THE SPACE-SHUTTLE: COUNTDOWN TO COMEBACKDiscovery ChannelFebruary 16, 2006 9pm ET1x60 min. documentaryIt has been more than two years since the space shuttle Columbia ripped apart in the Texas sky and fell to the Earth in a shower of hot metal. In the wake of the tragedy, NASA scientists and engineers have been consumed by a single desire...to get America's space program back on track.