Turtles Trading Post- Space Exploration 1991 FDC  #2568-77 Artcraft- 10 Covers

Very nice set of 10 different covers.  The stamps include:

2568 Mercury, Mariner 10

2569 Venus, Mariner 2

2570 Earth, Landsat

2571 Moon, Lunar Orbiter

2572 Mars, Viking Orbiter

2573 Jupiter, Pioneer 11

2574 Saturn, Voyager 2

2575 Uranus, Voyager 2

2576 Neptune, Voyager 2

2577 Pluto

No markings on back, never sealed