“ The United States should go with a spaceplane design instead of a rocket. It would be MUCH more efficient, and help decrease launch costs to allow... (read full comment) ” 

Posted on November 21, 2009 at 5:14 PM EST

“ SpaceX Engines How reliable are these engines? Are they throttlable? If so, are these being sold? (read full comment) ” 

Posted on November 21, 2009 at 4:48 PM EST