dscc5887.jpg

The sign accompanying the Explorer/Beacon backup unit. It reads

Explorer I

America's First Successful Satellite

Explorer I was America's first space success. Four additional Explorers were launched in 1958, but only two achieved orbit.

The final Explorer (Explorer VI) was renamed Explorer-Beacon. The slightly elongated spacecraft was modified to carry a tightly packed, highly reflective silver mylar balloon. Once in orbit, the upper section of the satellite would be jettisoned and the 12-foot-diameter balloon would inflate. Scientific experiments to bounce radio and light signals off the inflated balloon from ground stations were planned. However, the satellite failed to reach orbit during its only launch attempt in October 1958.

The Explorer on display above was an actual backup unit to the original satellite. It was modified for the Beacon program (notice the silver balloon still folded up in the satellite), but the program was cancelled before this modified unit could be launched.

The Beacon mission was the first (and only) launch of a Juno I in which NASA participated (NASA began operations on October 1, 1958, and the Beacon launch occurred on October 23).