Author Topic: ULA Vulcan Rocket Q&A with ULA's Dr. George Sowers - April 14, 2015  (Read 68553 times)

Offline georgesowers

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Hello, Dr. Sowers.

Thank you for taking the time to discuss the Vulcan rocket plans with us!

I have a question regarding the use of Centaur. All things being equal, it would seem the Centaur (with its balloon tankage and common bulkhead) is a more complicated stage to build, transport and prepare for launch than, say the Delta IV's DCSS (separate tanks). Would a DCSS-derivative not offer a cheaper stage for Vulcan than Centaur?

Everything is not as it seems.  Centaur is lower cost  than DCSS.  And better mass fraction.

Offline Kryten

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Dr. Sowers;

 Is the new upper stage planned to be referred to as ACES indefinitely, or will there be a name selection/competition as there was for Vulcan?

Offline The Amazing Catstronaut

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Dr. Sowers, reading your response on the possibility of a three core Vulcan made me think a little. For what practical purposes does the first stage of the Vulcan inherit characteristics from the Common Core Boosters/Common Booster Cores of today, given that it will use entirely new engines and propellant?

-

Also (apologies for the sneaky two part question, feel free to ignore this part at your discretion) - will the stars and stripes paint job on the first stage make its way onto the final LV?

Thank you so much for spending your time with us Doctor.  :D It's exciting work you guys n' gals are doing.
« Last Edit: 04/17/2015 07:24 PM by The Amazing Catstronaut »
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Offline georgesowers

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Hi, Dr. Sowers.  To repeat everyone else, thanks for answering our questions.

Concerning the previously announced IVF technology to be used in Vulcan and specifically the ACES, how far along is ULA in developing an internal combustion engine that can run on hydrogen and oxygen and survive the implied temperatures and pressures (plus the vibration regime of a solids-assisted launch), be able to maintain lubrication over weeks and/or months spent quiescent in orbit, etc.?

We have a prototype engine with several hundred hours of operating time.

Offline georgesowers

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Dr. Sowers; In the recent past (2010) here on NSF there was a thread which discussed in depth an American equivalent to the Russian Vulcan, to be flown by Energya. http://www.k26.com/buran/info/hercules/vulkan.html. That potential LV system was called AJAX http://forum.nasaspaceflight.com/index.php?topic=22266.msg618244#msg618244 and used varying numbers of Atlas CCBs as LRBs to cover a wide range of lift requirements ranging from 70 tonnes to 280 tonnes to LEO, from 2 LRBs up to 8 LRBs. It even specifically called for the use of ULA's ACES upper stage. The 3 most difficult engineering problems were the flexible locations of the LRB interfaces, avionics with the ability to manage variable numbers of LRBs and the structural integrity of any upper stage imposing limiting factors on the usable lift capacity. None of these engineering conditions are too difficult to address so I looked at the potential of ULA's new Vulcan potentially filling that role. What was revealed yesterday was a single core with varying numbers of SRBs, but I noticed that the central core could just as easily accommodate 2, 4 or even 6 additional Vulcan cores in the role of LRBs. Such a vehicle would offer the United States, indeed the entire world, the ability to have a single LV family capable of covering Medium, Heavy and Super Heavy lift capabilities, without the expense of designing, building and flying many different vehicles, by simply varying the LRB count. So my question would be do you believe it would be a smart business move to design the Vulcan in such a way that does not preclude the on-demand ability to satisfy the less common needs of a Heavy or even a Super Heavy launch? Even though such large lift requirements would not be the norm, just knowing there was a vehicle available to handle it would likely free DoD and NASA mission planners to make use of the capacity.

Interesting idea.  We proposed something similar using Atlas or Delta cores as part of the MSFC heavylift study back in 2010.  Prior to SLS. 

Nothing we're doing would preclude going in that direction someday in the future, though there would be significant additional investment to get there.

Offline georgesowers

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Dr. Sowers,
  Thank you for your invaluable insight and for giving us the opportunity to interact with the pros of the industry.
I'm wondering about the Vulcan's core tank tooling. I'm assuming you'll be re purposing the Delta IV LOX tank tooling. But I also saw that you are trying to get it to be manufacturable, and Delta IV is not exactly know for that. So, are you going to basically put two appropriately sized DIV LOX tanks on top of the other with an intertank and an external down comer, or are you going to add improvements like internal down comer, common bulkhead and improved alloys (like Al 2195 or Al 2050), etc.? Can you elaborate on some of the improvements?

The tanks will have the same diameter as DIV but everything else is being looked at for improvement. Focus is lower cost, higher performance.  Everything you mentioned is on the list.

