Newsgroups: sci.space.shuttle
Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!uupsi!rodan.acs.syr.edu!amichiel
From: amichiel@rodan.acs.syr.edu (Allen J Michielsen)
Subject: Re: Computer Controlled Landing?
Message-ID: <1991Mar19.154959.19464@rodan.acs.syr.edu>
Sender: amichiel@sunrise.acs.syr.edu
Organization: Syracuse University, Syracuse, NY
References: <1077@uncw.UUCP> <1991Mar15.163810.17593@zoo.toronto.edu>
Date: Tue, 19 Mar 91 15:49:59 GMT

In article <> henry@zoo.toronto.edu (Henry Spencer) writes:
>In article <1077@uncw.UUCP> session@uncw.UUCP (Zack C. Sessions) writes:
>>... I read when the shuttle first came into being,... that it's computer... 
>>could launch, orbit, and land all under complete computer control. I also
>>read a few years ago that while the computer is capable of landing
>>the shuttle, they haven't trusted it to do so yet...

>In theory, I think the only thing the computer can't do is lower the
>landing gear. ...  In practice, I believe
>it is still the case that all landings to date have been manual.

Part of the arguable difference is the EXACT terminology being refered to.
When NASA & Henry say that every landing has been manual so far, they really
mean that the pilot controlled the stick and put the gear on the ground.
What is being left out, is that the pilot only took control away from the
computer a very short time before this event.  If my memory serves, the first
flights, used the computer to fly the shuttle down to about 100 feet.
Now, if you ask me, the computer has done (virtually) every part of the
landing except put the wheels on the ground.  While the computer is probably
supposed to be able to do this. The risks are crazy given the skill level
required and the ability of the manned pilots sitting in the seats.....
The ground is a nasty place with thermal currents, unpredictable cross winds,
gusts and other 'features', these are/can be quite small, but with (basically)
a dc-9 glider on a falling stone glide path, a very small error could be fatal
to craft and crew.  There is a magic touch to add to a perfect approach as
soft a landing as possible, which is nearly impossible to write in software.
If you want an idea how difficult it is, buy a rc glider and try flying and
landing it.  Experience counts....
al


































































-- 
Al. Michielsen, Mechanical & Aerospace Engineering, Syracuse University
 InterNet: amichiel@rodan.acs.syr.edu  amichiel@sunrise.acs.syr.edu
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