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#360 by meberbs on 26 Aug, 2020 19:38
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As you know, I have elsewhere provided a detailed, fact based breakdown of problems with SLS that explain why it is not something that should be pointed to as evidence that something is not obsolete. There still have been no actual rebuttals that I have seen. The details don't belong here other than that SLS is not a justification for the solid rocket main stage of OmegA not being obsolete.The SLS is obsolete, it uses old tech in a worse way than it's original use.
This again?
It seems like you couldn't be bothered to even click the link to see the quote from a European commissioner about the future of European rockets. Instead you dismiss what he has to say based solely on the title of the news source that quoted him.Those other mentions are small boosters, not large ones, significant difference, and your claim of 20-30 years is a baseless assertion. Ariane has already started looking towards an actual next gen rocket with reuse.
Yes, let's cite Teslarati as a source. I'm sure Teslarati is an objective outlet with no biases whatsoever.
https://www.teslarati.com/spacex-reusable-falcon-rockets-europe-response/amp/
When you can't even directly address what I had to say, it does not say good things about the validity of your position. -
#361 by meberbs on 26 Aug, 2020 19:42
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Some important context was removed when I was quoted here, it is jadebenn, who used the "no true scotsman" fallacy to disparage anyone who did not fully support OmegA.Quote "This is a classic "no true Scotsman" fallacy/insult. "
Years ago when Mike Meyers was on SNL, he performed a skit where he was a Scotsman who owned a gift shop/curio store called "If it ain't Scottish, it's Crap!" He would get angry and yell at all the patrons who would come in the shop, looking for 4 leaf clovers, leprechaun figures, Blarney stones etc.... "Scottish-Irish what's the difference?" "I'll tell ya Lassie!!!..." 
Today it would be "If it ain't SPACEX it's Crap!"
Unfortunately thats all too true. I absolutely love SpaceX, watch almost every launch and hope they continue to kick butt. But they're not the only shinny object in town that matters. -
#362 by Coastal Ron on 26 Aug, 2020 19:58
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OmegA was an honest attempt to develop an affordable vehicle for the Air Force's needs.
How, in any way, was it "affordable"?
And I'm assuming when you say "affordable" that you mean it would have cost less than what the USAF has currently been paying to ULA and SpaceX, because otherwise the word "affordable" is not the right one to use.QuoteUnfortunately, it appears to not have been flexible enough outside this niche, but it still developed new technologies and infrastructure that will be useful in future projects.
What technologies would that be? Because solid rocket boosters were not new technologies, so at best one could say they matured the SRB technology a little more. But "new"?
OmegA was a head scratcher program from the beginning since it had no inherent advantages over current launchers, and no ability to be improved to any significant degree.
No one should have been surprised that the program was cancelled. The only surprise is that it made it this far... -
#363 by TrevorMonty on 26 Aug, 2020 20:47
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Without DoD contracts Omega would've been entering a very competitive commercial launch market, soon to be serviced by 3 new LVs (Vulcan, Ariane6 and NG) one existing low cost F9R. Can also add JAXA H3 and ISRO GSLV to that list. The GTO market hasn't grown enough to support all these LVs and may actually shrink or move to smallsats. When comes to smallsats the LV market is even more competitive. If GTO competition had just been A6 and F9R, then they may of had a go.
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#364 by tmoesser on 26 Aug, 2020 21:00
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As for Ares I, there is a clear lineage from Ares I to Liberty to Omega, according to this NSF article:
Can I please debunk this? Except for the visual similarity (i.e. "The Stick"), there is actually very little in common with OmegA and Liberty or Ares I.
"Despite the Constellation program’s cancellation, Orbital ATK, the predecessor of which would have built the five-segment SRB for Ares I and the company that is now building the five-segment dual SRBs for SLS, continued to see a usefulness for the overall Ares I design. This initially translated in 2011 to the Liberty rocket, a five-segment SRB first stage with an Ariane V core serving as the upper stage.
By May 2016, this overall design was incorporated into Orbital ATK’s participation and contract award from the U.S. Air Force as part of the Air Force’s Rocket Propulsion Systems Development project to replace the Russian-made RD-180 engine used on United Launch Alliance’s Atlas V rocket and to also streamline the EELV (Evolved Expendable Launch Vehicle) program to reduce the overall cost and increase efficiency of U.S. rockets used for national security and government missions."
