STP-H5-Electro-Hydro Dynamics (STP-H5 EHD) - 06.20.18

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

ISS Science for Everyone

Science Objectives for Everyone
Spacecraft and sensitive instruments rely on heating and cooling pumps to keep electronics cool and to maintain consistent temperatures, but current systems use mechanical parts that can fail during the intense shaking of launch. STP-H5-Electro-Hydro Dynamics (STP-H5 EHD) studies a prototype pump that uses electric fields to pump coolant, eliminating fragile mechanical parts and reducing weight.
Science Results for Everyone
Information Pending

The following content was provided by Jeffrey Didion, M.S., and is maintained in a database by the ISS Program Science Office.
Experiment Details


Principal Investigator(s)
Jeffrey Didion, M.S., Goddard Space Flight Center, Greenbelt, MD, United States

Information Pending

Information Pending

Sponsoring Space Agency
National Aeronautics and Space Administration (NASA)

Sponsoring Organization
Technology Demonstration Office (TDO)

Research Benefits
Space Exploration

ISS Expedition Duration
September 2016 - August 2018; -

Expeditions Assigned

Previous Missions
Information Pending

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Experiment Description

Research Overview

  • NASA is investigating the feasibility of embedded thermal control subsystems to optimize hardware for size, weight and power consumption (SWaP).
  • Characterization and demonstration of long term embedded convective thermal control system at meso-scale.
  • STP-H5-Electro-Hydro Dynamics (STP-H5 EHD) demonstrates feasibility of multifunctional structures in spaceflight hardware.


The main objective of the STP-H5-Electro-Hydro Dynamics (STP-H5 EHD) demonstration shows that a prototype pump can withstand the extreme launch loads as the rocket lifts off and hurtles toward space. Should it survive the vibration, the technology achieves a major milestone in its development. This means that it is at or near operational status, making it a viable technology for use on spaceflight instruments.
The technology promises significant advantages over more traditional cooling techniques. Unlike current technologies used today by instrument and component developers, EHD does not rely on mechanical pumps and other moving parts. Instead, it uses electric fields to pump coolant through tiny ducts inside a thermal cold plate. From there, the waste heat is dumped onto a radiator and dispersed far from heat-sensitive circuitry that must operate within certain temperature ranges. Electrodes apply the voltage that pushes the coolant through the ducts.  Without mechanical parts, the system is lighter and consumes less power, roughly half a watt. But perhaps more importantly, the system can be scaled to different sizes, from larger cold plates to microscale electronic components and lab-on-a-chip devices.
ISS EHD research effort demonstrates the long-term operation of an EHD thermal-control system, These multifunctional devices could be used as stand-alone, off-the-shelf components ideal for quick-turnaround spacecraft -- a capability that particularly interests the Air Force -- or as units embedded within the walls of the electronic device. The next step is placing the technology on circuit cards, with the ultimate goal of scaling it to the chip level where the ducts would be no larger than 100 microns (0.0039 inch), or about the width of a human hair.

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Space Applications
An electrohydrodynamic pump uses electric fields to pump coolant through tiny ducts on a small thermal plate. Waste heat is dispersed onto a radiator, and allowed to dissipate far from heat-sensitive circuits. This is a more efficient means of dissipating heat than mechanical pumps, which are currently used in most spacecraft instruments and components. This investigation demonstrates that the prototype pump can survive the extreme gravity forces and shaking of launch, and that it is a viable cooling method for use in future spacecraft instruments.

Earth Applications
The devices in this investigation could be used as standard, off-the-shelf component for rapid-turnaround spacecraft, which benefits the military. The devices could be further miniaturized to the microchip level, enabling their use in computers and personal devices.

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Operational Requirements and Protocols
None provided.

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Decadal Survey Recommendations

Information Pending

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Results/More Information

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Related Websites

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NASA Image: ISS050E052652 - Space Test Program-H5 (STP-H5). Photo taken during Expedition 50.

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