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NASA?s full Artemis plan revealed: 37 launches and a lunar outpost
In article ,
says... Agreed. What's not clear to me is what happens when they run out of SRB segments. The press hasn't reported on this much. I think the original plan was that they'd switch to 'advanced boosters' at that point, but I think those may be too far out now to make the timeline. Also the original plan was to have a Block 1A vehicle that got the new 'advanced boosters' before the Block 1B EUS milestone (which at that point would have been Block 2). Block 1A was cancelled, adding EUS became Block 1B, and Block 2 was moved to after that. A little poking around tells me that there is enough SRB hardware for 8 SRB sets, which will carry them through 2027 or so. They currently have 4 RS-25 engine sets and contracts for another set and a half of 'new' RS-25 engines. This gets them into 2026. Another half engine set (2 more engines) would get them through 2026. There are apparently 3 AJ10-190 engines available for use on the Orion Service Module. That gets them through 2024 and the first landing, at which point they'll have to change engines. There are engines currently in production that they could use, like the AJ10-118k used on Delta II. Nit: Delta II stopped flying last September. https://aerospace.org/article/final-...elta-ii-rocket From above: The end of an era arrived Saturday morning, September 15, 2018 with an Earth-shaking roar and a brilliant flash of light as the world?s last Delta II rocket rose into the morning sky above Vandenberg Air Force Base. Still, it hasn't been out of production for very long. And I'm sure Aerojet Rocketdyne would be more than accommodating when it comes to building new engines. For a price, that is. So in summary the real long pole is the SRB hardware. There are contracts and contingencies in place for the other two pieces of the system that are limited by availability of old Shuttle hardware, but once those SRB components are gone, they're GONE and the program to replace those boosters is way out there. I'm still betting on composite wound casings that have been developed for Omega. I believe that the segment casings are at least the right size. A bit of poking around turned up this: https://www.nasaspaceflight.com/2018...synergy-omega- sls-solid-boosters/ From above: "What we've done [with OmegA's CBSs] is we've turned [the booster casing] design into a composite, much lighter, much more efficient from a production perspective, case then what's used in those large, heavy steel cases. So we can, through the use of some automated fiber placement tools and winding machines, produce segmented cases far more efficiently than what we could previously." "So these are our manufacturing process efficiencies that at some point could very well benefit SLS if they were able to adapt some of these. And there's talk of that happening at some point in time." Jeff -- All opinions posted by me on Usenet News are mine, and mine alone. These posts do not reflect the opinions of my family, friends, employer, or any organization that I am a member of. |
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NASA's full Artemis plan revealed: 37 launches and a lunar outpost
Jeff Findley wrote on Fri, 24 May 2019
16:40:45 -0400: In article , says... Jeff Findley wrote on Fri, 24 May 2019 06:28:51 -0400: In article , says... Jeff Findley wrote on Thu, 23 May 2019 06:52:56 -0400: In article , says... On 2019-05-20 22:05, Fred J. McCall wrote: You understand that the Gateway isn't in an orbit around the Moon, right? It's in a LaGrange halo orbit. Was not aware of that. I was under the impression it was in lunar orbit. Orion has nowhere near the delta-V capability of the Apollo CSM. True, but I don't see why it matters since the CSM had about twice as much delta-v as required. Orion has about a third less than the Apollo CSM, so it still has enough to do the missions that Apollo did. And I'm not sure that getting into an L2 NRHO is that much 'cheaper' when it comes to delta-v. Orion simply does not have the delta-V to enter a low lunar orbit and then get back to earth and have the margins that NASA requires. This fact is all over all of the online space forums. But I've done a quick search for an actual NASA study. This looks promising: Options for Staging Orbits in Cis-Lunar Space https://ntrs.nasa.gov/archive/nasa/c...0150019648.pdf LEO was ruled "infeasible" for use by Orion by NASA. See Table 6 on page 8 of the above document. Note that the figures they used to rule out LLO underestimate the capability of the Orion/SM combination. It has about 12% more fuel than they state (9 tonnes vice 8 tonnes) and more delta-v than they say (1800 vice 1650). Note that with 1800 m/s delta-v LLO changes from infeasible to feasible. You'll need to tell that to NASA because they're not changing their minds about this isuse. Gee, a bureaucracy that doesn't want to reevaluate a decision once it's in train. I'm surprised! And you'll need to tell every space publication out there like this one: Does the Gateway make sense? by Eric R. Hedman http://www.thespacereview.com/article/3502/1 From above: Orbit The proposed orbit for LOP-G is a Near Rectilinear Halo Orbit (NRHO). A NASA paper on the rationale for selecting the orbit includes a table on page 8 that spells out the reasoning behind the choice. The ideal choice, if the only factors for landing and returning to lunar orbit were delta-V requirements for the lander and access to any landing site, is a polar low lunar orbit. This is ruled out because the Orion spacecraft and service module can?t reach it due to the limited delta-V capability of the