ULA is not its own company. Is this development being done on ULA funds or have the parent companies okayed it?
Dr. George Sowers - VP, Advanced Concepts and Technologies (new rocket development is within his department) has kindly agreed to take questions on the NGLS (Named Vulcan) that was revealed April 13.Dr. Sowers is a great friend of the site and has provided some superb Q&As here, for which we're very grateful.I'm opening this now, ahead of Dr. Sowers answering questions on Tuesday, April 14, MT.One question per member to ensure Dr. Sowers isn't overloaded with questions. Ensure your question is well presented, readable and worthwhile and please read the coverage of the reveal here: http://forum.nasaspaceflight.com/index.php?topic=37251.0 - to ensure you don't ask a question already addresses (or that you ensure it asked for clarification of an answer).
All best with the Vulcan. It has turned me into a ULA fan and many others judging by forum activities and name voting.Do ULA plan to introduce IVF on Centuar or will it wait for ACES?.
Hi Dr. Sowers,Thanks very much for doing this with us. Can you talk about any timelines or capabilities for Vulcan human launch? That wasn't touched on at all during the press conference, but with CST-100/Atlas making a lot of news, I'm sure things like pad access etc are in the works.Thank you.
Thank you Dr. Sowers for your offer of answering NGLS/Vulcan questions.If you and your rival are equally successful at your respective first stage "reuse" strategies, how well will they compete in terms of increasing overall annual launch frequency of each vendor?Thank you again in advance for answering my humble question.
Thank you Dr. Sowers for the opportunity.My question is whether the vehicle (or a specific configuration) be rated for nuclear payloads (IE: science missions with Plutonium)?
Hi Dr. Sower, Thank you very much for taking the time to answer these questions. Tory Bruno has stated that the SMART Reuse system won't be used on the Vulcan initially, but will be phased in. How long do you think it will take for them to start using it? And do you believe it will be done gradually, alla SpaceX or will it be much more rapid, say one or two experimental launches, then going full engine reuse?Cheers,
Dr. Sowers, thank you again for coming back to answer more questions about your new rocket. I can't wait to watch it come together over the next few years, and hope Blue Origin can be persuaded to release engine testing videos.If I recall correctly, ACES was a modular family that would fly with varying numbers of engines and even varying sizes of tanks to accomodate different mission requirements. Is that still the plan for the future Vulcan upper stage?Thank you again. Go Vulcan! Go Centaur!
Thanks for taking the time again, Dr. Sowers (and Chris).What is the largest PLF under consideration, even for 2023+ ACES?(btw, a good name for said stage would be "Centaur Prime")
Thanks for sharing with us Dr Sowers.I am curious about the versatility of the ACES stage, is it foreseen to be used with any other current, planned and/or future boost stages?
Dr. Sowers, welcome back and thank you for again taking the time.I watched the presentation and one thing struck me about upper stage being proposed. Didn't the original ACES paper have them switching from the current Centaur Stainless tank to a larger Al-Li tank. Tory made it quite clear the new upper stage being proposed will use new Stainless tanking. Care to elaborate on the ACES's switch from the new tank using Al-Li to Stainless? Why is it superior? Better mass fraction? Easier to make? Cheaper to make? 70 years of experience manufacturing balloon tanks with Stainless?I am just curious why it is superior for the new upper stage.Thanks.
Quote from: Chris Bergin on 04/13/2015 10:41 pmDr. George Sowers - VP, Advanced Concepts and Technologies (new rocket development is within his department) has kindly agreed to take questions on the NGLS (Named Vulcan) that was revealed April 13.Dr. Sowers is a great friend of the site and has provided some superb Q&As here, for which we're very grateful.I'm opening this now, ahead of Dr. Sowers answering questions on Tuesday, April 14, MT.One question per member to ensure Dr. Sowers isn't overloaded with questions. Ensure your question is well presented, readable and worthwhile and please read the coverage of the reveal here: http://forum.nasaspaceflight.com/index.php?topic=37251.0 - to ensure you don't ask a question already addresses (or that you ensure it asked for clarification of an answer).Before I dive into the questions, I'd like to thank Chris for giving me the opportunity to do this Q&A. As I wrote in a recent op ed (http://dpo.st/1albze6 ) developing new rockets is a good as it gets for someone in our business. It's clear that all of you share my enthusiasm. And that makes answering your questions really fun.
