Author Topic: What would a better CxP have looked like?  (Read 37073 times)

Offline RocketmanUS

Re: What would a better CxP have looked like?
« Reply #40 on: 02/21/2013 12:49 AM »
As the moon was to be the first stop.
Design a reusable Lunar lander ( hypergolic ).
Design tug to place lander in LLO and for sending propellants and cargo to LLO.
Use existing launchers to place in LEO.

First missions robotic.
Later land needed hardware for when crew arrives.

This could have been going on while replacing the shuttle with a LEO crew transport and cargo. Once they have the shuttle replacement , retire shuttle and start work on BEO launch system and crew capsule for EML1/2 and LLO.

So to send crew to Lunar the BEO rocket could be 70mt and the capsule less mass than Orion designed for Lunar for a crew of 4. For Mars it only needs to get to and from EML1/2 from LEO. Or the crew capsule could use the tug ( human rated ).

For Mars use the 70mt launcher for LEO assembly. Could use the TLI crew capsule stage for direct to Mars for orbital probes and small surface cargo.
Mars and beyond, human exploration
The grass is always greener on the other side. When you stand on top of the hill you see both sides!

Offline Patchouli

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Re: What would a better CxP have looked like?
« Reply #41 on: 02/21/2013 02:44 AM »

Two problems with that:
1. Thanks to the Shuttle lobby, no competitive human launch system would be developed simultaneously with Shuttle. (Just look at the history of cancelled projects) That's why Shuttle had to go away to allow replacements (be it Orion or CCrew)
2. Shuttle-C only made sense if run together with Shuttle, to allow sharing of infrastructure/costs. With shuttle gone, Shuttle-C no longer makes any sense.

That why I would have slowly transitioned the shuttle to an unmanned system with it eventually becoming Shuttle-C and then the Jupiter 130.
ATK gets their money and KSC workers stay employed etc.
Some of the orbiter contractors will loose out but they could bid on the next vehicles.
Same goes for workers in the orbiter processing facility but many of them could end up being reassigned to other tasks.
In the interests of absolute crew safety, my pet idea was a modified DIVH with an RS25 on the core, RS68A on each booster, and no upper stage. I reckon that would make for an impressively reliable vehicle.

I had the same idea but kept the DCSS.

Cancel the Shuttle program immediately after Columbia.


I would have rushed the X38 as some sort of assured access vehicle in that case.

Finish the prototype and build two more then stick one on an Atlas V for an all up uncrewed test.

Use the aerodynamic prototypes for LAS testing.

You'll also need to build a space tug for the EELVs so they can finish assembly ISS.
Something like the SS/L 1300 based tug might work.
« Last Edit: 02/21/2013 02:55 AM by Patchouli »

Offline DLR

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Re: What would a better CxP have looked like?
« Reply #42 on: 02/21/2013 04:18 AM »
Phase 1:

Commercial EELVs (Atlas V, Delta IV Heavy) + limited Lunar surface hardware -> to get "our feet wet" quickly

Phase 2:

Larger EELVs (Atlas V Phase 2) + Depots / SEP-Tugs + extensive Lunar surface hardware -> Lunar outpost and extensive exploration, deep space missions

Phase 3:

Turn over space launches and lunar base supply delivery to private sector (COTS), NASA responsible for operation of in-space exploration equipment and lunar surface research installation.
« Last Edit: 02/21/2013 04:20 AM by DLR »
"Bei der Eroberung des Weltraums sind zwei Probleme zu lösen: die Schwerkraft und der Papierkrieg." - Wernher von Braun

Offline pathfinder_01

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Re: What would a better CxP have looked like?
« Reply #43 on: 02/21/2013 04:43 AM »

Phase 3:

Turn over space launches and lunar base supply delivery to private sector (COTS), NASA responsible for operation of in-space exploration equipment and lunar surface research installation.

Only problem is that the private sector already handles all launches except the shuttle therefore it just duplicates in NASA what is being done already.

In short if you are using Atlas or Delta there would be no need for COTS for the launcher and maybe a cots program for the spacecraft.
« Last Edit: 02/21/2013 04:43 AM by pathfinder_01 »

Offline RocketmanUS

Re: What would a better CxP have looked like?
« Reply #44 on: 02/21/2013 05:07 AM »

Two problems with that:
1. Thanks to the Shuttle lobby, no competitive human launch system would be developed simultaneously with Shuttle. (Just look at the history of cancelled projects) That's why Shuttle had to go away to allow replacements (be it Orion or CCrew)
2. Shuttle-C only made sense if run together with Shuttle, to allow sharing of infrastructure/costs. With shuttle gone, Shuttle-C no longer makes any sense.

That why I would have slowly transitioned the shuttle to an unmanned system with it eventually becoming Shuttle-C and then the Jupiter 130.
ATK gets their money and KSC workers stay employed etc.
Some of the orbiter contractors will loose out but they could bid on the next vehicles.
Same goes for workers in the orbiter processing facility but many of them could end up being reassigned to other tasks.
In the interests of absolute crew safety, my pet idea was a modified DIVH with an RS25 on the core, RS68A on each booster, and no upper stage. I reckon that would make for an impressively reliable vehicle.

I had the same idea but kept the DCSS.

Cancel the Shuttle program immediately after Columbia.


I would have rushed the X38 as some sort of assured access vehicle in that case.

Finish the prototype and build two more then stick one on an Atlas V for an all up uncrewed test.

Use the aerodynamic prototypes for LAS testing.

You'll also need to build a space tug for the EELVs so they can finish assembly ISS.
Something like the SS/L 1300 based tug might work.
Orion was being developed before shuttle was retired.
They should have just made a 4 crew version for Lunar and use it for ISS also until a commercial replacement could there.
It should have been lite enough for DIVH or Atlas V551 for LEO.
For the SM ( service module ) have droppable escape engines placed on the sides of the SM. The propellant would be used for the escape or in space use.

And for shuttle C that should be side mount.
No problem with base heating or for the SSME's. For reasons for upgrades the inline would be the better choose. However 70mt to LEO should be all we need and side mount should have flown by now and could have flown along side shuttle. It would have used the same ET so shuttle could have flown longer if needed. Could have brought in the next generation shuttle by commercial if they wanted it ( manned or unmanned ).
Mars and beyond, human exploration
The grass is always greener on the other side. When you stand on top of the hill you see both sides!

Offline DLR

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Re: What would a better CxP have looked like?
« Reply #45 on: 02/21/2013 06:22 AM »

Phase 3:

Turn over space launches and lunar base supply delivery to private sector (COTS), NASA responsible for operation of in-space exploration equipment and lunar surface research installation.