The OmegA Common Booster Segment (CBS) motors actually have much more in common with the Titan IV-B Upgraded SRBs (120" diameter, 3-segment composite cases) and the Stratolaunch Eagles LV first and second stage motors (146" diameter monolithic composite), and for that matter with the CASTOR 30/30XL/120 family of motors (92" diameter monolithic composite) and with the GEM family of motors (40 to 63" diameter, monolithic composite, open aft dome), than they do with RSRMV, the 5-segment steel-case motor derived from the Shuttle RSRM developed for Ares I, now the booster for SLS. What is common between RSRM/RSRMV and CBS? They're close enough in diameter to use some of the same facilities, handling tools, inspection equipment maybe, and railcar covers -- that's about it. RSRMV uses a completely different family of propellants (different polymers for sure -- at the chemical level most of the propellant is AP and aluminum, but even those are differentiated at the particle size level to produce different burn rates), different production tooling, even insulation materials and methods. Each of the CBS nozzles is a unique design for optimized performance, and broke ground for new materials and processes -- and as the C600 static fire showed we were able to learn some things. The CBS motors were designed to be a versatile commercial offering, tailored for an EELV-/NSSL-class launch system meeting SPRD & SIS requirements when paired with an appropriate upper stage, not a human-rated vehicle for LEO only like Ares I and Liberty. Now that the LSP contract has been awarded, I expect the CBS motors will show up in the motor catalog, replacing the RSRM/RSRMV-derived motors.
OmegA did not use "1970s Shuttle technologies" in its designs, at least to the extent the industry media and informed outsiders seem to believe. If we're honest about it, at least give us the benefit of using "1990s technologies" epitomized by CASTOR 120 (Athena I/II, Taurus/Minotaur-C) and Titan IV-B SRMU. Perhaps just as significantly, the future, evolved SLS booster (see "BOLE" Program in other thread topics) is leveraging CBS designs and technologies -- not the other way around.
That doesn't even touch how different the Liquid Upper Stage on OmegA is from Ares or Liberty. It's as though the 5-meter DCSS on Delta IV or Centaur-G (which are the closest physical analogues to the dual-RL10 OmegA LUS) were comparable to the J-2X powered Ares I Upper Stage or Ariane 5 core stage repurposed as a second stage. Completely different systems. -
#365 by Coastal Ron on 26 Aug, 2020 21:54
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Can I please debunk this? Except for the visual similarity (i.e. "The Stick"), there is actually very little in common with OmegA and Liberty or Ares I.
Well the common concept between the three of them is that the 1st stage is a solid rocket motor, which has never been fielded as a 1st stage engine, only as boosters.
That key detail is why all three are looked at as the pretty much the same, even though the bits and pieces that make up everything else might be different between the three.
And I think the U.S. Taxpayer should be happy that no more of their money went to support this concept, since it was hard to see how it could evert result in an improvement in the end result that mattered - $/kg to orbit. -
#366 by tmoesser on 26 Aug, 2020 22:38
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Yes, that's the correct definition of "affordable." I am reasonably confident that the propulsion system and launch vehicle development funded by the RPS and LSA contracts resulted in four competitors for the LSP contract, all of which proposed Firm/Fixed Price services to the government that were more affordable, i.e. cost less to you and me the taxpayers, than is currently being paid to ULA and SpaceX under the current block buy for equivalent services. The press release from the Air Force says this process has saved them $7 billion so far, even accounting for RPS and LSA spending. LSA did its job, in that it brought as many competitors as possible to the table in a mature enough state that the government could trust them to launch these missions, at a price much lower than it is currently paying. Maybe the bean counters at the GAO will have a different conclusion, but I take the following at face value:OmegA was an honest attempt to develop an affordable vehicle for the Air Force's needs.
How, in any way, was it "affordable"?
And I'm assuming when you say "affordable" that you mean it would have cost less than what the USAF has currently been paying to ULA and SpaceX, because otherwise the word "affordable" is not the right one to use.
https://www.af.mil/News/Article-Display/Article/2305576/space-force-awards-national-security-space-launch-phase-2-launch-service-contra/QuoteThis competitive acquisition adds to the considerable savings the NSSL program has achieved since the 2013 Phase 1 Block Buy award. The total life cycle cost reduction since the February 2013 program rebaseline now stands at $22 billion. The NSSL program has returned approximately $7 billion in procurement funds to the Department of the Air Force and National Reconnaissance Office, enabling them to fund additional capabilities. The Space and Missile Systems Center’s Launch Enterprise garnered these savings by creating innovative acquisition strategies, procuring launch services in economic order quantities, and fostering robust competition precipitated by investments in new commercial launch systems that also meet more stressing NSSL needs.
I think this is the purpose of "government investment." You do R&D to try to get breakthroughs, maybe that's technology and capability, out-do our international competitors/adversaries, and specifically for RPS to develop an alternative to the RD-180. Interestingly the drop-in RD-180 replacement of the AR-1 was not selected for RPS, because the technical merits of the other proposals offered more to the government. ULA's 2014 vehicle configuration trade study down-selected that option out in favor of the BE-4 option. In the case of LSP, the breakthrough appears to be primarily in cost -- with the minimum threshold for technical merit and performance set very high.