This is my first post on the forum but I suppose it's a good way to start by asking a question.
Firstly, congratulations. Exciting time ahead.I'm curious as to what specifically was meant by "pad innovations"? What new designs and methodologies will be developed?Thanks and the very best of luck.
Thanks Dr.Sowers for taking the time to answer our questions. We're all very excited about the preliminary details revealed in today's announcement.My question is: What key factors set the architecture in favor of multiple solid boosters instead of a multiple common core configuration as seen on other heavy lifters such as the Delta IV Heavy, Falcon Heavy, Angara V?
Dr. Sowers, very exciting presentation today. Thanks for taking our questions. I have the following question: Isn't there a risk for ULA to team up with a competitor such as Blue Origin given that Blue's objective is to eventually make their own LV?Thanks,YG
Could you please elaborate on the distributed launch option?I would really like to know the kind of mass you could put in GTO or GEO if the first launch is a fuel tanker. How would it compare to the Delta-IV heavy?Thank you.
Hello Dr. Sowers,Will the design be scarred such that a tri-core vehicle is possible should future demand require one?
Dr. Sowers, thank you for taking the time to answer questions!My question is, how will the vehicle be delivered and processed at the pad? First transportation; will the stages be transported by barge or by air from the factory? For launch site integration; will it be like Atlas V (vertical rocket integration and a mobile transporter to the pad), Delta IV (horizontal rocket integration, erected at the pad and vertical payload integration with a mobile service tower) or like Falcon 9 (horizontal integration and erected at the pad)?Thanks again! I am excited to see Vulcan fly!
Dr. Sowers,why will Vulcan start out with an upper stage based on RL-10 instead of a BE-3?There is certainly more experience with the BE-3 engine already, than with the BE-4 engine you plan to use in the 1st stage. BE-3 has already gone through acceptance testing while BE-4 has yet to be build, not to say test-fired. You could start developing an upper stage with a BE-3 engine right away and demonstrate it on either an Atlas or Delta rocket.Same question in other words: If you are preprared to use an engine in development like the BE-4 in 2019, why is it important to first gather flight experience with the BE-3 before using it with the new rocket some time in 2023?
George,I'm excited to see the progress on this new rocket, and glad you guys are able to talk more openly about orbital refueling and such! Hopefully I get a chance to say hi when we're down at the symposium tomorrow.My question is sort of boring, but do you have any numbers you can publish about expected performance for Vulcan, both with various numbers of strapons and the existing Centaur stage, and then with various numbers of strapons and the new ACES stage?~Jon
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: 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.
I'd like to know more about any plans for depots and the extremely long-lived side of ACES. You mentioned months. Does this include some sort of sunshield? Can I sneak one in on second stage recovery?
Dr Sowers,Thank you for taking our questions. With the addition of more powerful solid rocket motors, I would like to know how the acceleration profile during flight will compare to that of the Atlas V / Delta IV now. Will the acceleration be higher? Or has this been offset by other factors?
Quote from: Antares on 04/14/2015 04:14 amULA is not its own company. Is this development being done on ULA funds or have the parent companies okayed it?I believe this was already answered at yesterday's webcast: "Funding for development is completely out of ULA's profits."--Thank you for doing this Dr. Sowers. I have a simple question: Will the stars and stripes paint scheme go on production vehicles or is it just artistic license for the renders? I think it looks gorgeous. Thanks, and I look forward to the first Vulcan launch!
ULA's press release says "In step two, the Centaur second stage will be replaced by the more powerful, innovative Advanced Cryogenic Evolved Stage (ACES), making the NGLS capability that of today’s Delta IV Heavy rocket.". Qualitatively will Vulcan with ACES match or exceed DIVH to all destinations from LEO to Saturn or will it be better for some orbits but not others? Quantitatively what's Vulcan with ACES's expected payload mass to LEO, 1500 m/s GTO, TLI, Mars, and Saturn? (Or better yet a plot of mass vs C3.)
Dr Sowers - are there any concepts discussed on how the 1st stage engine booster inflatable heat shield will be made of and tested for use?
