And I stand corrected on the Minuteman III Stage-3 per the attachment provided
by Henry.
Charles E. (Chuck) Rogers
In a message dated 3/26/2020 7:20:23 PM Pacific Standard Time,
dmarc-noreply@xxxxxxxxxxxxx writes:
The blow-off ports on the Minuteman I and II Stage-3 were for Delta-V control.
Minuteman I and II had an interesting challenge. With an all-solid ICBM, how
do you control the final velocity, to get high accuracy on the missile? The
Minuteman I and II guidance systems would continuously check the inertial
velocity and blow the ports on Stage-3 at the appropriate time. With multiple
ground and flight tests, you could calibrate the time delta from signal sent to
thrust cut-off completed, and what Delta-V would occur during the shutdown. To
ensure good accuracy, the Stage-3 motor was sized so the blow-off ports had to
be blown every time, whether under or over performing.
Minuteman III of course had a liquid post-boost stage, so any under or over
performance Delta-V wise would be made up by the post-boost stage. You'd make
sure that some Delta-V was always required by the post-boost stage, so if the
solid stages over-performed, you'd just run the axial motor on the post-boost
stage a shorter length of time. Hence Minuteman III had no blow-off ports on
it's Stage-3.
Blow-off ports on the solids that were considered early on the Space Shuttle
program, and which can be seen on some early Space Shuttle renderings, were
purely to shut down the solids to help the Shuttle separate from the external
tank and the solids to assist in an abort. They disappeared from the Shuttle
program, and I believe they disappeared pretty early on. One issue may have
been that a glide back to the launch site gets very difficult above Mach 3-4
(in fact studies I've seen of this have a propulsive turn before the vehicle
glides back), so after shutting down the solids and separating the Shuttle,
exactly where do you glide to? I can think of some possible islands where a
Shuttle capable runway could have been added. It would be interesting to find
the early studies where they looked at this and see how feasible it was
considered. This may have been a contributing reason, in addition to cost, why
the blow-off ports on the Shuttle solids were deleted.
Charles E. (Chuck) Rogers
In a message dated 3/26/2020 3:43:09 PM Pacific Standard Time,
rocketmaster.ken@xxxxxxxxx writes:
Doesn't seem precise enough though vs the 560&&1000 LbF verniers on a Thor or
Atlas which creep up to the target V.
On Thu, Mar 26, 2020 at 3:33 PM Ian M. Garcia <ian@xxxxxxxxxxxxx> wrote:
Maybe it’s actual thrust termination, to get a controlled DV?
--
Ian M Garcia
From: Anthony Cesaroni
Sent: Thursday, March 26, 2020 6:29 PM
To: arocket@xxxxxxxxxxxxx
Subject: [AR] Re: Valley Tech throttleable restartable solids (!)
Minuteman termination. That’s funny. Must have been for range safety during
testing.
Anthony J. Cesaroni
President/CEO
Cesaroni Technology/Cesaroni Aerospace
http://www.cesaronitech.com/
(941) 360-3100 x101 Sarasota
(905) 887-2370 x222 Toronto
From: arocket-bounce@xxxxxxxxxxxxx <arocket-bounce@xxxxxxxxxxxxx> On Behalf Of
roxanna Mason
Sent: Thursday, March 26, 2020 6:17 PM
To: arocket@xxxxxxxxxxxxx
Subject: [AR] Re: Valley Tech throttleable restartable solids (!)
That's what I thought, an engineering challenge to say we did it. Going back to
the 60's, at CSD I saw a Minuteman stage 3 with thrust termination/cancelling
ports, no restarting though.
On Thu, Mar 26, 2020 at 2:55 PM Anthony Cesaroni <anthony@xxxxxxxxxxx> wrote:
Depends on the mission and engineering bias I suppose.
Anthony J. Cesaroni
President/CEO
Cesaroni Technology/Cesaroni Aerospace
http://www.cesaronitech.com/
(941) 360-3100 x101 Sarasota
(905) 887-2370 x222 Toronto
From: arocket-bounce@xxxxxxxxxxxxx <arocket-bounce@xxxxxxxxxxxxx> On Behalf Of
roxanna Mason
Sent: Thursday, March 26, 2020 4:09 PM
To: arocket@xxxxxxxxxxxxx
Subject: [AR] Re: Valley Tech throttleable restartable solids (!)
Where would this be preferable over a well designed liquid or even hybrid?
On Thu, Mar 26, 2020 at 9:23 AM Anthony Cesaroni <anthony@xxxxxxxxxxx> wrote:
Anthony J. Cesaroni
President/CEO
Cesaroni Technology/Cesaroni Aerospace
http://www.cesaronitech.com/
(941) 360-3100 x101 Sarasota
(905) 887-2370 x222 Toronto
From: arocket-bounce@xxxxxxxxxxxxx <arocket-bounce@xxxxxxxxxxxxx> On Behalf Of
D K
Sent: Wednesday, March 25, 2020 9:53 PM
To: arocket@xxxxxxxxxxxxx
Subject: [AR] Re: Valley Tech throttleable restartable solids (!)
Cool. Thanks.
Doug Knight
On Wed, Mar 25, 2020, 9:18 PM Anthony Cesaroni <anthony@xxxxxxxxxxx> wrote:
I can’t comment on it but there was a lot of work done on this in the early
60’s I have an interesting press release from Aerojet that illustrates a nice
approach to the principle. I will post it here when I get back to KSRQ tomorrow.
Best.
Anthony J. Cesaroni
President/CEO
Cesaroni Technology/Cesaroni Aerospace
http://www.cesaronitech.com/
(941) 360-3100 x101 Sarasota
(905) 887-2370 x222 Toronto
From: arocket-bounce@xxxxxxxxxxxxx <arocket-bounce@xxxxxxxxxxxxx> On Behalf Of
D K
Sent: Wednesday, March 25, 2020 9:10 PM
To: arocket@xxxxxxxxxxxxx
Subject: [AR] Re: Valley Tech throttleable restartable solids (!)
Looks like Aerotech Hardware and Nozzle from a different video they have. No
disrespect, Anthony. Outside looking in.
Doug Knight
On Wed, Mar 25, 2020 at 9:00 PM Anthony Cesaroni <anthony@xxxxxxxxxxx> wrote:
A customer.
Anthony J. Cesaroni
President/CEO
Cesaroni Technology/Cesaroni Aerospace
http://www.cesaronitech.com/
(941) 360-3100 x101 Sarasota
(905) 887-2370 x222 Toronto
From: arocket-bounce@xxxxxxxxxxxxx <arocket-bounce@xxxxxxxxxxxxx> On Behalf Of
George Herbert
Sent: Wednesday, March 25, 2020 8:17 PM
To: arocket@xxxxxxxxxxxxx
Subject: [AR] Valley Tech throttleable restartable solids (!)
No more info than watching their presentation but... interesting...
https://twitter.com/mil_std/status/1242911601965047809?s=21
Sent from my iPhone