lot of 34 Colorano Silk Space Covers
2 Yuri A. Gagarin First Man In Space Russian FDC's
1972 Apollo 16 Lift Off
1973 Project Skylab - Second Spacewalk
1974 Project Skylab - Splashdown
1977 Project Voyager Lift Off
1978 Space Achievements A.S.D.A Interpex '78 Official Cover
1979 Apollo 11 10th Anniversary National Postage Stamp Show Official Cover
1980 Miami Stamp Expo '80 Space Shuttle x 3 two different Cachet's
1985 Challenger 51-F  19th Space Shuttle Mission
1985 Challenger 51-I 20th Space Shuttle Mission
1985 ASC-1 Satellite Deployed 20th Space Shuttle Mission
1989 Magellan Spacecraft to Mars  29th Space Shuttle Mission
1991 Launch of the Columbia STS-40
1991 Return of the Columbia STS-40
1992 Space Shuttle Discovery STS-53
1993 Gemini Astronaut Inductees
1993 Space Shuttle Discovery STS-56
1993 Spartan - 201 Satellite Deployed
1993 Spartan - 201 Satellite Recaptured
1993 Space Shuttle Columbia STS-55
1993 Launch of the of the Discovery STS-51
1993 Space Shuttle Columbia STS-58
1993 Launch of the Space Shuttle Columbia STS-58
1993 Return of the Space Shuttle Columbia STS-58
1993 Space Shuttle Endeavour STS-61
1993 First Extravehicular Activity (EVA) 59th Space Shuttle Mission
1993 Second Extravehicular Activity (EVA) 59th Space Shuttle Mission x 2
1993 Third Extravehicular Activity (EVA) 59th Space Shuttle Mission
1994 Office of AeroNautics and Space Technology (OAST-2) 61ST Space Shuttle Mission
1994 Return of the Columbia STS-65

All the covers look in nice shape, I don't see any staining,

Please ask all questions before bidding.
thanks