Author Topic: SLS General Discussion Thread 2  (Read 210434 times)

Online oldAtlas_Eguy

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Re: SLS General Discussion Thread 2
« Reply #1080 on: 11/09/2017 03:10 PM »
Cross post from the SC thread:
http://forum.nasaspaceflight.com/index.php?topic=44132.msg1745841#msg1745841
Probable realistic launch plan schedule for SLS:

EM-1   May 2020
SM-1   July 2023
EM-2   June 2024
EM-3   June 2025
SM-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.

This schedule does not look quite so speculative anymore.

A 1 month slip of the best case Dec 2019 launch date and EC would not make it's June 2022 window. But for EM-2 going first NASA may want a lighter weight ML and then there is the problem of not enough time to construct a ML-2 for support of manned EM-2 plus EM-2 would be the first flight of EUS as well. But an ML-2 must be budgeted. It is not in the 2018 budget. It needs an RFI (to get the detailed cost of a second ML and how long it would take to construct it). Then funds and a contract. Do not expect a start work (detailed design) prior to Oct 2018. Add a probable 4 years which may be too short since the build rate is highly dependent on yearly budget and Congress is stingy. That give a probable EM-2 date of NET Sept 2022. Fortunately this is low likelihood of slip readiness date for the ML-2 since the contractor so far building the pad infrastructure when they gave a readiness date they have met it. It has only been that NASA has been adding additional requirements and changes due to flight hardware changes that the schedule for the pad systems has slipped out.

It is likely to take 33 months after ML-1 to be made ready and support EM-2 stacking. An effort that would likely start 6 months prior and need a completed ML for use but I believe the the 33 months includes that consideration. This gives an earliest EM-2 date of if ML-1 is used of Sept 2022 (NASA gave June 2022) as well if EM-1 actually launches Dec 2019. But for each month EM-1 slips so does this EM-2 date when using the ML-1. A worst case date of June for EM-1 is a worst case earliest launch date when using ML-1 (funds for an ML-2 does not get appropriated) of Mar 2023. In this case it would be better to launch EC (SM-1) than EM-2 since it's second window is Jul 2023.

It is possible for NASA (and its contractors currently contracted and the way that the contracts are written) to do two SLS launches separated by 6 months. So if EM-1 is earlier than April 2020 then an EM-2 can be done in Jan 2023 with an SM-1 in Jul 2023, a 4 month slip of the EM-1 NET date of Dec 2019.

Now a second problem consideration. NASA is running the SLS, Orion  and related projects at a 1% budget margin. Such that if anything happens the schedule slips out since there is no funds to absorb problems and maintain schedule. This condition exist not just for the current FY 2018 but for out year FY. NASA plans do not have any budget reserves available in their NET EM-1 Dec 2019 planning date. So that means in order to meet the Dec 2019 there has to be no weather events, no production errors, no handling mishaps, no engineering errors requiring rework, etc. In 2017 theses events caused a 6 month schedule delay in the core stage (it was already 6 months behind this just made it impossible to ignore the core stage schedule pushing the launch date out a year). There are 2 more years to get to Dec 2019. Hopefully 2018 and 2019 will not be as challenging as 2017 has been.

NOTE: ML stands for Mobile Launcher platform.

Online Khadgars

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Re: SLS General Discussion Thread 2
« Reply #1081 on: 11/09/2017 03:53 PM »
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.

Not per the latest article.  June 2020 is worst case scenario.

https://www.nasaspaceflight.com/2017/11/sls-managers-troops-slip-2020/

Offline UltraViolet9

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Re: SLS General Discussion Thread 2
« Reply #1082 on: 11/09/2017 04:26 PM »
June 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.
« Last Edit: 11/09/2017 04:35 PM by UltraViolet9 »

Offline ncb1397

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Re: SLS General Discussion Thread 2
« Reply #1083 on: 11/09/2017 05:24 PM »
June 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.