Only problem is that the private sector already handles all launches except the shuttle therefore it just duplicates in NASA what is being done already.

In short if you are using Atlas or Delta there would be no need for COTS for the launcher and maybe a cots program for the spacecraft.

I would like NASA to procure launches just like any other organization would procure space for shipping containers on cargo vessels.

This would require the development of one or several standard payload envelopes, sort of like a "shipping container" for space.

NASA would simply specifiy the payload dimensions and launch parameters (upmass, destination, inclination) and select the best bid. In Phase 1 it would still be constrained to Atlas V / Delta IV Heavy as launch vehicles, in Phase 3, all US-based launch providers (international probably wouldn't fly politically) would be considered.

NASA says:

We need to launch a hydrogen tank, dimension standard large, mass 40mT into the following orbit: altitude 300km, inclination 28°, destination: interplanetary vessel assembly station, provisional launch date: 28th Jan 2030.

SpaceX says: We'll do it for $100.000.000!
ULA says: We'll do it for $90.000.000!
Blue Origin says: We'll do it for $85.000.000!

Nasa says: Great, Blue Origin it is, we'll sign the main contract with you, payment upon delivery. Fallback contract with ULA will also be signed.
"Bei der Eroberung des Weltraums sind zwei Probleme zu lösen: die Schwerkraft und der Papierkrieg." - Wernher von Braun

Offline Lobo

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Re: What would a better CxP have looked like?
« Reply #46 on: 02/22/2013 12:00 AM »
Well that was a big and inefficient post but I'll respond. I really think you need to be more coherent and keeps things concise. It's really an issue for me with your posting style and it leads me to glazing over many of your responses around the boards.

Space it out more, say more with less. Improve your signal to noise ratio.


Well, I won’t deny I can be verbose in my post.  But we all can’t be professional writers like you are apparently.  If my posts bother you so much, please feel free to not respond to them.  I promise I won’t loose any sleep over it.   Is that concise enough for you?


Most of your argument seems to center around overhead.

Well SLS DDT&E costs rival those costs and it gets 0mt of useful payload to orbit every year until it does a test flight in 2017 and then again in 2021.

What it really amounts to is jobs @ KSC vs jobs @ MSFC.

If LAS is a big problem for some then they're welcome to refuse to ride. It's their choice.

Perhaps Apollo CSM shouldn't have been cancelled. The U.S. seems to have a history now of cancelling good working spacecraft. This is the problem I have.

Development costs are huge for new hardware. There's no way around that.

Sidemount wasn't that big an issue. Big money has been spent of things like OBSS and on orbit tile fixing methods. STS-1 landed without some of the tiles. Columbia had a big down mass putting stress on it.

Commercial crew/cargo seems to be taking an eternity to come online and by that time ISS is going to be old and needing serious repairs costing big money to keep it in orbit.

Yes shuttle would've needed OMM to keep going but that's a good thing. Upgrades were made on them all the time making them better. A new orbiter could have been built too. That would be so much cooler than a SLS.

I think we can agree on one thing. It would've been nice to keep shuttle going while commercial crew is in development. A smooth handover without the large cost of manned spaceflight on the Soyuz would be a good thing.

Yes the shuttle had problems but most of them had been ironed out in sunk cost. Going through all that again with SLS is going to be tiresome even if it is a more robust system to begin with. It's not exactly built from the ground up as a RAC2 like vehicle would be.

Instead of doing SLS money could've been put into the F-1 engine so that when the time is right MSFC could start working on the better design for SLS. I still believe this will happen anyway. Shuttle derived design work might have wasted lots of time/money but that doesn't bother me at all.

This seems like a big and inefficient post to me, but I’ll respond anyway…
;-)

Most of your argument seems to center around DDT&E costs. 

But those could have been just a fraction of what they are turning out to be with a different approach than Ares 1/5 and later SLS.  An Orion with a LEO service module could be flying to the ISS on an Atlas-552 as soon as the CSM was ready.  But those are acceptable DDT&E costs for the Orion CSM itself, because we need something new or we’ll never leave LEO flying on the Shuttle ever again…LAS concerns aside.  Atlas-552 would only need a man-rating development costs.   Both of those are reasonable without the overhead of the entire shuttle stack and hardware.

The HLV to go with Orion flying on an Atlas 552 would be a significant DDT&E cost.  But again, unless you want to stay in LEO forever, we need a new LV.  Although, there were far better ways to go about this than Ares V and SLS without breaking the bank on DDT&E costs.  A pair of upgraded Delta IV heavy’s could get over 100mt to LEO, or a 7-core Delta Super Heavy could get almost 100mt to LEO.  Couple that with Orion on Atlas-552 with 5m upper stage (which could launch full BLEO Orion), and you have a 2-launch lunar architecture with Apollo-scale capability.  And synergy with EELV’s is maintained.  Delta IV doesn’t need to be man-rated, as it would just be a cargo launcher. 
IF you want CxP scale, then add an upgraded D4H launch of the lander for EOR with the EDS on D4SH, and Orion on Atlas-552/w 5m US, and there you go.  Minimal DDT&E  from what was already flying…just the addition of a larger upper stage, and some other upgrades to the EELV’s.    Overhead is just a fraction of the Shuttle stack (or Ares 1/5 or SLS), because ULA already has all of the capabilities running anyway for USAF/DoD.

Conversely, Direct 3.0 could have been chosen, with Atlas-552 still used for ISS servicing by Orion, and Orion riding on J-130 and J-246 on lunar missions.  This would have probably not cost much more DDT&E than D4SH, but the overhead costs of it would probably be more than all EELV-derived because nothing else will use the 8.4 core, SRB, RS-25, or JUS.   Still, it would have used all the kept most all of the Shuttle infrastructure and personnel in place while using the Shuttle’s proven hardware, and taken us to BLEO again.

Either way likely would have only cost a fraction of the DDT&E costs that it turned out, and not required a commercial cargo or crew program to be funded (for better or worse, depending on your point of view…) as Orion (as Orion was originally envisioned in ESAS) would have taken care of both of those roles.

Offline spectre9

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Re: What would a better CxP have looked like?
« Reply #47 on: 02/26/2013 02:36 AM »

Well, I won’t deny I can be verbose in my post.  But we all can’t be professional writers like you are apparently.  If my posts bother you so much, please feel free to not respond to them.  I promise I won’t loose any sleep over it.   Is that concise enough for you?


Just offering some friendly advice, please don't take anything personally. I like you and I enjoy your postings, I just want to help you improve so your posts get read by a bigger audience. I'm not a professional writer, I was educated by the public system. I wouldn't expect you to lose any sleep over anything I write but projecting proper spelling and grammar helps with the way you're perceived on a site like this with many highly intelligent contributors.


