X-15 test pilot and astronaut, killed in a flying accident in 1967. Commemorative cover with a stamped cachet honoring the X-15 and Edwards Air Force Base, signed under the cachet in black ink, “Mike Adams.” Cover also bears an April 28, 1967, Edwards cancellation stamp. In fine condition, with lined out collector’s notation under signature, and a small address label to lower right. One of the rarest and most difficult to acquire space autographs. COA Scott Cornish and R&R COA.
