Author Topic: Q&A: Pegasus Designer Dr. Antonio Elias  (Read 137084 times)

Offline Cretan126

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Re: Q&A: Pegasus Designer Dr. Antonio Elias
« Reply #375 on: 10/25/2007 01:46 AM »

Jim,

Actually, about 90% of Orbital's Launch Systems Group is based in Chandler - it is a bit more than just a production facility.  It was part of the acquisition, circa 1990, of Space Data Corporation by Orbital (not Space Vector) that Antonio referred to earlier.  Other than Pegasus and Taurus (and Taurus II, apparently), all other launch vehicle programs are run out of Chandler


Offline antonioe

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Re: Q&A: Pegasus Designer Dr. Antonio Elias
« Reply #376 on: 10/25/2007 02:56 AM »
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Cretan126 - 24/10/2007 8:46 PM

Jim,

Actually, about 90% of Orbital's Launch Systems Group is based in Chandler - it is a bit more than just a production facility.  It was part of the acquisition, circa 1990, of Space Data Corporation by Orbital (not Space Vector) that Antonio referred to earlier.  Other than Pegasus and Taurus (and Taurus II, apparently), all other launch vehicle programs are run out of Chandler

Right you are - 40%-45% of the Orbital staff work in Chandler - half of them (more or less) "engineers" and "scientists" (the latter being more of a rank or title that a job description - mostly they do what we would call engineering...) about 45%-50% at Dulles, the rest in various other locations, including Maryland (Greenbelt and Wallops I.) and California (VAFB).

Taurus II/Cygnus (alas! the T II monicker is starting to gell... when General Susan Helms call it "Taurus II" you start wondering...) is being designed by a combined Dulles/Chandler team.

Program Director Dave Steffy, Chief Engineer Mike Dorsch, Deputy PM Kurt Eberly, Stage 1 Manager Brian Winters and about 10-15 more people are at Dulles (actually at a luxurious off-site location dubbed "COSTCO View Estates" by Dave Steffy).

Deputy PM Mike Laidley (former Minotaur PM) and his staff of about 10 are at Chandler, responsible for the Upper Stage, Avionics, Structures (including fairing), Ordnance, specialty engineering (e.g., aero) and EGSE.  Needless to say, these numbers will swell to about 50-60 after December.

MGSE, contracts, sales (Bob Richards, who "owns" the product) and vehicle integration is based at Dulles.  For the first 5 or so flights, the program is managed out of Advanced Programs Group (yours truly), after that, from Launch Systems Group (Ron Grabe).  Similar to what we did with Pegasus 20 years ago.

ARS LONGA, VITA BREVIS...

Offline aero313

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Re: Q&A: Pegasus Designer Dr. Antonio Elias
« Reply #377 on: 10/25/2007 09:23 PM »
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GncDude - 17/10/2007  9:50 PM

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antonioe - 16/10/2007  3:30 PM

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aero313 - 16/10/2007 10:09 AM

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Skyrocket - 28/9/2007 11:11 AM

If i remember correctly, in the early 90ies 'Cygnus' was also the name of a proposed ground launched, wingless Pegasus.

This was a Chandler design. Performance was something like 100 lbs to LEO. Ironically, this vehicle became the GMD booster.

Thanks, Joe.  Yes, Chandler in the the early 90's, under Steve F.'s leadership, indeed "marched to the beat of a different drummer" than the rest of Orbital...


Chandler?

Arizona

Offline aero313

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Re: Q&A: Pegasus Designer Dr. Antonio Elias
« Reply #378 on: 10/25/2007 09:31 PM »
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antonioe - 24/10/2007  10:56 PM

Taurus II/Cygnus (alas! the T II monicker is starting to gell... )


I though Orbital had finally learned the trick of reusing the name of an existing program to simplify the range approval process.  Ask your new Lockmart friends why every Martin Marietta launch vehicle was named "Titan".  For that matter, even the Chandler folks learned that trick when the demo GMD booster was named "Taurus Lite".

