Author Topic: NASA requests alternative options to RS-25s on SLS core stage  (Read 5407 times)

Offline envy887

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Rather than asking for alternative options for the RS-25s, they should have asked for alternative options for the entire core stage. No restrictions on engine size, quantity, or propellants. Just performance.

SLS doesn't work well unless the upper stage, boosters, and pad support all match the core stage. Which either puts a pretty strict set of bounds on what the core stage looks like, or results in a near-complete redesign of most of the program.

Offline Steve G

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That would obviously be part of the stipulation. It would have been interesting if SpaceX or Blue Origin would have accepted the challenge.

Offline Jim

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Rather than asking for alternative options for the RS-25s, they should have asked for alternative options for the entire core stage. No restrictions on engine size, quantity, or propellants. Just performance.


not a viable option

Offline AncientU

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Rather than asking for alternative options for the RS-25s, they should have asked for alternative options for the entire core stage. No restrictions on engine size, quantity, or propellants. Just performance.

SLS doesn't work well unless the upper stage, boosters, and pad support all match the core stage. Which either puts a pretty strict set of bounds on what the core stage looks like, or results in a near-complete redesign of most of the program.

The procurement should be for the entire launch capability (100-200t to orbit annually? or 50-100t to the Lunar vicinity annually?), but then there would be more than one bidder, which NASA and its cohort cannot tolerate.
"If we shared everything [we are working on] people would think we are insane!"
-- SpaceX friend of mlindner

Offline SWGlassPit

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Rather than asking for alternative options for the RS-25s, they should have asked for alternative options for the entire core stage. No restrictions on engine size, quantity, or propellants. Just performance.

SLS doesn't work well unless the upper stage, boosters, and pad support all match the core stage. Which either puts a pretty strict set of bounds on what the core stage looks like, or results in a near-complete redesign of most of the program.

The procurement should be for the entire launch capability (100-200t to orbit annually? or 50-100t to the Lunar vicinity annually?), but then there would be more than one bidder, which NASA and its cohort cannot tolerate.

Umm... they did that more or less, within the confines of their procurement policies.  You clearly have no idea what you're talking about.  You do know that there are multiple contractors building this, right?  Where do you think the contracts came from?

Offline AncientU

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Rather than asking for alternative options for the RS-25s, they should have asked for alternative options for the entire core stage. No restrictions on engine size, quantity, or propellants. Just performance.

SLS doesn't work well unless the upper stage, boosters, and pad support all match the core stage. Which either puts a pretty strict set of bounds on what the core stage looks like, or results in a near-complete redesign of most of the program.

The procurement should be for the entire launch capability (100-200t to orbit annually? or 50-100t to the Lunar vicinity annually?), but then there would be more than one bidder, which NASA and its cohort cannot tolerate.

Umm... they did that more or less, within the confines of their procurement policies.  You clearly have no idea what you're talking about.  You do know that there are multiple contractors building this, right?  Where do you think the contracts came from?

More less than more...
The SLS vendors were dictated by Congress, as a carry-over from a cancelled program called Constellation, completely ignoring their own body of procurement policies.  Since they also skipped the program budget definition step, the contractors got a blank check to spend whatever was given to them and extend the period of performance indefinitely -- at which they are succeeding famously.

Nothing in Federal law prohibits NASA from procuring launch services competitively... in fact, they are by law required to procure services commercially whenever possible.

Quote
To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0
Thanks for the frequent reminder, Robotbeat

In this case, 50-100t annually to the Lunar vicinity starting in 2025, they probably would get bids from 4 companies, bidding six rockets/services approaches(in no particular order):
1. Vulcan/CentaurV with distributed launch
2. Falcon Heavy
3. New Glenn, possibly with distributed launch
4. Next Generation Launcher/Heavy
5. BFR/BFS
6. New Armstrong

The USAF is soliciting launch services with flights starting in 2022 from this same gaggle of commercial providers, so don't tell me they don't exist or the USG cannot just buy launch services.

NOTE: If SLS Block 1B tried to enter the bidding for USAF services, it wouldn't be ready in time.  The SLS maiden launch might not even occur before a majority of these launchers are flying.
« Last Edit: 04/12/2018 08:39 PM by AncientU »
"If we shared everything [we are working on] people would think we are insane!"
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Online Lars-J

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Why is this needed? Haven't AJR been contracted to restart production with a $1.5 billion contract? At this point, all they should have to do is issue a purchase contract for new RS-25 engines.

But AJR is the master of huge contracts with little or nothing to show for it. Remember the domestic RD-180 contract? Yeah, we can do this. Oh wait you actually wanted us to do it?   :-X

Offline Steve G

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Rather than asking for alternative options for the RS-25s, they should have asked for alternative options for the entire core stage. No restrictions on engine size, quantity, or propellants. Just performance.


not a viable option

Why not a viable option? (It's not going to happen, but absolutely viable). What would prevent SpaceX or Blue Origin from building a core alternative?

Online woods170

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Rather than asking for alternative options for the RS-25s, they should have asked for alternative options for the entire core stage. No restrictions on engine size, quantity, or propellants. Just performance.


not a viable option

Why not a viable option? (It's not going to happen, but absolutely viable). What would prevent SpaceX or Blue Origin from building a core alternative?

They won't be interested given that they have other things on their mind: actually flying stuff in stead of being a jobs program.
« Last Edit: 04/13/2018 07:18 AM by woods170 »

Offline rst

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Why not a viable option? (It's not going to happen, but absolutely viable). What would prevent SpaceX or Blue Origin from building a core alternative?

Doubtful that either SpaceX or Blue has any interest in building anything that has the same interfaces to other launcher components (solid-fuel boosters, upper stages, etc) as the current core stage. They'd both probably be thrilled to bid their next-generation superheavy projects as clean-sheet replacements for SLS as a whole, if that were ever put out to bid. (And there was recently a bit of discussion in the ULA section about them bidding ACES and distributed lift, in the same unlikely hypothetical situation.) But that would require scrapping a lot of the Congressional mandates for the SLS project as it currently exists.
« Last Edit: 04/13/2018 06:52 PM by rst »

Offline oldAtlas_Eguy

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In rocket design the engines define the rocket design. If the rocket design is not to be changed at all. The the engines have to be the same as current.

The RFI will go nowhere and may not even get a response from AJR.

Offline A_M_Swallow

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In rocket design the engines define the rocket design. If the rocket design is not to be changed at all. The the engines have to be the same as current.

The RFI will go nowhere and may not even get a response from AJR.

When someone is going to give you a large sum of money it is polite to allow him to tick off a box on his task sheet by sending a sales proposal.

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