SLS with Dark Knights as boosters but iCPS as an US has never been discussed or given a block designation. But what if Block I started flying with no money for EUS or pad mods and then runs out of booster sections. If NASA somehow wound up having to fly this configuration, what are estimates of performance to LEO and BLEO? My guess is that Dark Knights wouldn't add too much because the US is still so underpowered.
If SLS were complete, Congress would still keep the usual suspects busy - most likely by building things for SLS to launch, and by building SLSes to launch them. Payloads are just as good for pork as rockets are.
Quote from: mme on 05/09/2018 09:42 pmI don't know what happened exactly but my understanding is that Obama wanted a new HLV based on actually using and developing new technologies. But that's not what Congress wanted and he had other battles that he felt were more important.I can't speak to the President himself, but I do know from personal experience that his team in charge of space activities wanted nothing to do with any of the HLV solutions what-so-ever.They were pushing hard for what I would term as "commercial all the way", and complete abandonment of the entire Shuttle infrastructure and all HLV derivatives.From what they expressed in front of me, they were not even fans of Delta and Atlas, only grudgingly acknowledging that they were acceptable if they were to compete - on a fair and unbiased basis - with the new entrants who were, at that time, just beginning to enter the scene.The Obama Administration wasn't interested in the Moon, Mars or anywhere else, and they specifically wanted anything that the previous administration had approved, to be dismantled forthwith - which seems to be 100% consistent with the clean-house attitude that every new administration has regarding NASA.Obviously the Congress pushed back - they had their own "requirements" - and given that it is actually Appropriations who really control the federal budget, they are the ones who - barring an unlikely veto - get the final say.The Administration had to accept it, but they curtailed it as much as possible, ultimately restricting the new architecture to the utterly uninspiring job of trying to visit an NEO.
I don't know what happened exactly but my understanding is that Obama wanted a new HLV based on actually using and developing new technologies. But that's not what Congress wanted and he had other battles that he felt were more important.
Quote from: kraisee on 05/10/2018 07:16 am1) Each Administration overturning everything that came before simply because they're now running the football,I've heard this idea a lot, but is there an actual example of that ever happening? Has any significant NASA project ever been canned that hadn't run it's course or had any life or hope still in it? Feels to me like the administration change is just the most convenient time to kill off the sickest programmes that are going nowhere anyway. All the successful large NASA projects have spanned multiple administrations.
1) Each Administration overturning everything that came before simply because they're now running the football,
Quote from: MATTBLAK on 05/09/2018 06:09 am The refurbishment of SRB's was negligible in savings. And the standing army of people, ships and facilities don't come for nothing - not to mention the disassembly, cleaning, coating, insulation, fuel and fuel mixing, restacking and reassembly of the boosters... The new and/or refurbished parachutes, the new pyros, new batteries, electrical systems, nosecones, nozzles, steering systems... The list goes on. Basically; only the cost of new segments is saved by reusing them.All the above was pointed out to me by a retired SRB technician in 2011, when I was at KSC covering the launch of STS-135. And the near-failure of Ares 1-X recovery speaks for itself; with no help from me - even though it did almost work...All good points Matt, and are what I understood as well. At best, recovering and reusing the boosters was a wash vs. if they'd just been expended, from what I understand. That wasn't the original intent, but the way the math worked in the end.Additionally, I don't think just any steel casings could be reused, these had special coatings/metellurgy in order to be able to be reused. This required a special foundry with like molten sodium (I think?) to be hot and ready indefinately because once you shut it down and it cooled, it couldn't be started up again...apparently. It was finally shut down in the late 2000's after the decision had been made on CxP that the boosters wouldn't be reused. And with it went the ability to manufacture any new casings. So what ATK had in stock at that point was all that there was. New boosters would be needed no matter what once they'd been flown out. All of the 4-seg boosters of the remaining STS flights were recovered and kept in inventory. Had Direct been adopted instead of SLS, then the existing casings making up the same 4-seg STS boosters could have probably been reused for quite some time launching Jupiter, as they'd be recovered and reused just like STS. But eventually new boosters of some sort would have had to have been developed, even for Jupiter, as more couldn't have been made once those finally wore out.I'd have to go fish the article out of an old thread about that foundry to share it, but that's how I remember it. It was as specialty subcontractor to ATK. "Cody Industries" or something?So keeping that foundry hot just so it could make a few replacement segments here and there was another cost of the reusable SRB's. The logistics costs of sending them all back to Utah to be refurbished and refilled, rather than doing it right there at the Cape was a big one too.Composites are probably damaged to a degree during use, so they can't be resused. As I imagine is the case with regular steel casings that weren't specially made/treated the way the Shuttle booster casings were so they could be reused.
The refurbishment of SRB's was negligible in savings. And the standing army of people, ships and facilities don't come for nothing - not to mention the disassembly, cleaning, coating, insulation, fuel and fuel mixing, restacking and reassembly of the boosters... The new and/or refurbished parachutes, the new pyros, new batteries, electrical systems, nosecones, nozzles, steering systems... The list goes on. Basically; only the cost of new segments is saved by reusing them.All the above was pointed out to me by a retired SRB technician in 2011, when I was at KSC covering the launch of STS-135. And the near-failure of Ares 1-X recovery speaks for itself; with no help from me - even though it did almost work...