Offline Skyrocket

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Re: Q&A: Pegasus Designer Dr. Antonio Elias
« Reply #379 on: 10/25/2007 10:51 PM »
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aero313 - 25/10/2007  11:31 PM
Ask your new Lockmart friends why every Martin Marietta launch vehicle was named "Titan".  

Just nitpicking: this launch vehicle must be a "Titan-2AS" (take a look at the company name)


Offline antonioe

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Re: Q&A: Pegasus Designer Dr. Antonio Elias
« Reply #380 on: 10/26/2007 03:07 AM »
O.K., O.K. white flag... I give up... how about "Taurus II XL - superAS"????
ARS LONGA, VITA BREVIS...

Offline simonbp

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Re: Q&A: Pegasus Designer Dr. Antonio Elias
« Reply #381 on: 10/27/2007 02:07 AM »
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Skyrocket - 25/10/2007  3:51 PM

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aero313 - 25/10/2007  11:31 PM
Ask your new Lockmart friends why every Martin Marietta launch vehicle was named "Titan".  

Just nitpicking: this launch vehicle must be a "Titan-2AS" (take a look at the company name)

It still applies; Atlas II was basically a completely new rocket, but they kept the same name they'd been using since 1951...

Simon ;)

Offline Jim

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Re: Q&A: Pegasus Designer Dr. Antonio Elias
« Reply #382 on: 10/27/2007 02:31 PM »
Not really.   It was Atlas III and V

Offline tnphysics

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Re: Q&A: Pegasus Designer Dr. Antonio Elias
« Reply #383 on: 10/27/2007 05:33 PM »
Could Cygnus have a flyback first stage? Will the third stage be used for all missions, or for high energy missions only?

Offline antonioe

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Re: Q&A: Pegasus Designer Dr. Antonio Elias
« Reply #384 on: 10/27/2007 06:36 PM »

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tnphysics - 27/10/2007 12:33 PM Could Cygnus have a flyback first stage? Will the third stage be used for all missions, or for high energy missions only?

No, no reuseability of any kind.  As I mentioned in previous pontifications, reuseability only pays off at a launch rate of 50-60 a year (for full reuseability).  We are talking 2 to 5 flights a year here, with luck!

No, expendables win hands down in this case...

There isn't a real "third stage" - the second stage has a big solid that gets separated, then a bipropellant low-thrust system takes over for orbital maneuvering, but it has way way less than 1/3 of the total ΔV capability of the stack (a "true" third stage would have about 1/3 of the total ΔV - on Cygnus, the combination of the solid and the biprop has about 1/2 of the total ΔV, so together they form kind of a second stage, except you DO stage the solid... sometimes the realities of what is available makes you do things different from "normal" designs...)

For missions where the accuracy of the final velocity of the orbital injection does not matter so much because "something else" (such as the the satellite's propulsion system) takes care of the precision, you can eliminate the biprop altogether.  A good example would be an escape (C3 >= 0) mission where a Star 48 replaces the biprop for an added "kick" to a much smaller payload.

For example, Cygnus is now showing a LEO payload in excess of 5,000 Kg, but only 1,000 Kg payload to C3=10 Km2/sec2, and this requires replacing the biprop with a Star 48.  Now, in THIS case the Star 48 DOES behave like a third stage (its ΔV is closer to being 1/3 of the total).

"Stagehood is in the eye of the bedesigner"

ARS LONGA, VITA BREVIS...

Offline tnphysics

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Re: Q&A: Pegasus Designer Dr. Antonio Elias
« Reply #385 on: 10/27/2007 07:14 PM »

Why not use the biprop for a large part of the delta-V? It has better performance than the solid.

The first stage providing half of the delta-V makes sense because it has the highest Isp.

What fraction of the delta-V does stage 3 currently provide?

Which hypergolic propellants are used by stage 3?

Funny line you created.  :laugh:


Offline tnphysics

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Re: Q&A: Pegasus Designer Dr. Antonio Elias
« Reply #386 on: 10/27/2007 07:25 PM »
What if you started to run out of NK-33 engines?

What is/will be the name of the stage engine? Is it new or not?

