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X-Ray Spectroheliograph, OSO IV


Display Status:

This object is on display in the Boeing Aviation Hangar room at Steven F. Udvar-Hazy Center in Chantilly, VA.

X-Ray Spectroheliograph, OSO IV

Collection Item Summary:

This is a flight prototype grazing incidence X-ray telescope similar to one that flew on the OSO-IV satellite in October 1967. This telescope, located in the stabilized portion of the craft (the "sail"), was designed to obtain X-ray images of the sun. Incoming photons were focused onto the detector by means of a grazing incidence mirror covered by an aperture, which admitted a thin ring of light. The photoelectric detector included a cesium iodide scintillator and a photomultiplier tube as well as a series of filters. The telescope was designed and built at American Science and Engineering (AS&E) under the direction of Riccardo Giacconi.

This object was donated to NASM by AS&E in 2003.

Collection Item Long Description:

Data Source

National Air and Space Museum


Do not reproduce without permission from the Smithsonian Institution, National Air and Space Museum

Credit Line

Gift of American Science & Engineering Incorporated.


Mixed metals, glass, electronics


3-D: 101.6 x 11.4 x 27.9cm (40 x 4 1/2 x 11 in.)

Country of Origin

United States of America



Inventory Number


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