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Space Test Program - Houston 3 - Variable emissivity radiator Aerogel insulation blanket Dual zone thermal control Experiment suite for Responsive space (STP-H3-VADER)


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

Experiment Overview

This content was provided by Andrew Williams, and is maintained in a database by the ISS Program Science Office.

Brief Summary

Space Test Program - Houston 3 - Variable emissivity radiator aerogel insulation blanket dual zone thermal control experiment suite for responsive space (STP-H3-VADER) investigation tests a variable emissivity radiator and a new form of multilayer insulation that uses Aerogel as the thermal isolator in order to protect the spacecraft from the harsh extremes of the space environment. The Aerogel material provides a more durable, lighter and cheaper alternative to traditional spacecraft thermal blankets. The use of this material could reduce the costs related to spaceflight by reducing the required spacecraft mass and increasing design efficiency.

Principal Investigator(s)

  • Andrew Williams, Air Force Research Laboratory, Wright-Patterson Air Force Base, OH, United States
  • Co-Investigator(s)/Collaborator(s)

  • Joy Stein, Jackson and Tull
  • Judd Sheets, Eclipse Energy Systems
  • Ken Shannon, Eclipse Energy Systems
  • Developer(s)

    United States Department of Defense Space Test Program, Johnson Space Center, Houston, TX, United States
    Air Force Research Laboratory, Kirtland AFB, NM, United States

    Sponsoring Space Agency

    National Aeronautics and Space Administration (NASA)

    Sponsoring Organization

    National Laboratory - Department of Defense (NL-DoD)

    ISS Expedition Duration:

    March 2011 - October 2013

    Expeditions Assigned


    Previous ISS Missions

    This is the first mission for STP-H3-VADER.

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    Experiment Description

    Research Overview

    • Space Test Program - Houston 3-Variable emissivity radiator aerogel insulation blanket dual zone thermal control experiment suite for responsive space (STP-H3-VADER) tests a robust, reconfigurable thermal control system that is focused primarily at small responsive space missions but is applicable to a wide range of missions and satellite classes.

    • This investigation tests a new form of multilayer insulation (MLI) protection using Aerogel material as the thermal isolator. This material is more durable, lighter and cheaper than traditional thermal blankets.

    • This investigation is one of four on the STP-H3 platform and is located at the EXPRESS Logistics Carrier site 3 (ELC-3).


    The primary data collected by VADER is the temperature-time history of the variable emissivity devices (VEDs) and the reference samples during each test run. In addition, the research team tracks the number of switching cycles, the emittance state, and the power for the VEDs. From these, the emissivity of the samples will be calculated in both the low and high emittance states as well as estimate the lifetime performance of the materials. As for the aerogel blanket, the research team measures the temperature gradient between the outer and inner layers of the blanket to assess the performance of the blankets. These thermal gradients provide performance data of the aerogel blanket as an insulator allowing for a comparison to traditional MLI systems. There are eight resistance thermal devices (RTDs) integrated into the blanket by design and additional four mounted to the bracket to which the blanket attaches. Any performance degradation due to exposure to the space environment will be noted. The results for both of these technologies are to be used to design the final thermal control approach to transition to responsive space-class spacecraft.

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    Space Applications

    The STP-H3-VADER investigation provides spacecraft performance information intended to reduce the design and development time and costs of related satellite components with regards to spacecraft thermal protection.

    Earth Applications

    The spacecraft that these technologies apply to include those supporting earth-bound communications. The improvements that STP-H3- VADER intends to demonstrate creates more robust and capable satellites that are used to interface with ground systems.

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    Operational Requirements

    Health, Status and Experiment Data are downlinked via standard ISS 1553 communications protocols. STP-H3 is comprised of a compliment of 4 individual investigations that shares a command window of 4 hours a day throughout the week. TReK is used for commanding and downlinking of data from the investigation hardware to the ground. There are 5 remote TReK Payload Operation Control Centers (POCC) that coordinate with the Payload Operations Integration Center (POIC) at MSFC via IVoDS.

    Operational Protocols

    STP-H3 is an external investigation that does not require crew internal operations;therefore, direct communication is not required. The TReK operators communicate with the POIC, specifically the Payload Rack Officer (PRO), to be enabled for commanding. The PRO in-turn communicates with the Payload Operations Director (POD) for authorization to command.

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    Results/More Information

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    Related Websites

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    image Schematic showing location of the STP-H3-VADER investigation.
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    image Preflight image showing the location of the STP-H3- VADER investigation.
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    Information provided by the investigation team to the ISS Program Scientist's Office.
    If updates are needed to the summary please contact JSC-ISS-Program-Science-Group. For other general questions regarding space station research and technology, please feel free to call our help line at 281-244-6187 or e-mail at JSC-ISS-Payloads-Helpline.