This seems like a big and inefficient post to me, but I’ll respond anyway…
;-)

Most of your argument seems to center around DDT&E costs. 

But those could have been just a fraction of what they are turning out to be with a different approach than Ares 1/5 and later SLS.  An Orion with a LEO service module could be flying to the ISS on an Atlas-552 as soon as the CSM was ready.  But those are acceptable DDT&E costs for the Orion CSM itself, because we need something new or we’ll never leave LEO flying on the Shuttle ever again…LAS concerns aside.  Atlas-552 would only need a man-rating development costs.   Both of those are reasonable without the overhead of the entire shuttle stack and hardware.

The HLV to go with Orion flying on an Atlas 552 would be a significant DDT&E cost.  But again, unless you want to stay in LEO forever, we need a new LV.  Although, there were far better ways to go about this than Ares V and SLS without breaking the bank on DDT&E costs.  A pair of upgraded Delta IV heavy’s could get over 100mt to LEO, or a 7-core Delta Super Heavy could get almost 100mt to LEO.  Couple that with Orion on Atlas-552 with 5m upper stage (which could launch full BLEO Orion), and you have a 2-launch lunar architecture with Apollo-scale capability.  And synergy with EELV’s is maintained.  Delta IV doesn’t need to be man-rated, as it would just be a cargo launcher. 
IF you want CxP scale, then add an upgraded D4H launch of the lander for EOR with the EDS on D4SH, and Orion on Atlas-552/w 5m US, and there you go.  Minimal DDT&E  from what was already flying…just the addition of a larger upper stage, and some other upgrades to the EELV’s.    Overhead is just a fraction of the Shuttle stack (or Ares 1/5 or SLS), because ULA already has all of the capabilities running anyway for USAF/DoD.

Conversely, Direct 3.0 could have been chosen, with Atlas-552 still used for ISS servicing by Orion, and Orion riding on J-130 and J-246 on lunar missions.  This would have probably not cost much more DDT&E than D4SH, but the overhead costs of it would probably be more than all EELV-derived because nothing else will use the 8.4 core, SRB, RS-25, or JUS.   Still, it would have used all the kept most all of the Shuttle infrastructure and personnel in place while using the Shuttle’s proven hardware, and taken us to BLEO again.

Either way likely would have only cost a fraction of the DDT&E costs that it turned out, and not required a commercial cargo or crew program to be funded (for better or worse, depending on your point of view…) as Orion (as Orion was originally envisioned in ESAS) would have taken care of both of those roles.


I don't deny that some sort of new capsule is needed but I prefer the Mercury/Gemini model to the giant lump which is Orion. How can a Mercury land a man for about 1.5 metric ton using half century old technology? Why can't the same or better be done today? I keep banging on with this point and it always falls of deaf ears. Even the Dragon is too big and that's because it's held to NASA requirements. Down massing human bodies doesn't require that much IMLEO. LAS was included in that design too so that's a moot point.

A new launch vehicle is not needed to go beyond LEO. Golden Spike and various other medium rocket EOR plans have shown this. Trying to build medium launchers that are a tad bigger than Delta IV Heavy isn't really a good idea, Delta IV Heavy is a great launcher and underutilised. Strapping on solids, building a new launch platform and putting extra RL-10s on the upper stage wouldn't cost that much compared to any HLLV development.

Now that J-2X is going to be finished that could be used for high powered refillable upper stages. That would destroy all future need for HLLVs unless there were payload volume constraints which can be overcome by using smaller landers and habitats.

Any version of Jupiter is going to cost about the same as SLS. It would keep MSFC in the rocket design business and they have no plans to build the smaller variants and reduce their spending and the consequent spending required at Michoud.

Yes there are better launch systems than shuttle but they all cost big money to develop and that's money that is coming out of the operational expenditure of the space shuttle program. NASA has moved from launch to development and will stay that way for about a decade and it doesn't matter which launch vehicle they chose to build if it didn't exist at the time shuttle was retired.

Offline Lobo

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Re: What would a better CxP have looked like?
« Reply #48 on: 05/07/2013 11:51 PM »
I’m bumping this with a bit of an addition parameter.

First, does anyone know in particular why McDonnel Douglas went with a hydrolox booster on Delta IV for the EELV competition?  Especially when it needed a new engine developed?  (I’m assuming Jim probably knows, :-) )
I mean, hydrolox isn’t the best 1st stage booster.  It required a much larger booster core than Atlas V or any similar performing kerolox booster. 
Delta II used the kerolox RS-27 engine.  There wasn’t a US made kerolox engine other than RS-27 that I know of, but there wasn’t a US made hydrolox booster engine either.  RS-25 is a sustainer engine, not really a booster engine.
So, if MD was going to evolved Delta II for EELV, why didn’t they stick with the RS-27, and grow the core to 5m, and put maybe five of them on there?  Or maybe four with GEM-60 SRB to get it off the pad?  Four of them had more thrust than the first RS-68, and not much less than RD-180. 
What was the thought process to switch to a brand new engine development, and a propellant that isn’t the best booster propellant, not to mention being one of the most temperamental propellants.   I see why the Russians and SpaceX use kerolox for the upper stage for commonality and because it’s a really easy propellant to handle and I think rockets that use kerolox are cheaper overall than hydrolox.  LH2 is the most difficult and so they wanted to make the whole rocket use it?
Hopefully someone can enlighten me on that.  Especially when the Delta II already used a 200klbs kerolox engine that probably could have been upgraded to get to around 250klbs without much trouble.

Ok, so I set this up for a bit of alternative history going back to the EELV program for this thread.
So, MD wants to create new 5m wide rocket core tooling, and a new engine, and a new upper stage using RL-10 engine for Delta IV?
What if instead, they went with a  5m wide kerolox booster, which either used 4-5 RS-27A’s (or upgraded versions with more thrust), or, instead of having PWR create the RS-68 new, have them dust off the F-1, and create maybe an “F-1S” version of the F-1A.  I guess the F-1B is going to be like this, but like the J2S, make the F-1S with a specific eye for being simple and cheap.  A big Merlin 1D in effect maybe?  Maybe a larger upper stage (because the GG F-1 won’t be as efficient as a stage combustion kerolox engine like the RD-180) and maybe RL-60’s on it.  They were 90% developed by 2003 anyway.
So, you have something similar to an Atlas V-phase 2, but with probably less first stage burn and more 2nd stage burn.  This LV should probably put somewhere between 20-25mt to LEO, which would fulfill the upper end of the EELV requirements I believe.  No need for a tri-core heavy version.  And while it would seem overpowered for the bulk of the EELV payloads that Atlas V and Delta IV Medium handle, would it be any more money than Delta IV?  It might be more money than Atlas V, because the US-made F-1B would be more expensive each than the RD-180’s.  But You have an LV that would be be shorter than a Delta IV medium, cost about the same, but put up D4H payloads.   GEM-60’s should bump that up easily if ever needed.  I mean, it’d basically be the same hardware as a Delta IV medium.

