Valve-shaped 7.75″ metal rod used in the successful launch of the Explorer 1 satellite on January 31, 1958. An integral part of the rod-spring combo designed to eject the plug, umbilical cord, and boom from the Jupiter C booster. The rod is suspended by wire to an 8.25 x 11.75 presentation sheet affixed to a same-size mat. In fine condition, with expected wear and grease to exterior. Accompanied by a copy of a handwritten letter of provenance from former NASA employee Russell Clay, in part: “I am sending you some souvenirs of our last satellite firing in a package which you should get in a day or two…I will tell you what they are, you can tell your dad and he can explain what they do. The valve shaped rod with a spring around it is used to eject the boom.”