Author Topic: Common US: DUUS/Pyrios Single Stick  (Read 25538 times)

Offline TomH

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Common US: DUUS/Pyrios Single Stick
« on: 08/29/2013 09:38 PM »
Quite a few threads have been discussing upper stages: tank diameters, new common tooling, engine upgrades, commonalities with EELV, etc. I have been thinking about how well the S-IVB filled a dual role on both Saturn LVs. I know there were minor differences in the engine, avionics, etc.

I have been wondering whether it could be even remotely feasible to construct a common stage that would serve as DUUS on top of the SLS core, but also fill a role similar to the Ares I US, but atop an SLS advanced liquid booster, as Dynetics illustrates in their promotional drawings.

On top of a Dynetics Pyrios, such an upper stage would need to do a very long burn. OTOH, if the AJ-1E6 were selected, perhaps a 3 engine variant would serve as an SLS booster, while a 2 engine variant could be used in single stick configuration, allowing the KeroLox stage to perform a longer burn, giving the HydroLox common US a more reasonable burn time.

I realize that RL-10/MB-60 is more optimal for DUUS and J-2X for the single stick configuration, so another thought might be common tanking but different engines for each of the separate applications.

If a common US did exist in a 1.5 launch architecture, there wouldn't actually be 2 separate rockets; the smaller rocket would simply be comprised of some of the components of the larger rocket.

Does this idea have any merit at all, or is it just off the wall?
« Last Edit: 08/29/2013 09:44 PM by TomH »

Offline RocketmanUS

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #1 on: 08/30/2013 03:32 AM »
DIV, Pyrios as single stick , and SLS use same or similar US?

DIV and Pyrios as single stick could be made to use a 5.5 meter diameter US. SLS 8.4 meter diameter US.
Use save avionics. Pyrios would already be controlled by SLS avionics on it's US, so it might be Delta IV getting upgraded or new modern avionics.

It might be what they are doing.

The LOX tank diameter might stay at 5.5 meters but be stretched in length for SLS. There would be two different diameter hydrogen tanks 5.5 and 8.4 meter.

Some were on the form I saw a picture of the SLS vertical weld tooling and saying it could make different diameter tanks.
« Last Edit: 08/30/2013 03:34 AM by RocketmanUS »

Offline TomH

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #2 on: 08/30/2013 03:50 AM »
Chris' article re. DUUS indicated that NASA was considering 5.0, 5.5, and 6.3 meter diameters. That would mean 5.5 meter tooling might possibly be shared for both stages. The issue with differing diameters is not the cylinder, but the ends. Agreed on the shared avionics. As I indicated before, the Pyrios US would function better with J-2X and the DUUS better with RL-10/MB-60, so I think a common engine might be the most problematic issue. I have no idea how close or different the propellant volume requirements might be.


Offline RocketmanUS

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #3 on: 08/30/2013 05:29 AM »
Chris' article re. DUUS indicated that NASA was considering 5.0, 5.5, and 6.3 meter diameters. That would mean 5.5 meter tooling might possibly be shared for both stages. The issue with differing diameters is not the cylinder, but the ends. Agreed on the shared avionics. As I indicated before, the Pyrios US would function better with J-2X and the DUUS better with RL-10/MB-60, so I think a common engine might be the most problematic issue. I have no idea how close or different the propellant volume requirements might be.


6.3 meter could work with SLS and Pyrios single stick.
Pyrios single stick would probably not handle 8.4m that well.
DIV might work with 6.3m, however I don't think they would go that route ( larger diameter fairing ).

Forgot about the end dome caps. The most likely would mean another tool if different diameters were used.

I would need the specs for Pyrios to see if it is worth using J-2X over RL-10 or NGE. Dry mass, propellant mass, ISP, and burn time ( would help with engine throttable range and thrust too ).

Offline Lobo

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #4 on: 08/30/2013 05:44 PM »
I have been wondering whether it could be even remotely feasible to construct a common stage that would serve as DUUS on top of the SLS core, but also fill a role similar to the Ares I US, but atop an SLS advanced liquid booster, as Dynetics illustrates in their promotional drawings.

On top of a Dynetics Pyrios, such an upper stage would need to do a very long burn. OTOH, if the AJ-1E6 were selected, perhaps a 3 engine variant would serve as an SLS booster, while a 2 engine variant could be used in single stick configuration, allowing the KeroLox stage to perform a longer burn, giving the HydroLox common US a more reasonable burn time.

I realize that RL-10/MB-60 is more optimal for DUUS and J-2X for the single stick configuration, so another thought might be common tanking but different engines for each of the separate applications.

If a common US did exist in a 1.5 launch architecture, there wouldn't actually be 2 separate rockets; the smaller rocket would simply be comprised of some of the components of the larger rocket.

Does this idea have any merit at all, or is it just off the wall?

I think if the DUUS used MB-60, and if it had a MPS that could accomodate 2 or 4 MB-60's, sort of like how ACES would be able to accomodate 2 or 4 RL-10's, then I think you could use a DUUS with four MB-60's on a Dynetics or Aerojet boosters.  (DUUS is originally conceived to use four RL-10's anyway which are about the same size and mass) Even though it's an oversized upper stage for such a booster, either LRB will have a huge T/W ratio because they are designed for massive thrust and short burn times to pull the extra mass of the SLS core up with them.  So they really will need large upper stages with a good deal of thrust, like the SAturn 1B needed from the S-IVB. 
Four MB-60's is pretty close in thrust to a single J2X, so they -should- work in place of a single J2X. 

Someone with more knowledge in that area than I can estimate the mass of the DUUS with four MB-60's, and mass of the booster core and see how much payload that could get to LEO.  The DUUS might burn itself out just getting to LEO so this might not have a lot of BLEO throw capability.  But, perhaps two MB-60's could be shut down later in ascent and save some fuel for a BLEO burn, if the payload mass wasn't too much.

If it could do it, then you just need a 5.5m to 8.4m interstage adaptor.  But that shouldn't be a big problem I wouldn't think. 
Then this LV could fly without needing a dedicated upper stage.

If the Aerojet version of this had four AJ-1E6's, two could be shut down during booster ascent to get some more performance out of the booster prior to staging if the g-loads would be too great other than that. 

Again, either booster would have a lot of power and a lot of lift capability, but not a lot of fuel if burning all enignes wide open as they'll probably be designed to do when launching on SLS. (although there will probably be some throttle down, just as the SRB's burn self-throttles during ascent).
The problem with existing upper stages such as the DCSS/ICPS is that a single RL-10 probably doesn't have enough power when these high power/short burning boosters will stage.  A DCSS/ICPS with an MB-60 might do better for LEO. 

Now, with all of that said, we have to ask what such an LV would be doing?  What could it lift that FH or D4H cannot? And those are already flying (or will be) as stand alone LV's, and will already have pads and infrastructure.
Remember the D4H launch two days ago was only the 5th payload in that class, and 6th launch overall, the first being a demo flight (if I counted correctly).  In about the last 10 years. 
So there's only been very limited government loads in that class.
Ariane V has launched a lot, but how many payloads have needed it's max payload? (a bit less than D4H with normal RS-68) vs. how many have been launching dual payloads which could have launched on smaller EELV-medium class LV's, if there was a better priced EELV-medium class launcher that could beat Ariane V's government subsidized price?
I think most of their payloads could be launched on smaller class launcher, but I'm not sure on that.

Anyway, a Dynetics or Aerojet booster will be competing in a very limited market that will already have two other US players in it.  So what would it be doing?
It could be an Orion launcher for a 1.5 architecture perhaps.  Just don't see much need for it other than maybe that.  And FH and D4H both could launch Orion for a 1.5 architecture too.

Offline Lobo

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #5 on: 08/30/2013 05:53 PM »

The LOX tank diameter might stay at 5.5 meters but be stretched in length for SLS. There would be two different diameter hydrogen tanks 5.5 and 8.4 meter.

Some were on the form I saw a picture of the SLS vertical weld tooling and saying it could make different diameter tanks.