So, let’s say MD developed that, and let’s say Boeing buys them.  And even if Boeing is caught stealing info from LM and ULA is formed, This version of Delta IV would exist.

So, during the ESAS evaluation, where NASA evaluated Atlas Phase 2, as well as an 8m wide Atlas X, they could evaluate this LV.  The single stick version should get Orion to LEO.  But it could be stretched, and have another F-1 added, and you basically have the Dynetics booster.  Now you have a crew launcher with direct synergy with EELV, and a cargo launcher with much synergy with EELV, except NASA could launch it from their pads at KSC (as Boeing would have had no reason to build the ability to launch a tri-core heavy from LC-37, since the single-stick would handle up to Delta IV-heavy roughly).
So the tri-core heavy would be only used by NASA.  And they could build the larger upper stage/EDS for it.  It only has two boosters, which was another requirement they seemed to fixate on in ESAS.  This cargo launcher would have six F-1 engines, and with a larger EDS, it should throw easily what Ares V was supposed to, to LEO.  NASA could have PWR develop the J2S (not the J2X) as was originally envisioned in ESAS on the cargo launchers.  It was mostly developed already, and should have been a relatively cheap and easy development, rather than the J2X which I understand was a very different engine than J2S.  And I don’t know if they could fit enough RL-60’s on it.  But it should be able to fit a couple of J2S under there. 

So, putting aside for a moment the politics of the time probably made SDHLV inevitable, this EELV derivative seems like it would have met all of what seemed to be NASA’s ESAS criteria.  No more than two boosters, 25mt crew launcher, 125mt cargo launcher, 1.5 architecture, etc.  And with a famous US-built engine. 
NASA evaluated Atlas Phase 2 heavy, but seemed to reject it as you’d need two of them for their planned architecture, and they wanted 1.5 architecture.  Atlas Phase 3A would have probably worked, but it had more than two boosters, and they said it wouldn’t even fit on any existing pad, which I think was because the four boosters were placed at 90 degrees to each other, making it just over 15m in depth as well as width, which I think is a problem to fit it on a ML with tower.

Could this have been the better CxP?  While having a lot of synergy with EELV’s? 
The only new developments over a Delta IV with single F-1 engine, would have been the stretched 5m core, making the tri-core heavy, man-rating it, and a new wide upper stage with J2S engines)
Compare that with CxP in developing a new 8.4m core (using existing tooling) a new Ares V upper stage, a new Ares 1 upper stage, J2S for Ares V anyway, air-startable SSME for Ares 1, and 5-seg booster. 

Offline gospacex

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Re: What would a better CxP have looked like?
« Reply #49 on: 05/08/2013 12:28 AM »
I thought about attaching this to a previous hypothetical thread of mine:

http://forum.nasaspaceflight.com/index.php?topic=30229.0

But, after reading a little more of the ESAS report when I had some time to kill, I ran across some things I hadn’t read before (over 700 pages, so that’s not too odd).

Now, the original version of CxP doesn’t seem -too- bad in theory really.  Air-started SSME, use of STS 4-seg for Ares 1 to get Oriong flying quickly.

Ares I was never needed. DIVH can do it even today, sans man-rating straw man, and dealing with that straw man is at most a few billion $.

Quote
The obvious answer for some on this will be “Direct”, and they seem to evaluate Direct-like LV’s.  LV 24 and 25.  A J-130 anyway.  But they seemed fixated on launching the crew on the stick, so the turned the ET-sized core with 4-seg boosters and 3XSSME into one Ares 1 launch plus two J-130 launches if I understand them correctly.  They really don’t seem to evaluate LV24/25 as a two-launch system with no Stick.  Am I missing something?  Or is that correct?

Exactly. That is what NASA should have done if it would be a somewhat inefficient, but still sane bureaucracy. Empirical evidence says it slid into a stage when "sane" no longer applies. It would rather destroy itself than go with a plan which is at least semi-reasonable.

Quote
1) What would have been the best CxP given what ESAS evaluated?

DIRECT team asked themselves this exact question, and come up with a detailed solution.

Quote
2) What was the best system not evaluated by ESAS for CxP?

Get out of LV business.

Offline RocketmanUS

Re: What would a better CxP have looked like?
« Reply #50 on: 05/08/2013 12:59 AM »
I’m bumping this with a bit of an addition parameter.

First, does anyone know in particular why McDonnel Douglas went with a hydrolox booster on Delta IV for the EELV competition?  Especially when it needed a new engine developed?  (I’m assuming Jim probably knows, :-) )
I mean, hydrolox isn’t the best 1st stage booster.  It required a much larger booster core than Atlas V or any similar performing kerolox booster. 
Delta II used the kerolox RS-27 engine.  There wasn’t a US made kerolox engine other than RS-27 that I know of, but there wasn’t a US made hydrolox booster engine either.  RS-25 is a sustainer engine, not really a booster engine.
So, if MD was going to evolved Delta II for EELV, why didn’t they stick with the RS-27, and grow the core to 5m, and put maybe five of them on there?  Or maybe four with GEM-60 SRB to get it off the pad?  Four of them had more thrust than the first RS-68, and not much less than RD-180. 
What was the thought process to switch to a brand new engine development, and a propellant that isn’t the best booster propellant, not to mention being one of the most temperamental propellants.   I see why the Russians and SpaceX use kerolox for the upper stage for commonality and because it’s a really easy propellant to handle and I think rockets that use kerolox are cheaper overall than hydrolox.  LH2 is the most difficult and so they wanted to make the whole rocket use it?
Hopefully someone can enlighten me on that.  Especially when the Delta II already used a 200klbs kerolox engine that probably could have been upgraded to get to around 250klbs without much trouble.