Dr Sowers; thank you for all your attention and time here. Question: might any ACES derivative be put forward as a possible 'Exploration Upper Stage' for the SLS?
Dr. Sowers,My first question is the fuel choice for the first stage: methane. What prompted the use of methane as opposed to the more traditional kerosene?My second question is how much payload could the first configuration of Vulcan (with Centaur as upper stage) put into orbit or even to Mars? The later part of the question relates to ULA's history with sending space probes out such as MAVEN and even Pluto-bound New Horizons. The size of such spacecraft ultimately depend on the capabilities of the rockets that launch them.
SpaceX has said their goal is to fly first stages back to the landing site and reuse them quickly -- gas and go. If SpaceX is successful in that, and continues an unbroken string of Falcon 9 launch successes, can Vulcan compete with that? Or is ULA betting the company that SpaceX will fail?
Dear Dr. Sowers,Is ULA considering the use of propellant densification via subcooling of the Vulcan first stage propellants as a way of increasing the performance of the vehicle?All the best, Steven.
Dr. Sowers, congratulations on the Vulcan reveal!Of the components and technologies announced and/or discussed today, which one most excites you personally, and why?
Dr Sowers, thank you for taking the time and trouble to answer questions.How long have you been working on the Vulcan concept and what approximate stage in development have ULA reached? (eg PDR, CDR etc)
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. SowersAFAIK the current ULA launchers were only used to launch NASA or USAF payloads.Does ULA plan to (re-)enter the market of commercial comsat launches with Vulcan?Spacediver
Dr. Sowers, If ULA is planning to attempt either full stage or Engine and Avionincs package recovery, whatis the particular method that you have in mind for such recovery? Powered descent to land, Parachute to sea, or a combination of these strategies?
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.
Dr. Sowers - What drove the decision to select an as-yet unbuilt and untested engine from a new player in the aerospace world (BE-4 from B.O.)? If ULA were selecting an existing engine with flight heritage (RS-68 for example) it would provide an obvious schedule acceleration benefit. But when considering a new American built engine, especially in the non traditional methalox category, for vertical integration reasons it would seem to make sense for ULA to develop its own. Removing my second question per request from mods.Did ULA consider using SpaceX engines on its rockets? Raptor will be methalox, and in the right thrust regime for a 2-engine Vulcan first stage. Is this even a feasible business move?
Dr. Sowers,I would like to ask question related to solid boosters:Shall Vulcan be human rated in configuration with multiple solid boosters, i.e. capable of capable of launching orion?Edit: reduced to one question.Thank you in advance!
Hi Dr. Sowers,ULA has a long history of successful missions, SpaceX is an emerging business, and Blue Origin an enigma. Overall, it seems that everyone is losing the PR war with the general public -most people just don't care. A number of space enthusiasts are excited for SpaceX's entry into the market, simply because of their grander stated ambitions (realistic or not).How can/will ULA help reinvigorate the public's appetite for spaceflight?Thanks!VulcanCafe(excellent rocket name choice!)
There was a mention of selecting the AR1 engine in 18 months if the Blue Origin engine isn't coming along as expected. What impact would that have on first stage design? Thanks!
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: 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.
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?
Dr Sowers,If follow-up questions are allowed (thanks for answering my first one!), can you talk about other items in the trade space that were examined but maybe rejected? I'm sure you looked at full-stage reuse, multiple engines, that sort of thing, but anything more fanciful like 4+ core vehicles, flyback/flythrough boosters, SSTO etc? Not sure how much you can talk about it, but your title *is* Chief Mad Scientist, so hopefully there's some real mad science stuff that you can talk about. I totally understand if none of that can be public until much later when a history of the development program can be written.Thank you again!
Thank you for answering my earlier question Dr. Sowers.You've talked about reusing an upper stage. After payload separation, you've got a free US - to reuse it would need to acquire orbit for new payload, prox ops, attach, execute a series of timed burns, and separate again.ACES/Centaur don't appear to be anything more than typical, autonomous US at the moment. Even Agena, which was more of a spacecraft than just an US, didn't have all of that to do the above. Nor are payloads attached to US without significant ground prep, spin table, etc. Had not heard Astrotech making on-orbit house calls yet Where's the extra SC part coming from that can "command" / "manage" / "handle" ACES/Centaur?Again, thank you from the NSF community here. We really appreciate it when you communicate with us like this.