service module. Given the constraints of requiring the use of SLS/Orion the NRHO is the only feasible choice for now. Of course if you look at the table in the paper, there are other columns in RED for low lunar orbit. So there is that. I don't need to go back and tell anyone anything. In fact, 'going back' is likely the root of the problem. I only need to make note of two facts: 1) The paper (which is what everything else is based on) was no doubt written using the original Constellation SM data, which is NOT what we've got. What we've got is a new design with a ton more fuel and a lot more delta-v. 2) Bureaucracies, particularly risk-averse bureaucracies like NASA, will virtually never go back and reevaluate decisions once they're headed down a path, particularly if they've already arrived at the conclusion they wanted going in, which is to justify Gateway. What next? Are you going to start using data from Altair to describe Blue Moon? -- "The reasonable man adapts himself to the world; the unreasonable man persists in trying to adapt the world to himself. Therefore, all progress depends on the unreasonable man." --George Bernard Shaw |
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NASA?s full Artemis plan revealed: 37 launches and a lunar outpost
Jeff Findley wrote on Fri, 24 May 2019
16:50:06 -0400: In article , says... Agreed. What's not clear to me is what happens when they run out of SRB segments. The press hasn't reported on this much. I think the original plan was that they'd switch to 'advanced boosters' at that point, but I think those may be too far out now to make the timeline. Also the original plan was to have a Block 1A vehicle that got the new 'advanced boosters' before the Block 1B EUS milestone (which at that point would have been Block 2). Block 1A was cancelled, adding EUS became Block 1B, and Block 2 was moved to after that. A little poking around tells me that there is enough SRB hardware for 8 SRB sets, which will carry them through 2027 or so. They currently have 4 RS-25 engine sets and contracts for another set and a half of 'new' RS-25 engines. This gets them into 2026. Another half engine set (2 more engines) would get them through 2026. There are apparently 3 AJ10-190 engines available for use on the Orion Service Module. That gets them through 2024 and the first landing, at which point they'll have to change engines. There are engines currently in production that they could use, like the AJ10-118k used on Delta II. Nit: Delta II stopped flying last September. https://aerospace.org/article/final-...elta-ii-rocket From above: The end of an era arrived Saturday morning, September 15, 2018 with an Earth-shaking roar and a brilliant flash of light as the world?s last Delta II rocket rose into the morning sky above Vandenberg Air Force Base. Still, it hasn't been out of production for very long. And I'm sure Aerojet Rocketdyne would be more than accommodating when it comes to building new engines. For a price, that is. So in summary the real long pole is the SRB hardware. There are contracts and contingencies in place for the other two pieces of the system that are limited by availability of old Shuttle hardware, but once those SRB components are gone, they're GONE and the program to replace those boosters is way out there. I'm still betting on composite wound casings that have been developed for Omega. I believe that the segment casings are at least the right size. A bit of poking around turned up this: https://www.nasaspaceflight.com/2018...synergy-omega- sls-solid-boosters/ From above: "What we've done [with OmegA's CBSs] is we've turned [the booster casing] design into a composite, much lighter, much more efficient from a production perspective, case then what's used in those large, heavy steel cases. So we can, through the use of some automated fiber placement tools and winding machines, produce segmented cases far more efficiently than what we could previously." "So these are our manufacturing process efficiencies that at some point could very well benefit SLS if they were able to adapt some of these. And there's talk of that happening at some point in time." Note that this is very like the ATK 'Dark Knight' proposal for 'advanced booster', but it uses a more energetic propellant. -- "The reasonable man adapts himself to the world; the unreasonable man persists in trying to adapt the world to himself. Therefore, all progress depends on the unreasonable man." --George Bernard Shaw |
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NASA?s full Artemis plan revealed: 37 launches and a lunar outpost
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NASA’s full Artemis plan revealed: 37 launches and a lunar outpost
On 5/20/2019 12:56 PM, wrote:
Developed by the agency's senior human spaceflight manager, Bill Gerstenmaier, this plan is everything Pence asked for—an urgent human return, a Moon base, a mix of existing and new contractors." See: https://arstechnica.com/science/2019...lunar-outpost/ Given the current political climate in DC I'd say this plan is even more still-born than was Constellation and President Bush's VSE a decade + 5 years ago. I agree with VP Pence's sense of urgency but it is disingenuous at best to think that the DC establishment and NASA in particular has the means or skills today to drive this effort. Making SLS a key component of this plan just exposes it as the fantasy it is. I know this is harsh. Too bad. I feel sorry for the senior leadership at NASA. Their hearts are in the right place, they are good people. They just don't realize that their methodology belongs to a long lost past that will not return. We'd be better served if NASA acted like an investment bank and Congress gave it the funds necessary to buy the desired end goal with as little micro-management as possible. That has not been the established paradigm and is not evident in this work of fiction either. Dave |
