Author Topic: Advanced boosters progress towards a solid future for SLS  (Read 38066 times)

Offline Lobo

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Re: Advanced boosters progress towards a solid future for SLS
« Reply #60 on: 02/27/2015 12:18 am »
Theoretical LRBs out perform SRMs.
Theoretical is nice, but it isn't sitting on a test stand in Utah right now.   

 - Ed Kyle

A bird in the hand is worth two in the bush.  :-)

Too bad they can't make more than a few pairs of them.  :-(

I think that's as much the jagged pill to swallow as anything.

Offline MP99

I have a feeling that the advanced boosters may get moved further into the future. There are a good number of steel cases left. I am not sure how many are around today but a few years ago there were enough to support 10 SLS flights.

That is very old information. After careful inspection, they said the number passing inspection was enough for only 4 flights. This has been about 2 years ago that this was announced. The other 60 something casings were not in flyable condition.

I'd *really* like to see a reference or link for that. It's not my understanding of the situation.

Cheers, Martin

Offline Endeavour_01

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Re: Advanced boosters progress towards a solid future for SLS
« Reply #62 on: 02/27/2015 03:10 pm »
It has always been about making sure that solids and only solids will be used for boosters. Period :)
There are solid (pun intended) reasons for sticking with solid boosters with out having to ascribe any political reasons. Advanced solids represent the lowest cost upgrade to Block 1B SLS. For liquids a lot of modifications to the pad and ground support equipment would be required. There is no room on the MPL for any more connections so a new one would have to be built. The existing RP-1 lines date from the Saturns and would be of no use. New piping, and storage tanks would be needed.

Oh I don't "need" to assign political reasons, but they are right there and up front about it being THE reason the payload requirements was chosen :) Hatch and the rest of the Utah delegation were quite proud of getting that exact number specified in the legislation because THAT number (they were assured by "experts") would require solid rocket boosters and nothing else would do. It's all on record. The whole LRB fiasco came along when it looked like Hatch might not be re-elected or might retire and a window of opportunity was seen but it was never a realistic option for the reasons you've given even if for no others.

Personally I'm thinking we might be missing an opportunity for international cooperation by asking the Brits to resurrect their HTP program and building us some new boosters but that's probably only me :)

Randy

Obviously there are political angles involved in where federal funding goes. That goes for ATK as well as for SpaceX. There is also a national security aspect to consider (solids launch our nukes and we need to keep the solid rocket scientists and engineers employed).

That said using advanced SRBs for SLS has a lot of practical benefit. Not having to redesign the support infrastructure is a huge advantage. You basically can plug and play with the Dark Knights. Then of course it is always good to have to have diversity in launch systems. SpaceX is going for all liquid with LOX/RP-1 with FH and from what I understand the future BFR while SLS is going LOX/LH2 with solid boosters.
I cheer for both NASA and commercial space. For SLS, Orion, Falcon 9, Falcon Heavy, Dragon, Starship/SH, Starliner, Cygnus and all the rest!
I was blessed to see the launch of Space Shuttle Endeavour on STS-99. The launch was beyond amazing. My 8-year old mind was blown. I remember the noise and seeing the exhaust pour out of the shuttle as it lifted off. I remember staring and watching it soar while it was visible in the clear blue sky. It was one of the greatest moments of my life and I will never forget it.

Online PahTo

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Re: Advanced boosters progress towards a solid future for SLS
« Reply #63 on: 02/27/2015 04:28 pm »
I have a feeling that the advanced boosters may get moved further into the future. There are a good number of steel cases left. I am not sure how many are around today but a few years ago there were enough to support 10 SLS flights.

That is very old information. After careful inspection, they said the number passing inspection was enough for only 4 flights. This has been about 2 years ago that this was announced. The other 60 something casings were not in flyable condition.

I'd *really* like to see a reference or link for that. It's not my understanding of the situation.

Cheers, Martin

It took some digging, but I believe Starlab90 was the one who broke the news--post 114 on this thread:
http://forum.nasaspaceflight.com/index.php?topic=34229.105

Then you yourself Martin chimed in here:
http://forum.nasaspaceflight.com/index.php?topic=30862.180

It's amazing how many times we have hashed through the whole SRB thing, which is why I won't go in to it anymore than to say I sure hope some/most/all of the development effort being put in to the 5-seg SRMVs (note I didn't use the prepending "R" since there is nothing reusable about these units) directly translates to development and production of the advanced boosters, otherwise it appears much cost/effort is going in to making just a handful of flights at best.

Offline TomH

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Re: Advanced boosters progress towards a solid future for SLS
« Reply #64 on: 02/27/2015 05:32 pm »
From the article, it seems like there is actually no advanced booster competition. That that it is only between black knights and F1b, and that the outcome between these two is known.
Am I getting it right?

