Author Topic: Q&A: Pegasus Designer Dr. Antonio Elias  (Read 196966 times)

Offline antonioe

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Re: Q&A: Pegasus Designer Dr. Antonio Elias
« Reply #500 on: 07/13/2012 06:48 PM »
We didn't just inspect the B-52, we flew 6 mission with it! (I was the LPO on missions 1 and 4)

B-52 s/n 0008 (good ol' "balls 8") had a large fuselage tank on the centerline as well as tanks on the the wings (but no tip tanks like later B-52 versions).  Pegasus was hung from the pylon on the starboard (right) wing.

After towing the Pegasus-carrying trailer under the wing, but before attaching the rocket, we transfered fuel to the starboard wing tanks to lower the starboard wing.

We then raised the trailer a bit and attached Pegasus to the pylon.

Next, we transfered fuel to the port side to lift the Pegasus up from the trailer (we also lowered the trailer bed.)

We then took off with more fuel on the port side to balance the Pegasus on the starboard side, making the B-52 weight-symmetric at takeoff.

Before drop, we transfered fuel to the starboard side to make the aircraft heavy on the rocket side by about ONE HALF THE ROCKET WEIGHT.

When the rocket was dropped, the aircraft became instantly port-heavy by the same amount (on-half the rocket weight).  The lateral aerodynamics of the B-52 were more than sufficient to handle these asymmetries.   Also, the left-turning tendency was used by the pilot to acheive lateral separation from the release flight path.

Before landing, the fuel was equalized so, again, the aircraft was weight-symmetrical.

Neat, uh?
« Last Edit: 07/13/2012 07:29 PM by antonioe »
ARS LONGA, VITA BREVIS...

Offline Robotbeat

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Re: Q&A: Pegasus Designer Dr. Antonio Elias
« Reply #501 on: 07/13/2012 07:18 PM »
Great explanation! Thanks. :)
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Offline gin455res

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Re: Q&A: Pegasus Designer Dr. Antonio Elias
« Reply #502 on: 07/29/2012 08:17 PM »
We didn't just inspect the B-52, we flew 6 mission with it! (I was the LPO on missions 1 and 4)

B-52 s/n 0008 (good ol' "balls 8") had a large fuselage tank on the centerline as well as tanks on the the wings (but no tip tanks like later B-52 versions).  Pegasus was hung from the pylon on the starboard (right) wing.

After towing the Pegasus-carrying trailer under the wing, but before attaching the rocket, we transfered fuel to the starboard wing tanks to lower the starboard wing.

We then raised the trailer a bit and attached Pegasus to the pylon.

Next, we transfered fuel to the port side to lift the Pegasus up from the trailer (we also lowered the trailer bed.)

We then took off with more fuel on the port side to balance the Pegasus on the starboard side, making the B-52 weight-symmetric at takeoff.

Before drop, we transfered fuel to the starboard side to make the aircraft heavy on the rocket side by about ONE HALF THE ROCKET WEIGHT.

When the rocket was dropped, the aircraft became instantly port-heavy by the same amount (on-half the rocket weight).  The lateral aerodynamics of the B-52 were more than sufficient to handle these asymmetries.   Also, the left-turning tendency was used by the pilot to acheive lateral separation from the release flight path.

Before landing, the fuel was equalized so, again, the aircraft was weight-symmetrical.

Neat, uh?

Yes, thanks for answering.

So the you halved the asymmetry, clever.

Offline fatjohn1408

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Re: Q&A: Pegasus Designer Dr. Antonio Elias
« Reply #503 on: 08/23/2012 09:24 AM »
Dear Antonio,

Thank you for this informative thread. I want to ask a general question about subsonic assisted launch. Why are all concepts multi-stage designs?
It has even been said that the Titan 2 first stage could reach orbit from the ground. In the links provided it gives data indicating a 28 construction mass ratio and a specific impulse of 258.

http://en.wikipedia.org/wiki/LGM-25C_Titan_II
http://www.braeunig.us/space/specs/titan.htm

Adding 300 m/s as assist velocity and 450 due to the rotation of the earth, one gets 9175 m/s of delta-V. Having less drag losses and less gravitational losses than the average launcher.