I'll avoid a Reddit-style question about if you prefer cakes or pies, and ask evolvability. Just how much can you upgrade this specific system by way of upmass, and where do you think is the top line for upmass? (say versus mulitple launches) in the future customer requirement market.
Hi Dr Sowers,Regarding aerocapture of the parachuting engine by helicopter, will it necessarily be a manned helicopter, or is there a possibility of an unmanned drone helicopter being used to reduce risk?Thanks for your time, sir.
Thanks Dr Sowers for all the great answers. Could the SMART system be applied to upper stage? Tory hinted at using it elsewhere.
Dr Sowers; you mentioned earlier in the thread that you would not rule out a future 'triple core' heavy version of Vulcan. Has ULA also looked at versions with 8 or even 10x solid boosters on a single corestage? It appears that many boosters might fit on a 5 meter stage. It would seem to me that such a launcher with an ACES upper stage would have a lot of capability!!
Dr Sowers,When eliminating turbine based units from the IVF system design, were sub-atmospheric 'inverted brayton cycles' such as outlined in the linked pdf, considered. This is a scheme for a residential scale CHP (high enthalpy) micro-turbine system, that reverses compressor and turbine sequence to produce very-low-power turbo-generators. Or would continuous combustion require too high a fuel flow to keep combustion temperatures sensible, (what is the peak combustion temperature in the IC engine anyway)?http://www.agileturbine.com/publications/Small%20Scale%20Combined%20Heat%20and%20Power.pdf thanksToby
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?
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. It's exciting work you guys n' gals are doing.
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!
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?
Dr. Sowers,Any chance the SRB's will be called Klingons?
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 ?
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.
Dr. Sowers:I'm extremely fascinated and impressed with the IVF design (why wasn't this addressed decades ago?) and the very smart implementation of an internal combustion engine, counter-intuitive as it may first appear. (And it's blowing a lot of minds in this forum, even though online documentation explains it all.)So, a question: How is the torque of such a rotating engine in microgravity compensated? That's the one detail I don't recall being explained. Two such engines, mounted in opposite directions might do it, but single-engine mode if one is shut down might require considerable thruster firing to maintain a stable vehicle attitude. But I'd like to think a simple solution is available.--Damon
Quote from: skater on 04/14/2015 04:09 pmThere was a mention of selecting the AR1 engine in 18 months if the Blue Origin engine isn't coming along as expected. What impact would that have on first stage design? Thanks!Since AR-1 uses RP fuel, the first stage design would look a lot like Atlas V.
Quote from: sanman on 04/16/2015 10:46 pmHi Dr Sowers,Regarding aerocapture of the parachuting engine by helicopter, will it necessarily be a manned helicopter, or is there a possibility of an unmanned drone helicopter being used to reduce risk?Thanks for your time, sir.Given the mass of the engines, it needs to be a big helicopter. Hadn't though about unmanned. What risk are you trying to mitigate?
George,There is a lot of interest in the IVF work; a q/a like this one with answers from Frank Zegler would be great if it can be arranged. Having had the chance to talk to him about it last week, I'm extremely impressed and think that it would be great if up to date information can be shared, to the extent possible. IVF is a game changer, as reusability will be (presuming SpaceX and/or you succeed).
Quote from: georgesowers on 04/19/2015 11:54 pmQuote from: sanman on 04/16/2015 10:46 pmHi Dr Sowers,Regarding aerocapture of the parachuting engine by helicopter, will it necessarily be a manned helicopter, or is there a possibility of an unmanned drone helicopter being used to reduce risk?Thanks for your time, sir.Given the mass of the engines, it needs to be a big helicopter. Hadn't though about unmanned. What risk are you trying to mitigate?Hi Dr Sowers / George, it just seemed that aerocapture of a multi-ton engine pod -- or multiple such engine pods, if you fly multicore -- would be very challenging, and potentially risky to the pilot(s). Have you considered using a ballute as your hypercone, and allowing it to serve as a flotation cushion after splashdown, to keep your engine from getting soggy?