Online oldAtlas_Eguy

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Re: SLS General Discussion Thread 2
« Reply #1084 on: 11/09/2017 05:52 PM »
June 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. 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.

Offline UltraViolet9

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Re: SLS General Discussion Thread 2
« Reply #1085 on: 11/09/2017 07:36 PM »
You can't take into account unknown unknowns. A meteor could take out the VAB,

That's a ridiculous example.

When developing new systems, there are always unknowns, like the welding issues in this project.  Gerst made reference to unknowns in his testimony today.

Well-managed developments incorporate schedule, budget, and technical margin to accommodate them.

Quote
Right now, it seems to be NET December 2019. May 2020 has like 5 months of schedule margin on the NET date.

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.


« Last Edit: 11/09/2017 07:52 PM by UltraViolet9 »

Offline spacetraveler

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Re: SLS General Discussion Thread 2
« Reply #1086 on: 11/09/2017 08:04 PM »
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.

Not per the latest article.  June 2020 is worst case scenario.

https://www.nasaspaceflight.com/2017/11/sls-managers-troops-slip-2020/

Not possible to know worst case date at this point.

Keep in mind we are only 6 months out from the decision to announce the slip from 2018 into 2019.

https://www.nasaspaceflight.com/2017/06/nasa-letter-congress-em-1-slip/

As we get closer to 2020, I suspect the discussion will have changed to one around whether a slip into 2021 can be avoided.

Online oldAtlas_Eguy

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Re: SLS General Discussion Thread 2
« Reply #1087 on: 11/09/2017 08:39 PM »
A point of perspective. As you get closer to the actual launch the higher the schedule risk.

Why? Because there is a tremendous number of unknowns in a first time launch with first time flight hardware and most of the GSE also first time. Simple things like wiring errors on connectors, umbilicals that are too long or not long enough, bolts / holes not matching up, software problems, and other additional integration and checkout, handling difficulties. NASA currently has a period of 6 months of schedule duration to handle all of this expecting that some tasks will take significantly longer than expected. That last portion of stacking, integrating, checkouts, and fueling will encounter problems. NASA believes that they have scheduled enough time for this difficult period.

Software/hardware interface problems with the first time checkouts of an integrated stack and pad GSE may be the largest problems encountered and the most difficult to overcome.

An current example is the FH with a possible launch date of best case of a launch at 1.5 months away could still slip easily as much as an additional month. So even if the SLS flight hardware and ground GSE meets the milestone delivery to the VAB for a Dec 2019 launch date the remaining tasks may not make the Dec date even then. In fact there is only a 50% likelihood for the process to be completed in just 6 months because the the 6 month period is the nominal expected (not the best nor the worst cases but the median case).

So if the Dec 2019 is the 3 sigma best case and June 2020 is the 3 sigma worst case then the 50% median likelihood date would be ~Mar 2020.

Online Khadgars

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Re: SLS General Discussion Thread 2
« Reply #1088 on: 11/09/2017 08:55 PM »
You 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.

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.”

Offline ncb1397

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Re: SLS General Discussion Thread 2
« Reply #1089 on: 11/09/2017 09:12 PM »
June 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.

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.
« Last Edit: 11/09/2017 09:20 PM by ncb1397 »

Offline UltraViolet9

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Re: SLS General Discussion Thread 2
« Reply #1090 on: 11/09/2017 09:32 PM »
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.”

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.

« Last Edit: 11/09/2017 09:34 PM by UltraViolet9 »

Offline copper8

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Re: SLS General Discussion Thread 2
« Reply #1091 on: 11/10/2017 02:54 PM »
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?

   

Offline Coastal Ron

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Re: SLS General Discussion Thread 2
« Reply #1092 on: 11/10/2017 03:21 PM »
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.

We're dealing with the physical world here, not the meta-physical world. The delays are based on real issues that have to be solved, so as they get solved there is less potential for schedule slippages.

