Path: utzoo!attcan!uunet!lll-winken!ncis.llnl.gov!helios.ee.lbl.gov!pasteur!ucbvax!decwrl!hplabs!hpda!hpcuhb!hpsel1!campbelr
From: campbelr@hpsel1.HP.COM (Bob Campbell)
Newsgroups: sci.space.shuttle
Subject: Re: QUESTION: Shuttle round trips to the moon?
Message-ID: <17360002@hpsel1.HP.COM>
Date: 19 Jan 89 22:51:15 GMT
References: <14549@oberon.USC.EDU>
Organization: Hewlett Packard, Cupertino
Lines: 37

>>The "best" design  [for Earth-Moon transport]
>>is still to use multiple vehicles designed for specific
>>tasks.

>Not necessarily true.  If a sufficiently flexible vehicle can be built that
>can do the whole trip, and can be built and operated inexpensively enough
>(read: mass produced and low operations cost) then that might be the "best"
>design.

Sure, if a Millenium Falcon with anti-grav drive could be built, it would
be swell.  I stand by my opinion that the most efficient design must exist in
three different environments and what you need for one is dead weight in
the others.

>  Case in point, Pacific-American Launch Co's "Phoenix" design.  This is
>a ballistic, single-stage-to-orbit, vertical-take-off/vertical-landing
>vehicle.  (Utilizing LH2/LO2 fuel and aerospike engine.  It's been mentioned
>around here before, I think).
>  This requires refueling in LEO, but one version of the Phoenix is configured
>as a 'tanker' to do the job.  Once refueled, the vehicle has sufficient
>delta-Vee to leave LEO for the Moon, soft land on the Moon, and return to
>Earth.  Since it's a ballistic VTOVL, landing on the moon presents no
>special difficulties, and it can land with sufficient fuel to take off again.

Of course this "tanker" has shown that the Phoenix is not designed for
the task.  That is, it is not a single solution.  Those "tankers" would
be modified enough in my mind to classify as another class of vehicle.

>   The catch is the orbital refueling, which could take as many as 10 tanker
>launches.  However, the Phoenix is designed to be *highly* reusable with
>low operations costs and rapid turnaround.

10 Launches!!!  Surely you admit that is not efficient!

Bob Campbell                Some times I wish that I could stop you from 
campbelr@hpda.hp.com        talking, when I hear the silly things you say.
Hewlett Packard                                    - Elvis Costello