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Shuttle Derived Launchers - Safe, Simple, Soon



 
 
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  #11  
Old June 26th 05, 05:32 PM
Brian Thorn
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On 26 Jun 2005 07:11:26 -0700, "Matt" wrote:

I have no doubt the SSME mod is doable. However, given that NASA is
preselecting a single source for the heavy-lifter engines, the
contractor is likely to hold up the government with cost estimates
bordering on extortion.


Well, once the Rocketdyne sale to UT/P&W goes through, there will only
be one source for heavy-lifter engines in the United States, so it
isn't as though NASA has a lot of options.

Brian
  #12  
Old June 26th 05, 05:41 PM
Brian Thorn
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On Sun, 26 Jun 2005 09:09:16 -0500, Herb Schaltegger
wrote:


http://www.safesimplesoon.com/media-images.htm


Ah, the joys of view-graph engineerning. Makes it look all so damned
easy, doesn't it? Kind of like sliding down a snowy slope with your
feet on two planks looks easy until the first time you try it.


Well, these pretty pictures are all definitely for public relations
and politics, not engineering. But you can easily make the same claim
about the LockMart Atlas-5 based heavy-lifter in this week's AvLeak.
At least for the SDLV, all the essential elements have either been
tested or are in service, even the 5-segment SRB. The Atlas 5 Super
Heavy seems to require new tooling for a wider core stage and a new
pad to launch it from.

Brian
  #13  
Old June 26th 05, 06:01 PM
Ed Kyle
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Brian Thorn wrote:
Well, these pretty pictures are all definitely for public relations
and politics, not engineering. But you can easily make the same claim
about the LockMart Atlas-5 based heavy-lifter in this week's AvLeak.
At least for the SDLV, all the essential elements have either been
tested or are in service, even the 5-segment SRB. The Atlas 5 Super
Heavy seems to require new tooling for a wider core stage and a new
pad to launch it from.


That part of that AWST issue that I found most
interesting was the statement attributed to Boeing VP
Chuck Allen. He said that the Northrop/Boeing's CEV
design could be launch by *existing* Delta IV vehicles.
That does not jive with pronoucements made by both
Griffin and ATK officials that the EELVs would need
new upper stages (just like "The Stick") to lift CEV.

- Ed Kyle

  #14  
Old June 26th 05, 07:16 PM
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From: Brian Thorn


Well, these pretty pictures are all definitely for public relations
and politics, not engineering. But you can easily make the same claim
about the LockMart Atlas-5 based heavy-lifter in this week's AvLeak.
At least for the SDLV, all the essential elements have either been
tested or are in service, even the 5-segment SRB. The Atlas 5 Super
Heavy seems to require new tooling for a wider core stage and a new
pad to launch it from.


For the SDLV, you're going to need new tooling: the "core" will be
substantially different, as it takes loads through different directions and
different attachment points; AFAIK, the 5-segment SRB isn't in service, and
finally, I believe it will need a new pad to launch from (as the engines are
in a different place on the vehicle, among other things).

Phil
  #15  
Old June 26th 05, 07:17 PM
Géza Meszéna
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Ed Kyle wrote:
Brian Thorn wrote:

Well, these pretty pictures are all definitely for public relations
and politics, not engineering. But you can easily make the same claim
about the LockMart Atlas-5 based heavy-lifter in this week's AvLeak.
At least for the SDLV, all the essential elements have either been
tested or are in service, even the 5-segment SRB. The Atlas 5 Super
Heavy seems to require new tooling for a wider core stage and a new
pad to launch it from.



That part of that AWST issue that I found most
interesting was the statement attributed to Boeing VP
Chuck Allen. He said that the Northrop/Boeing's CEV
design could be launch by *existing* Delta IV vehicles.
That does not jive with pronoucements made by both
Griffin and ATK officials that the EELVs would need
new upper stages (just like "The Stick") to lift CEV.

- Ed Kyle


Sure, the CEV is not goint to be heavier than 20 t even if they decide
and if it will have wings. So it can be lauched by a Delta IV heavy.
Sending them to the Moon requires 4 lauches, 1 additional to the lunar
module and 2 for the booster stages, which are considerably heavier,
than the spacecraft to be boosted. So, at the end of the day, they have
to develop new ("upgraded") lauch vehicle for the booster stages AND
still use 4 launches to reach the intended destination.

Sure, the SRB-based new manned launcher does not seem to be a great idea.

Géza Meszéna

  #16  
Old June 26th 05, 07:19 PM
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From: "Ed Kyle"


Brian Thorn wrote:
Well, these pretty pictures are all definitely for public relations
and politics, not engineering. But you can easily make the same claim
about the LockMart Atlas-5 based heavy-lifter in this week's AvLeak.
At least for the SDLV, all the essential elements have either been
tested or are in service, even the 5-segment SRB. The Atlas 5 Super
Heavy seems to require new tooling for a wider core stage and a new
pad to launch it from.


