Xref: utzoo sci.space:11749 sci.space.shuttle:3254
Newsgroups: sci.space,sci.space.shuttle
Path: utzoo!henry
From: henry@utzoo.uucp (Henry Spencer)
Subject: Re: space news from May 1 AW&ST
Message-ID: <1989Jun4.055452.12921@utzoo.uucp>
Organization: U of Toronto Zoology
References: <1989May29.032320.2277@utzoo.uucp> <486@cybaswan.UUCP>
Date: Sun, 4 Jun 89 05:54:52 GMT

In article <486@cybaswan.UUCP> iiit-sh@cybaswan.UUCP (Steve Hosgood) writes:
>>NASA to test a parafoil system, developed by Pioneer Aerospace, for
>>precision landings by parachute of launcher components...
>
>Wasn't this originally invented by Dr Francis Rogallo in about 1963? ...

If I haven't got the terms mixed up, no, they are not the same thing.
Rogallo's concept was a flexible wing, with shape held by rigid members
or shroud lines or both.  Typically it had a single surface and was
triangular.  A parafoil is a gliding parachute, with two surfaces kept
apart by ram pressure and a rectangular shape.  Parafoils have largely
replaced circular parachutes for high-performance sport parachuting.
They are parachutes first and wings second.

>[Rogallo effort] an attempt to come up with a method for dry-landing
>Apollo (and other) manned space capsules. It was scrapped because NASA found
>that the wet-landing system developed over many years worked OK and there
>was no real need to change.

Not quite right, if I'm not mistaken.  According to Michael Collins's
"Liftoff", Apollo opted for a wet landing very early because it clearly
involved less on-board weight.  Gemini originally was going to use a
Rogallo wing in hopes of developing pinpoint landing techniques.  The
wing idea ran into problems, and Gemini's most important job was to
prove technology for Apollo, which wasn't going to use it anyway, so
Gemini switched to wet landing.  If Apollo's schedule had not forced
the issue, Gemini might well have stayed with the Rogallo wing; being
able to make a pinpoint landing on land was clearly superior to splashing
down in the ocean and having to be picked up.  The motive to change was
there all right, but short-term schedule problems took priority.
-- 
You *can* understand sendmail, |     Henry Spencer at U of Toronto Zoology
but it's not worth it. -Collyer| uunet!attcan!utzoo!henry henry@zoo.toronto.edu