In my opinion, that lack of an ROI to the government, even a hypothetical return, is why SpaceX lost on the LSA contract. Funding BFR/SH+SS, as cool a breakthrough in technology that might/will be, was not going to save the government any money nor offer any additional service they were asking for, and perhaps would not even comply with their basic requirements. (Was SpaceX ever planning to launch BFR from both KSC/CCAFS and VAFB? If not, they failed to comply with at least one SPRD requirement.) If SpaceX proposed a $200-$300M development of MSTs at both launch sites for vertical integration and a stretched 5-meter fairing and payload adapter/fitting for FH to comply with SIS Category C payload requirements, it would have been a slam dunk and money in the bank. Their strategic mistake to propose BFR.
If you consider SpaceX's offering to the government, whatever dollar figure that is for all the products and services and white-glove treatment that National Security Space Launch entails (of which classified operations is no small part), to be "affordable," then I hate to burst your bubble, but so was ULA's offering, and Northrop's offering, and Blue's offering. The government did not give this contract to the two lowest bidders.
SpaceX might be offering dirt-cheap rides on F9/FH to commercial customers, but that's not what they're offering the U.S. Government. Or they're making it up in services and amortizing the cost of that MST and fairing over the next 6 years. OmegA would have been very affordable to USSF/SMC, but so far, SpaceX has undercut other domestic launchers so much that nearly all commercial customers and even civil payloads designed for Pegasus are transitioning to F9. Good for them. Competition makes us all better. -
#367 by tmoesser on 26 Aug, 2020 23:04
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Well the common concept between the three of them is that the 1st stage is a solid rocket motor, which has never been fielded as a 1st stage engine, only as boosters.
No 1st stage solid rocket motors ever on space launchers, except on, let's see...
Athena I and II, Taurus (now Minotaur-C), all other flavors of Minotaur based on ICBM stages and Titan 4 (the core was air-lit, Stage 0 was the solid boosters), all of which use(d) NG/ATK-built first stage domestic solid rocket motors. Let's also throw in Conestoga and Super Strypi as examples, though with an asterisk. Looking internationally, we can add M-5 now Epsilon (Japan), Start-1 (Russia), CZ-11 (China), KT-2 (China), Kuaizhou (China), PSLV (India), Shavit (Israel), SS-520 (Japan), Vega (Europe), and ZQ-1 (China). Of note, PSLV and Vega have built quite the impressive flight history, and are still flying or will be returning to flight imminently.
If you mean, no solid rocket motor of this size has ever been fielded as a 1st stage, then yes. Vega currently holds that record with the P80, soon to be out done by the Vega-C with the P120. If you mean "segmented", then also yes, unless you include the Titan 4B SRBs as Stage 0.
Hat tip to Ed Kyle's http://spacelaunchreport.com/library.html for refreshing my memory. -
#368 by jadebenn on 26 Aug, 2020 23:43
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As you know, I have elsewhere provided a detailed, fact based breakdown of problems with SLS that explain why it is not something that should be pointed to as evidence that something is not obsolete. There still have been no actual rebuttals that I have seen. The details don't belong here other than that SLS is not a justification for the solid rocket main stage of OmegA not being obsolete.
Past experience has lead me to believe that our positions are fundamentally irreconcilable, and I see no reason to once again devolve into posting screeds of text and exchanging heated PMs if there's no room for compromise between us. So, okay, maybe pithy little responses are a rather childish and uncivil way to express my disagreement, but I have no interest or obligation to sit at my laptop for an hour or two to produce a 1,000+ word response when I know it's not going to result in anything positive.
To put it more simply: I disagree. Let's leave it at that.OmegA did not use "1970s Shuttle technologies" in its designs, at least to the extent the industry media and informed outsiders seem to believe. If we're honest about it, at least give us the benefit of using "1990s technologies" epitomized by CASTOR 120 (Athena I/II, Taurus/Minotaur-C) and Titan IV-B SRMU. Perhaps just as significantly, the future, evolved SLS booster (see "BOLE" Program in other thread topics) is leveraging CBS designs and technologies -- not the other way around.
I blame this tendency on the technology industry. A 10-year old processor is almost worthless. A modern processor will be unequivocally superior in every way (cost, efficiency, performance).
A 10-year old rocket engine, first of all, is never actually 10-years old when you account for all the changes made since then, and even if it was (and it's not), it's not like the laws of thermodynamics have fundamentally changed since then. I mean, the RL10 is still the premier US upper stage hydrolox engine. The modern RL10 is a modern engine, but you can still trace its heritage more than half-a-century back.
Fundamentally, chemical rocketry is a fairly mature field of technology that runs at the limits of what's thermodynamically possible. All that's really changing is how we build the engines, not how they work. -
#369 by jbenton on 27 Aug, 2020 02:12
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...
One more point, the government had to balance Technical/Risk scoring on one hand and Price on the other. In that case, a Value determination had to be made, which add some subjectivity. It was the job of the source selection committee to determine the Best Value (60%) and Next Best Value (40%) offerings, in a one-choice-at-a-time method. It was not a unanimous determination, but it wasn't a close call either.
...
I'd also like to echo what Tory Bruno said on Twitter recently, that if you look at the values of the contract task orders (i.e. missions) that were awarded at the LSP announcement, "the identity of the lowest price provider might surprise you..."