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NASA?s full Artemis plan revealed: 37 launches and a lunar outpost
Jeff Findley wrote on Sat, 25 May 2019
08:47:58 -0400: In article , says... On 2019-05-24 06:34, Jeff Findley wrote: Because if you look at the damn picture of the proposed time-line that's all over online, *none* of the stages of the lunar lander are launched by SLS. They're *all* launched on *separate* commercial launch vehicles. Are the separate launches all going to "Gateway" to deliver their hardware, or would there be LEO dockings involved before the combined parts get to Gateway ? Everything possible goes to Gateway in order to justify its existence. The only exception would be uncrewed landers with surface instruments, robotic rovers, or modules/supplies to be prepositioned on the surface for longer term crewed missions. Well, there's that and there's the problem that if you combine everything in LEO now you need an upper stage with enough grunt to get the whole works to where it's going all at once. Sending little pieces is easier. That's one of the 'justifications' for doing a Gateway is to give an 'assembly area' to send pieces too without having to send them all at once. Could they get the Europeans to build a service module that supports Dragon2, and be launched on Falcon or Falcon Heavy? No one is seriously considering something like this at this time. And if they were, SpaceX could build its own augmented service module for Dragon 2. SpaceX doesn't need ESA to do it for them. I wouldn't expect something like this to happen until after SLS is canceled. This isn't a path that SpaceX is interested in pursuing, since their intended path forward is to use Starship and Falcon Super Heavy for everything. And even if SLS were canceled, I'd expect NASA to come up with a way to launch Orion and a TLI stage on separate commercial launches in order to duplicate the functionality of SLS/Orion. That's pretty much what Bridenstine was looking into to accelerate EM-1. But, that was more a tactic to "light a fire" under Boeing to get SLS back on track than it was a serious proposal, IMHO. I personally don't think Bridenstine took that option very seriously. Given that they'd need a high energy upper stage to use 'commercial' launchers I don't see the 'commercial' path gaining them lots of schedule. After all, the high energy upper stage for SLS (the EUS that gets them from SLS Block 1 to SLS Block 1B) is way behind schedule. While Falcon9 or Falcon Heavy don't have the "oumph" to launch crewed vehicle to Gateway, it would have the capability to launch modules and fuel separately to LEO after which, the stuff going to Moon would have plenty of fuel. What Mayfly doesn't realize is that just getting things to LEO doesn't solve the problem. You still need some sort of high energy upper stage and, in the case of his 'plan' that stage needs to be refuelable on orbit and you need a tanker that can go up and refuel it. I'd think Falcon Heavy might be able to launch a Dragon 2 to Gateway, but I seriously doubt that would ever happen, because it would destroy the illusion that SLS and Orion are both necessary. Remember, NASA is the one in charge here and they're still quite beholden to the SLS/Alabama mafia, like it or not. You could probably get it out there but you probably would want a real service module with fuel, which might make you too heavy to get the excess mass there. -- "The reasonable man adapts himself to the world; the unreasonable man persists in trying to adapt the world to himself. Therefore, all progress depends on the unreasonable man." --George Bernard Shaw |
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NASA's full Artemis plan revealed: 37 launches and a lunar outpost
JF Mezei wrote on Sat, 25 May 2019
14:50:39 -0400: After the Lionair 737 crash, it was quickly found out that the MCAS system forced the plane to head down and crash. Sales and deliveries of 737s continued so Boeing didn't put priority on fixing the software. False. That changed after 737s were grounded following 2nd crash. Now, Boeing saw revenus cut, and potential for huge sums of compensation for airlines who paid for their 737s and can't use them. There is no string incentive to fix it ASAP. No, it didn't change. In fact, the software update was already well in work and close to done. What 'changed' was that it could no longer just be released like a 'normal' update and instead is requiring all sorts of extra 'touching' with various regulatory bodies. Back to SLS: is it fair to state that until Pence set a 2024 deadline, there was no penalty for SLS contractors to be late, and being paid cost+, they would benefit from stretching the project as long as possible? Wrong. First, Pence didn't set that date. Trump did. Second, 'cost plus' contracts don't work like you appear to think they do. In fact, what I think you're thinking of when you say 'cost plus' is legally prohibited. If you assign 20 engineers to scrw in a lightbulb, being cost+, you get more profits, so very little incentive to be fast and efficient. Wrong. If everyone knows this SLS thing is just a demo thing without long term potential, woudln't contractors prefer to stretch development over as long a period as possible so they get profit during that time? No, because they don't get profit during that time. In that point of view, Pence imposing a 2024 deadline to deliver something (even if unrealistic deadline) is likely a warning to