This artist's concept depicts James Webb Space Telescope at work. Webb, which is scheduled for launch this fall, is the largest space telescope ever built. It is also the most complicated and expensive, with a total price tag nearing $10 billion. It will assume a station roughly one million miles from Earth, where it will have a clear view of the cosmos, unobstructed by Earth or the Moon. Its mirror (gold surface, at top) consists of individual segments that will unfold and lock into position in space. The telescope will study newborn stars, exoplanets, early galaxies, and many other objects and phenomena. It will be protected from the Sun's rays by a multi-layer shield (bottom), which makes it look like the telescope is surfing through space. [NASA]