Space Test Program - Houston 4 - Global Awareness Data-Exfiltration International Satellite (STP-H4-GLADIS) - 09.17.14

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Science Objectives for Everyone
Space Test Program - Houston 4 - Global Awareness Data-Exfiltration International Satellite (STP-H4-GLADIS) demonstrates the performance of small, lightweight and low-power antennas. It includes dual-channel Ultra High Frequency (UHF) and Very High Frequency (VHF) antennas to provide two-way communications to an ocean-monitoring network of sensors. During a one-year mission, the investigation enables new types of data-collecting spacecraft, including networks of unattended sensors using small, low-cost satellites.

Science Results for Everyone
Information Pending

The following content was provided by Jay Middour, and is maintained in a database by the ISS Program Science Office.

Experiment Details

OpNom STP-H4

Principal Investigator(s)

  • Jay Middour, Naval Research Lab, DC, United States

  • Co-Investigator(s)/Collaborator(s)
    Information Pending
    Naval Research Laboratory, Washington, DC, United States

    Sponsoring Space Agency
    National Aeronautics and Space Administration (NASA)

    Sponsoring Organization
    National Laboratory - Department of Defense (NL-DoD)

    Research Benefits
    Information Pending

    ISS Expedition Duration
    March 2013 - March 2015

    Expeditions Assigned

    Previous ISS Missions
    Information Pending

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    Experiment Description

    Research Overview

    • Spaceflight testing is required for miniature, lightweight spacecraft components and systems.

    • The Space Test Program - Houston 4 - Global Awareness Data-Exfiltration International Satellite (STP-H4-GLADIS) measures how well small, lightweight, power, thermal, antenna, and radio frequency technologies work during a one year space flight.

    • Successful demonstration will enable cost effective space missions such as management and collection of distributed unattended sensor arrays using small, inexpensive satellites.


    The objective of the Space Test Program - Houston 4 - Global Awareness Data-Exfiltration International Satellite (STP-H4-GLADIS) hosted payload experiment is to design, build and test an inexpensive space system to collect and share global situational awareness data.  The purpose of the payload is to extract data from unattended maritime and terrestrial sensors.  The payload is designed to survive for three years in low Earth orbit using standard commercially available electronics.  The two-way data extraction payload operates at UHF frequencies between 385 and 410 MHz. The communications protocol is based upon the previously designed Ocean Data Telemetry Micro-satellite Data Link.  The STP-H4-GLADIS system is optimized to communicate with unattended sensor arrays outfitted with a small, inexpensive, and low power communications terminal.  The STP-H4-GLADIS hosted payload uses a specially designed small lightweight antenna array to ensure reliable communications between the space payload and the maritime and terrestrial sensors.  

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    Space Applications

    The investigation demonstrates miniaturized power supplies, thermal protection, antenna and radio frequency technology for a nano-satellite system. Improved miniaturized devices will enable future generations of very small satellites, which will be less expensive to launch.

    Earth Applications

    Networked sensors provide critical data for un-wired regions of the planet, including rural areas and disaster areas where communications are interrupted. Improved designs for distributed, unattended sensors will improve safety and environmental monitoring.

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    Operational Requirements

    The payload is operated for approximately 200 orbital passes overhead of ground test sensors.  The initial 50 passes should take place as early as possible after launch in order to assess the health of the payload.  The remaining passes take place during the remainder of the flight.  Additional passes may be required if more ground test sensors are identified.  The payload transmitter is not operated during certain ISS operations such as crew extravehicular excursions and during certain portions of resupply craft operations.  The payload transmitter is equipped with a triple redundant safe mechanism to ensure RF safety.

    Operational Protocols

    Initial on-orbit checkout verifies payload commanding, telemetry, power, thermal and RF systems.  Thereafter the STP-H4-GLADIS data extraction payload operates as opportunity permits while overhead of ground test equipment.  The payload is commanded to use its transmitter to interrogate the ground test equipment.  The payload then receives data transmitted from the ground equipment.  This extracted data is sent back to the experimenter’s laboratory via the ISS communications link.  The payload and the data are analyzed for quality over a variety of collection geometries and local weather conditions.  

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    Results/More Information

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    Related Websites

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    image Computer generated image of GLADIS.
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