In the mid 1980s, space shuttle flights had become relatively commonplace - at least in the view of some people at NASA. Somehow, the idea began to grow that it was time to have a "regular person" fly on the shuttle along with the astronauts. One of the people who tried to get on was none other than singer John Denver. John probably would have been a good choice - reasonably healthy and a pilot himself. But someone at NASA wanted to get young children more interested in the shuttle flights. (Which sounds kind of silly when you think about it. Shouldn't young children already be interested in something so exciting?)
Anyway, if you've ever suspected that the people at PBS are in cahoots with the government higher-ups, this is material to add to your conspiracy theories. Someone at NASA contacted Carroll Spinney, the puppeteer of Big Bird and Oscar on "Sesame Street." Big Bird was being offered the chance to fly higher than most of us will ever go in this lifetime! Big Bird on the space shuttle! Needless to say, that would have been a very memorable episode of Sesame Street. It likely would have gone on for weeks, the way the New Mexico and Hawaii episodes did, as well as the later "Slimey on the moon" series.
But it was not meant to be- the Big Bird puppet was, well, too big. It's quite a large costume, and not exactly the kind of thing that can be easily packed away. (Although it's fun to imagine what Big Bird would have looked like floating around in zero gravity. "Woaaaah!!!")
But there was another alternative- the idea arose of sending Big Bird's teddy bear, Radar, into space instead. Radar would have been easier to pack. And it still would have allowed for a "Sesame Street" connection to the flight. But again, somebody (probably the same guy who said John Denver couldn't go) said no, no teddy bear. So both Radar and Spinney were out, and eventually they decided to pick an even more "normal" person - a teacher. The teacher they eventually chose was Christa McAuliffe. Today, we remember her and her crewmates as the heroes who died in the tragic accident on the Challenger.
Had Spinney died on the space shuttle Challenger, the history of Sesame Street would have been quite different. How would they have handled this death? Thankfully, we'll never know the answer to that. Both Spinney and Denver lived on to do some great work. John Denver's great song "Flying for Me" was written in tribute to the Challenger crew.
Of course, Sesame Street did eventually go into space, if only on the TV show. Oscar's pet worm Slimey has the distinction of being first worm on the moon. He along with his crewmates flew to the moon in what must be the longest flight to the moon in history. (The Apollo guys got there in about 3 days; Slimey and crew took a couple of months!) That series, in a way, was the end of an era for Sesame Street. For after it was over, and the next season began, a new part of the show had been added called "Elmo's world." Nothing would be the same after that. :)
Here's a clip from an article from the Variety website mentioning the Spinney/Challenger issue:
Little-known fact: Spinney was approached by NASA to fly on the space shuttle. "They wanted the children of America to be more interested in NASA," he says. "They thought Big Bird could go up in it and we would do an actual production. I said yes ... but then they found out there was absolutely no place to store (the) Big Bird (costume), so I couldn't go. They selected Christa McAuliffe to go instead, and now you know the rest of the story. What a tragedy."
Spinney mentioned the tragedy during some of his personal appearances. You can read about them here: