This Jack Kinzler, whose ingenuity saved Skylab, Signed Skylab I Envelope comes with a James Spence (JSA) COA, ensuring its authenticity. The envelope features the signature of Kinzler, a NASA engineer who played a key role in the development of Skylab, the United States' first space station. This collectible item is a must-have for space enthusiasts and those interested in the history of space exploration. Its originality and historical significance make it a valuable addition to any collection.