From the Dynetics paper on L2 (not sure if it's been posted to the public side yet?) Dynetics said outright that they'd use the 5.5m A1US tooling already bought and installed in MSFC.

"Both tanks feature one-piece spun formed domes with integral attachment chords and one-piece barrel sections, up to 11 feet long, produced by state-of-the-art equipment. LOX tank Slosh Baffles will be installed in the barrels prior to tank welding. Tanks are then friction stir welded with circumferential welds for the RP Tank and LOX tank. Completing the structural arrangement are manhole covers on the forward domes and sump outlet fittings with baffles on the aft domes.
The manufacturing approach is to use qualified suppliers to build major components such as domes, chords, and thrust structures. The tanks and associated structures will then be assembled using self-reacting FSW equipment located at NASA MSFC facilities. The cylindrical sections will be welded on just two tools, shown in Figure 8. Based on a limited build schedule, the workforce across multiple programs will be shared to ensure a low-cost manufacturing and test process."

I thought the A1US tooling was at MAF, not MSFC?  Per this article.

http://www.nasaspaceflight.com/2011/08/boeing-complete-sls-pathfinder-tank-maf-et-operations-end/

So I'm a little confused about what tooling they are talking about.

Offline quanthasaquality

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #6 on: 09/25/2013 01:44 AM »
Of the advanced boosters, I like Pyrios the best.

The engine is a big, simple gas generator cycle engine, ie, potentially cheap. The 1,600 tons of thrust, is similar to the 1,600 ton peak thrust of the 5 segment solid booster. Potentially, there could be 2 different boosters for the SLS: the cheaper, existing 5 segment solid booster, and the higher capacity, pyrios booster. If http://www.spacelaunchreport.com/sls0.html is to be believed, the advanced composite booster will gain 80 tons of fuel, at a loss of 20 tons of casing. For Aerojet's booster, I hear, staged combustion, and I think expensive.

The pyrios rocket booster, and Ares I upper stage could be made in the same factory. Two different rockets could be derived: the ~22 ton Ares 1, and the ~33 ton pyrios based rocket.

The pyrios booster weighs less than half of the 5 segment solid booster, so the crawlerway might be able to withstand an SLS with 4 pyrios boosters.


Some people here have estimated the cost of a Delta IV core, from the Delta IV Heavy, at over $100 million, but with a per RS-68 engine price about $20 million, most of the cost is non-engine.  Astronautix http://www.astronautix.com/stages/shulesrb.htm gives a price of about ~$45 million inflation adusted for 4 segment solid booster. How much would a pyrios core, with an Ares 1 upper stage, end up costing? Pyrios would have to compete with the Atlas V, Delta IV, Falcon 9, and Antares, for the mere ~7 annual US govt launches. There should be some elimination.

Offline TomH

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #7 on: 09/25/2013 02:12 AM »
The pyrios booster weighs less than half of the 5 segment solid booster, so the crawlerway might be able to withstand an SLS with 4 pyrios boosters.

There are a number of problems with that.

Liftoff thrust is mismatched with core thrust, mass, and payload.

Thrust to weight ratio is going to put a lot of G load on the vehicle.

Upper thrust beam is designed for two boosters. Modification would be expensive.

Flame trench would need significant modification.

Mobile launcher would need significant modification and (I don't know for sure, but) this might not even be possible due to the arrangement of VAB, its cranes, other equipment, ML layout, etc.

Offline Jim

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #8 on: 09/25/2013 08:22 AM »
Pyrios would have to compete with the Atlas V, Delta IV, Falcon 9, and Antares, for the mere ~7 annual US govt launches. There should be some elimination.

It would be Pyrios from the beginning.

Offline 93143

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #9 on: 09/25/2013 09:40 AM »
Potentially, there could be 2 different boosters for the SLS: the cheaper, existing 5 segment solid booster, and the higher capacity, pyrios booster.

Part of the intent with the advanced boosters is to reduce cost.  Pyrios in particular looks good for this (to me), with low-part-count gas-generator engines and simple, conservative tanks made from conventional materials with advanced automated tooling in the same facility used to manufacture the core.

It also gives higher performance, yes.  But if liquids win the advanced booster competition, keeping solids around beyond completion of  the development would just add cost to no purpose (and prevent utilization of the VAB office spaces).  If you want worse performance on a given launch, just short-fuel the boosters or something...
« Last Edit: 09/25/2013 09:45 AM by 93143 »

Offline Lobo

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #10 on: 09/25/2013 05:14 PM »
Pyrios would have to compete with the Atlas V, Delta IV, Falcon 9, and Antares, for the mere ~7 annual US govt launches. There should be some elimination.

It would be Pyrios from the beginning.

Yea, this is the question I keep asking of those who'd hope to make a stand alone Pyrios booster.  Not that I don't like the idea of having commonality between SLS and ELV's that USAF/DoD would use.  This could have been the case had STS mounted boosters like Pyrios, and we were already flying F-1's when STS was being hatched.  Pyrios could have been a good booster for USAF/DoD to have used so they were so married to launching their payloads on the STS Orbiter.  (as I understand they were uncomfortable about that, but political forces were such that STS would be the launcher for all government launches)
Although, perhaps then Pyrios would mount just a single F-1A engine, as a two engine version would have some pretty heafty acceleration due to it's very high T/W ratio.

However, things are different now.  There's already a pseudo-commercial company that provides the USAF/DoD all the lift capacity they need.   Already infrastructure and launch facilities dedicated to those two EELV's.  Pyrios would need all of that plus a new upper stage.

And even if had all of that, what's it going to compete for?  USAF/DoD contracts?  ULA is already catered to that, and it appears SpaceX will be starting to compete for those too in a few years. 
Commerical Contracts?  Well, good luck competing price wise with SpaceX.  Antares could be a player too depnding on how Orbital goes forward and if they can secure a reliable supply of engines.  At least in the smaller commercial market.  Delta II class and such.
Then there's always the European subsidized ArianeSpace trying to undercut any US commercial provider.  If Ariane 6 is cheaper than Ariane 5 per payload, they could be even a little more competative.
Then there's Soyuz and Proton.

So I don't see really any case today for Pyrios as it's own LV.  Although that could change at some point in the future if ULA were to go out of business due to a change in USAF/DoD policy on what they feel they need to subsidize to have assured access to space.  But I find that scenario pretty unlikely. 
And even if so, can Pyrios even be allowed to compete commercially?  Since it was developed with NASA money for a specific NASA purpose?  Isn't there some legal issues preventing something like that to then be offered commercially where it's development was paid for with taxpayer dollars?
Not sure about that. 
« Last Edit: 09/25/2013 05:16 PM by Lobo »

Offline Lobo

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #11 on: 09/25/2013 05:32 PM »
The pyrios booster weighs less than half of the 5 segment solid booster, so the crawlerway might be able to withstand an SLS with 4 pyrios boosters.

There are a number of problems with that.

Liftoff thrust is mismatched with core thrust, mass, and payload.

Thrust to weight ratio is going to put a lot of G load on the vehicle.

Upper thrust beam is designed for two boosters. Modification would be expensive.

Flame trench would need significant modification.

Mobile launcher would need significant modification and (I don't know for sure, but) this might not even be possible due to the arrangement of VAB, its cranes, other equipment, ML layout, etc.

Yea, I don't think there's any chance of SLS launching with more than two boosters ever, without the core being so redesigned, it'd be a new rocket. And all the other reasons TomH mentions.  In which case, why not drop the core entirely, and cluster of 3 boosters together to make the first stage?
Actually three Pyrios boosters put together in a tri-core heavy configuration, with cross feed and a single, center mounted engine on the central core should fit everywhere SLS does.  It would need a new upper stage though, with the DUUS on top.  Or a stretched DUUS with J2X or a cluster of MB-60's on it. 
Rembember, the F-1B will be about 1.8Mlbs thrust, where the four engines on the SLS core are putting out a little over 2Mlbs at vacuum and about1.6Mlbs at sea level.  So a single F-1B would be a good replacement for the first portion of ascent from a thrust standpoint.  The core doesn't go to orbit so it can stage before the lower F-1B ISP gets to be too big of a hit.

