TLS signed "Alan B. Shepard, Jr.," one page, 8 x 10.5, NASA letterhead, May 31, 1961. Letter to Reverend W. Frederick Addison, in full: "Thank you for your congratulations and thoughtfulness. The people of the United States, indeed the entire free world, are very happy and proud because of our successful space flight. Project Mercury is planning for more flights in the future. Let us hope that success follows success." Shepard adds a brief handwritten sentiment after his signature: "My warm personal regards and thanks." In fine condition, with a few bands of toning and a smudge to postscript. Accompanied by a full letter of authenticity from Zarelli Space Authentication. Shepard became the first American in space when his Mercury-Redstone 3 spacecraft launched from Cape Canaveral's Launch Complex 5 on May 5, 1961. Although the flight of Freedom 7 lasted a mere 15 minutes and 22 seconds, its singular overall success laid the framework for all successive manned American spaceflight. A fantastic letter written in the same month as his historic voyage.