This is a lithograph of two Priority Mail stamps that were issued at the World Stamp Expo 2000 in Anaheim, CA, an international philatelic event hosted by the USPS. The left stamp, based on a computer-generated NASA image, shows a hologram of a space shuttle docking with the International Space Station. Astronauts working outside the space station are featured on the stamp at the right. That stamp image was developed from an artist's conception. The selvage photograph is of astronauts David Leestma and Kathryn Sullivan working in space shuttle Challenger's open cargo bay in October of 1984.