I'm not on Twitter. Do we know which of the three was cheapest? Which was second? -
#370 by Coastal Ron on 27 Aug, 2020 02:50
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Well the common concept between the three of them is that the 1st stage is a solid rocket motor, which has never been fielded as a 1st stage engine, only as boosters.
...If you mean, no solid rocket motor of this size has ever been fielded as a 1st stage, then yes.
Obviously I was talking about a launcher "of this size" since OmegA was competing for the NSSL program...
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#371 by Sam Ho on 27 Aug, 2020 04:04
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...
One more point, the government had to balance Technical/Risk scoring on one hand and Price on the other. In that case, a Value determination had to be made, which add some subjectivity. It was the job of the source selection committee to determine the Best Value (60%) and Next Best Value (40%) offerings, in a one-choice-at-a-time method. It was not a unanimous determination, but it wasn't a close call either.
...
I'd also like to echo what Tory Bruno said on Twitter recently, that if you look at the values of the contract task orders (i.e. missions) that were awarded at the LSP announcement, "the identity of the lowest price provider might surprise you..."
I'm not on Twitter. Do we know which of the three was cheapest? Which was second?
You don't need to be "on" Twitter to read a Tweet. In this case, Tory Bruno's tweet did not go beyond the quoted statement, nor could it until the Source Selection Statement is published.Quote from: Tory BrunoYou might want to check the prices in that competition. The identity of the lowest price provider might surprise you...
https://twitter.com/torybruno/status/1296112418070855682 -
#372 by su27k on 27 Aug, 2020 04:11
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In my opinion, that lack of an ROI to the government, even a hypothetical return, is why SpaceX lost on the LSA contract. Funding BFR/SH+SS, as cool a breakthrough in technology that might/will be, was not going to save the government any money nor offer any additional service they were asking for, and perhaps would not even comply with their basic requirements. (Was SpaceX ever planning to launch BFR from both KSC/CCAFS and VAFB? If not, they failed to comply with at least one SPRD requirement.) If SpaceX proposed a $200-$300M development of MSTs at both launch sites for vertical integration and a stretched 5-meter fairing and payload adapter/fitting for FH to comply with SIS Category C payload requirements, it would have been a slam dunk and money in the bank. Their strategic mistake to propose BFR.
Hmmm, what additional service BFR/Starship could have provided, let's see:
1. 100t to LEO
2. 100t to anywhere in the cislunar space
3. 100t to anywhere on Earth under an hour
4. 8m x 22m fairing envelope, SLS level of fairing volume is possible if expendable
5. Very low marginal launch cost, in the single digit millions
6. Very high launch rate, daily launches
7. Rapid response launches
8. Satellite inspection/servicing/retrieval
9. In orbit assembly of gigantic structures
10. BLEO Crewed flights
And that's just what I come up with in 5 minutes. There's no question it would save government money, even on their existing launches, but it can potentially provide so much more. It is true that AF didn't ask most of these, but various other part of the US government has shown interest in all of these, so it's very much wrong to say BFR/Starship wouldn't provide ROI to the government, in fact it's the complete opposite, it could provide a huge unprecedented ROI to the USG, which makes its dismissal from LSA criminally shortsighted.QuoteSpaceX might be offering dirt-cheap rides on F9/FH to commercial customers, but that's not what they're offering the U.S. Government. Or they're making it up in services and amortizing the cost of that MST and fairing over the next 6 years.
Of course SpaceX is going to include the cost of MST and fairing in there, where else are they going to get this money? You are not seriously suggesting SpaceX should provide service to government for free, are you? -
#373 by tmoesser on 27 Aug, 2020 04:32
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I still don't see how this a category error, solid first stage propulsion for an EELV. I see it as well-bounded. Plenty of Small-class launchers use in-line solids as a first stage, and plenty of Super Heavy-class launchers use solids for 80-100% of their liftoff thrust. Putting solid strap-ons on a solid core is not a new invention either (PSLV). CASTOR 600 for OmegA Intermediate is pretty close to the same size as the Titan 4B SRMU, and CASTOR 1200 for OmegA Heavy is roughly the same size as the 5-segment RSRMV for Ares I and SLS (but cheaper and with a better Isp and mass fraction). The CASTOR 300 second stage is a little bit larger than the Vega-C P120C first stage.Well the common concept between the three of them is that the 1st stage is a solid rocket motor, which has never been fielded as a 1st stage engine, only as boosters.
...If you mean, no solid rocket motor of this size has ever been fielded as a 1st stage, then yes.
Obviously I was talking about a launcher "of this size" since OmegA was competing for the NSSL program...
I grant that the elegance of all those shiny metal parts in a liquid rocket engine screams "Science!" in a way that a dumb firecracker or bottle-rocket scaled to the size of small skyscraper does not. But what does that have to do with it? (Strawman argument here, but one I read elsewhere.)
