Historical Photo of the Month - January 2008

Project Deal/Explorer
Photograph Number 331-2903A

In October 1957 the Soviet Union launched Sputnik 1 and in November, Sputnik 2. In December the U.S. Navy attempted to launch the first U.S. satellite (Vanguard) but the launch vehicle failed and burst into flames on live public TV. Attention then turned to the JPL-Army team working on another satellite and launch vehicle - Project Deal, renamed Explorer after launch, with a Jupiter C launch vehicle. By that time, much of the work had already been done at JPL, Huntsville, and the University of Iowa.

Henry Richter, at left, Research Group Supervisor for Explorer Design and Development, holds the low power transmitter. George Ludwig, at right, was a graduate student from the University of Iowa working with Dr. James Van Allen on the cosmic ray instrument as his thesis project. He is holding this instrument in the photo. Ludwig temporarily moved his young family to Pasadena in November 1957, bringing the prototype instrument and related hardware packed in his car, while Van Allen was traveling home from a trip to the Antarctic. In anticipation of problems with the Vanguard program, the cosmic ray instrument had been adapted so it would also fit the measurements of the Deal satellite.

By January, the flight instruments (cosmic ray detector, micrometeorite detector, and temperature sensors) were fabricated, and the three upper stages were finalized at JPL, along with the ground communications system. Everything was brought together at Cape Canaveral for a successful launch on the night of January 31, 1958.

For more information about the history of Explorer, contact the JPL Archives for assistance. You can also check the Explorer web site for stories relating to the 50th anniversary of the Explorer launch. [Archival and other sources: Photo albums, photo indices, Dr. Henry Richter, Dr. George Ludwig, Explorer I (JPL 400-1321).]