And TomH makes a good point with the Pyrios booster having a really high T/W ratio, so it would accelerate very fast as a stand alone LV when it's not trying to lug an SLS core up with it.  Although, that could be worked around if F-1B were modified to have a deeper throttle than just the 70% step down point.  That might make F-1B not such a cheap engine though, if it is even "cheap" to begin with.





Offline quanthasaquality

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #12 on: 09/25/2013 09:59 PM »
And TomH makes a good point with the Pyrios booster having a really high T/W ratio, so it would accelerate very fast as a stand alone LV when it's not trying to lug an SLS core up with it.  Although, that could be worked around if F-1B were modified to have a deeper throttle than just the 70% step down point.  That might make F-1B not such a cheap engine though, if it is even "cheap" to begin with.

I don't have L2, so I don't know for sure. Compared to the ~350 ton Zenit first stage, 5.5 meter diameter is double the area of 3.9 meter diameter, and ~50% longer. I had also read someplace I forgot, that Pyrios had 150 second burn time. The F-1 has a 270 ISP at sea level. Both would suggest a fuel/oxidizer mass of ~900 tons, and I assume ~100 tons of structure. Put a ~150 ton Ares 1 like stage on top, and I get a reasonable rocket. The Zenit booster has a dry weight of ~30 tons, an ~800 ton thrust engine, and it worked on Energia.

Offline quanthasaquality

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #13 on: 09/25/2013 10:20 PM »
However, things are different now.  There's already a pseudo-commercial company that provides the USAF/DoD all the lift capacity they need.   Already infrastructure and launch facilities dedicated to those two EELV's.  Pyrios would need all of that plus a new upper stage.

If one sticks with American made boosters, then yes. The military launches satellites of a variety of masses. There are foreign rockets available from American allies, that are reliable, and already have financed quality assurance. Specifically, the European Ariane 5, and the Japanese H-2A/B. I assume rockets can be stored on American soil. If alternatives are needed, there is Proton, Zenit, Falcon 9, and Long March 3B. In another decade or two, there will also be the GSLV, Angara, and Long March 5. But, there are some big, heavy, and very important spy satellites that only the Delta IV Heavy can lift. If a Pyrios could take up the Delta IV Heavy's burden, Delta IV Heavy would no longer be irreplacable.

Offline quanthasaquality

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #14 on: 09/25/2013 10:30 PM »
Potentially, there could be 2 different boosters for the SLS: the cheaper, existing 5 segment solid booster, and the higher capacity, pyrios booster.

Part of the intent with the advanced boosters is to reduce cost.  Pyrios in particular looks good for this (to me), with low-part-count gas-generator engines and simple, conservative tanks made from conventional materials with advanced automated tooling in the same facility used to manufacture the core.

It also gives higher performance, yes.  But if liquids win the advanced booster competition, keeping solids around beyond completion of  the development would just add cost to no purpose (and prevent utilization of the VAB office spaces).  If you want worse performance on a given launch, just short-fuel the boosters or something...

The Atlas V and Delta IV were both designed specifically to be low cost rockets. The RS-68 was designed to be a low cost rocket engine ($14 million?). The RD-180 contract was signed, at a low price ($20 million), when the Russian economy was bad. Today, a Delta IV Heavy launch costs >$400 million, for 3 cores, and one upper stage. So, yes, I expect higher cost liquid boosters. For solid fuel rockets, I can hope that Wind turbine blade manufacturing has lead to automation in composite manufacturing.

Offline 93143

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #15 on: 09/25/2013 10:46 PM »
The Atlas V and Delta IV were both designed specifically to be low cost rockets.

So was the Falcon 9.

The EELVs were low-cost for their time, at a much higher flight rate than actually materialized.  That was then; this is now.  SLS systems are being designed with low flight rate in mind, using much more advanced manufacturing technology, with SpaceX in the back of everyone's minds as an existence proof.

Besides which, the DIVH launch price is for everything, not just the hardware.  Pyrios is only a new booster for a rocket that already exists; besides booster hardware cost differences, it would have a mostly beneficial effect on logistics and ground handling and otherwise not result in much change.

Solids tend to have high infrastructure costs to go with their low unit costs.  The carrying cost for the STS boosters worked out to a surprisingly large chunk of the annual SSP budget, as I recall...
« Last Edit: 09/26/2013 01:21 AM by 93143 »

Offline baldusi

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #16 on: 09/26/2013 01:00 AM »
Today, a Delta IV Heavy launch costs >$400 million, for 3 cores, and one upper stage.
Then how come LM paid less than 350M for EFT-1. This includes the adaptor, launch, space tracking and telemetry and even capsule recovery. Commercial cost of DIVH is probably less than 300M. Problem is Ariane 5 is 200M, and SLYDAS is bigger than the Delta's solution. And the fact that you have a lead time of 30 months for DIVH and you'd get bumped for any DoD or Planetary launch. And I think that EFT-1 still had to pay 30M to Boeing per core in development money recovery, which, I believe, after 2016 there won't apply. So I think that you could probably get a DIVH for 250M if procured purely commercially, next year. Integration, mission analysis, mission specific modifications and mission assurance at an extra cost, of course.

Offline TomH

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #17 on: 09/26/2013 02:25 AM »
O.K. guys, you are way OT.

...So I don't see really any case today for Pyrios as it's own LV...

Lobo, you vectored off into all other kind of territory. As I stated clearly at the top, this thread's purpose is to consider the technical possibilities. The thread is not about comparing Pyrios with all your (plural-this is to all of you) favorite other launchers. The thread is to examine the technical possibilities of there being a common upper stage. I am not interested in whether it can be used to offer launch services commercially. I am interested in a technical analysis of whether it could serve the role that S-IVB did with two Saturn LVs.

Lobo, I enjoy a lot of your speculation and inquisitiveness, but I'd like to ask you to consider that you do posit an awful lot of, "What if this? What if that?" and you are wordy in what you say. I am not trying to be unkind, however I would recommend you try to focus your thesis points and be more succinct. I'd like you to accept the fact that I am not advocating the use of the single stick Pyrios; I am being like you with some inquisitiveness. I want to analyze whether this could work; that's it.

You other guys, please take your discussion of Delta, Atlas, and Falcon somewhere else. Thanks.

Offline Robotbeat

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #18 on: 09/26/2013 04:25 PM »
However, things are different now.  There's already a pseudo-commercial company that provides the USAF/DoD all the lift capacity they need.   Already infrastructure and launch facilities dedicated to those two EELV's.  Pyrios would need all of that plus a new upper stage.

If one sticks with American made boosters, then yes. The military launches satellites of a variety of masses. There are foreign rockets available from American allies, that are reliable, and already have financed quality assurance. Specifically, the European Ariane 5, and the Japanese H-2A/B. I assume rockets can be stored on American soil. If alternatives are needed, there is Proton, Zenit, Falcon 9, and Long March 3B. In another decade or two, there will also be the GSLV, Angara, and Long March 5. But, there are some big, heavy, and very important spy satellites that only the Delta IV Heavy can lift. If a Pyrios could take up the Delta IV Heavy's burden, Delta IV Heavy would no longer be irreplacable.
False. There are two other rockets that can lift such payloads: Falcon Heavy and Atlas V Heavy (if ordered 30 months ahead of time).

Pyrios would be entering an already far-overcrowded launch market. It's pointless except to amuse Internet speculators (such as ourselves).
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

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Offline Lobo

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #19 on: 09/26/2013 05:39 PM »
O.K. guys, you are way OT.

...So I don't see really any case today for Pyrios as it's own LV...

Lobo, you vectored off into all other kind of territory. As I stated clearly at the top, this thread's purpose is to consider the technical possibilities. The thread is not about comparing Pyrios with all your (plural-this is to all of you) favorite other launchers. The thread is to examine the technical possibilities of there being a common upper stage. I am not interested in whether it can be used to offer launch services commercially. I am interested in a technical analysis of whether it could serve the role that S-IVB did with two Saturn LVs.