The reason for the schedule slippages is that the SLS and Orion were not fully defined when Congress mandated NASA build them - and Congress defined the SLS and it's initial operational date of 12/31/2016, which obviously was not based on reality.

That makes it impossible for anyone to define valid schedules when there are so many variables and unknowns, so what happens is that everyone starts using "best case" estimates in order to appease the politicians, and also because they know that those in Congress who wanted the SLS and Orion were likely to keep supporting the programs. Boeing and Lockheed Martin know there are no downsides to the schedule slippages, because they will still get paid, and NASA is stuck looking like they don't know what they are doing. Which in a way they don't, because NASA has never been fully in control of the SLS and Orion programs.

Given enough time and funding the SLS and Orion will fly, and likely fly safely. The question is whether there is enough time and money...

Quote
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.

Apples vs oranges, since the Falcon Heavy has not been a priority for SpaceX - Falcon 9 and Dragon Cargo & Crew have been the bigger priorities. The SLS and Orion are priorities for NASA according to Congress, although their schedule slippages have not impacted any customers... because, you know, there pretty much aren't any...   ;)
If we don't continuously lower the cost to access space, how are we ever going to afford to expand humanity out into space?

Online AncientU

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Re: SLS General Discussion Thread 2
« Reply #1093 on: 11/10/2017 04:00 PM »
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.”

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.

OIG(?) reports that SLS/Orion funding margin is less than 1%.  'Buying down' the risk that is already identified, let alone emergent risk, takes dollars -- don't think 1% is much help.
« Last Edit: 11/10/2017 04:05 PM by AncientU »
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Online AncientU

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Re: SLS General Discussion Thread 2
« Reply #1094 on: 11/10/2017 04:24 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.
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Offline dwheeler

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Re: SLS General Discussion Thread 2
« Reply #1095 on: 11/10/2017 07:16 PM »
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?
   

From https://www.space.com/38746-smith-disappointed-with-lack-of-progress-on-sls-and-orion.html

Quote
...
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.
...

I seems like there's been a lot of this lately... announce you're going to retire from public office and only then say what you're really feeling.

Offline Space Ghost 1962

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Re: SLS General Discussion Thread 2
« Reply #1096 on: 11/10/2017 07:33 PM »
Agree that the chickens are coming home to roost even more. All of the "Senate Launch System" contrivances to have a govt LV strategy their way, have led to time/cost stumbles. While fewer stumbles elsewhere may have changed the game.

The "knock on" effect. More gradual erosion. (We can now compare BO, SX, Ariane Group, ULA, NG/OA versions of "gradatim", FWIW.)

Pick you poison? Is there a way to just avoid the poison and build/fly?

Online AncientU

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Re: SLS General Discussion Thread 2
« Reply #1097 on: 11/10/2017 08:34 PM »
Competition.

Put heavy lift out to bid...  400tonnes/year to pick-an-orbit, X crew members per year to destination specified...
then compare the numbers to the cash currently being spent for much, much less.
« Last Edit: 11/10/2017 08:37 PM by AncientU »
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Offline ncb1397

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Re: SLS General Discussion Thread 2
« Reply #1098 on: 11/10/2017 11:30 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).
« Last Edit: 11/10/2017 11:33 PM by ncb1397 »

Online oldAtlas_Eguy

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Re: SLS General Discussion Thread 2
« Reply #1099 on: 11/11/2017 12:21 AM »
...
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).
As I was trying to point out and will try to clear up is that the SLS/Orion program is fairly normal for such complex  LV development programs. The number one driver for the slips is not the fact that there are problems but that there is no funds reserves to deal with them. From experience the costs of the solving and handling of problems is about 20-30% of the funds needed for all the tasks if no problems were ever encountered. But this is where the fact that SLS/Orion program has gotten itself into trouble. They have moved the cost margins down to almost nothing to be able to then have sooner end date. But if problems occur that need that 20-30% of extra funds the result is a 20-30% or even more schedule growth.

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