The argument here is "solids haven't done as a first stage for NSSL"... ignoring that the Titan family was the workhorse vehicle of the national security space community for decades, with its largest variants deriving 100% of its liftoff thrust from burning aluminum. But apply that argument to LOX/methane, and obviously anything using the BE-4 is destined to fail and Raptor will never get off the ground. Right? Or is it that it just hadn't been tried before?
No, I think the argument is really a mask for an ad hominem. Anything coming out of the solid rocket motor factories in Utah is bad, has no place launching stuff into space, which is good, just by definition. Right? -
#374 by tmoesser on 27 Aug, 2020 04:54
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Maybe you and I read a different RFP, but none of the things you listed were part of LSA or LSP. If I were a government reviewer and compared that list to my requirements, where I have exactly 12 reference missions with specific orbit and payload requirements not (a hundred tonnes to anywhere between here and the moon), I would have tossed the proposal in the trash heap. SpaceX learned their lesson it seems, because they hit it out of the park with their LSP proposal which offered the Air Force/Space Force something that they actually wanted and asked for.In my opinion, that lack of an ROI to the government, even a hypothetical return, is why SpaceX lost on the LSA contract. Funding BFR/SH+SS, as cool a breakthrough in technology that might/will be, was not going to save the government any money nor offer any additional service they were asking for, and perhaps would not even comply with their basic requirements. (Was SpaceX ever planning to launch BFR from both KSC/CCAFS and VAFB? If not, they failed to comply with at least one SPRD requirement.) If SpaceX proposed a $200-$300M development of MSTs at both launch sites for vertical integration and a stretched 5-meter fairing and payload adapter/fitting for FH to comply with SIS Category C payload requirements, it would have been a slam dunk and money in the bank. Their strategic mistake to propose BFR.
Hmmm, what additional service BFR/Starship could have provided, let's see:
1. 100t to LEO
2. 100t to anywhere in the cislunar space
3. 100t to anywhere on Earth under an hour
4. 8m x 22m fairing envelope, SLS level of fairing volume is possible if expendable
5. Very low marginal launch cost, in the single digit millions
6. Very high launch rate, daily launches
7. Rapid response launches
8. Satellite inspection/servicing/retrieval
9. In orbit assembly of gigantic structures
10. BLEO Crewed flights
And that's just what I come up with in 5 minutes. There's no question it would save government money, even on their existing launches, but it can potentially provide so much more. It is true that AF didn't ask most of these, but various other part of the US government has shown interest in all of these, so it's very much wrong to say BFR/Starship wouldn't provide ROI to the government, in fact it's the complete opposite, it could provide a huge unprecedented ROI to the USG, which makes its dismissal from LSA criminally shortsighted.QuoteSpaceX might be offering dirt-cheap rides on F9/FH to commercial customers, but that's not what they're offering the U.S. Government. Or they're making it up in services and amortizing the cost of that MST and fairing over the next 6 years.
Of course SpaceX is going to include the cost of MST and fairing in there, where else are they going to get this money? You are not seriously suggesting SpaceX should provide service to government for free, are you?
"Shortsighted"? Are you expecting government/military bureaucrats to be visionary? The last time a launch system was promised to them that was the be-all end-all, it was the Shuttle, and that turned out poorly for them. Look again at your list, scale down the numbers a tad, and imagine you're Air Force general in 1972 hearing this in the context of something called the "Space Transportation System." <sigh>
Of course I expect SpaceX to make money on this, to pay for their infrastructure development. It just might surprise you how much though.
Sorry -- This is now off topic, and I'm in part to blame. So I'll just throw out there that OmegA Heavy would be extremely affordable to the tax payer, even fully expendable. -
#375 by Coastal Ron on 27 Aug, 2020 05:17
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I still don't see how this a category error, solid first stage propulsion for an EELV.Well the common concept between the three of them is that the 1st stage is a solid rocket motor, which has never been fielded as a 1st stage engine, only as boosters.
...If you mean, no solid rocket motor of this size has ever been fielded as a 1st stage, then yes.
Obviously I was talking about a launcher "of this size" since OmegA was competing for the NSSL program...
The use case for a single-SRM launcher of this category is very limited. It would never be human-rated like the Falcon 9 and Vulcan specifically because of the studies the Air Force did on Ares I. And it could be argued that the vibration issues of Ares I were never fully addressed then, and likely still not addressed for OmegA.
Add on top of that the inflexibility of a sustainer motor that can't be throttled, and you have a limited set of use cases that the launcher is able to compete in.
Then there is the cost, which is really the deal killer. Northrop Grumman admitted that OmegA would never have a high cadence, and that is one of the factors needed to either lower costs or maintain them. But there is likely no way for OmegA to lower costs since so much of its cost base is in fixed infrastructure, including the buildings and equipment needed at KSC.QuoteI grant that the elegance of all those shiny metal parts in a liquid rocket engine screams "Science!" in a way that a dumb firecracker or bottle-rocket scaled to the size of small skyscraper does not.
