Usage Conditions May Apply 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 Usage Conditions May Apply 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 Usage Conditions May Apply 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

This is the engineering model for the Interplanetary Monitoring Platform A (IMP-A or Explorer 18). It is the first of a series of seven satellites designed to be launched before and during Apollo flights. IMP-A carried instruments designed to measure cosmic rays, the solar wind, and interplanetary magnetic fields beyond the earth's magnetic field. The sphere on top of the boom contained a sensitive magnetometer. Four windmill-like solar panels provided operating power. The satellite was launched on November 26, 1963 aboard a Delta vehicle resulting in a highly elliptical orbit that ranged from 110 to 122,800 miles. Data from the mission led to the discovery of a new layer of radiation beyond the Van Allen belt and confirmed the existence of a standing shock wave in the solar wind around the earth's magnetic field. This object was transferred to NASM by NASA in May 1976.

 Display Status

This object is on display in Space Science at the Steven F. Udvar-Hazy Center in Chantilly, VA.

Space Science
Object Details
Country of Origin United States of America Type SPACECRAFT-Uncrewed Manufacturer NASA, Goddard Space Flight Center
 Dimensions Overall: 4 ft. 5 in. tall x 2 ft. 5 in. wide x 1 ft. 1 in. diameter, 75 lb. (134.62 x 73.66 x 33.02cm, 34kg)
 Materials Mixed metals, solar cells, electronics
 Alternate Name IMP-A satellite Inventory Number A19761835000 Credit Line Transferred from the National Aeronautics and Space Administration Data Source National Air and Space Museum Restrictions & Rights Usage conditions apply
For more information, visit the Smithsonians Terms of Use.