Probable realistic launch plan schedule for SLS:EM-1 May 2020SM-1 July 2023EM-2 June 2024EM-3 June 2025SM-2 2026 (whenever the launch window in this year occurs) (plus this is the first flight of the RS-25Es, ASAP will want a unmanned flight of these engines first before a manned one) (this engine set will not be available to support a flight until this time anyway so it could not be done any earlier)EM-4 2028 (it takes 2 years to deliver 4 RS-25Es on the current contract) (It will require a bigger budget and a new contract to increase the build rate to deliver 4 engines per year instead of the current contract delivery rate of 2 engines per year)Unless the engine build rate is increased there is no more launches in the 2020's.Assumptions:a) That ML-1 is modified to be a cargo only SLS-1B support.b) That an ML-2 is constructed with lessons learned to make a crew version of the ML with a budget funded at a level allowing it to be constructed in 5 years starting Oct 2018. This gets a ML available to support the June 2024 EM-2 date at better than 6 months prior to launch date plus a few months of margin. c) That EC is ready for launch by 6 months prior to its launch date in July 2023.d) That Europa Lander is ready for launch 6 months prior to its window in 2026.
Let's face it, there's pretty much a zero percent chance that it doesn't slip into 2020.The most optimistic scenarios are continually projected publicly because SLS needs all the political support it can get if it's going to survive.I'd bank on a Q3 or later launch in 2020 at this point.
June 2020 is worst case scenario.
Quote from: Khadgars on 11/09/2017 03:53 pmJune 2020 is worst case scenario.Per Chris on the development thread, June 2020 is what's "realistically possible" when the known schedule risks are analyzed. It's not worst case.Worst case in any development is always more unknown risks popping up. If June 2020 provides little or no margin for unknown risks, it is not the worst case.Also per this week's OIG report, SLS is also in the unfortunate position of having no budget margin to deal with unknowns.This leaves management with only three options: remove content (for which there are limited options on a launch vehicle), increase risk (reduce testing), or slip schedule.
Quote from: UltraViolet9 on 11/09/2017 04:26 pmQuote from: Khadgars on 11/09/2017 03:53 pmJune 2020 is worst case scenario.Per Chris on the development thread, June 2020 is what's "realistically possible" when the known schedule risks are analyzed. It's not worst case.Worst case in any development is always more unknown risks popping up. If June 2020 provides little or no margin for unknown risks, it is not the worst case.Also per this week's OIG report, SLS is also in the unfortunate position of having no budget margin to deal with unknowns.This leaves management with only three options: remove content (for which there are limited options on a launch vehicle), increase risk (reduce testing), or slip schedule.You can't take into account unknown unknowns. A meteor could take out the VAB, the mobile launcher and the pad next week Chelyabinsk style. In those cases, scheduling or setting dates based on that stuff is simply a pointless exercise which is why it doesn't factor into schedule timelines. Right now, it seems to be NET December 2019. May 2020 has like 5 months of schedule margin on the NET date.
You can't take into account unknown unknowns. A meteor could take out the VAB,
Right now, it seems to be NET December 2019. May 2020 has like 5 months of schedule margin on the NET date.
Quote from: spacetraveler on 11/09/2017 03:06 amLet's face it, there's pretty much a zero percent chance that it doesn't slip into 2020.The most optimistic scenarios are continually projected publicly because SLS needs all the political support it can get if it's going to survive.I'd bank on a Q3 or later launch in 2020 at this point.Not per the latest article. June 2020 is worst case scenario.https://www.nasaspaceflight.com/2017/11/sls-managers-troops-slip-2020/
Quote from: ncb1397 on 11/09/2017 05:24 pmYou can't take into account unknown unknowns. A meteor could take out the VAB, It's this kind of extreme optimism that gets NASA into trouble in the first place.According to Gerst, the launch date of June (not May) 2020 is only "possible". Not likely or probable. Just possible.December 2019 works only if NASA perfectly manages every known risk. The agency won't.The difference between the two is not margin.
“While the review of the possible manufacturing and production schedule risks indicate a launch date of June 2020, the agency is managing to December 2019,” said acting NASA Administrator Robert Lightfoot. “Since several of the key risks identified have not been actually realized, we are able to put in place mitigation strategies for those risks to protect the December 2019 date.”
Quote from: ncb1397 on 11/09/2017 05:24 pmQuote from: UltraViolet9 on 11/09/2017 04:26 pmQuote from: Khadgars on 11/09/2017 03:53 pmJune 2020 is worst case scenario.Per Chris on the development thread, June 2020 is what's "realistically possible" when the known schedule risks are analyzed. It's not worst case.Worst case in any development is always more unknown risks popping up. If June 2020 provides little or no margin for unknown risks, it is not the worst case.Also per this week's OIG report, SLS is also in the unfortunate position of having no budget margin to deal with unknowns.This leaves management with only three options: remove content (for which there are limited options on a launch vehicle), increase risk (reduce testing), or slip schedule.You can't take into account unknown unknowns. A meteor could take out the VAB, the mobile launcher and the pad next week Chelyabinsk style. In those cases, scheduling or setting dates based on that stuff is simply a pointless exercise which is why it doesn't factor into schedule timelines. Right now, it seems to be NET December 2019. May 2020 has like 5 months of schedule margin on the NET date.The NET Dec 2019 date is if everything goes perfectly. When was the last time any development of a LV went perfect no problems.
