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.
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!