Mercury astronaut who perished in the Apollo 1 flash fire that also claimed the lives of Chaffee and White. TLS signed “Virgil I. Grissom,” one page, 8 x 10.5, NASA letterhead, August 4, 1961. Two weeks after his launch into space, Grissom thanks a supporter. 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 of our successful space flight. Project Mercury is planning for more flights in the future. Let us hope that success follows success.” Accompanied by the original mailing envelope. In fine condition, with expected mailing folds. R&R COA.