Enterprise, Columbia, Challenger, Discovery, Atlantis, Endeavour

I remember when Enterprise took its flight off the back of an airplane way back in 1976.
We’ve followed the shuttle program since then, although it has become less riveting as the successful missions piled up. It’s always been cutting-edge dangerous but repetition made us blasé.
They had a fleet of 4 shuttles in service. Columbia was the first, launched in 1981, followed in 1983 by Challenger, in 1984 by Discovery, and in 1985 by Atlantis.

Then Challenger went and blew up on liftoff in 1986. The missions had been going off so well they had even brought a school teacher along for the ride. Besides bringing home the inherent danger of riding a missile, it also created a bunch of jokes that those of us of a certain age will always remember.
What was the last thing Christa McAuliffe said? - Hey, what does this big red button do?
What does NASA stand for? - Need Another Seven Astronauts.

After a suitable delay, the missions went on. They launched Endeavour in 1992 to bring their fleet back up to 4 shuttles and missions progressed again. In 2003, Columbia disintegrated upon reentry due to a failing of its thermal shield. That caused almost a two year delay before the next mission.

Rather than risk more accidents, they have phased out the remaining shuttles this year with Discovery finishing her 39 mission in February, Endeavour finishing her 33 mission in May, and Atlantis just finishing her 25 mission today.

It’s the end of an era.