In article , Keith Willshaw keithNoSpa
writes
The RD-180 is a closed cycle engine meaning that the expanding
O2 used to power the fuel pumps is used in the combustion chamber
rather than dumped outboard as is the practise in American engines.

Is that the one that was subject to a BBC Horizon (or similar) where
some US rocket engineers were shown a warehouse full of engines they
themselves had considered impossible having failed to get them to work?

--
John