Newsgroups: sci.space.shuttle
Path: utzoo!henry
From: henry@utzoo.uucp (Henry Spencer)
Subject: Re: shuttle computers; big solids
Message-ID: <1988Oct9.221530.26333@utzoo.uucp>
Organization: U of Toronto Zoology
References: <6689@nsc.nsc.com> <1543@hp-sdd.HP.COM> <1988Oct1.230542.11512@utzoo.uucp> <212@obie.UUCP>
Date: Sun, 9 Oct 88 22:15:30 GMT

In article <212@obie.UUCP> wes@obie.UUCP (Barnacle Wes) writes:
>  [MX first stage]  ...  As a matter of fact, the Shuttle
>SRBs are basically derivatives of this motor; they are approximately the
>same size, and according to a book Thiokol published as a promo item a
>few years ago, the fuel compounds are very similar...

You're sure about this?  Remember that shuttle SRB development goes back
to the mid-70s.  Remember also that big solid motors are pretty similar;
the shuttle SRBs are not derivatives of the Titan SRBs even though they
are both segmented designs using similar propellants.  And I expect that
the MX first stage doesn't have field joints, which is a major practical
difference.  (The shuttle SRB segments shipped to the Cape actually are
each two casing segments joined at a factory joint before propellant
casting.  The factory joints have never given the slightest problem, and
in fact they are still using the pre-Challenger seal design.)

>> Large one-piece solids were built and fired a number of years ago -- by NASA
>> in fact!
>
>Well, actually, it was Aerojet Corp., during the design & analysis phase
>of the MX contract award...

We're thinking about different events, although it may have been the same
contractor -- Aerojet sounds familiar.  NASA-plus-contractor built and fired
several non-segmented 260-inch solids (much bigger than either the shuttle
SRB or the MX) circa 20 years ago.  No relation to MX.
-- 
The meek can have the Earth;    |    Henry Spencer at U of Toronto Zoology
the rest of us have other plans.|uunet!attcan!utzoo!henry henry@zoo.toronto.edu