What is/will be the name of the stage 2 motor. Is it new?

Offline antonioe

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Re: Q&A: Pegasus Designer Dr. Antonio Elias
« Reply #387 on: 10/28/2007 01:23 PM »
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tnphysics - 27/10/2007 2:14 PM

Why not use the biprop for a large part of the delta-V? It has better performance than the solid.

We can't find a biprop with the thrust and duration needed to do that.

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The first stage providing half of the delta-V makes sense because it has the highest Isp.

The rule of thumb that sez "give the stage with the highest Isp most of the ΔV" works only for "rubber components", i.e., where you can arbitrarily specify the thrust, thrust duration, etc. of the propulsive units.  If you have to work with what's available, you have to break the rules of thumb.

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What fraction of the delta-V does stage 3 currently provide?

As I said before, we don't really have a true "Stage 3".  But if you are asking "what fraction of the ΔV does the biprop subsystem provide", the answer is: for low-altitude, high-payload missions, probably about 10%.  For higher-altitude, low-payload missions, more.

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Which hypergolic propellants are used by stage 3?

We are stealing that system from StarBus, so - N2O4 and Hydrazine;  that's what everybody tries to use these days...

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Funny line you created. :laugh:

Uh? Which one?  I try to create as many funny lines as I can (keeping mental sanity and all that, you know...)

ARS LONGA, VITA BREVIS...

Offline antonioe

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Re: Q&A: Pegasus Designer Dr. Antonio Elias
« Reply #388 on: 10/28/2007 01:38 PM »

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tnphysics - 27/10/2007 2:25 PM What if you started to run out of NK-33 engines

The question is not IF, but WHEN.  The answer is we start building them here in the good 'ol USA.  But we have a few years to get ready for that - if the 60 units or so run out in less than 10 years, we will be swimming in cash.  Reality is, it will take more than 10 years to go through 60 units (30 flights...) so we have plenty of time to get ready.

It may take as much money to qualify the US-built NK-33's as to develop Taurus II (not because qualifying US-build NK-33's costs a lot, but because we are developing Taurus II with very, VERY little money... about $150M)

So, in the spirit of "fund a little - develop a little (and wait for customers to buy a little)", we are waiting until we burn about 50% of the NK-33 inventory before funding THAT part. 

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 What is/will be the name of the stage engine? which stage? Is it new or not?

Which stage?  You mean the biprop?  It's a Japanese (IHI) unit... we use IHI biprops on all our StarBuses as the Apogee propulsion unit...

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What is/will be the name of the stage 2 motor. Is it new?

Yes, but it's being developed by somebody else, so I can't talk about it until the other party agrees we can do so...

ARS LONGA, VITA BREVIS...

Offline antonioe

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Re: Q&A: Pegasus Designer Dr. Antonio Elias
« Reply #389 on: 10/28/2007 02:08 PM »

Did I mention that Dan Tani, who is going to be "up there" for a while, worked several years at Orbital?  He worked on the Transfer Orbit Stage (TOS) and was our Test Conductor during the Mars Observer launch on Sep 25, 1992 (a day I remember very well - I was the Orbital senior at our control room at the Cape - I ate a whole jar of Planter's shelled peanuts while on-console and gained 5 lbs - aero313 was the Chief Engineer, if I remember correctly... Joe?).

The Titan 34D carrying M.O. atop our TOS was the FIRST launch from the newly-refurbished LC-40, sporting the world's heaviest structure to move on land (the Titan-IV sized, 6,000 tons Service Structure!!)  The service structure was so heavy, as a matter of fact, that its motion disturbed the alignement of the TOS IMU, almost causing a scrub!  Also, the Service Structure interfered with the umbilical tower, so the Martin-Marietta guys used a HYDRAULIC JACK to deform the unbilical tower in place!!!  The Titan 34D barely reached two-thirds of the way up...

That great behemoth is no more.  LC-40 was designed to launch a Titan "every 15 to 19 days"... today, with the great structure gone, LC-40 is a wasteland.

ARS LONGA, VITA BREVIS...

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