass and power, enhanced heat transport and thermal switching in diverse, extreme thermal environments, and the passive nature of these devices has the potential to increase the reliability of thermal management systems.

Description

The Advanced Passive Thermal eXperiment (APTx), is a collaboration between the Johnson Space Center (JSC), Marshall Space Flight Center (MSFC), University of Texas, and Advanced Cooling Technologies, to address the current technical gaps in thermal management systems. Three new technologies are selected for testing on board the International Space Station (ISS):  (1) a new hybrid wick, warm biased integrated reservoir, variable conductance heat pipe developed that can passively adjust to changing thermal conditions allowing efficient energy transport in warm conditions and power conservation in cold conditions in both microgravity and planetary gravity environments; (2) a high conductivity plate (HiK™) for heat acquisition and heat sharing; and (3) an early concept of an electro-wetting heat pipe that may ultimately have the potential to increase heat transport by orders of magnitude over existing heat pipes completely gravity independent. The testing of these devices in a relevant extended micro-gravity environment will add essential information to on-going ground testing to help improve performance and understanding of these devices and will increase the Technology Readiness Level (TRL) in preparation for use in deep space missions, Lunar/Mars landers and rovers and other future spacecraft architectures. The use of these technologies is aimed at reduction in space system mass and power, enhanced heat transport and thermal switching in diverse, extreme thermal environments, and the passive nature of these devices has the potential to increase the reliability of thermal management systems for extended space missions compared to traditional passive and active (mechanically pumped) systems.
 
The APTx suite on-orbit testing provides the needed data to verify the devices performance and fluid flow characteristics in micro-gravity. Some specific objectives are shown below for each device:
 
Hybrid wick, warm integrated reservoir Variable Conductance Heat Pipe (VCHP):
Demonstrate start-up of VCHP in space under microgravity conditions.
Demonstrate passive thermal switching by the VCHP in microgravity.
Measure heat transport and degree of isolation; turn down ratio.
Demonstrate overall operation of integrated thermal management solution (hik plate and vchp) in space to elevate TRL and validate design concept.
HiKTM plate:
Determine in-plane conductance in space at different thermal conditions.
Demonstrate freeze-thaw survivability.
Demonstrate operation in space to elevate TRL.
Electro-Wetting Heat Pipe (EWHP):
Demonstrate the ability to move working fluid with electric fields.
Determine microgravity impact on droplet motion.

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Applications

Space Applications
Future human exploration activities require thermal management systems to provide higher reliability, adaptability, mass and power reduction, and increased performance. The use of these technologies is aimed at reduction in space system mass and power, enhanced heat transport and thermal switching in extreme thermal environments. The passive nature of these devices has the potential to increase the reliability of thermal management systems for extended space missions compared to traditional passive and active (mechanically pumped) systems.

Earth Applications
Although designed for spacecraft architectures, the development of new thermal management devices can also be used in earth applications.

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Operations

Operational Requirements and Protocols

The APTX suite leverages on existing fluid cooling capabilities of another existing experiment, the Phase Change Heat eXchanger (PCHX). It is composed of two payloads that fit in the top deck of the PCHx assembly. The express rack provides both payloads with power and data. Each tray is tested sequentially, and, once each tray is assembled into PCHx there is little to no crew interaction with the payload since it is completely controlled via ground software.
 
Description of payload content:
Payload 1: Contains a VCHP/HiK™ plate assembly.
Payload 2: Contains a HiK™ plate and the EWHP experiment.

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Decadal Survey Recommendations

Information Pending

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Results/More Information

Information Pending

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Related Websites

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Imagery