Newsgroups: sci.space.history
From: henry@spsystems.net (Henry Spencer)
Subject: Re: Vostok/Voskhod LES?
Date: Sun, 19 Sep 1999 16:01:00 GMT

In article <37E4BEF9.C1EAF7B8@yahoo.com>,
Justin Wigg  <justinwigg@yahoo.com> wrote:
>Would the Vostok ejection have required a jettisoning of the launch
>shroud first?  Surely they would not have had the pilot eject *through*
>the shroud?

That's actually not unthinkable.  There are aircraft ejection systems
which go through the canopy.  (This does require that the overhead area
of the canopy be relatively thin, and often the seat is equipped with
"canopy breaker" prongs to help the process.)  It does permit very rapid
ejection, without waiting for preliminaries, which is the major reason
why it's done.

(Different militaries have different priorities, depending on their
history and their idea of what they spend most of their time doing.  The
USAF tends to prefer thick one-piece canopies, thick to protect the pilot
and one-piece so there are no frames to get in the way of vision, for air
combat; this requires jettisoning the canopy before ejection.  The RAF
emphasizes low-level flying more, so they tend to demand instantaneous
ejection -- 50ft off the ground in a malfunctioning aircraft, there is no
time to lose -- even if it means a frame between the front windshield,
which is necessarily thick for protection against birdstrikes, and the
overhead canopy.)

As others have noted, simply putting a door in the shroud is the other
possibility.
--
The good old days                   |  Henry Spencer   henry@spsystems.net
weren't.                            |      (aka henry@zoo.toronto.edu)

Newsgroups: sci.space.history
From: henry@spsystems.net (Henry Spencer)
Subject: Re: Vostok/Voskhod LES?
Date: Mon, 20 Sep 1999 01:06:45 GMT

In article <memo.19990919224334.14771A@sjbradshaw.compulink.co.uk>,
Simon Bradshaw <filter@sjbradshaw.cix.co.uk> wrote:
>As far as I know, all RAF aircraft with 'instantaneous' ejection do not,
>strictly speaking, eject *through* the canopy.  Rather, an explosive
>miniature detonator cord (MDC) is threaded through the canopy and is fired
>to shatter it as the ejection seat is initiated.

Hmm, I thought only some of them had that... but it's not an area where
I'm current.  The "canopy breakers" certainly have existed on ejection
seats in the past, although I can't cite a specific aircraft at the
moment.

>Of course, this is only an option where the obstacle to be ejected through
>is friable.

Quite so.  But a launch fairing (the original subject of discussion) can
be pretty thin.  Of course, there's likely to be a substantial spacecraft
hatch underneath...

>...However, the Vostock launcher *did* (and still
>does) use LOK/Kerosene.  Did the Russians use a more powerful ejection
>system, or were they simply more sanguine about the prospect of ejecting
>from an exploding booster?

They may have had better seats, or lower estimates of booster hazard
radius (much of the "accepted wisdom" on these things in the West is
perilously close to guesswork), but mostly they were in a hurry to beat
the Americans, and needed to take shortcuts where they could.
--
The space program reminds me        |  Henry Spencer   henry@spsystems.net
of a government agency.  -Jim Baen  |      (aka henry@zoo.toronto.edu)