Lobo, I enjoy a lot of your speculation and inquisitiveness, but I'd like to ask you to consider that you do posit an awful lot of, "What if this? What if that?" and you are wordy in what you say. I am not trying to be unkind, however I would recommend you try to focus your thesis points and be more succinct. I'd like you to accept the fact that I am not advocating the use of the single stick Pyrios; I am being like you with some inquisitiveness. I want to analyze whether this could work; that's it.

You other guys, please take your discussion of Delta, Atlas, and Falcon somewhere else. Thanks.

TomH,

No, I don't think you are unkind, and yes, I can be verbose.  ;-)

However, going back to your post that initialized this thread, you didn't seem to be asking only about the theoretical technical merit for a booster that you acknowledged would have not real "purpose" in today's launch market.  It sounded like you were asking about the feasibility of a stand along Pyrios LV.

In fact, to quote you:


I have been wondering whether it could be even remotely feasible to construct a common stage that would serve as DUUS on top of the SLS core, but also fill a role similar to the Ares I US, but atop an SLS advanced liquid booster, as Dynetics illustrates in their promotional drawings.

*snip*

Does this idea have any merit at all, or is it just off the wall?

Note you didn't ask that you were only looking for "technical possibilities" of a Pyrios LV, but asking if it was feasible and had merit.  I assumed you were proposing adding another LV to the market.  So while verbose, I don't think I was off topic or wondering at all.  In my first [verbose] post I was addressing your questions of feasibility and merit as I understood them.  (In short, I don't believe there is any feasibility or merit to a stand alone Pyrios booster today).
In my 2nd [verbose] post I was following up to Jim's [always very pithy] post in response to quanthasaquality's post.  ALthough perhaps I hit some points form my 1st post again.
Any mention I made to other LV's were only to illustrate that there's likely to be little feasibility in the Pyrios LV due to a crowded market.  Pyrios would need paying customers to be "feasible" or to be an LV with "merit" would it not?  And I don't know who those would be.

So, I'll be less wordy here.  :-)

I don't think a Pyrios booster has much any feasibility or economic merit.

I do think it has technical merit, and in a different time and situation, it could very well have been a viable "Companion ELV" to STS, had STS been designed that way from the beginning...with expendable liquid boosters using F-1A engines rather than SRB's in the pursuit of a reusable system.
And even more directly, that WAS the concept behind CxP.  Except they unfortunately wanted to make a "Pyrios" booster out of an SRB instead of an F-1 powered LRB.  Although again, it still wouldn't have really served a purpose that was not already being served by the EELV's which existed during CxP.  That wasn't the case during the 70's, so it would have made more sense then.  More "Energia/Zenit" like.

However, if there actually were any need for it, I don't see why Pyrios couldn't mount a DUUS with perahaps four MB-60's, as a companion to SLS.   The mass of the DUUS could keep Pyrios's acceleration in check where a smaller/lighter  5.5m upper stage could have acceleration issues due to the high T/W of Pyrios. 

Is that better?
;-)


« Last Edit: 09/26/2013 05:43 PM by Lobo »

Offline Lurker Steve

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #20 on: 09/26/2013 05:55 PM »
How about a different approach /

Let's assume a F-1X can be manufactured cheaper than 2 RD-180s.

If ULA ever gets to that Common Core / Atlas Phase 2 idea, would it be better to use a single F-1X engine
instead of the RD-180s ?

Offline baldusi

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #21 on: 09/26/2013 10:41 PM »
How about a different approach /

Let's assume a F-1X can be manufactured cheaper than 2 RD-180s.

If ULA ever gets to that Common Core / Atlas Phase 2 idea, would it be better to use a single F-1X engine
instead of the RD-180s ?
The RD-180 has significant more isp and about same T/W. Consider that current Phase 2 concepts still use SRB for thrust augmentation. Thus, the core works a bit like a sustainer. F-1B works best for no thrust agumented core and high T/W.

Offline Lobo

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #22 on: 09/27/2013 03:49 PM »
How about a different approach /

Let's assume a F-1X can be manufactured cheaper than 2 RD-180s.

If ULA ever gets to that Common Core / Atlas Phase 2 idea, would it be better to use a single F-1X engine
instead of the RD-180s ?


I think any real Atlas Phase 2 concepts have been shelved, as has Atlas V Heavy.  The upgrade to D4H with RS-68A has better performance and can handle that occasional payload. 
Not for sure, but I think it was conceived to give USAF an option to standardize on just the Atlas LV, and give NASA HLV options too?
And if they went for it, then perhaps D4H would be retired in favor of AVP2 and probably they'd also develop a common 5m upper stage accross the EELV line. 
But, those ships have pretty much sailed, so I kinda doubt ULA is interested in doing something like AVP2 with F-1X anyway.

Offline Lobo

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #23 on: 09/27/2013 04:31 PM »
How about a different approach /

Let's assume a F-1X can be manufactured cheaper than 2 RD-180s.

If ULA ever gets to that Common Core / Atlas Phase 2 idea, would it be better to use a single F-1X engine
instead of the RD-180s ?
The RD-180 has significant more isp and about same T/W. Consider that current Phase 2 concepts still use SRB for thrust augmentation. Thus, the core works a bit like a sustainer. F-1B works best for no thrust agumented core and high T/W.

Although, I think you -could- use an F-1X still, it's just not as efficient as the RD-180 in the latter part of the booster ascent.  But Boeing had a concept for the Saturn V-B that used a modified S-1C stage, dropped the four outter engines during ascent, and then the central F-1 engine boosted the core all the way to orbit in sort of a 1.5 stage to orbit.  I'm guessing it wasn't super efficient but supposedly it'd put payloads in excess of SAturn 1B in LEO.  More if the core was stretched a little.
RS-27A is an H-1 simple gas generator sustainer engine. 

But yea, in general a high thrust, lower ISP engine like the F-1 series is best for an unaugmented booster stage.  It's inherrently intended to be it's own booster with it's spec's.

While I don't think there's any market for such an LV today (it would probably fall in the  D4H, and FH performance area...and there's been very few payloads in that range over the last 10 years), I think that had something like this been considered during ESAS, we could have had something.  Except rather than having basically an AVP2 with one F-1 engine on it, have the Pyrios booster, and go with just a single core Orion launcher, and tri-core heavy cargo launcher.  Except make each core wider, maybe 6.5m, so the tri-core can fit through the VAB doors and the stage isn't as tall.  The single core with perhaps an existing DCSS should be able to put Orion into LEO.  The tri-core could have crossfeed to make it a 1.5 stage booster, and then a large upper stage powered by some J2S engines (or perhaps a cluster of MB-60's or RL-60's, depending on the performance needed.  Both of those engines were already under development at the time of ESAS, so either would probably have been much cheaper to finish than J2X was form basically scratch).
In this way, NASA only need develop one new CCB, one completely new engine (F-1X), and one new large upper stage (which would basically be a JUS combination 2nd stage and EDS) which would use an engine that almost already totally developed.
It'd basically be F9/FH on steriods, but with a much higher performance upper stage.

I could have really seen something like that as nice version of "CxP" which could have gotten Orion flying to the ISS for crew and cargo service as originally intended with much less expense than ARes 1 turned out to be.  and then once that was established and STS retired, develop the large upper stage for the cargo launcher, and you are ready to rock and roll.  Basically for the price of the SLS advanced booster and the DUUS development by themselves, you have both your crew launcher and your cargo launcher for your 1.5 launch  lunar architecture.

Offline TomH

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #24 on: 09/27/2013 06:34 PM »
You guys are still OT. You have hijacked the thread. No one has even remotely addressed the question that the thread is about. The question is not about Pyrios, it is about DUUS. I am curious to know whether DUUS is appropriately sized such that it could serve as the US on top of Pyrios, and if not whether slight modifications could make it work.

I have no interest in discussing Atlas, Delta, or Falcon. If NASA winds up building or purchasing both Pyrios and DUUS (and they wind up both already being in existance), I just want to know whether they could put DUUS atop Pyrios and have a viable LV. I am not interested in cost, politics, or anything other than the technical aspects. Can you guys stick to that question, please?

