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Date: Wed, 2 Dec 92 05:05:47
From: Space Digest maintainer <digests@isu.isunet.edu>
Reply-To: Space-request@isu.isunet.edu
Subject: Space Digest V15 #485
To: Space Digest Readers
Precedence: bulk
Space Digest Wed, 2 Dec 92 Volume 15 : Issue 485
Today's Topics:
Shuttle replacement
Welcome to the Space Digest!! Please send your messages to
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"Subscribe Space <your name>" to one of these addresses: listserv@uga
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(THENET), or space-REQUEST@isu.isunet.edu (Internet).
----------------------------------------------------------------------
Date: Wed, 2 Dec 1992 04:30:41 GMT
From: Bruce Dunn <Bruce_Dunn@mindlink.bc.ca>
Subject: Shuttle replacement
Newsgroups: sci.space
Robert J Woodhead writes:
> Autorotation not only works very well, but demonstrating the ability
> to make an autorotation landing is a pre-requisite for a helicopter
> pilot certificate.
>
> There is a very large amount of energy in a spinning heli blade, and
> the principle of autorotation is to maintain that energy while using
> the drag of the blades to maintain a steady (albeit high) rate of
> descent until just before landing, when the rotational energy is
> used to decelerate the heli.
>
It would be very interesting for this general line of argument to
compare the descent rate of a helicopter in the high rate part of an
unpowered descent with the descent rate of an aerobraked DC-1. Both vehicles
are falling at a substantial terminal velocity, and have to do a well
controlled maneuver to deaccelerate just before touchdown. I suspect that
the margins in terms of "hovering time" probably are a bit less tight on the
DC-1. Since this is apparently a routine maneuver in helicopter training,
this would argue that the rocket powered analog might not be so hard as many
people are making out.
--
Bruce Dunn Vancouver, Canada Bruce_Dunn@mindlink.bc.ca
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End of Space Digest Volume 15 : Issue 485
------------------------------