Or can there still be other participants?

The obvious question is, for instant, can a certain company X offer their planned huge reusable rocket as a booster?

Risk reduction funding was awarded to ATK for advanced solids, to Dynetics for F-1B, and to Aerojet for AJ-1E6. It was announced that there would be a competition beyond that and any could enter-anyone of those 3 as well as others. Later it was announced that the competition would not happen and that the pad and tower modifications necessary for an advanced liquid booster would not be included in planning for the future.

Offline TomH

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Re: Advanced boosters progress towards a solid future for SLS
« Reply #65 on: 02/27/2015 05:33 pm »
Theoretical LRBs out perform SRMs.
Theoretical is nice, but it isn't sitting on a test stand in Utah right now.   

 - Ed Kyle

Neither is an advanced solid.

Offline arachnitect

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Re: Advanced boosters progress towards a solid future for SLS
« Reply #66 on: 02/27/2015 05:52 pm »
Theoretical LRBs out perform SRMs.
Theoretical is nice, but it isn't sitting on a test stand in Utah right now.   

 - Ed Kyle

Neither is an advanced solid.

Sorry. Somebody said that we have SRBs because of the infamous "130t requirement" I was trying to point out that it's more like we have SRBs in spite of said requirement.

We have SRBs because of the "shuttle derived" and schedule desires. But when it comes to the "130t requirement" they need either 1. a new core or 2. LRBs or 3. ignore 130t language.

Offline TomH

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Re: Advanced boosters progress towards a solid future for SLS
« Reply #67 on: 02/27/2015 06:01 pm »
I'd *really* like to see a reference or link for that. It's not my understanding of the situation.

How about you? Would you consider your own self to be a reliable source?

http://forum.nasaspaceflight.com/index.php?topic=30862.msg1202276#msg1202276

http://forum.nasaspaceflight.com/index.php?topic=30862.msg1203715#msg1203715

Don't feel bad though. I'm in my 60s now and forget all kinda stuff. Sometimes I think need an Alzheimer's test.  :o
« Last Edit: 02/27/2015 06:16 pm by TomH »

Offline TomH

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Re: Advanced boosters progress towards a solid future for SLS
« Reply #68 on: 02/27/2015 06:08 pm »
Theoretical LRBs out perform SRMs.
Theoretical is nice, but it isn't sitting on a test stand in Utah right now.   

 - Ed Kyle

Neither is an advanced solid.

Sorry. Somebody said that we have SRBs because of the infamous "130t requirement" I was trying to point out that it's more like we have SRBs in spite of said requirement.

We have SRBs because of the "shuttle derived" and schedule desires. But when it comes to the "130t requirement" they need either 1. a new core or 2. LRBs or 3. ignore 130t language.

Hmmm, were you replying to me or to Ed? My post to him was to state that the advanced solid (which will be required if SLS flies more than four times) is no more sitting on a test stand than is an advanced liquid.

Offline notsorandom

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Re: Advanced boosters progress towards a solid future for SLS
« Reply #69 on: 02/27/2015 07:34 pm »
It has always been about making sure that solids and only solids will be used for boosters. Period :)

Randy
There are solid (pun intended) reasons for sticking with solid boosters with out having to ascribe any political reasons. Advanced solids represent the lowest cost upgrade to Block 1B SLS. For liquids a lot of modifications to the pad and ground support equipment would be required. There is no room on the MPL for any more connections so a new one would have to be built. The existing RP-1 lines date from the Saturns and would be of no use. New piping, and storage tanks would be needed.
IMHO the EUS was the right call. Advanced boosters in the Block 1A configuration could put 105 mt in LEO or more depending on the booster chosen. Beyond LEO is where SLS is needed and Block 1A isn't very much of an upgrade when the only upper stage is the ICPS. Block 1B without any advanced boosters can also do 105 mt to LEO but also around 40mt to TLI and similar trajectories. With the flat and limited funding SLS has it was either advanced boosters or EUS. The EUS enables more missions more quickly.

Offline notsorandom

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Re: Advanced boosters progress towards a solid future for SLS
« Reply #70 on: 02/27/2015 07:41 pm »
More steel casing could be made. This was the plan for constellation which would have used 15 casings and two half casings for every lunar mission. Also recovery could be added back in. Its not like the limited number of casings is a brick wall, more like a very high speed bump. It may be the cost to upgrade to dark knights is low enough and the per unit savings is high enough that it just makes more sense to just go ahead and do them.

