Newsgroups: sci.space.shuttle
Path: utzoo!henry
From: henry@utzoo.uucp (Henry Spencer)
Subject: Re: Heavy Lift Capacity Boosters
Message-ID: <1988Sep30.165056.18848@utzoo.uucp>
Organization: U of Toronto Zoology
References: <677@eplrx7.UUCP> <2240@ssc-vax.UUCP> <1402@viper.Lynx.MN.Org> <2248@ssc-vax.UUCP> <6936@ihlpl.ATT.COM>
Date: Fri, 30 Sep 88 16:50:56 GMT

In article <6936@ihlpl.ATT.COM> knudsen@ihlpl.ATT.COM (Knudsen) writes:
>... don't the SSMEs go into orbit?
>Does their pod need both retro-rockets and an ablative heat shield
>to re-enter safely before deploying the chutes?
>Also, aren't the complex liquid engines more easily damaged
>by the splashdown and salt water corrosion while they're
>waiting to be fished out of the water?

Yes, recovering the engines is a headache.  Depending on the design, they
get either all the way into orbit or very nearly so.  Retrorockets are no
big deal, but heat shielding is a nuisance, and keeping them dry with an
ocean splashdown is also a headache.  This sort of thing is why the current
Shuttle-C proposals don't envision engine recovery.  (Admittedly, Shuttle-C
is intended for a low launch rate and deliberately accepts higher per-launch
costs for the sake of simpler development.)

>BTW, do the Russians use ablative shields on their Mir re-entries,

Yes.  As they would probably say:  "Why not?  They work quite well."

>or has something better been developed?

Define "better".
-- 
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