You know it has nothing to do with "science". Liquid engine launchers provide far more flexibility.QuoteNo, I think the argument is really a mask for an ad hominem. Anything coming out of the solid rocket motor factories in Utah is bad, has no place launching stuff into space, which is good, just by definition. Right?
Whoa there, I think you are taking the loss of business in Utah a little personal. SRM's don't have inherent flaws because of where they are built, they have inherent flaws because of the alternatives to them.
ULA gets a lot of flack for not building a reusable launcher when it was clear reusability was possible and practical, but ULA has built in advantages over Northrop Grumman due to its long history of launching everything the government needed. But there will come a time (I think NSSL 3) where ULA won't have that advantage anymore, and they will see how an expendable Vulcan was not the best choice to compete in an increasingly reusable launch market.
I don't think OmegA had a chance in the NSSL competition, and having an SRM as the 1st stage was just one of them.
My $0.02 -
#376 by Steven Pietrobon on 27 Aug, 2020 06:03
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tmoesser, thank you very much for replies. They have been very informative. I do have some questions that I hope you can answer.
1) Why wasn't the four segment CASTOR 1200 used to replace RSRMV? I was surprised to learn that BOLE is using a new five segment booster with the segments being about the same length as in RSRMV, which are shorter than the segments in CASTOR 1200.
2) Could CASTOR 600, 900 or 1200 be used to replace the first stage of Antares? If so, would it be cheaper than the existing stage? -
#377 by tmoesser on 27 Aug, 2020 08:44
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The use case for a single-SRM launcher of this category is very limited. It would never be human-rated like the Falcon 9 and Vulcan specifically because of the studies the Air Force did on Ares I. And it could be argued that the vibration issues of Ares I were never fully addressed then, and likely still not addressed for OmegA.
Human-rating was not a design criterion for CBS/OmegA, as it is not for the Air Force for this procurement. Early on, we held out for a commercial crew customer, was willing to design around their requirements. Boeing and SN opted for ULA, and given their perfect track record it's hard to blame them. So we optimized around the EELV requirements, and tailored the vehicle for them with commercial satellite market in mind. Human-rating is or was a requirement for RSRM/Shuttle, RSRMV/Ares-SLS, BOLE/SLS, GEM 63/Atlas V and GEM 63XL/Vulcan. Human rating is safety factors, reliability allocations, and qualification standards at the element level and G's vs. Duration at the vehicle level. It makes your vehicle heavier (and thus needs to be bigger) and more expensive, but it's worth it if you're flying crew. If you're not going to fly crew, it's a con not a pro.
Vibration issues is another misconception that needs debunking. "It's a solid, must be a rough ride. Ares I!" Yes, solids are big organ pipes that tune at certain frequencies, and if your natural frequencies stack up around your vehicle, the payload is going to feel the chaos happening below. But do LREs not POGO anymore? There things that can be done to detune the vehicle or dampen those oscillations, and yes we have mitigation strategies. We designed OmegA to comply with all SIS requirements, and that includes random vibe and axial vs lateral acceleration limits.QuoteAdd on top of that the inflexibility of a sustainer motor that can't be throttled, and you have a limited set of use cases that the launcher is able to compete in.
I concede, continuous throttleability a la RD-180 or being able to shutdown one or more of your nine engines on Falcon prior to burn out is actually a very nice pro that a long burning liquid first stage has which a two-stage solid booster replacement does not. You can throttle down deeply through Max Q to limit your loads, you can closely control the acceleration environment you experience when you separate your fairing, and you can run at or near max acceleration as you approach burnout. You can schedule your throttle for your specific vehicle configuration, payload and mission. That is a nice knob to have when optimizing your trajectory. A colleague I partnered with at ULA for some early trade studies pre-RPS called this "shifting your impulse around", and it does add flexibility to mission planning.
But that flexibility is not a dealbreaker; it just means you have to design such that you don't violate the requirements when your solids burn in hot +3sigma conditions with a -3sigma payload. So your payload's nominal launch environment is … actually kinda benign. They're only going to see 6 g's in the most extreme cases, which is virtually never. For bigger configurations, we're actually way above the atmosphere when the fairing separates, which is good for the payload's free molecular heating environment. Feature, not a bug, right?
What that means for performance, though, is that the vehicle is suboptimal because you can't satisfy every design constraint and performance requirement simultaneously; throttle gives you a knob to re-optimize that you have access to after the vehicle is designed. We can't recast those solids to add or remove a fin on launch day. As a solid boost vehicle, OmegA has to be able to handle a huge range of Max Q's as a result of the 0-6 strap-ons for the first phase, and it has to live with a sustainer second stage that's hamstrung by the acceleration requirements of the lightest configuration and payload. You're going to incur more delta-V losses (gravity loss, drag loss, vectoring loss) and that loses performance compared to a single-config LV optimized for a single payload and mission flying a perfect gravity turn into orbit.
