How many space shuttles are there?

[Serena]

I don't remember.

[mickeyfan29]

there were 4- columbia (was), discovery, atlantis, and endeavour.

[Serena]

thank you.

[Towncrier]

And of course there was Challenger. I believe that they had originally planned to have only 4 working shuttles with the 5th one being used for spare parts. When the Challenger disaster occured, they made the spare parts shuttle flight worthy.

[Dan Murphy]

http://kids.msfc.nasa.gov/Rockets/ShuttleNames.asp

[mickeyfan29]

I know endeavour was built to replace Challenger. I think Columbia should been replaced as well but I read it went through a 17 month overall in September,1999

[Towncrier]

This was Columbia's 28th mission. According to one news report, the shuttles were designed for a useful life of 100 flights. Columbia first flew in 1981 and was the oldest shuttle in the fleet.