Talk-Polywell.org

XCOR Aerospace today announced the firing of a full piston pump-powered rocket engine. According to the company, “This breakthrough is the foundation for fully reusable spacecraft that can fly multiple times per day, every day. It is a game changing technology that has the power to fundamentally alter the way we as a society view, visit, and utilize the abundant resources around our planet and in our solar system.”

The full article:

http://moonandback.com/2013/03/26/xcor- ... echnology/

Weird warddrobe.
Very nerdy. Not that there is anything wrong with that

Some speculation. Pumping fuel to the engine may be done in three ways- pressure fed, turbine and piston engine. My understanding is that the turbine advantage is that it can pump more with a lighter and smaller package. A piston pump might be more durable, but is the weight penalty tolerable? That is the real question.

Note that gravity and some other feed mechanisms might be considered. How about a Wankel engine?

Dan Tibbets