But we're talking DV losses on the order of several 100s (pick your unit, ft/s or m/s) translating into payload to orbit losses also on the order of several hundreds (lbm or kg). Less optimal than a liquid stage. Not impossible, not disqualifying. For a fleet of LVs that's intended to serve a very wide range of payloads and reference missions, every launcher is going to have compromises.
Aside, nobody seems to consider that a two-stage boost solution gives you the ability to optimize the nozzle expansion ratio for sea-level for the first stage, high altitude for the second stage, and vacuum for the third stage. An extra design knob, instead of a compromise.
Acknowledging my priors (phrase for the year), I actually agree with you that a solid-only boost vehicle is not the best technical solution. My ideal launch vehicle looks more like a Saturn V with huge strap-on solids, and maybe swap out the RP for LNG if the right engine can be designed. What I'm arguing is that solid boost vehicle is not a disqualifying solution. It is, however, the one that my company, the pairing of Orbital Sciences Launch Vehicles Division and ATK Propulsion Systems Division, and my colleagues and our leadership felt that we could offer to the government while meeting their performance and schedule requirements in the race-to-the-bottom launch market SpaceX created. And, believe it or not, we dang near did it.QuoteThen there is the cost, which is really the deal killer. Northrop Grumman admitted that OmegA would never have a high cadence, and that is one of the factors needed to either lower costs or maintain them. But there is likely no way for OmegA to lower costs since so much of its cost base is in fixed infrastructure, including the buildings and equipment needed at KSC.
I wish I could point you to non-public evidence to the contrary which I have access to, because you may be surprised. And it could be that Starship and New Glenn wipe out all our notions about how much access to space really costs in a few years. But to the U.S. Government, under LSP, for NSSL missions and all the rigmarole that entails, OmegA was very competitive on price, even at a low launch cadence, and especially for Heavy-class missions.QuoteWhoa there, I think you are taking the loss of business in Utah a little personal. SRM's don't have inherent flaws because of where they are built, they have inherent flaws because of the alternatives to them.
Yeah, sorry you're right. I do have a good reason to take it personally; I have been attached to this program (and since before it was a program) for 6 years, and I'm bummed that it looks more and more likely that I won't get to see it fly.* And I said elsewhere, participating in the development of a launch system like this is likely a once-in-a-generation opportunity that I won't see again. I'm really proud of what we accomplished.
The other motivation for my remark is that there are fanatics out there, who are reading this, for whom Elon Musk and SpaceX is the only thing that matters in the world (it seems) or who really do believe that anything that smells of ATK is tainted with original sin. I politely disagree with those people, and see SpaceX as my competition, whereas based on comments I read I feel like I am their enemy and must be destroyed, a leach on society. In this world of anonymous internet posting, it's very easy to dehumanize those you have a disagreement with. I just want to point out that there are real people here, and we really care about our work, and we accomplished some great things. We all still have jobs thankfully, but as much as I will miss working on OmegA*, I will miss working with my colleagues in Chandler and Dulles even more... much more.
It was unfair of me to paint with so wide a brush of "those people" to include you, Ron -- please accept my apology and socially distant handshake.QuoteULA gets a lot of flack for not building a reusable launcher when it was clear reusability was possible and practical, but ULA has built in advantages over Northrop Grumman due to its long history of launching everything the government needed. But there will come a time (I think NSSL 3) where ULA won't have that advantage anymore, and they will see how an expendable Vulcan was not the best choice to compete in an increasingly reusable launch market.
Yes they do get more flack than they deserve, and yes they do have some built-in advantages. But they also revolutionized their company and the way they do business in the space of 6 years since Tory Bruno took over, in response to the aforementioned race to the bottom and existential threat that SpaceX posed... I take my hat off to them. From what I see, they slashed their expenses (as did their major suppliers*), and cut as much of the fat as they could, and they deserve the win they got as far as I'm concerned. Good game. Go Vulcan!
SpaceX has been working NSSL under the current block buy for several years already. The evidence I see points to SpaceX matching or exceeding ULA when it comes to customer satisfaction. It may surprise you how the final evaluation came out. As a citizen with an interest in national security, I am well pleased by SpaceX's technical evaluation on the proposal and am reassured that they will be able to execute and deliver. Go SpaceX!QuoteI don't think OmegA had a chance in the NSSL competition, and having an SRM as the 1st stage was just one of them.
How about in spite of the technical challenges of an SRM 1st stage, and everything else, OmegA actually had a very good chance. We were always the dark horse candidate in this race (since we're in an election year), and some would think 4th out of 4. But we did very well on the evaluation, and very nearly unseated one of the incumbents. We scored some electoral votes in this contest.
My $0.02
And since I do still have a job, I should get some sleep and mute this discussion for awhile to avoid the temptation to write more essays as replies come in. I do still need to keep an accurate timecard, and if I'm on NSF I'm on my own time. Bills to pay, kids to raise, etc.
Thanks for the opportunity to vent some feelings and share one perspective on this adventure.
