It depends on which shuttle is scheduled for a mission. The only spaceworthy shuttles right now are Atlantis, Endeavour and Discovery.

There are technically four, but only three are spaceworthy:

OV-103 aka Discovery

OV-104 aka Atlantis

OV-105 aka Endeavour

OV-101 aka Enterprise exists but is a non-flying shuttle. It was built as a demonstrator but was never built to fly in space although in theory it could have been dismantled and made spaceworthy -- a very expensive proposition.

Although the space shuttle Enterprise was the first shuttle built and test flown, it never had a space flight. The first shuttle to be launched into space was the Columbia, it was first launched on 12 April 1981. Columbia was the first spaceworthy shuttle in NASA's fleet.

The space shuttle Columbia was the first spaceworthy shuttle that entered service in April 1981. It completed 27 missions, before being destroyed shortly before completion of the 28th, during re-entry into the earth atmosphere on February 1st 2003.

All seven crew members died;

Commander: Rick D. Husband,

Pilot: William C. McCool

Payload Commander: Michael P. Anderson

Payload Specialist: Ilan Ramon

Mission Specialist: Kalpana Chawla

Mission Specialist: David M. Brown

Mission Specialist: Laurel Clark