L2 and the James Webb Space Telescope
The James Webb Space Telescope (red) will orbit the Sun at a special gravity island called L2 (Lagrange Point 2). L2 is located 1,519,000 km beyond the Earth (blue).
Ordinarily, being further from the Sun would mean that a spacecraft would orbit the Sun more slowly, and it would quickly fall behind the Earth. However, the spacecraft feels the combined gravity of the Sun and Earth, and a stronger pull of gravity means a faster orbit. If the distance is just right, the increased orbit speed causes it to match the Earth’s orbit speed, and it stays permanently in the Earth’s shadow.
For those who are interested in how location of the L2 point is computed, see here: http://www.maththoughts.com/blog/2011/l2-what-is-it-and-where-is-it/