After over 20 years of service NASA's space shuttle Endeavour is ready for its final flight.<br/> <br />But this time it's not soaring into orbit, it's heading west to Los Angeles to begin a new role as museum exhibit.<br/> <br />Built to replace Challenger, the shuttle lost in a 1986 launch accident, Endeavour rode piggyback on a specially modified Boeing 747.<br/> <br />The shuttle had a relatively short lifespan, flying 25 missions with 299 days in space.<br/> <br />Those missions included repairing the Hubble Space Telescope and building and outfitting the International Space Station.<br/> <br />Its final mission in May 2011 was to deliver and install a 2 billion dollar particle detector on the ISS that is searching the cosmos for signs of dark matter and other phenomena.
