(1) NASA Manned Spaceflight Crew Signed Covers

Mercury Redstone-3 and MR-4
Mercury Atlas-6 and MA-7
Mercury Atlas-8 and MA-9
Gemini Titan-3 and GT-4
Gemini Titan-5 and GT-7
Gemini Titan-6 and GT-8
Gemini Titan-9 and GT-10
Gemini Titan-11 and GT-12
Apollo 7: First Apollo 3-man Earth orbital flight
Apollo 8: First manned lunar orbital flight
Apollo 9: First test of the LM in earth orbit
Apollo 10: First CSM and LM Lunar orbit flight
Apollo 11: Armstrong and Aldrin walk on the moon
Apollo 12: Second lunar landing
Apollo 13: Oxygen tank explosion cancels moon land
Apollo 14: Alan Shepard commands 3rd lunar landing
Apollo 15: Fourth lunar landing featured a rover
Apollo 16: John Young commands 5th lunar landing
Apollo 17: Cernan leaves final footprints on moon
Skylab 1/SL-2
Skylab 2/SL-3
Skylab 3/SL-4
Apollo-Soyuz Test Project (ASTP)
STS-1 and STS-2
STS-3 and STS-4
STS-5 and STS-6
STS-7 and STS-8
STS-9/Spacelab-1 and STS-41B
STS-41C and STS-41D
STS-41G and STS-51A
STS-51C and STS-51D
STS-51B and STS-51G
STS-51B and STS-51I
STS-51J and STS-61A
STS-61B and STS-61C
STS-51L Challenger
STS-26 and STS-27
STS-29 and STS-30
STS-28 and STS-34
STS-33 and STS-32
STS-36 and STS-31
STS-41 and STS-38
STS-35 and STS-37
STS-39 and STS-40
STS-43 and STS-48
STS-44 and STS-42
STS-45 and STS-49
STS-50 and STS-46
STS-47 and STS-52
STS-53 and STS-54
STS-58 and STS-55