Offline falconeer

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Hi Dr. Sowers,

Two quick questions if I may:

1) Will ACES upper stage cost more or less than Centaur (actual cost not performance based)?

2) What is the cost of the second stage relative to the first? I believe current ratio is ~40/60 for Atlas, will this ratio go up or down for Vulcan?

Thanks again for answering our questions!
« Last Edit: 04/17/2015 11:06 PM by falconeer »

Offline kevin-rf

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Dr. Sowers,

Thanks for answering my earlier question on why Stainless for ACES tank. May I take a follow-up one step further?

You indicated that Stainless Balloon tanks had the cost / mass fraction advantage for the upper stage. So what tips the balance towards conventional Al tanks for the first stage? Cost? Ease of handling? Tooling? or will we see a return of a Stainless Balloon tank on the first stage?

Thanks again for taking the time.

I really like the special anodize job in the Vulcan videos and images. Any chance we will see that on the real Vulcan? Or will be the same boring copper coat we see on current Atlas's?
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Offline georgesowers

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Dr. Sowers,

Congratulations for a new beginning! May it live long and prosper !

The timeline that was given in the presentation predicts three events for 2019 being - Vulcan flight no1, Delta IV retire, Atlas V ban validation.
It was also noted that Vulcan will only be certified ~3 years later.
That leaves 3 years in which ULA will have only one legal alternative for all USAF payloads which is DIVH.
Assuming the law won't change, I would like to know how ULA is addressing this apparent problem.

Thanks

Assuming the law won't change, the AF has a number of options.  Fly Falcon 9 and Heavy (assuming the latter  vehicle, which has yet to fly, becomes certified).  Process a waiver for Atlas V.  Accelerate the certification of Vulcan.  Fly DIV H.

This situation was discussed in detail in the recent house hearing.

Offline georgesowers

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Dr Sowers, some years ago, ULA put out a horizontal lunar lander based on a ACES tank. Is that concept still possible if the ACES has balloon tanks? Thanks.

I love that concept.  Called XEUS, we've looked at it for both Centaur and ACES.  Pressure stabilized tanks are no problem.  Quite strong when pressurized and the landing loads are far less than earth ascent loads.

Offline georgesowers

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Dr Sowers, What vehicle configuration naming system are you going to employ on Vulcan since you will now need a fourth number to distinguish the change now between the Centaur US and ACES US; and would that naming system have to be altered to account for any additional stages the customer selects such as Castor 30 and/or Star-37FM??

For now, we will retain the current Atlas based numbering scheme, though now up to 6 strap-ons.  TBD what happens when ACES comes on line.  Might be Vulcan II? 

We don't fly third stages enough to devote a number to them.

Offline georgesowers

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Hi Dr. Sowers,

This is my first post on the forum but I suppose it's a good way to start by asking a question.

Since Vulcan is a medium-heavy class vehicle, there will be a void left by the retirement of Delta II. What is the reasoning behind not replacing Delta II?
1) ULA cedes Delta II-class payload to other launch service providers to concentrate on EELV-class payload or
2) Future payload will all exceed Delta II's capabilities or
3) Vulcan will still be used for small payload through dual/multi-launching like Ariane 5.

Thank you!

The main reason is that there is very little market in that class.  We were never able to sell the last DII; Antares has made no sales beyond CRS.  But if something changes, we can address through dual or multi-launch or create a Vulcan small.

Offline georgesowers

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Thank you, Dr. Sowers, for coming here to answer our questions.

I'm a little late to the party, but on the chance that you see this and wish to respond, here is my question.

Even before the Vulcan announcement, ULA was pursuing a path of product enhancements and cost improvements: GPS-based tracking, common Delta IV CBC, common upper stage engine (RL-10C), common avionics, and common upper stage.  What is the current roadmap for rolling out these enhancements (do you have specific missions identified yet)?

Thanks.

We have been aggressively driving our costs down for several years now.  Those saving are financing the Vulcan development.  GPS tracking is flying now as is RL10-C.  Common Avionics is a phased implementation flying on Atlas late this year.  The common Delta core is in the next year or two.  Common upper stage has become ACES.

Offline georgesowers

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Thank you for offering to answer our questions, Dr. Sowers.

Are you planning to recover and reuse the solid rocket boosters, either initially or eventually?

Nope.

Got to run again, but I'm committed to answer every question.
a somewhat related follow on to the above question: Are you also planning to offer the option to deploy suborbital payloads on Vulcan via the External Payload Carrier (XPC) as was developed and made available on Atlas V programme??
Reference: EELV Partially Reusable Booster (2010 PDF) Section IV, Pages 5-6
ULA Paper Link: http://www.ulalaunch.com/uploads/docs/Published_Papers/Evolution/EELVPartialReusable2010.pdf

The XPC is a great concept and is compatible with Vulcan.  We have never been able to find that crucial first customer.