Offline M129K

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #25 on: 09/27/2013 06:36 PM »
I think the DUUS is a little too wide for for the 5 meter Pyrios, you'd get an Ares 1 kind of situation. However, the 5 or 7.5 meter CPS proposed for Block 1A would probably fit, and if it has enough thrust it could probably take the role just perfectly.

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #26 on: 09/27/2013 07:15 PM »
You guys are still OT. You have hijacked the thread. No one has even remotely addressed the question that the thread is about. The question is not about Pyrios, it is about DUUS. I am curious to know whether DUUS is appropriately sized such that it could serve as the US on top of Pyrios, and if not whether slight modifications could make it work.

I have no interest in discussing Atlas, Delta, or Falcon. If NASA winds up building or purchasing both Pyrios and DUUS (and they wind up both already being in existance), I just want to know whether they could put DUUS atop Pyrios and have a viable LV.



Tom,

I believe I answered that question in my earlier post.  Should we have an admin lock the thread now so it's not highjacked any further?

;-)

Part of the problem is you get worked up about myself or someone else discussing the feasibility of of Pyrios with the DUUS on top as it's own LV...but then turn around and say that you want to discuss the feasibility of Pyrios with the DUUS on top as it's own LV.

So I've been confused what -exactly- you want to discuss.  Perhaps you should elaborate more specifically what you mean by "feasible"?   To me, that means "feasible" means affordable and practical, and the only way for it to be that is for there to be a NEED for it and a paying customer.  And thus I've discussed how I don't think there is due to existing LV's in it's potential payload range...  Which is neither hijacking your thread nor off topic.  On the contrary, it's very on topic.


I am not interested in cost, politics, or anything other than the technical aspects. Can you guys stick to that question, please?

So you are just wondering if Pyrios can get off the pad with the DUUS and payload?  I'm sure it can.  Lots of things -could- do that without being "feasible".

« Last Edit: 09/27/2013 07:29 PM by Lobo »

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #27 on: 09/27/2013 07:31 PM »
I am curious to know whether DUUS is appropriately sized such that it could serve as the US on top of Pyrios, and if not whether slight modifications could make it work.

I think there are four sub-questions:

Mechanical loads: is the first stage physically sturdy enough to carry the second stage, both on the pad and in flight?

Liftoff: is the thrust of the first stage sufficient to lift the combination of its own mass and the mass of the second stage?

Performance: assuming it flies, does it reach orbit and if so with about what payload?

Limits: would the ascent trajectory impose unacceptable environments (acceleration; vibration) on the payload?

Which of those interest you?
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Offline Lobo

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #28 on: 09/27/2013 07:40 PM »
I think the DUUS is a little too wide for for the 5 meter Pyrios, you'd get an Ares 1 kind of situation. However, the 5 or 7.5 meter CPS proposed for Block 1A would probably fit, and if it has enough thrust it could probably take the role just perfectly.

Pyrios would be 5.5m, no?

5.5m to 8.4m would actually be less percentage diameter increase than Titan IV was from it's 3.05m core to it's 5.1m PLF.  As long as you didn't put a PLF any wider than the DUUS on it, I'd think it'd be ok.  Although there'd have to be wind tunnel testing and such to confirm that.

It'd look like a scaled up Ares 1.  I don't know if Ares 1's probablem were due to it's geometry so much as having a long SRB as it's first stage, creating both TO problems and 1st stage performance issues which needed to be made up by the upper stage engine.




Offline Lobo

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #29 on: 09/27/2013 08:03 PM »
Liftoff: is the thrust of the first stage sufficient to lift the combination of its own mass and the mass of the second stage?


I haven't found any numbers for gross mass of Pyrios (if there are some, I'd be curious).
But, assuming it's about the same gross mass as the S-1B-II stage which alwasy had two F-1 engines:

http://en.wikipedia.org/wiki/Saturn_C-3

That's 1,600 klbs.
The DUUS should be about 264klbs
So not including payload, interstage, or PLF, you should have 2X 1800klbs of thrust per F-1B, or 3600klbs of thrust total, trying to lift 1,864 klbs off the pad. almost a 2:1 T/W ratio.
So it should litterally leap off the pad. 

But, that's probably too high of a T/W.  The F-1B's have a throttled set point of 70%.  So if launching at that. or stepping down to it shortly after lift off, you'd have 2520klbs of thrust.  1.35:1 T/W ratio.  If you throw in maybe 10klbs for PLF and interstage adaptor (guess) and 93klbs of payload (30mt), that comes down to about 1.28:1 T/W.

However, I don't know if the stock DUUS with either four RL-10's or two MB-60's would have enough thrust at staging to make orbit, nor enough fuel.  The Ares 1 upper stage that Dynetics mentions using with Pyrios actually has more propellant than the DUUS.  304klbs propellant for A1US vs. 231klbs for DUUS.
It would have a J2X with more than double the thrust of four RL-10's or two MB-60's.  (If DUUS were designed to mount 2 or 4 MB-60's, like it could mount 4 RL-10's, then that might work with 4 MB-60's)

http://www.nasa.gov/pdf/231430main_UpperStage_FS_final.pdf

At least with the payload capability of 32mt to LEO that Dynetics claims in their paper with Pyrios and the A1US.

Someone who can model rocket performance would have to actually generate numbers on if it can get any usable payload to LEO or not, assuming it doesn't splash into the ocean after staging.




Offline TomH

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #30 on: 09/27/2013 09:46 PM »
Part of the problem is you get worked up.

Worked up? No. Do I feel like I'm trying to herd a pride of ferrel cats? Yes.

...about myself or someone else discussing the feasibility of of Pyrios with the DUUS on top as it's own LV...but then turn around and say that you want to discuss the feasibility of Pyrios with the DUUS on top as it's own LV.
No. You guys all keep wandering off into endless speculation about everything else in the rocketverse. I'm not angry. (In fact I like all of you.) I'm just trying to steer you back on topic.

Offline quanthasaquality

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #31 on: 09/28/2013 12:53 AM »
You guys are still OT. You have hijacked the thread. No one has even remotely addressed the question that the thread is about. The question is not about Pyrios, it is about DUUS. I am curious to know whether DUUS is appropriately sized such that it could serve as the US on top of Pyrios, and if not whether slight modifications could make it work.

I have no interest in discussing Atlas, Delta, or Falcon. If NASA winds up building or purchasing both Pyrios and DUUS (and they wind up both already being in existance), I just want to know whether they could put DUUS atop Pyrios and have a viable LV. I am not interested in cost, politics, or anything other than the technical aspects. Can you guys stick to that question, please?

There was some talk about an 'Ares IV/Ares V Lite', that would use the same upper stage as the Ares I. The Ares I upper stage size is >130 tons. The SLS's upper stage is >230 tons. The block I SLS puts >90 tons into LEO with NO upper stage, so if you just want to chunk a big payload into LEO, the Ares I upper stage should do fine. If you want to go to Mars, I don't know.

As for Mike Griffin on the Ares V Lite, http://www.spaceref.com/news/viewsr.html?pid=32351 , he is opposed to it. If you scroll down to paragraph 9),
Quote
Finally, the Ares-5 Lite is nearly as expensive to develop as the Ares-5, but offers significantly less payload to the moon when used

There is a picture of the Ares IV on wikipedia http://en.wikipedia.org/wiki/Ares_V. A low density payload on the Ares IV may not fit inside the VAB.
« Last Edit: 09/28/2013 12:54 AM by quanthasaquality »

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #32 on: 09/28/2013 05:46 PM »
I am curious to know whether DUUS is appropriately sized such that it could serve as the US on top of Pyrios, and if not whether slight modifications could make it work.
It could, but it would not be efficient.  The relatively limited thrust of DUUS (about 55 tonnes max) would limit how much propellant could be loaded onto the stage (offloaded from the maximum 130 tonnes possible), which would reduce payload.  My estimate is that the LEO payload of a "Pyrios/DUUS" would be something like 25 tonnes, assuming a minimum DUUS T/W of 0.4, which would require a 40 tonne propellant offload.  Now if more thrust could be provided (six engines?) the tanks could be full and LEO payload could easily surpass 30 tonnes.  But, of course, this creates a new stage with added expense.

