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?
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.?
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 CCB’s as LRB’s to cover a wide range of lift requirements ranging from 70 tonnes to 280 tonnes to LEO, from 2 LRB’s up to 8 LRB’s. 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 LRB’s 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 SRB’s, but I noticed that the central core could just as easily accommodate 2, 4 or even 6 additional Vulcan cores in the role of LRB’s. 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.
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?
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
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.
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??
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 or2) Future payload will all exceed Delta II's capabilities or3) Vulcan will still be used for small payload through dual/multi-launching like Ariane 5.Thank you!
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.
Quote from: georgesowers on 04/15/2015 09:59 pmQuote from: Bubbinski on 04/14/2015 03:21 amThank 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 5-6ULA Paper Link: http://www.ulalaunch.com/uploads/docs/Published_Papers/Evolution/EELVPartialReusable2010.pdf
Quote from: Bubbinski on 04/14/2015 03:21 amThank 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.
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?
Quote from: georgesowers on 04/16/2015 04:28 pmQuote from: Lar on 04/14/2015 12:57 pmAnother 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.
Quote from: Lar on 04/14/2015 12:57 pmAnother 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.
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?
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!).
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?