Updated Saturn V

[Mr. Justice]

Let us assume that the F-1 is chosen for the booster engines of SLS.

Then, the question must be asked does it make sense to develop SLS or should simply an updated Saturn V fly. Consider that the Saturn V first stage was powered by five F-1s, its second stage by five J-2s, and the third stage by one J-2 for a total lift of a 130 tons. SLS will ultimately carry 130 tons or a little more. The SLS core would be powered by five RS-25e engines,  its boosters would  be four F-1 engines, and its upper stage would have a yet to be determined number of J-2x engines. That means SLS will have to solely support the cost of three different engine programs: the RS-25e, J-2x, and the "F-1b."

Under these circumstances would it not make more sense, even though it may delay flights several years, to simply fly an updated Saturn V. Seeing as the J-2x offers a nice improvement in efficiency and performance over the J-2 and that the F-1a offered a nice improvement over the F-1 it is quite probable that the "F-1b" would offer a nice improvement over the F-1a. As the Saturn V required a short third stage burn to get into orbit, perhaps, when all is said in done the performance of the original Saturn V could be equaled or surpassed without the need for a third stage burn.

Thoughts?

[Jorge]

Let us assume that the F-1 is chosen for the booster engines of SLS.

First phase of SLS will still use SRBs. F-1 is under consideration for *subsequent* phases of SLS.

Seeing as the J-2x offers a nice improvement in efficiency and performance over the J-2 and that the F-1a offered a nice improvement over the F-1 it is quite probable that the "F-1b" would offer a nice improvement over the F-1a. As the Saturn V required a short third stage burn to get into orbit, perhaps, when all is said in done the performance of the original Saturn V could be equaled or surpassed without the need for a third stage burn.

Saturn V did not require a third stage to get to LEO. It launched Skylab with only two.

For beyond-LEO flights, using a first burn of the third stage to get into LEO results in higher payload than just using the first two stages. The benefit is too big to ignore.

[edkyle99]

Let us assume that the F-1 is chosen for the booster engines of SLS.

Then, the question must be asked does it make sense to develop SLS or should simply an updated Saturn V fly. ...

NASA already asked these questions during its 2010-2011 RAC studies.  The answer was SLS as we know it.
http://www.spacelaunchreport.com/sls4.html

 - Ed Kyle

[Mr. Justice]

Edkyle99: Thanks. I was aware NASA considered such an option and it was ultimately not chosen but not the rational for its rejection, particularly in light of the fact the F-1 may be returned to service.

Jorge: Yes, I am aware the first two, and perhaps three flights, are suppose to use the SRBs. Should we really base a the program on a rocket that will fly one test flight and one other flight? I think not.

Yes, I misspoke when I said that Saturn V "required" the third stage to get into orbit. However, the question becomes with greater thrust and efficiency in both the "F-1b" and the J-2x and how close can we get to 130 tons on two stages. There is certainly nothing wrong with keeping the S-IVB. 

[Jim]

1.  particularly in light of the fact the F-1 may be returned to service.

2.  Jorge: Yes, I am aware the first two, and perhaps three flights, are suppose to use the SRBs. Should we really base a the program on a rocket that will fly one test flight and one other flight? I think not.

3.  Yes, I misspoke when I said that Saturn V "required" the third stage to get into orbit. However, the question becomes with greater thrust and efficiency in both the "F-1b" and the J-2x and how close can we get to 130 tons on two stages. There is certainly nothing wrong with keeping the S-IVB. 

1.  That is not a given

2.  I think so.  SRB's exist.  F-1 don't

3. Not close enough.

There is no point in recreating the Saturn V, it was a point solution

[marsavian]

Let us assume that the F-1 is chosen for the booster engines of SLS.

Then, the question must be asked does it make sense to develop SLS or should simply an updated Saturn V fly. Consider that the Saturn V first stage was powered by five F-1s, its second stage by five J-2s, and the third stage by one J-2 for a total lift of a 130 tons. SLS will ultimately carry 130 tons or a little more. The SLS core would be powered by five RS-25e engines,  its boosters would  be four F-1 engines, and its upper stage would have a yet to be determined number of J-2x engines. That means SLS will have to solely support the cost of three different engine programs: the RS-25e, J-2x, and the "F-1b."