Fair to note that S-IVB on Saturn IB wasn't the most efficient design either, but it allowed testing of the stage for Saturn V and provided a way to test Apollo too.

But of course Saturn IB didn't have a Delta IV Heavy already flying.  A Pyrios/DUUS must have a reason to exist, and with the performance numbers presented above I don't think it does.

 - Ed Kyle

Offline 93143

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #33 on: 09/28/2013 07:01 PM »
He did mention the idea of switching out the engine cluster for a J-2X for this application, and having two versions of the stage.  You'd have to change a lot, though...

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #34 on: 09/28/2013 08:05 PM »
For efficient two stage to orbit launch vehicles is there a "rule of thumb" for the ratio of first stage thrust to second stage thrust? (Ratio might imply linearity, which I don't mean to do, but is there any general formula for this?)
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Offline Robotbeat

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #35 on: 09/28/2013 08:35 PM »
Not really. You'd look at the ratio between masses (which depends on the sea-level and vacuum Isp of the first stage versus vac isp of the upper stage) to find the optimal, but you also have to determine which spread of orbits you want to get to. The most profitable are usually high-energy orbits, which means an upper stage with lower T/W ratio.

In general, the upper stage doesn't actually need a T/W ratio greater than 1. Obviously the first stage does (without complicated schemes).

It heavily depends on the upper stage Isp.
« Last Edit: 09/28/2013 08:35 PM by Robotbeat »
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Re: Common US: DUUS/Pyrios Single Stick
« Reply #36 on: 09/29/2013 04:42 AM »
He did mention the idea of switching out the engine cluster for a J-2X for this application, and having two versions of the stage.  You'd have to change a lot, though...
If change is needed, why not go all the way?  Here's one idea.  Top the 2xF1B first stage with a complete two stage Delta 4.  There's still plenty of liftoff thrust.  If the RS-68 could be air started, such a machine, with a 5 meter diameter (or the similar interim SLS upper stage) on paper puts 48 tonnes to LEO, more than 20 tonnes to GTO, or more than 16 tonnes to escape velocity.   That, or something similar, would be a design that could put all of that ridiculous thrust to good use.  (Note that this is essentially a Saturn C-3.)

EDIT:  Might look something like this.  Height might be an issue.

 - Ed Kyle
« Last Edit: 09/29/2013 05:57 AM by edkyle99 »

Offline MATTBLAK

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #37 on: 09/29/2013 05:25 AM »
Is it more feasible to air start an RS-68 than an RS-25, which had some early traction as the late, unlamented Ares 1 upper stage engine? An RS-68 is a really heavy engine with relatively low specific impulse - albeit better than a hypergolic or hydrocarbon upper stage engine. Since the J-2X is already mostly developed now; would using 2x those in a 5 meter diameter stage be feasible? I remember some discussions on the old Ares 1 threads that had 2x J-2X as possible, but a bit of a tight fit. Or since we'd want to leave the Delta IV stage unaltered, I suppose, making the RS-68 airstartable is the easiest option?
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Re: Common US: DUUS/Pyrios Single Stick
« Reply #38 on: 09/29/2013 06:22 AM »
That Pyrios/Delta is one looooonngg, skinny dude, eh? ;)
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Re: Common US: DUUS/Pyrios Single Stick
« Reply #39 on: 09/29/2013 06:26 AM »
That Pyrios/Delta is one looooonngg, skinny dude, eh? ;)

Side-mount it!
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Re: Common US: DUUS/Pyrios Single Stick
« Reply #40 on: 09/29/2013 08:17 AM »
That Pyrios/Delta is one looooonngg, skinny dude, eh? ;)

Side-mount it!

 :D  ;) Don't you start!!
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Offline Lobo

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #41 on: 09/30/2013 10:04 PM »
I am curious to know whether DUUS is appropriately sized such that it could serve as the US on top of Pyrios, and if not whether slight modifications could make it work.
It could, but it would not be efficient.  The relatively limited thrust of DUUS (about 55 tonnes max) would limit how much propellant could be loaded onto the stage (offloaded from the maximum 130 tonnes possible), which would reduce payload.  My estimate is that the LEO payload of a "Pyrios/DUUS" would be something like 25 tonnes, assuming a minimum DUUS T/W of 0.4, which would require a 40 tonne propellant offload.  Now if more thrust could be provided (six engines?) the tanks could be full and LEO payload could easily surpass 30 tonnes.  But, of course, this creates a new stage with added expense.


Ed, as I mentioned above, the current DUUS concept looks like it could mount either four RL-10's, or two MB-60's, right?  In following Tom's hypothetical, could the DUUS not be made to mount 2 or 4 MB-60's, as MB-60 really is about the same size as RL-10.  Sort of like how ACES would be made to mount either two or four RL-10's?  So just two MB-60's would be used on SLS, but four MB-60's could be used as a Pyrios US.  That's 240klbs of thrust with very good ISP.  Less thrust than J2X but better ISP.  And I think four MB-60's would be about the same or less than a single J2X.

Could that make a "TUUS" out of the "DUUS"?  Triple Use Upper Stage?


But of course Saturn IB didn't have a Delta IV Heavy already flying.  A Pyrios/DUUS must have a reason to exist, and with the performance numbers presented above I don't think it does.

That was my only reason easlier in my comments about the need for it as "feasible".  It's not feasibel if there is no reason for it, even if it's technically a sound LV.




Offline Lobo

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #42 on: 09/30/2013 10:07 PM »
He did mention the idea of switching out the engine cluster for a J-2X for this application, and having two versions of the stage.  You'd have to change a lot, though...

Hence my thought of plumbing the DUUS for two or four MB-60's.  The concepts are plumbed for either two MB-60's or four RL-10's already and those engines are very similar in size.  Would mean the DUUS would need MB-60 and not RL-10 though.

Either that or give the DUUS a single J2X in from the start for use on SLS.  Basically make an S-IVB stage out of it.  Obviously in Boeing's paper on the use of the DUUS for LEO and BLEO payload they evaluated the four RL-10 version and single J2X version.  If there was a need for a Pyrios LV, then that'd give a reason to go with the J2X on it.
« Last Edit: 09/30/2013 10:08 PM by Lobo »

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #43 on: 09/30/2013 10:12 PM »
That Pyrios/Delta is one looooonngg, skinny dude, eh? ;)

The Manute Bol of the rocketverse?

Online edkyle99

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #44 on: 10/01/2013 03:50 PM »
Ed, as I mentioned above, the current DUUS concept looks like it could mount either four RL-10's, or two MB-60's, right?  In following Tom's hypothetical, could the DUUS not be made to mount 2 or 4 MB-60's, as MB-60 really is about the same size as RL-10.  Sort of like how ACES would be made to mount either two or four RL-10's?  So just two MB-60's would be used on SLS, but four MB-60's could be used as a Pyrios US.  That's 240klbs of thrust with very good ISP.  Less thrust than J2X but better ISP.  And I think four MB-60's would be about the same or less than a single J2X.
A Pyrios with an up-thrusted DUUS (either two MB/RL-60s or a J-2X) would lift 32-ish tonnes to LEO.  Addition of an ICPS third stage would get 17 tonnes to GTO or 14 tonnes to escape velocity.  Those numbers are better than Delta 4 Heavy, but not substantially.  Performance is limited by DUUS thrust to weight.

The problem is that DUUS would have two different configurations, one for SLS and one for Pyrios.  Pyrios/Delta 4, or something like it that takes advantage of that 3.6 million pounds of liftoff thrust, still looks like a better idea to me.

And by the way, Pyrios, because it is designed for SLS forward lift, has a lousy propellant mass fraction compared to a purpose-built serial stage.  If not for the SLS compromise, a Pyrios/Delta 4 would lift more than 55 tonnes to LEO or 24 tonnes to GTO!

