LONG BEACH, Calif. The rocket equation has always had one
frustrating yet inevitable consequence: For every pound of
payload headed for, say, the lunar surface, NASA needs hundreds
more pounds of hardware and propellant during low Earth orbitand
many times that on the launchpad. For example, NASA's planned
Ares V vehicle (a modern-day replacement for the Saturn V that
delivered our first visitors to the moon over 30 years ago) will
weigh more than 3500 tons prior to launch from Cape Canaveral,
Fla., but land just 18 tons of weight on the moononly two tons
of which aren't the lander itself. Because each post-shuttle era
launch will cost billions of dollars, NASA is crunching the
numbers on how to get more lunar payload "bang" for its
transport vehicle "buck." Boeing proposed what might be the
ultimate problem solver at the AIAA (American Institute of
Aeronautics and Astronautics) Space 2007 conference here last
week: a low Earth orbit gas station, or propellant depot, to
refill the lunar-injection vehicle tank