kaled - 6:40 pm on Mar 17, 2009 (gmt 0)

Based on the current maximum mirror size...

Using an array of small mirrors rather than a single large mirror, it may be possible to achieve a higher resolution for a given mass. I have no idea if spy satellites use this approach but I have a vague idea that it has been proposed for a new deep-space telescope.

The maths should be similar to that used with arrays of radio telescopes.

Kaled.