Ok, so I set this up for a bit of alternative history going back to the EELV program for this thread.
So, MD wants to create new 5m wide rocket core tooling, and a new engine, and a new upper stage using RL-10 engine for Delta IV?
What if instead, they went with a  5m wide kerolox booster, which either used 4-5 RS-27A’s (or upgraded versions with more thrust), or, instead of having PWR create the RS-68 new, have them dust off the F-1, and create maybe an “F-1S” version of the F-1A.  I guess the F-1B is going to be like this, but like the J2S, make the F-1S with a specific eye for being simple and cheap.  A big Merlin 1D in effect maybe?  Maybe a larger upper stage (because the GG F-1 won’t be as efficient as a stage combustion kerolox engine like the RD-180) and maybe RL-60’s on it.  They were 90% developed by 2003 anyway.
So, you have something similar to an Atlas V-phase 2, but with probably less first stage burn and more 2nd stage burn.  This LV should probably put somewhere between 20-25mt to LEO, which would fulfill the upper end of the EELV requirements I believe.  No need for a tri-core heavy version.  And while it would seem overpowered for the bulk of the EELV payloads that Atlas V and Delta IV Medium handle, would it be any more money than Delta IV?  It might be more money than Atlas V, because the US-made F-1B would be more expensive each than the RD-180’s.  But You have an LV that would be be shorter than a Delta IV medium, cost about the same, but put up D4H payloads.   GEM-60’s should bump that up easily if ever needed.  I mean, it’d basically be the same hardware as a Delta IV medium.

So, let’s say MD developed that, and let’s say Boeing buys them.  And even if Boeing is caught stealing info from LM and ULA is formed, This version of Delta IV would exist.

So, during the ESAS evaluation, where NASA evaluated Atlas Phase 2, as well as an 8m wide Atlas X, they could evaluate this LV.  The single stick version should get Orion to LEO.  But it could be stretched, and have another F-1 added, and you basically have the Dynetics booster.  Now you have a crew launcher with direct synergy with EELV, and a cargo launcher with much synergy with EELV, except NASA could launch it from their pads at KSC (as Boeing would have had no reason to build the ability to launch a tri-core heavy from LC-37, since the single-stick would handle up to Delta IV-heavy roughly).
So the tri-core heavy would be only used by NASA.  And they could build the larger upper stage/EDS for it.  It only has two boosters, which was another requirement they seemed to fixate on in ESAS.  This cargo launcher would have six F-1 engines, and with a larger EDS, it should throw easily what Ares V was supposed to, to LEO.  NASA could have PWR develop the J2S (not the J2X) as was originally envisioned in ESAS on the cargo launchers.  It was mostly developed already, and should have been a relatively cheap and easy development, rather than the J2X which I understand was a very different engine than J2S.  And I don’t know if they could fit enough RL-60’s on it.  But it should be able to fit a couple of J2S under there. 

So, putting aside for a moment the politics of the time probably made SDHLV inevitable, this EELV derivative seems like it would have met all of what seemed to be NASA’s ESAS criteria.  No more than two boosters, 25mt crew launcher, 125mt cargo launcher, 1.5 architecture, etc.  And with a famous US-built engine. 
NASA evaluated Atlas Phase 2 heavy, but seemed to reject it as you’d need two of them for their planned architecture, and they wanted 1.5 architecture.  Atlas Phase 3A would have probably worked, but it had more than two boosters, and they said it wouldn’t even fit on any existing pad, which I think was because the four boosters were placed at 90 degrees to each other, making it just over 15m in depth as well as width, which I think is a problem to fit it on a ML with tower.

Could this have been the better CxP?  While having a lot of synergy with EELV’s? 
The only new developments over a Delta IV with single F-1 engine, would have been the stretched 5m core, making the tri-core heavy, man-rating it, and a new wide upper stage with J2S engines)
Compare that with CxP in developing a new 8.4m core (using existing tooling) a new Ares V upper stage, a new Ares 1 upper stage, J2S for Ares V anyway, air-startable SSME for Ares 1, and 5-seg booster. 

I think they developed the RS-68 so they could have a single engine.

For the RS-27, five engines do to lower thrust and ISP than the RD-180.
There was the RS-76 concept.
http://www.spaceandtech.com/spacedata/engines/rs76_specs.shtml
That could have made a good American 1st stage engine if the cost was the same or lower than the RS-68.

If they could have gone down that road with one engine with a short 1st stage and two engines for a taller 1st stage we would have had a like Atlas phase II. They would have needed to use the more powerful Atlas V solid boosters. Then with the triple core for NASA at LC-39 we would of had 70mt. That would have given us Orion, Lunar and even Mars. The single core would have been all what the Air Force needed and for NASA until they headed to the moon or Mars with the 70mt version.

As the RS-76 was being developed for the fly back boosters for the space shuttle they would have been human rated. We could have seen the LEO Orion before shuttle retirement. All the money wasted on Ares I could have been well spent on the LEO version of Orion and the cargo versions too.

Now that bring me to What if the Direct's Jupiter had been picked over SLS. They could have made the J-130 with just three RS-25's ( no fourth for J-246 at this point ). It could have flown just as shuttle was retired. It was stated that there was about 100 launches left in the shuttle's 4 segment SRB's. I was figuring on 60 launches of the block I J-130. This could have been for Orion Lunar and a small lunar program before the block II J-130/246.  Block II J-130/246 with advanced boosters ( competition ) by 2025 for crew Mars by 2030 ( the Bush administration plan date ). This would have given time to develop the needed tech for the JUS. The block I J-130 could have used the iCPS/CPS. For the small Lunar program I figured about fourteen J-130 would have been needed, up to four for the Lunar Orion test flights. Six as spares. That would leave forty for other types of missions ( Mars , deep space probes, larger modules to LEO, EML1/2 station, ect. ). About four to six flights a year up till 2025 and then block II. Block II with JUS, advanced boosters for up to 130mt, and the core to have three or for RS-25's. By then the RS-25E could have been available. The J-130 needed no new tech. The iCPS would have been a Delta IV modified US. The CPS would have had some new tech with being able to function up to 5 days in space with the RL-10 restartable by the fifth day for LLO insertion burn if needed.

So I think we should have gone with the J-130 with just three engines to start of with if we still had the option of the shuttle 4 seg SRB's back in later 2009 or 2010. Then later upgrade if we needed to the block II version. Either way after up to 60 flights of block I with the 4 seg SRB's replace them with the advanced boosters.

Only was planning for 60 flights with the shuttle 4 seg SRB's do to a possible loss of a pair or two of them.

I thought about attaching this to a previous hypothetical thread of mine:

http://forum.nasaspaceflight.com/index.php?topic=30229.0

But, after reading a little more of the ESAS report when I had some time to kill, I ran across some things I hadn’t read before (over 700 pages, so that’s not too odd).

Now, the original version of CxP doesn’t seem -too- bad in theory really.  Air-started SSME, use of STS 4-seg for Ares 1 to get Oriong flying quickly.