Offline TomH

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Re: Advanced boosters progress towards a solid future for SLS
« Reply #71 on: 02/27/2015 08:38 pm »
More steel casing could be made. This was the plan for constellation which would have used 15 casings and two half casings for every lunar mission. Also recovery could be added back in. Its not like the limited number of casings is a brick wall, more like a very high speed bump. It may be the cost to upgrade to dark knights is low enough and the per unit savings is high enough that it just makes more sense to just go ahead and do them.

Supposedly they are cheaper, yet more profitable at the same time. I remember other threads where those with direct information said ATK moved quickly to shut down that kiln because there was more money to be had in the composites.

Offline Lobo

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Re: Advanced boosters progress towards a solid future for SLS
« Reply #72 on: 02/27/2015 10:00 pm »
More steel casing could be made. This was the plan for constellation which would have used 15 casings and two half casings for every lunar mission. Also recovery could be added back in. Its not like the limited number of casings is a brick wall, more like a very high speed bump. It may be the cost to upgrade to dark knights is low enough and the per unit savings is high enough that it just makes more sense to just go ahead and do them.

Supposedly they are cheaper, yet more profitable at the same time. I remember other threads where those with direct information said ATK moved quickly to shut down that kiln because there was more money to be had in the composites.

Yes, in some other threads it was discussed.  Something about the forge/kiln needing to be kept hot and on active standby during the entire STS program because if it ever cooled, it couldn't be restarted again.  I don't know much about forging of such things to know how/why that is the case, but there were documents that indicated that.  The contractors were happy to be done with them too (as I recall...ATK didn't actually forge the casings...other contractors had those facilities), as they'd been keeping those dedicated facilities operational only for those SRB's, and some of those companies didn't necessary do that kind of work 30 years later.  So they were oddities kept alive by NASA.  I think it was probably decided that if SRB's survived the cancellation of CXP then they'd go to a composite casing that'd have lower overhead and utilized more modern technologies. 

To Notsoradnom's comment, in that same topic, I don't believe more steel casings -can- be made any more.  That's the point.  Once the forge/kiln and associated facilites were shut down, they were quickly dimantled.  It'd all have to be created from scratch now.  -That- is why there isn't any official talk of more steel casings, becuase as we all know, if something is currently working for NASA, political inertia makes it difficult to change up.  I think if keeping the new steel 5-seg boosters indefinately were as easy as just ordering more casings form existing facilites, there probably wouldn't be any talk of composite boosters (or any other kind of boosters) for a long time, as a Block 1B SLS with 5-seg boosters will provide NASA with all the capacity they can put a payload on for some time.  It's a brand new booster after all.  And was to be the PoR booster indefinately for CxP.  NASA had no issue using it forever.  But during CxP the facilites still existing to make those casings.  That's not longer the case as I understand. 

The real question is, why were 5-seg's selected for SLS if they are a dead end booster?
That's the real issue, not about subsequent advanced boosters. 
Likely because they were already in developent and money already spent on them for CxP, and ATK had enough influence to see them carried into SLS.  4-seg STS boosters could have been used and reused (aka Direct) , but they'd be a dead end too, as new casings still could not be made.  And they'd be ready to fly sooner than some all new booster.  A complete new from scratch booster would have pushed SLS's original timeline of 2017 out farther.
The better alternative would have been a RAC-2 type LV.  RAC-2 won all of the competitions vs. RAC-1 SDHLV...except the political competition.  RAC-2 would mean no boosters needed at all.  Just a new core and new upper stage...which RAC-1 needed anyway.  Then the whole topic of dead-end steel booster or subsequent advanced boosters is moot.

« Last Edit: 02/27/2015 10:01 pm by Lobo »

Offline newpylong

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Re: Advanced boosters progress towards a solid future for SLS
« Reply #73 on: 02/27/2015 10:55 pm »
The 5 segments were used simply because they were nearly qualified. The issues that came to light going from DM to QM were not anticipated. It was always understood there was only a finite number of cases and then the advanced competition would bappen. ATK contracted lines for steel were shutdown in the  period before the 5 segs were resurrected for SLS.

Going from steel to composite even without a competition is a step forward.

Arguing the RAC this vs that is a moot point.

Online AnalogMan

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Re: Advanced boosters progress towards a solid future for SLS
« Reply #74 on: 02/28/2015 12:56 am »
Regarding re-start of steel casing manufacture - see the document referenced in the following post (and comments in the post that follows):

http://forum.nasaspaceflight.com/index.php?topic=27714.msg1212409#msg1212409

(This was the situation as viewed in 2005.)

Offline Lobo

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Re: Advanced boosters progress towards a solid future for SLS
« Reply #75 on: 03/02/2015 04:37 pm »
Regarding re-start of steel casing manufacture - see the document referenced in the following post (and comments in the post that follows):

http://forum.nasaspaceflight.com/index.php?topic=27714.msg1212409#msg1212409

(This was the situation as viewed in 2005.)

