NASA’s James Webb Space Telescope – inside the Ariane 5 rocket it will ride to space – has arrived at its final location on Earth: the Arianespace ELA-3 launch complex at Europe’s Spaceport located near Kourou, French Guiana. Webb is scheduled for liftoff at 7:20 am EST Saturday, Dec. 25. With Webb and its rocket securely on the pad, the team will run electrical diagnostics to ensure all lights are green for launch. Teams will power on the observatory while at the launch pad to run one final aliveness test to ensure all systems have power and are working before liftoff.