Under these circumstances would it not make more sense, even though it may delay flights several years, to simply fly an updated Saturn V. Seeing as the J-2x offers a nice improvement in efficiency and performance over the J-2 and that the F-1a offered a nice improvement over the F-1 it is quite probable that the "F-1b" would offer a nice improvement over the F-1a. As the Saturn V required a short third stage burn to get into orbit, perhaps, when all is said in done the performance of the original Saturn V could be equaled or surpassed without the need for a third stage burn.

Thoughts?

With the dual F-1 booster SLS will ultimately carry 150 tons which is a clear step above either the SRB SLS or Saturn V. The F-1 would also not be ready for the early SLS missions which are clearly needed to maintain ongoing political support for SLS. The dual F-1 booster is clearly the best advanced booster solution, it matches the the 5-seg SRB thrust but with greater Isp and probably greater propellant burn time. With no thumbs on any invisible behind the scenes scales it should clearly win the advanced booster competition if it is ever held. Delta IV Heavy should also be fully manrated so it can be a dedicated Orion MPCV launcher so 1.5 missions could be carried out with whatever SLS eventually is.

[Ronsmytheiii]

Saturn V was 10 meters in diameter, and as such any vehicle trying to recreate a Saturn V class LV would require new infrastructure, which as we had seen with Ares V would have been very expensive.

Also F-1 and J-2X are no where near close to being assured picks in the future.  It will be very hard to switch to kerosene boosters once the SRB's for SLS have been flying a while, and F-1 really would not have synergy with any other programs that the Aerojet design would (Rengined Atlas and/or RBS)

[spectre9]

The LRB NASA wants is still 3x1mlb RP-1/LOX.

The problem is this engine doesn't exist.

PWR doesn't want to invest in one, they'd rather bring back the F-1.

Aerojet on the other hand might be. There just isn't enough details out there for me to be able to tell for sure one way or the other. Merger talks complicate things even more.

The SLS was always about making use of existing technologies and that means using ATK segmented solids to get the high thrust needed.

So if this new liquid booster existed I'd expect a different look to the next SLS core. Block II or whatever it will be called by then.

2-3x RS25E and 4 of those crazy boosters.

200mt fantasy land here we come 

...or NASA gives into prop depots (but back to the HLLV fetishism because that's more fun) 

[Downix]

Uprated Saturn V we get 130 metric tons.

SLS with F-1 boosters and SSME core, we get 150 metric tons.

Nope, I'd still rather have the SLS configuration as it is.  The parallel staging with SSME core is more capable and more reliable than the Saturn V's serial staging.

[RyanC]

Mr. Justice:

That means SLS will have to solely support the cost of three different engine programs: the RS-25e, J-2x, and the "F-1b."

Actually, it's worse.

It will have to support:

1.) 5-Segment ATK Solids
2.) RS-25D (use up historic Shuttle main engines)
3.) RS-25E (all new expendable)
4.) RL-10B-2 (Interim CPS based on DCSS)
5.) J-2X (for the ultimate EDS)
6.) Whatever is picked for 'advanced booster'

Same issue with the various core components:

Two Boosters (ATK-5 Segment and whatever replaces it)

Two Upper Stages (DCSS and whatever replaces it)

There was to be also two core stages; one with four RS-25D, then transitioning to one with five RS-25E; before they realized how dumb that was and decided to start it off with five engines from the beginning.

Under these circumstances would it not make more sense, even though it may delay flights several years, to simply fly an updated Saturn V.

NASA actually did look at this during SLS studies.

There were three trade groups:

RAC-1: Basic Shuttle Derived Vehicles. These guys won; SLS is the result of this.

RAC-2: Kerolox vehicles. Their final was I think a monolithic inline similar to Saturn V.

RAC-3: EELV Group; their proposal was to cluster a lot of Delta IV or Atlas V cores together.

RAC-2 had lower per flight costs; but higher overall up front costs to develop; while RAC-1 had higher per flight costs, but cost much less to develop.

So due to that, and along with the Congressional "Thumb on Scale" mandate to use STS components "where practicable"...NASA repeated the same mistake they made in the 1970s when picking the final STS design.

Downix:

Uprated Saturn V we get 130 metric tons.

