Newsgroups: sci.space.history
From: henry@spsystems.net (Henry Spencer)
Subject: Re: Why was the LM double engined?
Date: Mon, 9 Aug 1999 14:14:27 GMT

In article <01bee25c$10d648e0$c58d4991@pc39807>,
Fokker Space <F.Space@fokkerspace.nl> wrote:
>Does anybody know the exact reason as to why the LM had both a descent and
>an ascent engine?
>Why didn't they have the ascent engine protrude through the descent stage
>and use it for both purposes.

There was serious discussion of doing it that way; there were arguments
both ways.  Having only one engine would certainly have been lighter,
although it would have meant propellant-feed connections between stages.
The convincing argument against it was that if there were two engines,
then you could recover from a failure of the descent engine by staging.
--
The good old days                   |  Henry Spencer   henry@spsystems.net
weren't.                            |      (aka henry@zoo.toronto.edu)