James Webb Space Telescope, designed to be the most powerful astronomical instrument ever sent to space, sits atop its Ariane 5 rocket in French Guiana, ready for launch on Christmas morning. The infrared telescope is designed to study exoplanets, young and dying stars, and the earliest stars and galaxies in the universe, among many other subjects. Webb is also the most expensive space telescope in history, with costs near $10 billion. It will travel to a point in space roughly one million miles from Earth, where it will unfold the segmented panels that comprise its primary mirror. That location will provide a better view of the sky than Earth orbit, and reduce the light and heat reflected from Earth and the Moon. [j]