 - Ed Kyle
« Last Edit: 10/01/2013 04:09 PM by edkyle99 »

Offline Lobo

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #45 on: 10/01/2013 10:48 PM »
Sounds kinda like what I was thinking.  It -could- be done, but there's really no reason for it.  Even by adding DCSS on top of the DUUS you don't get much more performance than the D4H with RS-68A's. 

On another note, I started a new thread to explore other Pyrios LV concepts other than just Pyrios/DUUS.  So as to not get OT on this thread.

http://forum.nasaspaceflight.com/index.php?topic=32976.0

I'd be curious to get Ed's input there.  :-)


Offline Lobo

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #46 on: 10/01/2013 10:51 PM »
Sounds kinda like what I was thinking.  It -could- be done, but there's really no reason for it.  Even by adding DCSS on top of the DUUS you don't get much more performance than the D4H with RS-68A's. 

That Pyrios/D4 concept is interesting though.  The "Manute Bol" Rocket.  ;-). 

On another note, I started a new thread to explore other Pyrios LV concepts other than just Pyrios/DUUS.  So as to not get OT on this thread.

http://forum.nasaspaceflight.com/index.php?topic=32976.0

I'd be curious to get Ed's input there.  :-)

Offline clongton

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #47 on: 05/17/2018 10:52 AM »
In my research wrt the Dynetics proposed LRB for SLS I came across this thread. It's been a long time since anyone posted here and I considered starting a new thread to ask the question I do at the bottom but wasn't sure if that would be appropriate given that events have long since overtaken some of the basis of this thread. TomH was right - it kept going OT which is why, imo, nobody got to what was to be an obvious conclusion for the existence of this proposed vehicle; a Pyrios booster/1st stage and a DUUS.

But of course Saturn IB didn't have a Delta IV Heavy already flying.  A Pyrios/DUUS must have a reason to exist, and with the performance numbers presented above I don't think it does.

That was my only reason earlier in my comments about the need for it as "feasible".  It's not feasible if there is no reason for it, even if it's technically a sound LV.

Ed and Lobo, as sharp as both of you are I'm surprised you both missed the obvious: it did have a purpose. It would be the CLV for Orion, in exactly the same manner as Ares-1 was to be the CLV for Ares-5.

A lot of water has gone under the bridge since you guys wrote this and a lot of things have changed. But there is 1 thing that remains a perpetual problem for Orion; there are no USGov owned LVs capable of carrying it to LEO except SLS and ULA's DIVH. But DIVH is (1) not human rated and (2) is now being discontinued.

It has become increasingly obvious to me that the USGov intends to maintain a government owned/operated launch system in spite of increasing commercial capabilities. The trouble is that SLS won't even fly once a year and when it does it is gawd-awful expensive. So if the USGov wants to fly Orion more often than that it needs a human rated launcher other than SLS. Pyrios with an appropriate upper stage was to be that launcher if it's existence could be justified as the LRB for SLS. That was Dynetics clear statement in their paper. Today that would take a political firestorm with ATK to make that happen but it is still an interesting thought.

So the question now becomes, staying on topic for this thread as TomH clearly wanted, can the SLS upper stage as currently configured, serve as a DUUS, be mounted on Pyrios and take Orion to LEO?
« Last Edit: 05/17/2018 11:02 AM by clongton »
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Offline brickmack

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #48 on: 05/17/2018 03:19 PM »
At a first order guess, no:

Pyrios has a propellant mass of ~1.1 million pounds and a mass fraction of ~0.865 (including nose cone, I'll assume an interstage is similar mass). So dry mass of ~171700 pounds and wet mass of 1271676 pounds. EUS has a total mass of ~262000 pounds and dry mass of ~27000 pounds. The USA weighs 9650 pounds. Orion is 56985 pounds, plus 3050 pounds for the SM fairing (not jettisoned until orbit), plus 16850 pounds for the LAS (dropped at first stage shutdown?).

Total liftoff mass then is 1603361 pounds. At first stage burnout, its 520235 pounds. At second stage start, 331685. At second stage burnout, 96685, though in reality the EUS burn would probably be so long it couldn't complete before entering orbit or reentering.

Pyrios liftoff thrust was 3.61 million pounds-force, so 2.25 TWR. Pretty good (remember, a pair of these were meant to lift a giant sustainer plus upper stage which were very nearly unpowered at liftoff, so its gonna be pretty overpowered for a single-stick). F-1B's ISP was 273-299 seconds at SL and vac respectively. So first stage delta v will be somewhere between  3.0 and 3.3 km/s. This is pretty low. RL10 has an ISP of ~460 seconds, so 5.56 km/s. Oh no. Total delta v (and remember, this is a best case, using vacuum ISP for the entire first stage flight and assuming that the second stage will have time to burn through all its propellant, which I've not even gotten to yet) is only ~8.9 km/s, about 0.5 short of the typically accepted requirement to get to LEO.

Interestingly, the Ares I upper stage actually performs *better*, despite being smaller and having a lower ISP engine. Because of the common bulkhead, and having the same diameter as Orion which eliminates the need for a heavy conical adapter, it actually has a higher wet mass but a comparable dry mass. And since it produces ~3x the thrust of 4 RL10s, it'll probably actually burn through all that fuel in a reasonable time.

If you're going to insist on EUS as it currently exists, you're probably going to have to make some changes elsewhere. Moving to composite intertank and interstage structures on Pyrios could save a couple tons. A common bulkhead would be even better (and could increase propellant mass while leaving the external dimensions the same, so it still fits on SLS). Since 2 F-1Bs are so overpowered for the single-stick configuration, you could save probably 6 or 7 tons by dropping one of them and adding a couple vernier engines for roll control/extra liftoff thrust. TWR would be lower, but it should still be manageable (~1.13). A structural-only version of the USA, without payload support, might shave off a bit. Orions tanks could be underfueled by a few tons on a LEO-only flight. And since this rocket is so much smaller (and lacks solids), you could probably halve the mass of the LAS. Even then its gonna be iffy though, because of the low thrust from the RL10s mainly, and thats a lot of modifications plus custom hardware.
« Last Edit: 05/17/2018 03:21 PM by brickmack »

Offline Oli

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #49 on: 05/18/2018 11:38 AM »
So the question now becomes, staying on topic for this thread as TomH clearly wanted, can the SLS upper stage as currently configured, serve as a DUUS, be mounted on Pyrios and take Orion to LEO?

?

Falcon, Vulcan, New Glenn and maybe even Omega could launch Orion to LEO. A departure stage could be launched separately by any of those rockets as well.

Offline clongton

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #50 on: 05/18/2018 12:34 PM »
So the question now becomes, staying on topic for this thread as TomH clearly wanted, can the SLS upper stage as currently configured, serve as a DUUS, be mounted on Pyrios and take Orion to LEO?

?

Falcon, Vulcan, New Glenn and maybe even Omega could launch Orion to LEO. A departure stage could be launched separately by any of those rockets as well.

Oli this is about a government-owned launch system. The US Gov will use commercial launchers for other things but definitely wants to maintain its own human launch capability. That's what this thread was predicated on - a US Gov owned and operated human launch system. NASA is ceding LEO to Commercial but want's it's own BLEO capability, including entering LEO to meet up with the BLEO mission hardware. This is CxP being resurrected.
« Last Edit: 05/18/2018 12:38 PM by clongton »
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Offline MaxTeranous

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #51 on: 05/18/2018 01:08 PM »
"Maintain" is an entertaining word in the circumstances. US Gov hasn't owned a HSF LEO capable vehicle since 2011, and a BEO one since 1973 !

Offline envy887

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #52 on: 05/18/2018 01:20 PM »
So the question now becomes, staying on topic for this thread as TomH clearly wanted, can the SLS upper stage as currently configured, serve as a DUUS, be mounted on Pyrios and take Orion to LEO?

?

Falcon, Vulcan, New Glenn and maybe even Omega could launch Orion to LEO. A departure stage could be launched separately by any of those rockets as well.

Oli this is about a government-owned launch system. The US Gov will use commercial launchers for other things but definitely wants to maintain its own human launch capability. That's what this thread was predicated on - a US Gov owned and operated human launch system. NASA is ceding LEO to Commercial but want's it's own BLEO capability, including entering LEO to meet up with the BLEO mission hardware. This is CxP being resurrected.

