Endeavor was the replacement orbiter for the lost Challenger. Many of us in the program (at least in my area of payload flight control) were in favor of naming it Phoenix, “out of the ashes,” but either that was not submitted in the school naming contest, or NASA headquarters was in favor of staying away from references to the lost orbiter and its crew, and the name Endeavor was selected. Endeavor was somewhat different from the other shuttles in the fleet, since previous experience in constructing the others enabled some “lessons learned” to be incorporated into its design, most notably a difference in the shape and application of the heat shielding tiles.
I worked payload control for STS-47, which was Endeavor's second mission and the 50th mission of the program (flight numbers notwithstanding; launch delays often scrambled the number sequencing, so eventually the numbers became more about the order of manifesting rather than launch). It carried the Spacelab Japan payload, an all-NASDA payload, as well as the first Japanese astronaut, Mamoru Mohri, the first black astronaut, Mae Jemison, and the first husband/wife astronaut team, Mark Lee and Jan Davis. Ground-breaking life- and materials-sciences experiments were performed aboard, and considerable information was gleaned about extremely long duration space flights upon organisms as well as details of materials manufacturing in the microgravity environment.
It was a good bird. It performed well and reliably.
Each final flight of a given Shuttle pained me considerably. Somewhere along the way, I started personifying them. They were almost as much old friends as some of the astronauts were to me. Once they were decommissioned, the process began of stripping them of internal components, preparatory to being sent to their respective sites. Someone sent me newspaper clippings of the process, and others emailed photos, which I have filed for historical purposes, but truthfully I could hardly stand to look at the imagery. It was, for me, something akin to watching a friend's autopsy.
And above all, it was the end of an era. The end of MY era.