Hi All

A couple of articles arguing over CATS...

Joe Latrell on CATS paper by Dinkin et.al.

Sam Dinkin responds

...interesting point was that Elon Musk is aiming at $250/kg launch costs by 2010. That's impressive - if true. Way cool - if it happens. Makes launching Space Elevator components even cheaper, and Lunar Space Elevator materials by extension.

My personal thoughts on the CATS issue is that high-volume rocketry is a good leg-up, but real space access won't happen until the SE or similar projected energy systems (say laser-launch or microwave-disk etc.) come online.

However, for Earth, SEs suffer from the need for challenging power supplies early in the launch. An SE massing 20 tons and climbing at 100 m/s needs ~ 20 MW power, which is really hard to supply. On the Moon it's 1/6 th that with no atmospheric losses. Plus the "drop off" rate is much faster - gravity's demands lessen rapidly. Huge flimsy solar collectors can be used without fear of wind damage.

Go SpaceX!

Adam