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From: mll@aio.jsc.nasa.gov (Mark Littlefield)
Newsgroups: sci.space.shuttle
Subject: Re: After Endeavour, what then?
Message-ID: <1991May7.212707.5380@aio.jsc.nasa.gov>
Date: 7 May 91 21:27:07 GMT
References: <346.281f448d@mwk.uucp>
Sender: news@aio.jsc.nasa.gov (USENET News System)
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In article <346.281f448d@mwk.uucp>, pittman@mwk.uucp writes:
|> Is Endeavour (OV-105) the absolutely last shuttle to be built?  Everything
|> I hear seems to indicate that, yet common sense tells me that with Freedom
|> going up over the next decade, the current shuttle fleet may be too old to
|> service it.  The older spacecraft are already about ten years old; that means
|> that at the point that Freedom becomes operational, Columbia would be
|> approaching twenty years of age.  The youngest orbiter, Endeavour, would then
|> be pushing ten.
|> 
|> Pardon my naivete, but what is the design lifetime of a shuttle orbiter?
|> 
|> 
|> -------------------------------------------------------------
|> --- Darrell Pittman        pittman@mwk.uucp               ---
|> --- M. W. Kellogg Co.      pittman%mwk@lobster.hou.tx.us  ---
|> --- Houston, TX            (713) 753-4410                 ---
|> -------------------------------------------------------------

If I remember correctly, the shuttle was originally designed for a
hundred cycles (flights).  That number was based on a flight schedule
of 1 flight a week, or a turn-around time of 4 weeks on a single
orbiter so I'm not sure what the current projections are.

Although we all love the shuttle, I doubt that it would last 100 years
at an average rate of a little over one flight a year (the current
average...counting the test program and Return to Flight).  It's
pretty clear that shuttle was a pathfinder and a true,
one-stage-to-orbut vehicle will be needed to service Space Station
Freedom and it's siblings.

=====================================================================
Mark L. Littlefield               Automation and Robotics Division
internet: mll@aio.jsc.nasa.gov      Intelligent Systems Branch   
USsnail:  Lockheed Engineering and Sciences 
          2400 Nasa Rd 1 / MS 19            
          Houston, TX 77258                 
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