^* NASA has now all but completed a vastly more powerful (and at eight billion dollars, much costlier) device, the James Webb Space Telescope, which is due to be launched from the European spaceport in French Guiana, in April 2019. The telescope will float almost a million miles from Earth, well beyond the reach of any shuttle-hoisted repair teams; consequently, its manufacture, and the planning of the deep-space maneuvers that have to be successfully accomplished before it can make a single observation, are being rehearsed over and over, to ensure that everything works down to the finest detail.