Ahhh..yea...there it is.  Bodycote that did the heat treating of the segments was the facility that once shut down couldn't be restarted.  Not the forge as I'd said.  And sounds like they wanted out of the SRB business pretty bad. 

That documents makes a pretty good case for why the STS SRB's shouldn't have been attempted to be retained for CxP, much less SLS.  I think the high price and complexity of the RS-25 makes the case to not retain them either.  Essentially, the Shuttle Derived concept should have been avoided for any launch system that is not the actual Shuttle.


Offline Oli

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Re: Advanced boosters progress towards a solid future for SLS
« Reply #76 on: 03/02/2015 07:39 pm »
RAC-2 won all of the competitions vs. RAC-1 SDHLV...except the political competition.

What's your definition of "political"? I'll quote from the "Preliminary Report Regarding NASA’s Space Launch System and Multi-Purpose Crew Vehicle":

Quote
In conducting its analysis and while maintaining a threshold safety requirement, the MSFC team performed an analytical hierarchy process and used weighted FOMs as follows:

Affordability: 55 percent
Schedule: 25 percent
Performance: 10 percent
Programmatic: 10 percent

The findings of the MSFC study showed that the 27.5-foot LOX/LH2/SSME HLV and 2Mlbf GG RP vehicles were highest rated across all of the FOMs. The 2.0 Mlbf RP engine vehicle scored better than the 1.25 Mlbf RP common engine because of its higher reliability (more engines would be required for 1.25 Mlbf). However, the LOX/LH2 RS-68 vehicle and the combined vehicles (LH core and RP strap-on boosters) did not fare well due to high potential costs and underrated performance.

and

Quote
The overarching goal of the SLS is to enable human exploration at the highest possible safety standards and the lowest life-cycle costs for beyond-LEO missions. Based on current information and analysis, the Reference Vehicle Design represents the lowest near-term costs, soonest available, and the least overall risk path to the development of the next, domestic heavy lift launch vehicle. Selecting this SLS architecture would mean that a new liquid engine in the near term would not need to be developed, thus shortening the time to first flight as well as likely minimizing the overall DDT&E cost of the SLS. However, the Reference Vehicle Design may not be affordable within expected budget levels. These issues are being considered in NASA’s ongoing trades and analyses, as outlined below.

Or Chris' article:

http://www.nasaspaceflight.com/2011/01/nasa-report-favors-sd-hlv-sls-complains-cant-afford-2016/

Offline Lobo

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Re: Advanced boosters progress towards a solid future for SLS
« Reply #77 on: 03/02/2015 10:03 pm »
What's your definition of "political"?

A member of this site who was part of the RAC-2 told me directly RAC-2 won all technical and economic criteria vs. RAC-1.  They even had a celebratory pizza party which the winning RAC team would get ( as a little friendly fun for the winner).  Then they were told that RAC-1 would win because of political pressures which were inisting on shuttle derived/Ares V-ish.

Of course, he could have been making all of that up...but...I'll opt to go with a direct source vs. the various thumb-on-the-scale official rationale...the same that got us Ares 1/5 vs. various other better options in ESAS and thus has already given us reason to be skeptical of their official rationales.

Offline MP99



I'd *really* like to see a reference or link for that. It's not my understanding of the situation.

How about you? Would you consider your own self to be a reliable source?

http://forum.nasaspaceflight.com/index.php?topic=30862.msg1202276#msg1202276

http://forum.nasaspaceflight.com/index.php?topic=30862.msg1203715#msg1203715

Don't feel bad though. I'm in my 60s now and forget all kinda stuff. Sometimes I think need an Alzheimer's test.  :o

Thanks, the second one affirms my understanding that more sets are available, but simply not on contract.

Following posts in this thread make interesting reading, though.

Cheers, Martin

Offline Oli

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Re: Advanced boosters progress towards a solid future for SLS
« Reply #79 on: 03/03/2015 01:51 am »
What's your definition of "political"?

A member of this site who was part of the RAC-2 told me directly RAC-2 won all technical and economic criteria vs. RAC-1.  They even had a celebratory pizza party which the winning RAC team would get ( as a little friendly fun for the winner).  Then they were told that RAC-1 would win because of political pressures which were inisting on shuttle derived/Ares V-ish.

Of course, he could have been making all of that up...but...I'll opt to go with a direct source vs. the various thumb-on-the-scale official rationale...the same that got us Ares 1/5 vs. various other better options in ESAS and thus has already given us reason to be skeptical of their official rationales.

Thanks! I found a slide that I think confirms you view. I guess its old news for many here and kind of off topic but I'll post it anyway.

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