the suppliers that they now need to deliver something. And if they fail to deliver, project gets cancelled. Trump is imposing the deadline. Pence is just the messenger in this case. He's imposing it because he wants a landing while he's still President. The date is about politics, not profits. The concerns about cancellation are also about politics (look at what each successive President did to the manned space program). Would it be correct to state that Rocketdyne has completed the SSME refurbishement of the 16 engines? I take it they are now working on building tooking to allow building more SSMEs when NASA triggers that option the contract? No, it would not be correct. You've been corrected on this over and over and over and over again, Mayfly. WRITE IT DOWN. WOuld building 4 SSMEs per year be considered a worthwile endeavour for Rocketdyne? Or is the money being made before they start to build them (design, build tooking etc)? Jesus but you're ignorant about how government contracting works! Yes, it would be worthwhile (and they'll have to build more than 4 per year) and you don't get fee until you hit a milestone, so no, all the money is not made before you deliver anything. SpaceX was able to lower costs by going with mass production of engines. Building 4 per year doesn't seem like something that would lower costs much. Costs are purportedly lower because the engines are 'single use'. hat about the SRBs? Has ATK/Grunman finished the 10 5 segment boosters? or has it done 1 and very very slowly building the second one? You don't want a bunch of multi-segment solids sitting around in a parking lot somewhere. I'm sure they assemble them as they're needed. Is Boeing the critical contractor that is causing delays? Or are they all late? Boeing. If some benefit from delays but others are hurt by it, eventially the others will statt to lobby govt to tell the one laggard to fix its problems and get on with the job. Nobody 'benefits from delays' other than in having more time to do the work (which leads to less profit per amount of time). Wondering if this is what happened to cause Pence to set a 2024 deadline. No. What happened to cause Pence to set a 2024 deadline is Trump telling him "I want a landing before the end of 2024". And Pence doesn't set deadlines or cancel programs (neither does Trump). That's CONGRESS. -- "Ignorance is preferable to error, and he is less remote from the truth who believes nothing than he who believes what is wrong." -- Thomas Jefferson |
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NASA?s full Artemis plan revealed: 37 launches and a lunar outpost
In article , says...
On 5/20/2019 12:56 PM, wrote: Developed by the agency's senior human spaceflight manager, Bill Gerstenmaier, this plan is everything Pence asked for?an urgent human return, a Moon base, a mix of existing and new contractors." See: https://arstechnica.com/science/2019...lunar-outpost/ Given the current political climate in DC I'd say this plan is even more still-born than was Constellation and President Bush's VSE a decade + 5 years ago. I tend to agree. Such a plan involves increasing NASA's budget significantly in later years. But the actual increase is a huge unknown to Congress. So they're likely to take whatever number NASA gives them and multiply it by 2x to 5x, depending on their faith in the estimating capabilities of NASA. That faith will be low, considering the massive burning dumpster fire that are the SLS/Orion programs. SLS in particular is years behind schedule and many billions of dollars over budget. I agree with VP Pence's sense of urgency but it is disingenuous at best to think that the DC establishment and NASA in particular has the means or skills today to drive this effort. Making SLS a key component of this plan just exposes it as the fantasy it is. Agree with the SLS point. At $2+ billion a year, SLS is a financial drag on any program that aspires to send crews beyond LEO. It's also a drag on the schedule since EM-1, the first crewed Orion mission, was to have flown on SLS in December 2017. It remains to be seen when EM-1 will fly, but my guess is NET 2021. At $2+ billion a year, that would project SLS to be at least $8 billion over budget. And if you added in the delays for the Exploration Upper Stage, that number would easily climb to over $10 billion. To put that into perspective, just the $10 billion that's over budget would buy 66 expendable Falcon Heavy launches. Just imagine what NASA could do with 66 expendable Falcon Heavy launches. Add in the rest of the money spent on SLS and it becomes clear that SLS is an absolutely insane waste of money. I know this is harsh. Too bad. I feel sorry for the senior leadership at NASA. Their hearts are in the right place, they are good people. They just don't realize that their methodology belongs to a long lost past that will not return. We'd be better served if NASA acted like an investment bank and Congress gave it the funds necessary to buy the desired end goal with as little micro-management as possible. That has not been the established paradigm and is not evident in this work of fiction either. Agreed. But the fact is that NASA is beholden to the SLS/Alabama mafia. Until that hold loosens, SLS will continue to be the keystone in the NASA plan of record to return a crew to the lunar surface. Jeff -- All opinions posted by me on Usenet News are mine, and mine alone. These posts do not reflect the opinions of my family, friends, employer, or any organization that I am a member of. |
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NASA?s full Artemis plan revealed: 37 launches and a lunar outpost
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