Quote from: Lobo on 05/10/2018 10:38 pmQuote from: MATTBLAK on 05/09/2018 06:09 am The refurbishment of SRB's was negligible in savings. And the standing army of people, ships and facilities don't come for nothing - not to mention the disassembly, cleaning, coating, insulation, fuel and fuel mixing, restacking and reassembly of the boosters... The new and/or refurbished parachutes, the new pyros, new batteries, electrical systems, nosecones, nozzles, steering systems... The list goes on. Basically; only the cost of new segments is saved by reusing them.All the above was pointed out to me by a retired SRB technician in 2011, when I was at KSC covering the launch of STS-135. And the near-failure of Ares 1-X recovery speaks for itself; with no help from me - even though it did almost work...All good points Matt, and are what I understood as well. At best, recovering and reusing the boosters was a wash vs. if they'd just been expended, from what I understand. That wasn't the original intent, but the way the math worked in the end.Additionally, I don't think just any steel casings could be reused, these had special coatings/metellurgy in order to be able to be reused. This required a special foundry with like molten sodium (I think?) to be hot and ready indefinately because once you shut it down and it cooled, it couldn't be started up again...apparently. It was finally shut down in the late 2000's after the decision had been made on CxP that the boosters wouldn't be reused. And with it went the ability to manufacture any new casings. So what ATK had in stock at that point was all that there was. New boosters would be needed no matter what once they'd been flown out. All of the 4-seg boosters of the remaining STS flights were recovered and kept in inventory. Had Direct been adopted instead of SLS, then the existing casings making up the same 4-seg STS boosters could have probably been reused for quite some time launching Jupiter, as they'd be recovered and reused just like STS. But eventually new boosters of some sort would have had to have been developed, even for Jupiter, as more couldn't have been made once those finally wore out.I'd have to go fish the article out of an old thread about that foundry to share it, but that's how I remember it. It was as specialty subcontractor to ATK. "Cody Industries" or something?So keeping that foundry hot just so it could make a few replacement segments here and there was another cost of the reusable SRB's. The logistics costs of sending them all back to Utah to be refurbished and refilled, rather than doing it right there at the Cape was a big one too.Composites are probably damaged to a degree during use, so they can't be resused. As I imagine is the case with regular steel casings that weren't specially made/treated the way the Shuttle booster casings were so they could be reused. Hey Lobo, I have searched for months for that article about the foundry that forged the ingots into booster cases. The article I remember had pics of the actual ingots being forged as well as the special sodium foundry that once cooled became unworkable, it was heated for decades.I'll do some searching using Cody Industries I was using Ladish, but they may have supplied the ingots to Cody? ? If you have it stashed somewhere easy to be gotten, I would appreciate a view if possible. Thanks.
Three companies were responsible for manufacture of the RSRM cases:Ladish - Forging nozzle & case steel components (D6AC steel alloy) from supplied billetsBodycote (Cal-Doran) - heat-treating steel components (this is where the continuously operating molten salt bath used for quenching comes in)STADCO - final machining of case joint interfacesSteel ingots/billets were supplied by Latrobe Steel.See pages 23 - 26 of the attached document for more details of the RSRM supply chain (I posted this previously in another thread - see https://forum.nasaspaceflight.com/index.php?topic=27714.msg1212409#msg1212409 for following discussions)
Quote from: Hog on 05/11/2018 03:39 pmQuote from: Lobo on 05/10/2018 10:38 pmQuote from: MATTBLAK on 05/09/2018 06:09 am The refurbishment of SRB's was negligible in savings. And the standing army of people, ships and facilities don't come for nothing - not to mention the disassembly, cleaning, coating, insulation, fuel and fuel mixing, restacking and reassembly of the boosters... The new and/or refurbished parachutes, the new pyros, new batteries, electrical systems, nosecones, nozzles, steering systems... The list goes on. Basically; only the cost of new segments is saved by reusing them.All the above was pointed out to me by a retired SRB technician in 2011, when I was at KSC covering the launch of STS-135. And the near-failure of Ares 1-X recovery speaks for itself; with no help from me - even though it did almost work...All good points Matt, and are what I understood as well. At best, recovering and reusing the boosters was a wash vs. if they'd just been expended, from what I understand. That wasn't the original intent, but the way the math worked in the end.Additionally, I don't think just any steel casings could be reused, these had special coatings/metellurgy in order to be able to be reused. This required a special foundry with like molten sodium (I think?) to be hot and ready indefinately because once you shut it down and it cooled, it couldn't be started up again...apparently. It was finally shut down in the late 2000's after the decision had been made on CxP that the boosters wouldn't be reused. And with it went the ability to manufacture any new casings. So what ATK had in stock at that point was all that there was. New boosters would be needed no matter what once they'd been flown out. All of the 4-seg boosters of the remaining STS flights were recovered and kept in inventory. Had Direct been adopted instead of SLS, then the existing casings making up the same 4-seg STS boosters could have probably been