The James Webb Space Telescope is planned as a successor to the Hubble Telescope, and is currently scheduled for launch in 2013. It's shown here in a computer-generated artist's conception. The giant dish is a folding mirror, 21 feet across, that will focus light from distant stars and other objects. Scientists hope, among other things, that the new telescope will detect traces of the Big Bang, and help find planets orbiting other stars.
(Goddard Space Flight Center/NASA)