Ares I was never needed. DIVH can do it even today, sans man-rating straw man, and dealing with that straw man is at most a few billion $.
Delta IV HR for LEO Orion and DIVH for Lunar Orion unmanned test flight. For crew Orion ( LEO or BLEO ) the J-130 was needed. I don't think DIVH had the performance to LEO for crew Lunar Orion with the escape tower and most of the propellant off loaded for LEO flight.
« Last Edit: 05/08/2013 01:06 AM by RocketmanUS »
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Online edkyle99

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Re: What would a better CxP have looked like?
« Reply #51 on: 05/08/2013 03:35 AM »
First, does anyone know in particular why McDonnell Douglas went with a hydrolox booster on Delta IV for the EELV competition?  Especially when it needed a new engine developed? 
My impression was that it had to do with development cost and the results of earlier Advanced Launch System studies.  Rocketdyne had done a lot of early work on the STME (Space Transportation Main Engine) for ALS.  McDonnell Douglas decided to leverage that already completed work so that it could spend less money on engine development.  RS-27A clusters were non-starters due to cost and performance.

Boeing proposed an SSME powered core.  Lockheed Martin (Marietta) was going to go with RD-180 or NK-33.  (McDonnell Douglas probably figured that Russian engines would be a non-starter for the USAF.)  Alliant was proposing big composite solid lower stages.  EELV was a winner take all competition to decide which company would control access to space for the foreseeable future.

The Air Force had seriously considered ALS and STME, so McDonnell Douglas probably thought LH2 was simply the way to go.  Rocketdyne served up RS-68, which was a cheaper, though lower ISP design than STME.  It all probably looked cheap compared to Titan IV and Space Shuttle back then.  Times were different.

Delta IV was developed and has been successful.  It is the only 25 tonne to LEO class launch vehicle in the inventory, and currently stands as the world's most capable launch vehicle.

 - Ed Kyle

Offline Ben the Space Brit

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Re: What would a better CxP have looked like?
« Reply #52 on: 05/08/2013 08:49 AM »
Just a one-liner but the thought jumped into my head and won't go away:

"Bias to flight".

What I mean by that is that the objective should have been to fly as soon as possible, working up capability in the background.  For a long time, I've thought that the gap is a potentially fatal problem as it allows the mind of the public to forget and lose interest.  The only away around that is to keep flying.
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Offline gospacex

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Re: What would a better CxP have looked like?
« Reply #53 on: 05/08/2013 10:08 AM »
Ares I was never needed. DIVH can do it even today, sans man-rating straw man, and dealing with that straw man is at most a few billion $.
Delta IV HR for LEO Orion and DIVH for Lunar Orion unmanned test flight. For crew Orion ( LEO or BLEO ) the J-130 was needed.

No, DIVH is sufficient for crew Orion to LEO.

Offline newpylong

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Re: What would a better CxP have looked like?
« Reply #54 on: 05/08/2013 04:42 PM »


No, DIVH is sufficient for crew Orion to LEO.


Barely, with no margin.

Offline Lobo

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Re: What would a better CxP have looked like?
« Reply #55 on: 05/08/2013 04:46 PM »
My impression was that it had to do with development cost and the results of earlier Advanced Launch System studies.  Rocketdyne had done a lot of early work on the STME (Space Transportation Main Engine) for ALS.  McDonnell Douglas decided to leverage that already completed work so that it could spend less money on engine development.  RS-27A clusters were non-starters due to cost and performance.

Boeing proposed an SSME powered core.  Lockheed Martin (Marietta) was going to go with RD-180 or NK-33.  (McDonnell Douglas probably figured that Russian engines would be a non-starter for the USAF.)  Alliant was proposing big composite solid lower stages.  EELV was a winner take all competition to decide which company would control access to space for the foreseeable future.

The Air Force had seriously considered ALS and STME, so McDonnell Douglas probably thought LH2 was simply the way to go.  Rocketdyne served up RS-68, which was a cheaper, though lower ISP design than STME.  It all probably looked cheap compared to Titan IV and Space Shuttle back then.  Times were different.

Delta IV was developed and has been successful.  It is the only 25 tonne to LEO class launch vehicle in the inventory, and currently stands as the world's most capable launch vehicle.

 - Ed Kyle

Costs on RS-27A’s?  They were basically updated H-1’s, right?  Weren’t H-1’s supposed to be pretty cheap, simple, and reliable?  Why would they be more expensive than a new hydrolox engine?  Especially if 4 or 5 were used per LV, so the economics of scale should decrease price. 
Performance?  Well, not quite sure about that when used as a booster.  Four RS-27A’s would have just over 800Klbs of thrust at take off, and the original RS-68 only had 650Klbs at take off.  As far as mass, a single RS-68 is 6.6mt, and a single RS-27A is 1.14mt.  So four of them is significantly less than a sing RS-68.  Five of them are still lighter.  Plus I think the RS-27 could be upgraded with more chamber pressure for better ISP as a booster?
Certainly the RS-68’s allowed for better performance during the latter booster burn due to their higher ISP.  So like I said, a kerolox powered Delta IV with RS-27’s would probably need a larger upper stage than the DCSS, with some more thrust.  Maybe two or four RL-10’s, or an RL-60 or something?

Anyway, I’m not trying to say I know more than the McDonnel Douglas engineers (obviously not) just trying to understand why such a radical departure from the Delta II for Delta IV?  Normally in a rocket evolution, don’t they just sort of grow the previous LV?  Atlas II had an RS-58 kerolox engine, then Atlas III went to the RD-180 kerolox engine, and then Atlas V kept the RD-180, and widened the booster stage.  All versions used SRB strap ons.

Seems more “logical” for Delta IV to have been kerolox like Delta II, maybe with a cluster of GEM-60’s like the Delta II/III used a cluster of GEM-46’s. 
And/or, if they wanted just one engine, why not have PWR build the RS-84?  It was being developed in the late 1990’s, early 2000’s, so it should have been as viable as an option as RS-68. 
Or, if they were going to do the wide 5m tooling, go with an update F-1A and have a single stick LV that would do up to D4H capability?

D4H, is a fine LV, don’t get me wrong.  But it’s not doing anything Atlas V-heavy couldn’t also be doing.  Or a D4H powered by RS-27A’s or RS-84’s, Or a single 5m wide F-1 powered kerolox LV. 
Just just curious as to the through process by MD there.  :-)

And if there had been a 5m F-1 powered kerolox version of Delta IV instead of hydrolox, could that have been a building block LV that NASA might have more readily wanted to use during the ESAS study?
A better CxP?
« Last Edit: 05/08/2013 04:48 PM by Lobo »

Offline RocketmanUS

Re: What would a better CxP have looked like?
« Reply #56 on: 05/08/2013 05:20 PM »
{snip]
And if there had been a 5m F-1 powered kerolox version of Delta IV instead of hydrolox, could that have been a building block LV that NASA might have more readily wanted to use during the ESAS study?
A better CxP?
The F-1 would have been over powered for liter mass payloads.
Making a little over half powered version of the F-1 might have been better.
Use two of the with a tall 1st stage and one with a stumpy 1st stage for liter payloads ( Atlas phase II like ).