*Opinions are that of the author, not authorized to speak on behalf of the company, not a forward-looking statement, past performance is not a guarantee of future results, your mileage may vary, not valid in all states, caveat emptor, nolo contendere, e pluribus unum, et cetera ad nauseam. -
#378 by tmoesser on 27 Aug, 2020 09:06
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tmoesser, thank you very much for replies. They have been very informative. I do have some questions that I hope you can answer.
Hard for me to speculate on question 1 because I've been so entrenched in OmegA and don't see what's happening elsewhere. CBS segments were pushing the limit, and sometimes breaking them, on what we could process and transport about plant and over rail. Somebody did a trade study and determined that size was not advantageous for SLS, or NASA said they liked segments to weigh no more than some number. Not sure, just a guess.
1) Why wasn't the four segment CASTOR 1200 used to replace RSRMV? I was surprised to learn that BOLE is using a new five segment booster with the segments being about the same length as in RSRMV, which are shorter than the segments in CASTOR 1200.
2) Could CASTOR 600, 900 or 1200 be used to replace the first stage of Antares? If so, would it be cheaper than the existing stage?
For #2, there's some yes and no there, but there are challenges to that idea. I will speak to the obvious. The burn time differences between Antares FS and any single large CASTOR motor developed so far do not indicate a drop in solution. There is a coast between first stage shutdown and second stage ignition on Antares, which hurts performance some, and that gets worse with any of those motors as a first stage alone with a 2-2.5 minute burn. We have studied a C600+C300+C30XL/Antares PLF as a possible vehicle option/hybrid. Can't say more, but if you do some back-of-the-envelope delta-V math it falls in the "it could work" category. At Wallops, there's infrastructure (bridges) and the TEL (VI vs. HI) that becomes a problem with large segmented solids. At KSC, we need the MLP and use of the VAB and pad to make something work, and that's an incomplete project today and status unclear. I don't know about the costs, and that would be proprietary anyway. -
#379 by Coastal Ron on 27 Aug, 2020 18:15
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Yeah, sorry you're right. I do have a good reason to take it personally; I have been attached to this program (and since before it was a program) for 6 years, and I'm bummed that it looks more and more likely that I won't get to see it fly.* And I said elsewhere, participating in the development of a launch system like this is likely a once-in-a-generation opportunity that I won't see again. I'm really proud of what we accomplished.
Space related stuff is an avocation of mine, not a vocation like you, so I'll leave my comments as is.
I would hope though that OmegA does not end up being the last "once-in-a-generation opportunity" for you. You might have to leave Utah in order for that to happen, but I think the future is bright at this point for space-related hardware.QuoteThe other motivation for my remark is that there are fanatics out there, who are reading this, for whom Elon Musk and SpaceX is the only thing that matters in the world (it seems) or who really do believe that anything that smells of ATK is tainted with original sin.
I have been interpreted to be one of those fanatics, so I'll just say this. I advocate for those things that lower the cost to space. Today SpaceX is leading the charge in that, but I also recognize that we need redundancy and competition in order to provide the right incentives for expanding humanity out into space, so I don't want a SpaceX monopoly, no matter how benign it could possibly be.
So for ULA, I cite their studies all the time because their engineering is top notch. But it is the management decisions that are made by ULA's owners that I have disagreements with, not only for their direction today, but for the monopolistic way of doing business they used to have. Their management of ULA is proof that capitalism can't lead us out into space.QuoteI politely disagree with those people, and see SpaceX as my competition, whereas based on comments I read I feel like I am their enemy and must be destroyed, a leach on society.
I originally started being active on space forums because I supported DIRECT, but real engineers steadily educated me on the cost aspects of the Shuttle system, and once I started applying my manufacturing cost accounting background I came to realize that even though DIRECT was a good reuse of existing hardware, it was not going to get humanity out into space in an affordable way.
Around that time I started following a young company called SpaceX, and came to appreciate their approach and goals. But they were competing against the giants of the government contracting world, and oh my gosh the advertising that was put out against them. Plus space forums were full of "Old Space" supporters, and SpaceX supporters were viewed in a very negative light.
So yes, many of us have "grown up" supporting and defending SpaceX from malicious posts. Have we become too defensive? I hope not.QuoteIt was unfair of me to paint with so wide a brush of "those people" to include you, Ron -- please accept my apology and socially distant handshake.
I accept the virtual handshake between two people that are passionate about space, and I never felt any sort of apology was merited. And I have to tell you that I am learning about OmegA from you, which may not be useful in my life, but I read a lot of stuff that isn't useful in my life because it is enjoyable. So thank you for that.
I wish you well in your current and future career!
Years ago when Mike Meyers was on SNL, he performed a skit where he was a Scotsman who owned a gift shop/curio store called "If it ain't Scottish, it's Crap!" He would get angry and yell at all the patrons who would come in the shop, looking for 4 leaf clovers, leprechaun figures, Blarney stones etc.... "Scottish-Irish what's the difference?" "I'll tell ya Lassie!!!..." 