NASA created posters for each shuttle with every mission the shuttle flew.
The Space Transportation System (STS)
...the crews of Challenger and Columbia...in memory still bright...will not be forgotten
The NASA download images are impressive even at 34" x42". The Atlantis poster does not include the last mission (STS 135) however I have added that mission logo to my copy (below).
Images are courtesy of NASA. See annotation about the Atlantis poster.
Where you can visit the retired shuttles:
The symbol holding "STS" and "135" is the Greek OMEGA - it represents the end of all Shuttle missions.
STS-135 shuttle ATLANTIS July 8, 2011 - July 21, 2011.