Elastic Memory Composite Hinge (EMCH) - 10.21.14
ISS Science for Everyone
Science Objectives for Everyone
Elastic Memory Composite Hinge (EMCH) will study the performance of a new type of composite hinge to determine its suitability for use in space. The experiment uses elastic memory hinges to move an attached mass at one end. Materials tested in this experiment are stronger and lighter than current materials used in space hinges and could be used in the design of future spacecraft.
Science Results for Everyone
Building new structures in space hinges on, well, hinges. This investigation looked at the performance of six new hinges developed by the Air Force Research Laboratory from a resin and carbon fiber laminate, materials lighter and stronger than those currently used. Researchers tested force and torque on the hinges and accuracy of deployment. Preliminary results demonstrated the robustness and reliability of the hinges in a variety of conditions, indicating that they meet performance goals for next-generation spaceflight. The experiment also confirmed engineering assumptions used to design the hinges and other deployable structures under development for space applications
United States Department of Defense Space Test Program, Johnson Space Center, Houston, TX, United States
Composite Technology Development, Incorporated, Lafayette, CO, United States
Sponsoring Space Agency
National Aeronautics and Space Administration (NASA)
Department of Defense (DoD) - Retired
ISS Expedition Duration
April 2007 - October 2007
Previous ISS Missions
The Lightweight Flexible Solar Array Hinge - LFSAH, a precursor to EMCH was flown on STS-93.
- Building new spacecraft structures in space necessitates deploying (unfolding) items that have been launched from Earth. This experiment will use the Elastic Memory Composite Hinge (EMCH) to move an attached mass at one end.
- The six hinges being evaluated were developed by the Air Force Research Laboratory from a resin and carbon fiber laminate.
- The study will measure the force and torque on the hinge, and the accuracy of the deployment.
- New materials that are reliable, light, and strong, will be important building blocks of future exploration spacecraft.
The Elastic Memory Composite Hinge (EMCH) experiment provided test data on new materials that will further space hardware technology. This technology may eliminate the need for highly complex deployment mechanisms by providing a simpler, lightweight alternative to mechanical hinges. EMCH builds on the previous Space Shuttle experiment, Lightweight Flexible Solar Array Hinge (LFSAH) flown on STS-93.
The six EMCH test articles tested on the International Space Station (ISS) were approximately 10 x 2.5 x 2.5 cm in dimension and made of a unique resin and carbon fiber laminate developed at Composite Technology Development, Inc. End fixtures and metrology devices were developed to allow the EMCH test articles to be deployed through remote actuation, while their force-torque history and deployment accuracy are recorded automatically. A resistive heater was embedded in the Elastic Memory Composite (EMC) laminates in the hinge to provide the heat necessary for actuation. The hinge was folded on the ground and deployed in space. A proximity sensor was attached to the end mass to determine the final position upon deployment. A second motion sensor was used to determine the deployment versus time history. The test articles were re-settable to allow for multiple deployments.
EMC materials tested in this experiment are stronger and lighter than current material used in space hinges and could be used in the design of future spacecraft.
Since composite materials are valued for being lightweight and strong, the hinges may have spin-off applications on Earth.
The crewmember applies power to the experiment, waits for the hinges to reach the appropriate temperature, and then proceeds to activate each hinge individually. Video and photo documentation of deployments is required. Reheating of the test articles will allow the crewmember to return the hinges to their stowed position using the control panel on the EMCH chassis. A full cycle (power on, hinge deployment, hinge reset) will be less than 90 Minutes. Once the hinges have been reset, deployments can be activated again. Data downlink of hinge deployments is required.
EMCH will be launched in a bag on the 12A.1. It will be transitioned to ISS and stored in a locker. During use, it will be attached to the outside of the ISS rack then returned. Photo and video will be required.
EMCH was successfully completed onboard the ISS during Expedition 15. The investigation was returned to Earth for a complete analysis by the investigator team in 2007. However, the preliminary assessment indicated that the experiment demonstrated the robustness and reliability of the TEMBO® EMC hinge in the zero-gravity environment. This test campaign consisted of both nominal and off-nominal conditions, with the final series of tests presenting the most challenging conditions for on-orbit TEMBO® hinges. The successful completion of these tests indicate that hinges meet the designed performance goals of a next-generation spaceflight-qualified actuator. Additionally, the science gained from this experiment confirms engineering assumptions used to design the TEMBO® EMC hinges, as well as other TEMBO® EMC deployable structures that are being developed for space applications. (Evans et al. 2009)
Ground Based Results Publications
Barret R, Francis W, Abrahamson E, Lake M. Qualification of Elastic Memory Composite Hinges for Spaceflight Application. 47th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference, Newport, RI; 2006 May 2006-2039.
Air Force Material Demand
Composite Technology Development, Inc.
Shown is the flight hardware containing several individual hinges enclosed visible through a lexan window that will be used for images of the hinges during testing. Image courtesy of Composite Technology Development, Inc.
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An alternative view of the flight hardware containing several EMCH hinges enclosed visible through a lexan window that will be used for images of the hinges during testing.
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NASA Image: ISS015E08404 - View of the Elastic Memory Composite Hinge (EMCH) Experiment assembly in the U.S. Laboratory/Destiny. Photo was taken during Expedition 15.
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NASA Image: ISS015E08434 - View of Expedition 15 astronaut and Flight Engineer (FE-2), Suni Williams, posing for a photo during the Elastic Memory Composite Hinge (EMCH) Experiment operations in the U.S. Laboratory/Destiny. The EMCH assembly (gold box) is visible on right of photo.
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