Astronomy's New Grail: The $1 Billion Telescope

The NY Times ^ | 123003 | DENNIS OVERBYE

[Physicist]

That's true, but you can scale the light gathering ability of a distributed telescope, whereas you can't do that with a single big one. If you have three telescopes, you can double your light gathering ability by adding three more. These can be (relatively) inexpensive units that have been prefabricated on Earth, and which can land on the moon by themselves (no constuction required). Ten years later, you can add more. Doubling the light gathering ability of a behemoth is probably never worth doing.