Offline georgesowers

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Another vote of thanks for agreeing to take questions, Dr. Sowers!

ULA surely did trades on full first stage recovery versus engine compartment midair... why is midair recovery so compelling, compared to the path SpaceX is on, which seems to offer the promise of far greater cost reductions?

I've promised to post a simple spreadsheet that will give some insight into the economics (probably next week).  But the gist goes like this:  We are recovering >60% of the cost of the booster for 1/6th of the performance loss (5% vs 30%) in a manner that completely shields the hardware from the harsh reentry environment.

Dr. Sowers I would like to reiterate the thanks everyone else have given for this opportunity. I look forward to your success in a big way.

I am curious though. How the extra performance gets monetized? It seems like the 1/6th number will rarely be realized since there will always be some mismatch of payload to capability. The shielded environment does seem like a good way to make recertification cheaper though.

Kilograms to orbit is why launch companies exist.  It's what we sell.  Therefore $/kg is the most important figure of merit for any launch system, call it E.  (Other criteria like reliability and timeliness can be easily monetized).  Minimizing E is the objective.

Monetizing performance is an important part of the business model.  It's why we have an architecture that allows us to add SRM's one at a time.  If you have only one vehicle, many customers are forced to buy more performance than they need. 

In the commercial GEOcomm market it's easy.  Almost every customer uses every gram of performance we can give them.  It's used to top off the SC fuel tanks or reduce the residual delta V to get to GEO.  AF missions also tend to use all the available performance as do NASA interplanetary missions.  We can probably tolerate a 5% performance loss to accomplish engine reuse, but 30% rarely.  Or you have to go to a larger vehicle (more SRMs).  SpX would have to jump all the way to a heavy.

To me, the CRS market is somewhat anomalous in that they routinely use only a fraction of the launcher capability.  If you calculate $/kg of delivered cargo, NASA is not getting a very good deal at all.

Secondary payloads is another way to monetize excess performance.

Offline georgesowers

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Dr. Sowers,
Thank you for taking questions on this exciting vehicle!  I hope you are able to answer mine.  My question is performance and possibly strategy related, so I understand if you can't answer it.  (It looks like three questions, but it's really one with multiple approaches.)

With Delta II soon to retire, Delta IV-M to go next, and Atlas V 401 also being phased out, how does Vulcan fit in with the Small- to Medium-class launch capability and market?  The Vulcan core booster seems oversized for those classes of missions, and oversized usually means overly expensive.  Will a Vulcan 401 be a reasonable replacement for the most frequently-flown vehicle configurations in your fleet, and if so, how or why?  Related, after the introduction of ACES in ~2023, will Centaur continue to fly to serve the Medium market?

Thank you in advance, and enjoy the heavy snow that we're sending your way (that is, drive home safely!).

The Vulcan 401 will be priced at less than $100m, a significant improvement to today's Atlas V 401 at $164M.  Vulcan's performance is a bit higher.  Once ACES comes online, we intend to retire Centaur.  We are still trading whether to have multiple length ACES configurations.

Offline Newton_V

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Dr. Sowers,
Any chance the SRB's will be called Klingons?  ;)

Offline john smith 19

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Hello Dr Sowers. My questions are about IVF.

IVF seems like such a win/win for both ULA and its customers I don't understand why it's been so difficult to find missions it can be tested on.  :(

Could it be tested in smaller parts (like thrusters, battery and engine for example) on different flights so your customers are more relaxed about having the whole package on a single flight?

Due to its size does it need a mission with a lot of excess capacity for it to be fitted in addition to the standard flight systems, just in case, or is it primarily customer nerves ?

"Solids are a branch of fireworks, not rocketry. :-) :-) ", Henry Spencer 1/28/11  Averse to bold? You must be in marketing."It's all in the sequencing" K. Mattingly.  STS-Keeping most of the stakeholders happy most of the time.

Offline ChrisWilson68

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Thank you for answering all these questions.

I'm very impressed by your showing here.  I'm impressed that you were willing to come on here and answer every single question.  I'm impressed that the answers are thoughtful and substantive and not just marketing fluff.  And this is coming from a SpaceX fan.

I hope ULA appreciates what you're doing here.  I suspect I'm not the only one whose opinion of ULA has been raised.

Offline georgesowers

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Dr Sowers, thanks for doing this Q&A. My question is this; during the development of Vulcan, was varying the amount of BE-4's for the first stage (more or less) considered?

yes

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