reused for quite some time launching Jupiter, as they'd be recovered and reused just like STS. But eventually new boosters of some sort would have had to have been developed, even for Jupiter, as more couldn't have been made once those finally wore out.I'd have to go fish the article out of an old thread about that foundry to share it, but that's how I remember it. It was as specialty subcontractor to ATK. "Cody Industries" or something?So keeping that foundry hot just so it could make a few replacement segments here and there was another cost of the reusable SRB's. The logistics costs of sending them all back to Utah to be refurbished and refilled, rather than doing it right there at the Cape was a big one too.Composites are probably damaged to a degree during use, so they can't be resused. As I imagine is the case with regular steel casings that weren't specially made/treated the way the Shuttle booster casings were so they could be reused. Hey Lobo, I have searched for months for that article about the foundry that forged the ingots into booster cases. The article I remember had pics of the actual ingots being forged as well as the special sodium foundry that once cooled became unworkable, it was heated for decades.I'll do some searching using Cody Industries I was using Ladish, but they may have supplied the ingots to Cody? ? If you have it stashed somewhere easy to be gotten, I would appreciate a view if possible. Thanks.Three companies were responsible for manufacture of the RSRM cases:Ladish - Forging nozzle & case steel components (D6AC steel alloy) from supplied billetsBodycote (Cal-Doran) - heat-treating steel components (this is where the continuously operating molten salt bath used for quenching comes in)STADCO - final machining of case joint interfacesSteel ingots/billets were supplied by Latrobe Steel.See pages 23 - 26 of the attached document for more details of the RSRM supply chain (I posted this previously in another thread - see https://forum.nasaspaceflight.com/index.php?topic=27714.msg1212409#msg1212409 for following discussions)
...it was mentioned that what was known as the Deep Space Gateway during the Obama administration became LOP-G specifically because of a desire to undo what Obama had done. This, of course, is a very minor example, since it's just a name change on something that wasn't even a formal program at the time.
I'm inclined to agree with you that the big programs that have failed to survive from one administration to the next were begging for cancelation anyway. CxP was slipping badly and had completely ridiculous out-year budget requirements.
ARM was just too transparently dumb to live (though notice that high-power SEP--a very useful thing--lives on: the Obama administration seems to have found a way to use Orion/SLS to promote something useful).
So now that we have our references correct, back to my point, having to have that furnace kept hot 24/7 was one of several additional costs that the shuttle boosters had in order to be reusable, that expendable boosters wouldn't have had. Hence why the costs ended up being about a wash.
The heat treating and salt-bath quenching process would have been required for the D6AC steel segments regardless if the SRM case was to be reuseable or expendable.
I've always advocated that Obama did not want the ARM, which was a program to fetch an asteroid and bring it to the region of our Moon so that astronauts could study it close to Earth. Obama spoke publicly about sending astronauts to an asteroid as part of eventually getting humans to Mars, so the ARM did not satisfy that requirement.However Obama also knew that because of his 2010 agreement with Congress to cancel the Constellation program, extend the life of the ISS, and create the Commercial Crew program, that the SLS and Orion programs would not leave any room for HSF missions to send humans to an asteroid. So I think Obama was fine with letting Senator Nelson and NASA Administrator Bolden propose the ARM as a way to use the SLS and Orion. Maybe it also got him political points with Shelby that he was able to use on non-NASA funding priorities.
As to how this relates to the SLS and it's supply-chain limitations, since Trump has shown no hint of wanting to review the SLS and Orion programs in any way, the future of the SLS and Orion will likely be left to the next President - whether that is 2021 or 2025.
Quote from: Hog on 05/11/2018 09:11 pmThe heat treating and salt-bath quenching process would have been required for the D6AC steel segments regardless if the SRM case was to be reuseable or expendable.Salt-bath quenching (the thing that we are essentially talking about here) not necessarily. You can alternatively oil-quench D6AC aircraft steel (before air-cooling it). It is possible that salt-bath quenching was needed for re-usability purposes.
Heat Treatment before temper. A ustenitized at 1650°F (899°C). Oil quenched and air cooled, or salt quenched at 400-425°F (204-218°C) for ten minutes and air cooled
Yes. Much as I liked much of Bridenstine's recent speech, it's clear that the Trump administration is not about to cancel Orion/SLS. NASA's HSF program will continue to drift for the next few years, whatever Bridenstine might prefer.
Quote from: Proponent on 05/12/2018 04:38 pmYes. Much as I liked much of Bridenstine's recent speech, it's clear that the Trump administration is not about to cancel Orion/SLS. NASA's HSF program will continue to drift for the next few years, whatever Bridenstine might prefer.I dont believe that anyone in this administration has strong opinions about space policy except for Bridenstine and Pence. Considering that Bridenstine convinced the Senate to confirm him despite starting with two strikes against, he does seem to have some political skill at convincing Senators. If Bridenstine has a plan the Senate will accept I have a hard time seeing the administration not adopting it.