The Postal Service commemorated the Challenger Space Shuttle, STS-7, with the issuance of a 3-dollar stamp on June 22, 1995 in Anaheim, California.
Designed by Phil Jordan of Falls Church, Virginia, the stamp features the Challenger Space Shuttle. The shuttle's name was printed in microtype and hidden within the image for security reasons. The mission number appears in the lower right corner of the design, outside the image area, directly opposite the 1995 year inscription.
This was the first time that the Postal Service used an actual photograph from a National Aeronautics and Space Administration mission, instead of an illustration based on a photograph.
The stamps were printed by Ashton-Potter USA, Ltd., in panes of 20 and in the offset/intaglio process.
Reference: Postal Bulletin (May 11, 1995)