Now why didn't you try to optimize a single stage vehicle for assisted air launch? I am asking this question because I am optimising launch assist vehicles for assisted launch and right now my optimisation shows that subsonically assisted launchers can reach orbit with a payload.

Is the extra payload brought by a multi stage vehicle worth that much more risk and complexety or am i forgetting something and is it actually close to impossible to bring a single stage into orbit from a subsonic assist.

Thank you.

Offline modemeagle

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Re: Q&A: Pegasus Designer Dr. Antonio Elias
« Reply #504 on: 09/23/2012 02:22 AM »
Antonio,
Finally ran the Pegasus though my simulator.  Solids are very time consuming to simulate and adding lift from the wing was the hardest part.  The simulator is really designed for one to three stage liquid engines without solids.  I did a lot of these for the Falcon series for SpaceX and did not want to leave Orbital out.  Will try the Antares when more data is released on the system.

Edit: corrected drag vs angle of attack
« Last Edit: 09/23/2012 01:19 PM by modemeagle »

Offline jcm

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Re: Q&A: Pegasus Designer Dr. Antonio Elias
« Reply #505 on: 09/26/2012 11:22 PM »
I read an item in Space News this week that took me to an Orbital press release back in August that we seem to have missed on this forum:

http://www.orbital.com/NewsInfo/release.asp?prid=825

"Dr. Antonio L. Elias, currently Executive Vice President and General Manager of Orbital’s Advanced Programs Group (APG), will become Executive Vice President and Chief Technical Officer, responsible for the company’s overall technical operations. In this new corporate capacity, Dr. Elias will oversee a 2,600-person functional organization consisting of the company’s engineering, production, supply chain, test and operations staff, as well as its safety and mission assurance professionals, in Virginia, Arizona and other locations."

Congratulations, Antonio! I hope that comes with a nice pay raise and a swankier office ;-)
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Offline ugordan

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Re: Q&A: Pegasus Designer Dr. Antonio Elias
« Reply #506 on: 09/27/2012 02:47 PM »
I read an item in Space News this week that took me to an Orbital press release back in August that we seem to have missed on this forum:

It wasn't missed: http://forum.nasaspaceflight.com/index.php?topic=15457.msg947180#msg947180

Offline jcm

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Re: Q&A: Pegasus Designer Dr. Antonio Elias
« Reply #507 on: 09/27/2012 10:58 PM »
I read an item in Space News this week that took me to an Orbital press release back in August that we seem to have missed on this forum:

It wasn't missed: http://forum.nasaspaceflight.com/index.php?topic=15457.msg947180#msg947180

Ah ok ... sorry about that. There is so much stuff on this site and the threads overlap enough that it's really easy to miss important stuff!
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Offline modemeagle

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Re: Q&A: Pegasus Designer Dr. Antonio Elias
« Reply #508 on: 10/15/2012 05:22 PM »
Antonio,
Finally ran the Antares though my simulator. All masses were estimated and excluded from the output to not spread bad information.  Only the payload is shown.  Had some interesting results trying to get a good trajectory and think I may have found how to get more accuracy of insertion using a liquid first stage and a solid second stage.  Being only a 2D simulator I can't use Yaw maneuvers to burn off excess velocity.  Unless ATK publishes a new curve for the Castor 30XL then I won't be able to model the uprated version in a future simulation.

Offline Kabloona

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Re: Q&A: Pegasus Designer Dr. Antonio Elias
« Reply #509 on: 03/24/2013 04:25 AM »
Antonio, when your benevolent overlords give you some free time away from Antares, could you please post your promised next installment "Run Silent, Run Deep," in your story of how Pegasus was developed?

And thank you for sharing so generously of your time and knowledge on this forum; it's great to hear straight from the horse's mouth, as it were!

Offline Galactic Penguin SST

Re: Q&A: Pegasus Designer Dr. Antonio Elias
« Reply #510 on: 04/22/2013 12:54 AM »
Bump!

Quote
Davie OPF - 26/8/2007 11:09 PM

Welcome back sir. This is a great Q&A.

