Rare pre-moon mission Duke ALS Moonwalker on the Apollo 16 mission. Rare ALS, one page, 5.25 x 7.5, NASA letterhead, no date. Letter written to David, mentioning the upcoming Apollo missions. In full, “You are right on. Those are some of the same arguments I use. Keep up the good work. I think we’ll convince many people of the programs value.” Under his signature Duke adds, “No material out yet on Apollo 16. Much like Apollo 15.” In fine condition, with mild strip of toning along top and right edge, lightly affecting some of the text, and a few creases and wrinkles. R&R COA.