The fifth of the US space shuttles. It made its first flight on 7 May 1992. Endeavour was built as a replacement for Challenger, destroyed in an explosion shortly after lift-off in 1986. It was used for the mission to repair the Hubble Space Telescope in 1993 and for the first assembly of the International Space Station (ISS) in 1998 that connected the Unity module to the Zarya module, as well as five more trips to the ISS before the Columbia disaster in 2003. It made the last shuttle flight before that tragedy, being launched on 23 November 2002 to change the resident crews and install truss hardware. This was Endeavour's nineteenth flight.