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 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 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 a vacuum tube used in the U.S. Navy Space Surveillance Fence. The system's three transmitter stations, located across the southern United States, emitted a continous wave of radio energy in a narrow fan-shaped pattern. Together the beams extended about 5,000 miles from west to east and about 15,000 miles into space. Any object passing through a beam was illuminated and the reflected signals acquired by one or more or the six receiving stations along the same latitude as the transmitting stations. Each of the receiving stations had many hundreds of these vacuum tubes to amplify the reflected signals during the early years of the system's operation. Unclassified and classified catalogs of all known objects in orbit were prepared from data from the Space Surveillance Fence and other sensors.

The Air Force assumed operation of the Space Surveillance Fence from the Navy in 2004. It was decommissioned in 2013, to be replaced by a space-based system.

RCA manufactured the vacuum tube. The Air Force transferred it to the Museum in 2014.

 Display Status

This object is not on display at the National Air and Space Museum. It is either on loan or in storage.
Object Details
Country of Origin United States of America Type EQUIPMENT-Electronics Manufacturer RCA
 Dimensions 3-D (Overall): 16.5 × 27.9cm, 7.3kg (6 1/2 × 11 in., 16lb.)
 Materials Non-Magnetic White Metal
Copper Alloy
Ferrous Alloy
Ink
Paint
 Inventory Number A20181525000 Credit Line Transferred from the United States Air Force Data Source National Air and Space Museum Restrictions & Rights Usage conditions apply
For more information, visit the Smithsonians Terms of Use.