Re: [ERPS] Multiple chamber engine

[Ian Woollard]

Michael Wallis wrote:

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The NUMBER of engines will be a big debate, but we're most
likely to develop multi-engine vehicles in the foreseeable future.

There's also the Russian N-1 'moon' rocket as a datapoint. It had:

1. 30 NK-33 LOX/kerosene engines; 10.1 million lb. total thrust.
2. 8 NK-43 LOX/kerosene engines; 3.1 million lb. total thrust.
3. 4 NK-39 engines; 360,800 lb. total thrust.
4. 1 NK-31 engine; 90,200 lb. thrust; trans-lunar boost stage.
5. 1 engine; 19,200 lb. thrust; lunar orbit insertion & initial lunar descent stage.

They NEVER managed to launch it successfully ;-)

I include it as an example of what you have to start to worry about if go with a lot more engines.

(The biggest problems they had was that their turbopumps weren't able to spool up quickly enough to keep the rocket pointing in the right direction, all those engines basically guaranteed multiple failures, and the system that detects engine failures tended to shut down the wrong engine... leaving that engine on fire, and so with a LOX supply- ouch.)

Based on the Russian experience I think I would vote for having less than 44 engines ;-)

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    Michael

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Michael Wallis   KF6SPF       (408) 396-9037        [EMAIL PROTECTED]
President, Wallis International                  http://www.wallis.com