(L-R) NASA Administrator Michael Griffin, NASA Assistant Administrator for Public Affairs David Mould and NASA Space Shuttle Manager Wayne Hale watch as the space shuttle Discovery comes in for landing at NASA's Kennedy Space Center in Florida on November 7, 2007. The shuttle completed a 15-day STS-120 mission to the International Space Station that included on-orbit construction of the station with the installation of the Harmony Node 2 module and the relocation of the P6 truss. (UPI Photo/Bill Ingalls/NASA)