That idea has been around for a while; it is pretty darn neat though.
The next 2-3 decades will prove to be very interesting as far as space exploration is concerned with the new moon missions being planned that should ultimately lead to mankind’s first moon base.
Any manned mission to Mars would then probably launch from the moon base as it would be a LOT easier and cheaper to escape the lunar gravity rather than fighting Earths much higher gravity.
You can keep up with alot of interesting science news at
www.rednova.com