Interested to hear what you meant by a Delta II replacement? We know there's moves to Delta IVs for commonality of ULA DOD launch service contracts, but a 'new' vehicle? A beefed up Pegasus? Do tell more if you can, sounds intriguing.
Orbital's US Government satellite products (NASA and some Defense/Intelligence) are slowly but steadily growing from Pegasus/Minotaur II class to the Minotaur IV/Delta II class. Orbital's market share in this class is, or was, growing.

The demise of Delta II threatens this growth. Much like what happened to us in 1987 (we had the idea for what became ORBCOMM, but not a suitable launch option, so we decided to start what became Pegasus) we have started what could become "son of Delta II" (some pundits suggest we call it Epsilon - the next letter in the greek alphabet, but DWT nixed that for obvious reasons.) Orbital is funding this effort at risk - like with Pegasus and Taurus, we do not have any contract or sponsorship to develop it - not even a COTS agreement!

Having said all this, I expect a torrent of questions pertaining to its configuration, propulsion technology, etc. The honest answer is that we are still trading options. We are spending several megadollars to proceed to CDR late this year (and, believe me, that buys a LOT of design at Orbital!); if we pass a number of hurdles, we will proceed to CDR in the fall of 2008 for a possible first launch in mid-2010. Now, here's the rub:

Any fool can design a profitable EXPENDABLE rocket if it is guaranteed to fly 12-20 times a year (50-60 for a reusable). Any fool can design an UNprofitable rocket that flies 2-3 times a year (well, even so it's not as easy as that, but you get the point.) The hard part is to design a launch product that will BREAK EVEN at 2-3 launches/year!!!

Unfortunately, the word "launch product" here includes the industrial infrastructure required to produce all its parts, inventory vs. quantity purchases vs. Letters-of-agreement games, fixed infrastructures, perhaps in more than one location, and possibly within 500 yeards of a vicious, rust-causing salt-saturated moist air, the perhaps small but irreducible number of engineers and technicians who have to be "current" in assembly and flight operations, government permits and customers' expectations of insight and flight assurance, reliability of supply lines that may not have any other customers... OH DEAR! OH MY!! Wouldn't it be wonderful it all that mattered was specific impulse, structural mass fraction, bending modes, lift and drag, shock propagation, acoustic levels and all that?

SO: we are NOT ready to unveil a configuration; we are not even ready to assure that come December's PDR we WILL continue the program - we will only do so if we are convinced we can do it for the non-recurring and recurring costs necessary to make it work.  It's not a matter of funding; as stated in another forum, Orbital has plenty of cash - more, indeed, than it would be PRUDENT to spend in this development. We are working very, very hard to make the cost numbers work; but is IS hard!

I CAN, though, say that the same people that designed, built and flow 52 Pegasus, Tauruses and Minotaurs are going to give it a hell of a try. We have been able to maintain a viable small launch vehicle product line for 17 years with an average of 3 flights/year (see enclosed chart, which only goes to 2006), so if anybody has a chance to pull this off, it's probably us.

We are targeting the same payload vs. altitude vs. inclination characteristics of the Delta 7920, it has a liquid (LOX/Kerosene) core and it has a 4 meter diameter fairing. As soon as it is prudent, I will share with you all the vehicle and operational details that ITAR would allow me to post in this forum, including sketches. No yellow ruled paper, though - we use IDEAS.

And please, PLEASE, don't call me "sir" (or "Dr.") - reminds me of my age! One of the advantages of having a name like Antonio is that you can be THE Antonio (you know, as in THE Donald?... ) so, if you call me "sir" again, YOU'RE FIRED<sup>®</sup>!!!
-----
Will design rockets for food

2065 days later, this rocket becomes a reality. This is the best time for some food for thought and some food for celebrations!

Antonio, when your benevolent overlords give you some free time away from Antares, could you please post your promised next installment "Run Silent, Run Deep," in your story of how Pegasus was developed?

And thank you for sharing so generously of your time and knowledge on this forum; it's great to hear straight from the horse's mouth, as it were!

Plus one vote for this!
Chinese spaceflight is a cosmic riddle wrapped in a galactic mystery inside an orbital enigma... - (not) Winston Churchill

Offline Robotbeat

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Re: Q&A: Pegasus Designer Dr. Antonio Elias
« Reply #511 on: 09/09/2013 05:48 PM »
What happened to Pegasus-Turbo?
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

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