Maybe it's just me, but it appears as though some child got left behind and then went to work for NASA's publicity department:
Yes, someone spelled the name of the shuttle wrong. Not the word, mind, but the shuttle Endeavour is actually spelled with the British "u" in the end because it's named after James Cook's ship and he was a Brit. And those Brits lurve their extraneous* u's...
Now, to be fair, rocket scientists are supposed to be good at *math* moreso than spelling, but still, one would suspect that someone working in advertising or PR would know how to spell the thing they were publicizing, no?
More on this here, if you're interested
* No, this one is actually necessary.