Satellite, Explorer I

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    Explorer

    Long bullet shaped cylinder with an aerodynamic nose cone painted with grey and white stripes.

    1 of 8

    Usage Conditions Apply

    There are restrictions for re-using this media. For more information, visit the Smithsonian's Terms of Use page.

    IIIF provides researchers rich metadata and image viewing options for comparison of works across cultural heritage collections. More - https://iiif.si.edu

    View Manifest

    View in Mirador Viewer

    Explorer

    Long bullet shaped cylinder with an aerodynamic nose cone painted with grey and white stripes.

    2 of 8

    Usage Conditions Apply

    There are restrictions for re-using this media. For more information, visit the Smithsonian's Terms of Use page.

    IIIF provides researchers rich metadata and image viewing options for comparison of works across cultural heritage collections. More - https://iiif.si.edu

    View Manifest

    View in Mirador Viewer

    Explorer

    Long bullet shaped cylinder with an aerodynamic nose cone painted with grey and white stripes.

    3 of 8

    Launch of Explorer I

    Launch of Jupiter-C/Explorer 1 at Cape Canaveral, Florida on January 31, 1958. 

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    Explorer 1 (backup)

    Explorer 1 backup on display in the Boeing Milestones of Flight Hall at the Museum in Washington, DC.

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    Explorer I Satellite

    Explorer I satellite.

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    Dr. William H. Pickering, Dr. James A. van Allen, and Dr. Wernher von Braun Holding the Explorer 1 Satellite

    Shown here are the three men responsible for the success of Explorer 1 (America's first Earth satellite), which was launched 31 January 1958.  At left is Dr. William H. Pickering, former director of JPL, which built and operated the satellite.  Dr. James A. van Allen, center, of the State University of Iowa, designed and built the instrument on Explorer that discovered the radiation belts which circle the Earth.  At right is Dr. Wernher von Braun, leader of the Army's Redstone Arsenal team which built the first stage Redstone rocket that launched Explorer 1.

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    Illustration Showing the Van Allen Belts

    This diagram showcases the Van Allen belts, which were first detected by instruments aboard Explorer 1 and Explorer 3. The Van Allen belts were the first major scientific discovery of the space age.  

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Display Status:

This object is on display in the Boeing Milestones of Flight Hall exhibition at the National Air and Space Museum in Washington, DC.

This artifact is one of several replicas and flight spare Explorer 1 spacecraft in the collection. It was identified as a fully instrumented flight spare of the Explorer-1 satellite attached to an empty fourth stage Sergeant rocket when it was transferred in 1961 to the collection by the NASA Jet Propulsion Laboratory, the builder of the object. It was initially displayed in the Arts and Industries Building. It was on loan to the Museum of Medical Progress in Madison, WI, (4/70-6/70) and briefly to WETA in Arlington, VA, (6/75-7/75). It was inspected in late 2005 and found to be empty of instrumentation save for the micrometeoroid sensor. But markings in the interior frame indicate it to be "Payload II" which was indeed the flight backup that was sent to James Van Allen's laboratory in Iowa for inspection and testing and then returned to JPL in 1958. That payload was donated to NASM by George Ludwig in 2006 (A20060086). The satellite is displayed in the Milestones of Flight Gallery at NASM.

Explorer-1 was the United States' first successful orbiting satellite. Following the failure of Vanguard in December 1957, the JPL- ABMA group was permitted to adapt the Jupiter-C reentry test vehicle to carry an instrumented satellite into earth orbit. The resulting Explorer-1 satellite was successfully launched and placed into Earth orbit on January 31, 1958. Explorer-1, also known unofficially as Satellite 1958 alpha, transmitted data on micrometeorites and cosmic radiation for 105 days. Data from this and two subsequent Explorer satellites led to the discovery by James Van Allen of a belt of intense radiation surrounding the earth.