They should have been able to make a 1,000,000lb thrust engine quickly back then. Higher thrust than the RD-180 do to lower ISP.
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Online edkyle99

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Re: What would a better CxP have looked like?
« Reply #57 on: 05/08/2013 05:50 PM »
Looking at the easier Delta 4M comparison, if the existing 4-meter second stage were used an RS-27A powered first stage would have to gross 500 tonnes (40% more than Atlas V CCB) and be powered by eight engines to match Delta 4M performance to GTO, which is the key mission.

An alternative would be to add one or more RL10s to the upper stage, allowing it to carry more propellant, but that would add cost and reduce upper stage specific impulse.  A Delta 4 Heavy type upper stage, but with two RL10 engines, might shrink the first stage down to 400 tonnes and six RS-27A engines.

RS-27A wasn't actually designed to be a booster engine.  It has a bigger nozzle than the previous H-1/RS-27 to get better vacuum ISP, but that came at the expense of liftoff thrust.  RS-27A doesn't throttle either, which would be a problem for an EELV. 

By the way, during the 1980s General Dynamics entered the CELV competition (won by Martin Marietta's Titan 4) with a rocket that might also have fit the bill for EELV.  It proposed a 200 inch diameter first stage powered by five "H-1D" engines, augmented by four 67 inch diameter solid rocket motors.  A Centaur G-Prime with two RL10 engines would have served as the upper stage.  This thing would have put 5 tonnes into GEO (probably 10 tonnes in GTO), but the solids were new (roughly equal to Japan's beefy SRB-A motors) and the first stage was new and all-new pads would have been needed, so it lost.  Still, the concept shows what was possible.

 - Ed Kyle
« Last Edit: 05/08/2013 07:19 PM by edkyle99 »

Offline Lobo

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Re: What would a better CxP have looked like?
« Reply #58 on: 05/08/2013 07:32 PM »
Looking at the easier Delta 4M comparison, if the existing 4-meter second stage were used an RS-27A powered first stage would have to gross 500 tonnes (40% more than Atlas V CCB) and be powered by eight engines to match Delta 4M performance to GTO, which is the key mission.

An alternative would be to add one or more RL10s to the upper stage, allowing it to carry more propellant, but that would add cost and reduce upper stage specific impulse.  A Delta 4 Heavy type upper stage, but with two RL10 engines, might shrink the first stage down to 400 tonnes and six RS-27A engines.

RS-27A wasn't actually designed to be a booster engine.  It has a bigger nozzle than the previous H-1/RS-27 to get better vacuum ISP, but that came at the expense of liftoff thrust.  RS-27A doesn't throttle either, which would be a problem for an EELV. 


So (after doing some Googling on DCSS, Delta II, III, and IV) it looks like a 4m DCSS was developed for Delta III.  Delta III only had 3 launches, two were failures, and was basically replaced shortly by Delta IV.  The 4m DCSS the Delta IV-medium uses was similar to the Delta III upper stage, but stretched and friction stir welded (from Wikipedia, so feel free to correct if that’s wrong).
So I could see them wanting to use that upper stage platform already developed for Delta III on Delta IV, but they already had to stretch it, so perhaps they could stretch it more?

As I understand RS-27A is a modified H-1, but modified for a longer sustainer core burn and better vacuum performance.  But the H-1 was designed to be a booster engine, so couldn’t the RS-27 be tweaked back to a booster engine?  An RS-27B or something?

But even if you wanted to use the existing RS-27A, then Delta IV could have had a wider diameter core, or 2 or 3 RS-27A with a cluster of the new GEM-60’s.  Just a scaled up Delta II. (Rather than trying to use the Delta II core and single engine the way the Delta III did).  Maybe a 4m core using a stretched 4m DCSS that Delta IV medium used anyway, but longer and maybe with two RL-10’s (or an RL-60 which was 90% developed anyway). 

Anyway, again, the MD-Boeing engineers had their reasons for going so far away from the Delta II/III platform in Delta IV.  And maybe Delta III made them think that platform wasn’t the best, and going a completely different direction was better?  Just curious.  Not only because it was so different than Delta II/III, and that hydrolox doesn’t really make the best booster propellan for various reasons.   It’s usually either an upper stage propellant where it’s high ISP is such a benefit and it’s relatively low thrust and high volume isn’t really a drawback.  Or used as a sustainer core propellant like STS, SLS, Ariane 5, and H-IIA which is basically a ground lit 2nd stage in effect.
The Delta IV is the only LV I’m aware of that uses hydrolox as the primary booster propellant, with a specially made booster engine, and SRB augmentation as an option, but not a requirement.  Are there others I’m unaware of? 
And I think there’s a reason hydrolox isn’t normally used in booster roles normally.

So one would think if the MD-Boeing engineers wanted to turn away from the Delta II/III platform for the next evolution of Delta, that they might go with something like an RS-84, which also was already in development at PWR, or an updated F-1A, which had been already developed before it was cancelled as we know.  I think either one could have been an decent kerolox option to the RS-68, even if it had had already much of it’s development done.



By the way, during the 1980s General Dynamics entered the CELV competition (won by Martin Marietta's Titan 4) with a rocket that might also have fit the bill for EELV.  It proposed a 200 inch diameter first stage powered by five "H-1D" engines, augmented by four 67 inch diameter solid rocket motors.  A Centaur G-Prime with two RL10 engines would have served as the upper stage.  This thing would have put 5 tonnes into GEO (probably 10 tonnes in GTO), but the solids were new (roughly equal to Japan's beefy SRB-A motors) and the first stage was new and all-new pads would have been needed, so it lost.  Still, the concept shows what was possible.

 - Ed Kyle

I’m guessing Titan IV was the favorite because it could use easily modified Titan III pads and infrastructure?
EELV wiped the slate clean, so yea, this General Dynamics CELV might have been an interesting concept.  And again, kinda interesting MD-Boeing didn’t go with something like that for Delta IV as it would be closer to a scaled up Delta II/III than Delta IV turned out to be.   Again, a single F-1A might have been an option instead of five H-1’s and four SRB’s.  The extra thrust of the F-1A would basically do the job of the H-1’s and SRB’s together…all with just a single liquid engine. 