Bzzt. Incorrect.

Uprated Saturn V we get 262 metric tonnes to 100 n.mi and 99.8~ tonnes to TLI with the SAT-V-23(L), which lengthened the first and third stages [MS-IC-24(L) by 20 feet and MS-IVB-24(L) by 16.5 feet] and added four 260" LRBs, each with a pair of F-1s.

[Patchouli]

Uprated Saturn V we get 130 metric tons.

SLS with F-1 boosters and SSME core, we get 150 metric tons.

Nope, I'd still rather have the SLS configuration as it is.  The parallel staging with SSME core is more capable and more reliable than the Saturn V's serial staging.

Also more flexible need more payload add more boosters don't need that much fly with less of them.
The Soviets came to a similar conclusion when they designed Energia which could orbit 175 metric tons in it's heaviest configuration and 34 metric tons in it's smallest.
http://www.k26.com/buran/html/energia_variants.html

[Downix]

Uprated Saturn V we get 130 metric tons.

Bzzt. Incorrect.

Uprated Saturn V we get 262 metric tonnes to 100 n.mi and 99.8~ tonnes to TLI with the SAT-V-23(L), which lengthened the first and third stages [MS-IC-24(L) by 20 feet and MS-IVB-24(L) by 16.5 feet] and added four 260" LRBs, each with a pair of F-1s.

Ok, since you wish to go down this level of scale:

SLS core, 5 SSME, 6 F-1 based LRB, stretched US using 4 J-2X + CPS using 2 J-2X

almost 300 metric tons.

Two can play on this extreme performance game.

[edkyle99]

Edkyle99: Thanks. I was aware NASA considered such an option and it was ultimately not chosen but not the rational for its rejection, particularly in light of the fact the F-1 may be returned to service.

The rationale was pretty simple.  NASA couldn't afford the big kerosene development effort, which in this case assumed everything had to be ready by 2020 or thereabouts.  Which is why it was pushed back to "Block 2" as an alternative, and why it is likely being further pushed back to essentially infinity. 

It is the Air Force, not NASA, that will most likely lead in the development of any new high-thrust staged combustion hydrocarbon rocket engine (the Air Force has no need for F-1 in any form), and the Air Force doesn't need a new engine until probably well into the 2020s.

Meanwhile, NASA is perfectly able, using the motors and engines it already has (SRMV, RS-25, and RL-10) to create the world's most capable launch vehicle.  Easily.  This is why SLS is marching forward.  It is a winning design.

 - Ed Kyle

[spacenut]

The launch pads at 39A and 39B can only take about 11 million lbs of thrust, which is what an upgraded Saturn V was capable of doing.  Upgraded F1A's were to have 2.2million lbs of thrust each.  Upgraded J2's were to have 250,000 lbs each.  I think there was no change in size, maybe stretched a littl, and it would have given 150 tons.  Anything else like strap-on's etc would have required major renovation of the launch pads. 

[Lobo]

Edkyle99: Thanks. I was aware NASA considered such an option and it was ultimately not chosen but not the rational for its rejection, particularly in light of the fact the F-1 may be returned to service.

The rationale was pretty simple.  NASA couldn't afford the big kerosene development effort, which in this case assumed everything had to be ready by 2020 or thereabouts.  Which is why it was pushed back to "Block 2" as an alternative, and why it is likely being further pushed back to essentially infinity. 

It is the Air Force, not NASA, that will most likely lead in the development of any new high-thrust staged combustion hydrocarbon rocket engine (the Air Force has no need for F-1 in any form), and the Air Force doesn't need a new engine until probably well into the 2020s.

Meanwhile, NASA is perfectly able, using the motors and engines it already has (SRMV, RS-25, and RL-10) to create the world's most capable launch vehicle.  Easily.  This is why SLS is marching forward.  It is a winning design.

 - Ed Kyle

Yea, that’s an interesting take I’d thought of too.  Especially if Block 1B is chosen, that’d put off needing new boosters into at least the mid 2020’s.  And if by then the USAF has developed the Reusable Booster System to replace EELV’s, then those could be available to utilize, and then SLS would have synergy with an active DoD rocket program.  Which would be a BIG plus.  The LRB’s wouldn’t necessarily be reusable, but they could use the same engines.