That part of that AWST issue that I found most
interesting was the statement attributed to Boeing VP
Chuck Allen. He said that the Northrop/Boeing's CEV
design could be launch by *existing* Delta IV vehicles.
That does not jive with pronoucements made by both
Griffin and ATK officials that the EELVs would need
new upper stages (just like "The Stick") to lift CEV.


It can't be difficult to make a CEV liftable by a Delta-IVH
if one so desired. (Heck, I thought they were making a mistake
building one so large it required the -H rather than one of
the heavier mediums).

It sounds like the new upper management at NASA has a direction
they want to go in ("The Stick") and will rewrite whatever other
requirements they need to to make their decision... stick.

pgf
  #17  
Old June 26th 05, 07:33 PM
Jorge R. Frank
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Brian Thorn wrote in
:

On Sun, 26 Jun 2005 09:09:16 -0500, Herb Schaltegger
wrote:


http://www.safesimplesoon.com/media-images.htm


Ah, the joys of view-graph engineerning. Makes it look all so damned
easy, doesn't it? Kind of like sliding down a snowy slope with your
feet on two planks looks easy until the first time you try it.


Well, these pretty pictures are all definitely for public relations
and politics, not engineering. But you can easily make the same claim
about the LockMart Atlas-5 based heavy-lifter in this week's AvLeak.
At least for the SDLV, all the essential elements have either been
tested or are in service, even the 5-segment SRB.


Well, except for the ET. The current ET is designed to absorb loads along
the side through the intertank (orbiter and SRB forward attach points) and
the aft ring (orbiter and SRB aft attach points). The SDLV ET will have to
take thrust loads through the bottom of the tank, and to take the weight of
the payload from the top (which will also necessitate redesigning the LOX
tank ogive). The ET is such a lightweight, optimized structure that you're
pretty much going to have to redesign it. And *then* you've got to move the
flame trench on the MLP and the pad to match where you just moved the main
engines. Possibly add more thermal protection to the SRB aft segments to
account for the increased proximity of the main engines. These are all
straightforward engineering problems, but to say that they're "tested or
are in service" is a bit of a stretch.

--
JRF

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check "Organization" (I am not assimilated) and
think one step ahead of IBM.
  #19  
Old June 26th 05, 07:44 PM
Murray Anderson
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"Ed Kyle" wrote in message
oups.com...
Brian Thorn wrote:
Well, these pretty pictures are all definitely for public relations
and politics, not engineering. But you can easily make the same claim
about the LockMart Atlas-5 based heavy-lifter in this week's AvLeak.
At least for the SDLV, all the essential elements have either been
tested or are in service, even the 5-segment SRB. The Atlas 5 Super
Heavy seems to require new tooling for a wider core stage and a new
pad to launch it from.


That part of that AWST issue that I found most
interesting was the statement attributed to Boeing VP
Chuck Allen. He said that the Northrop/Boeing's CEV
design could be launch by *existing* Delta IV vehicles.
That does not jive with pronoucements made by both
Griffin and ATK officials that the EELVs would need
new upper stages (just like "The Stick") to lift CEV.

- Ed Kyle


If it's a 20 ton CEV Delta IV should have no problem, with 25 tons it would
probably need twin RL10's and an upper stage with more propellant than the
small Delta IV upper stage, but less then the large upper stage.
It's the same with the SRB launcher, the 20 ton might get away with a J2
engine, but 25 tons would require an SSME. This is a bait-and-switch type
situation, whereby a nonexistent launcher with J2/SSME is proclaimed better
than an existing launcher that needs a comparatively minor upgrade to the
upper stage - then we learn that only the SSME (with extended nozzle, and
altitude start capability) will work, and the lower stage will require a bit
of work to make the steering function in a highly unstable design.

Murray Anderson


  #20  
Old June 26th 05, 07:46 PM
Henry Spencer
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In article ,
Brian Thorn wrote:
Well, once the Rocketdyne sale to UT/P&W goes through, there will only
be one source for heavy-lifter engines in the United States...


That's been true for a long time... partly thanks to NASA's long-standing
unwritten policy that all its big engines are built by Rocketdyne. (To
the point that for the SSME, NASA basically took technology developed by
P&W and gave it to Rocketdyne to build an engine with.)

I think the only other US company that has ever designed and built big
liquid rocket engines -- at least, ones that have made it to full
qualification and production -- is Aerojet, and they've been out of that
business for decades except for minor upgrades to the Titan engines.
--
"Think outside the box -- the box isn't our friend." | Henry Spencer
-- George Herbert |
 




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