Not according to the article.Quote“While the review of the possible manufacturing and production schedule risks indicate a launch date of June 2020, the agency is managing to December 2019,” said acting NASA Administrator Robert Lightfoot. “Since several of the key risks identified have not been actually realized, we are able to put in place mitigation strategies for those risks to protect the December 2019 date.”
If things go "perfectly" from now on, the LV would have had major problems in its development. They would just be prior to November 9th, 2017. I mean, you are basically assuming any date set ever will be delayed. In which case, you could never reach a launch date with an actual launch. Each date would have to be delayed prior to arriving on that date.
I could equally assume that the Falcon Heavy will be delayed because it has been "this year" for the last several years. Maybe it will, maybe it won't. Eventually, it will launch on time though.
Quote from: Khadgars on 11/09/2017 08:55 pmNot according to the article.Quote“While the review of the possible manufacturing and production schedule risks indicate a launch date of June 2020, the agency is managing to December 2019,” said acting NASA Administrator Robert Lightfoot. “Since several of the key risks identified have not been actually realized, we are able to put in place mitigation strategies for those risks to protect the December 2019 date.”Lightfoot is talking about "mitigation strategies", ways to buy down risk and buy back lost schedule.Lightfoot does not mention schedule margin, time added to a confident date to deal with risks as they emerge.They're not the same thing. If you're managing a development project, it's unwise to conflate the two.
...The NET Dec 2019 date is if everything goes perfectly. When was the last time any development of a LV went perfect no problems. Even SpaceX had lots of problems and slipped dates especially for their SHLV the FH about 2+ years of slip now. The original planning date for SLS was Oct 2017 BTW when the program was started. Just a 2+ year slip over a development that will be 8+ years in duration is not actually that bad compared to other similar complex large space projects.
Apparently Lamar Smith (R-TX) who chairs the House Science committee, made a number of comments yesterday expressing 'disappointment' and 'frustration' at the latest schedule and warning that additional delays could build support for unspecified alternatives. I've been under the impression that this committee has been an SLS booster up to this point. Frustrated congressmen who hold the purse strings would not seem like a good sign. Is this a change in the signals that Congress is sending regarding SLS funding?
...Smith, who announced Nov. 2 he would not run for reelection next year ......Smith'`s comments represent one of the strongest rebukes to date by a leading member of Congress regarding progress on SLS and Orion. Other members of the committee expressed few, if any, reservations about the programs at the hearing despite the latest delay....
Quote from: oldAtlas_Eguy on 11/09/2017 05:52 pm...The NET Dec 2019 date is if everything goes perfectly. When was the last time any development of a LV went perfect no problems. Even SpaceX had lots of problems and slipped dates especially for their SHLV the FH about 2+ years of slip now. The original planning date for SLS was Oct 2017 BTW when the program was started. Just a 2+ year slip over a development that will be 8+ years in duration is not actually that bad compared to other similar complex large space projects.Dec 2019 (8yrs total) is a 33% slip in a six-year program (assuming that you completely write off the real start of this program in 2006); Summer 2020 is a 50% slip. When SLS flies could be well beyond these dates... vastly more likely than Dec 2019; nonetheless, we'll spend the next two years talking about SLS launching in 2019. Mission accomplished Mr. Lightfoot.
Quote from: AncientU on 11/10/2017 04:24 pmQuote from: oldAtlas_Eguy on 11/09/2017 05:52 pm...The NET Dec 2019 date is if everything goes perfectly. When was the last time any development of a LV went perfect no problems. Even SpaceX had lots of problems and slipped dates especially for their SHLV the FH about 2+ years of slip now. The original planning date for SLS was Oct 2017 BTW when the program was started. Just a 2+ year slip over a development that will be 8+ years in duration is not actually that bad compared to other similar complex large space projects.Dec 2019 (8yrs total) is a 33% slip in a six-year program (assuming that you completely write off the real start of this program in 2006); Summer 2020 is a 50% slip. When SLS flies could be well beyond these dates... vastly more likely than Dec 2019; nonetheless, we'll spend the next two years talking about SLS launching in 2019. Mission accomplished Mr. Lightfoot.Careful. All constellation ended up being was trying to build a crew vehicle to replace ISS crew rotation flights. That could just as easily be lumped in with commercial crew and here we are...11 years later and still waiting.And the lack of progress since 2006 could also be an argument for why we shouldn't do the same thing all over again that was done in 2010(reset everything for some other shiny bauble).