Space exploration tribute cover

The purpose of the particular "Space Tribute" cover was to promote the Endeavor Launch on September 30th, 1994. The cover is a souvenir of a stamp , one of 500,000 flown in space onboard the mission which is framed within the gold window.

This was a promotional issue from the United States Postal Service in cooperation with the National Aeronautics and Space Administration to provide philatelists with an "authentically flown in space" stamp, utilizing the most recent issued space-themed stamps, the 25th anniversary first class and Express Mail rate which was issued on July 20th, 1994.