Re: Depressing
You're spot on except for one minor point... these engines never had a successful launch. There were being designed to power the Russian manned moon program but the program was shut down for two reasons. The first was that the US got there first. The second was that the designer was killed on the Launchpad when a rocket being fueled blew up. He never finished refining the design. So... proven? err.... No!!
However, the design still holds a lot of promise if they can get the thing to stop blowing up.