Thanks a lot. Very interesting! > For this reason you usually have a large imbalance of one propellent to the other to keep the temperature down. So how large

Thanks a lot. Very interesting! > For this reason you usually have a large imbalance of one propellent to the other to keep the temperature down. So how large is that imbalance usually, or in the case of the Merlin 1C? > although the Space Shuttle Main Engines are a US-design example of Staged combustion. Is this, why their exhaust is so clean? How much more efficient is this engine compared to the Merlin? PS: I'm excited, this engine will be used again in the new super heavy lift [1] that NASA is developing, though obviously, I can't tell if its a good idea. [1] http://en.wikipedia.org/wiki/Space_Launch_System#Core_stage http://en.wikipedia.org/wiki/Space_Launch_System#Core_stage