*** FIRST TWO LETTERS ARE SIGNED BY GORDON COOPER & DATED JUNE 25, 1970 & JULY 29TH, 1970.
*** THE THIRD LETTER IS SIGNED BY CHARLES GORDON & DATED MAY 6TH, 1973.
*** EACH VINTAGE LETTER LETTER HEAD " NATIONAL AERONAUTICS AND SPACE ADMINISTRATION LYNDON B. JOHNSON SPACE CENTER, HOUSTON, TEXAS 77058 ".
*** LETTERS ARE IN VINTAGE USED CONDITION.
*** GENUINE VINTAGE NASA LETTER EXAMPLES.