Anyway, maybe I’ll start a thread over in the ULA section specifically about Delta IV.  I’m sure some people must have some inside info on MD-Boeing’s decision making process in the Delta IV.  It’s got my curiosity up!

Offline Lobo

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Re: What would a better CxP have looked like?
« Reply #59 on: 05/20/2013 08:04 PM »
I think many of us have advocated using Atlas V as a crew launcher in any "1.5" architecture, and that the focu should have been on Orion and the Atlas crew launcher to be launching by the time STS was retired before too much time and money was spent worrying about a new HLV.

However, quoting from page 382 of the ESAS report:

"The EELV options examined for suitability for crew transport were those derived from teh Delta IV and Atlas V families.  The study focused on the heavy-lift version of both Delta and Atlas families, as it became clear early in the study that none of the medium versions of either vehicle had the capability to accomodate CEV lift requirements.  Augmentation of the medium-lift class systems with solid strap-on boosters does not provide adequate capaability and poses an issue for crew saefey regarding small strap-on SRB's reliability, as determined by the OSP-ELV Flight Safety Certification Study Report, dated March 2004.  Both vehicles were assessed to require modifications for human rating, particularly in the areas of avionics, elementry, structures, and propulsion systems. 

Both Atlas- and Delta-derived systems required new upper stages to meet the lift and humanrating
requirements. Both Atlas and Delta single-engine upper stages fly highly lofted
trajectories, which can produce high deceleration loads on the crew during an abort and, in
some cases, can exceed crew load limits as defined by NASA Standard (STD) 3000, Section 5.
Depressing the trajectories flown by these vehicles will require additional stage thrust to bring
peak altitudes down to levels that reduce crew loads enough to have sufficient margins for offnominal
conditions. Neither Atlas V nor Delta IV with their existing upper stages possess the
performance capability to support CEV missions to ISS, with shortfalls of 5 mT and 2.6 mT,
respectively.
Another factor in both vehicles is the very low Thrust-to-Weight (T/W) ratio at liftoff, which
limits the additional mass that can be added to improve performance. The RD–180 first-stage
engine of the Atlas HLV will require modification to be certified for human rating. This work
will, by necessity, have to be performed by the Russians. The RS–68 engine powering the
Delta IV HLV first stage will require modification to eliminate the buildup of hydrogen at the
base of the vehicle immediately prior to launch. Assessments of new core stages to improve
performance as an alternative to modifying and certifying the current core stages for human
rating revealed that any new core vehicle would be too expensive and exhibit an unacceptable
development risk to meet the goal of the 2011 IOC for the CEV. Note the EELV costs shown in
Figure 6-17 do not include costs for terminating Shuttle propulsion elements/environmental
cleanup. Finally, both the EELV options were deemed high-risk for a 2011 IOC.
CLV options derived from Shuttle elements focused on the configurations that used an RSRB,
either as a four-segment version nearly identical to the RSRB flown today or a higher-performance
five-segment version of the RSRB using HTPB as the solid fuel. New core vehicles
with ET-derived first stages (without Solid Rocket Boosters (SRBs)) similar to the new core
options for EELV were briefly considered, but were judged to have the same limitations and
risks and, therefore, were not pursued. To meet the CEV lift requirement, the team initially
focused on five-segment RSRB-based solutions."

-------------

But Atlas is being developed now for CST-100 and Dreamchacer.  CST-100 will use one Atlas SRB.
No new upper stage will be needed for CST-100 or DC (although it will be the first time a 2 engine Centaur is used I think)

High lofted trajectories?  high deceleration loads on the crew during an abort?  Atlas V-heavy not being able to get Orion to the ISS?

Is all of that valid?
I mean, why would a fully fueled Orion need to get to the ISS anyway?
Why wouldn't they do a short fueled Orion to the ISS like they sent short-fueled APollo CSM's to Skylab?
I'd think they could actually send the ORion SM up empty or almost empty.  Just a small de-orbit burn that Orion CM RCS system could probably do itself.  So you could probably leave the tanks and the engines off the SM entirely for the ISS.  That's probably trim the CSM mass down to around 12mt (plus LAS).  Maybe a bit lighter as a LEO Block 1 Orion should weigh less than a full BLEO Orion.

And an Atlas V heavy, or Atlas Phase 1-551 could get the full BLEO Orion CSM to 28.5 deg. orbit for a lunar mission.

So, was NASA just fudging the numbers to get Ares 1? Or, by their stated criteria, were EELV's really unsuitable for it?

Seems like getting US crews to the ISS should have been priority 1 for CxP.  And doing that as quickly, easily, and cheaply as possible should have been paramount. 
Even NASA developing just Ares 1, was two brand new stages, and a new upper stage engine. And although the first stage would be used as the ARes V boosters, Ares V would have been an additional new core and new upper stage.

Even if they really thought EELV's were legitimately unsuitable for launching Orion to the ISS and to EOR for lunar missions, why didn't they evaluate just a new kerolox booster that could use RD-180 engines.  Maybe it could use a man-rated 5m DCSS initially, transitioning to something else later.
And then do a tri-core heavy version for their HLV.  That way that one single new core gets them both their crew launcher, and their heavy cargo launcher.  I mean, they danced around that idea in ESAS, evaluating various new 5.4m and 8m and 8.4m kerolox and hydrolox cores for Ares 1 upper stage, Atlas Phase X (8m core with five RD-180's), Atlas Phase 2, 8.4m hydrolox with both Delta and Atlas boosters and RS-25 and RS-68 core engines.
They danced around this a lot, and had no problem looking at a new diameter core in their concepts.  KSC can't handle an 8 or 8.4m tri-core LV, but the 5-5.4m wide hydrolox LV is a little to small.  And they didn't seem to like the 5-5.4m wide kerolox Atlas Phase 2 because it needed 2-launches of tri-core LV, or a 5-core AVP3a and NASA didn't like that many boosters and the depth dimension.
But no one thought to look at maybe a 6-6.5m kerolox core with 3-4 RD-180's?
It's over powered but workable for a crew launcher, and a tri-core version is as capabile as the LV 27.3 they chose.

One new core, and one new upper stage (it would need J2S but so did LV27.3), and NASA has both a new crew launcher, and cargo launcher.  And the crew launcher could probably use Delta's existing DCSS like I said, for a little more synergy with EELV.
The cores could be produced at a reasonable clip at MAF, along with the new HLV upper stage (when needed, down the road). 

Seems like such an obvious option, what am I not seeing?  Why wasn't it even looked at, even if they opted for Ares 1/5 anyway. 

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