Wouldn't it be faster and cheaper to use commercial to get to LEO (since commercial will be well-established there anyway) and use a USG owned and operated deep space transfer vehicle to go BLEO? E.g. Orion with a large refuelable hypergol stage, or bought and owned "off-the-shelf" technology similar to ACES/XUES.

Offline clongton

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #53 on: 05/18/2018 06:19 PM »
So the question now becomes, staying on topic for this thread as TomH clearly wanted, can the SLS upper stage as currently configured, serve as a DUUS, be mounted on Pyrios and take Orion to LEO?

?

Falcon, Vulcan, New Glenn and maybe even Omega could launch Orion to LEO. A departure stage could be launched separately by any of those rockets as well.

Oli this is about a government-owned launch system. The US Gov will use commercial launchers for other things but definitely wants to maintain its own human launch capability. That's what this thread was predicated on - a US Gov owned and operated human launch system. NASA is ceding LEO to Commercial but want's it's own BLEO capability, including entering LEO to meet up with the BLEO mission hardware. This is CxP being resurrected.

Wouldn't it be faster and cheaper to use commercial to get to LEO (since commercial will be well-established there anyway) and use a USG owned and operated deep space transfer vehicle to go BLEO? E.g. Orion with a large refuelable hypergol stage, or bought and owned "off-the-shelf" technology similar to ACES/XUES.

Yes it would be faster and cheaper. But remember you're dealing with government bureaucracies that are hory with age. Common economic sense has no meaning. The power brokers in DC are fine with supporting commercial capabilities but not at the expense of a US Gov capability. Over time that may change but not until the ancients that occupy the hallowed halls of of Congress have been replaced by people that have spent more of their lives outside of Congress than in it. Their calling card is "that's the way we've always done it", and their "always done it" is history half a century past. None of us like that, but it is what it is. YMMV
« Last Edit: 05/18/2018 06:20 PM by clongton »
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Offline TomH

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #54 on: 05/19/2018 01:37 AM »
I started this thread way back when Pyrios seemed a real possibility and reusable rockets were a pipe dream. Pyrios has long since died, F9 Block 5s are flying, Raptor has thousands of minutes testing, and there is a Mastadon sized elephant in the room ready to walk all over SLS.

If we are going to rehash this subject, let's all remember that it is purely an academic review of how things could have been different, and that it has no bearing on today's reality. Something infinitely more efficient will soon be flying and we're only debating what ifs of ancient history.

Offline Oli

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #55 on: 05/19/2018 04:01 AM »
So the question now becomes, staying on topic for this thread as TomH clearly wanted, can the SLS upper stage as currently configured, serve as a DUUS, be mounted on Pyrios and take Orion to LEO?

?

Falcon, Vulcan, New Glenn and maybe even Omega could launch Orion to LEO. A departure stage could be launched separately by any of those rockets as well.

Oli this is about a government-owned launch system. The US Gov will use commercial launchers for other things but definitely wants to maintain its own human launch capability.

I think it's less about the government operating rockets but about subsidizing the industry, that is Boeing, ATK and Aerojet. Providing a guarantee for NASA launches on Vulcan/Omega might be a way to get away from SLS while keeping contractors happy.


Offline TomH

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #56 on: 05/19/2018 04:46 AM »
The only viable way I see SLS actually being productive is through this radical change. I know it isn't going to happen because of the too numerous political and economic interests involved. But if those entities wanted it to work, they could make it work.

I would forget advanced boosters, new RS-25s, upper stages, pad changes, man-rating iCPS. I would slightly downsize the SLS core, strengthen its walls, put J2-X engines on it and turn it into a single disposable massive high-energy upper stage. I would then pay SpaceX to launch this thing on top of BFB. You could easily send Orion with a lander to the moon. You could reprop  the thing in LEO and send a mission to Mars. Boeing would still get its pork, AJR would get to build engines, SpaceX would get more income from using its giant booster. Only Orbital-ATK would lose out. (How close is Hatch to retirement?)

Yes, it would mean redesign and more delays, but J2-X is done. Again, no more pad mods, no EUS to deal with, no man-rating iCPS, no tower mods, no advanced boosters, no RS-25E. Yes, you'd have flight control hardware and software integration headaches, but you'd have one single main stage to pay for and you'd get a lot more than 130 mT to LEO and real throw weight to BLEO. And you could probably do a lot more than one launch per year.

But I know. Ain't gonna happen. If you want a high energy disposable US to deep space though, this would be one hell of a rocket. Isn't landing BFS on the moon a lot cheaper? Of course it is! But that doesn't send any pork to Boeing and AJR; this does.
« Last Edit: 05/19/2018 06:09 AM by TomH »

Offline Zed_Noir

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #57 on: 06/04/2018 07:46 AM »
The only viable way I see SLS actually being productive is through this radical change. I know it isn't going to happen because of the too numerous political and economic interests involved. But if those entities wanted it to work, they could make it work.

I would forget advanced boosters, new RS-25s, upper stages, pad changes, man-rating iCPS. I would slightly downsize the SLS core, strengthen its walls, put J2-X engines on it and turn it into a single disposable massive high-energy upper stage. I would then pay SpaceX to launch this thing on top of BFB. You could easily send Orion with a lander to the moon. You could reprop  the thing in LEO and send a mission to Mars. Boeing would still get its pork, AJR would get to build engines, SpaceX would get more income from using its giant booster. Only Orbital-ATK would lose out. (How close is Hatch to retirement?)

Yes, it would mean redesign and more delays, but J2-X is done. Again, no more pad mods, no EUS to deal with, no man-rating iCPS, no tower mods, no advanced boosters, no RS-25E. Yes, you'd have flight control hardware and software integration headaches, but you'd have one single main stage to pay for and you'd get a lot more than 130 mT to LEO and real throw weight to BLEO. And you could probably do a lot more than one launch per year.

But I know. Ain't gonna happen. If you want a high energy disposable US to deep space though, this would be one hell of a rocket. Isn't landing BFS on the moon a lot cheaper? Of course it is! But that doesn't send any pork to Boeing and AJR; this does.

Interest concept. Presuming SpaceX don't offered to put something like a half size 12 meter diameter ITS booster core with a few Raptor Vac engines on top of the BFB as a cheaper and more capable alternative. The problem with keeping the 8.4 meter core size is that it limits the capabilities  of the launcher in comparison to future launchers in the 9 to 15 meters range.

Offline Lobo

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #58 on: 06/06/2018 11:00 PM »
In my research wrt the Dynetics proposed LRB for SLS I came across this thread. It's been a long time since anyone posted here and I considered starting a new thread to ask the question I do at the bottom but wasn't sure if that would be appropriate given that events have long since overtaken some of the basis of this thread. TomH was right - it kept going OT which is why, imo, nobody got to what was to be an obvious conclusion for the existence of this proposed vehicle; a Pyrios booster/1st stage and a DUUS.

But of course Saturn IB didn't have a Delta IV Heavy already flying.  A Pyrios/DUUS must have a reason to exist, and with the performance numbers presented above I don't think it does.

That was my only reason earlier in my comments about the need for it as "feasible".  It's not feasible if there is no reason for it, even if it's technically a sound LV.

Ed and Lobo, as sharp as both of you are I'm surprised you both missed the obvious: it did have a purpose. It would be the CLV for Orion, in exactly the same manner as Ares-1 was to be the CLV for Ares-5.

A lot of water has gone under the bridge since you guys wrote this and a lot of things have changed. But there is 1 thing that remains a perpetual problem for Orion; there are no USGov owned LVs capable of carrying it to LEO except SLS and ULA's DIVH. But DIVH is (1) not human rated and (2) is now being discontinued.

It has become increasingly obvious to me that the USGov intends to maintain a government owned/operated launch system in spite of increasing commercial capabilities. The trouble is that SLS won't even fly once a year and when it does it is gawd-awful expensive. So if the USGov wants to fly Orion more often than that it needs a human rated launcher other than SLS. Pyrios with an appropriate upper stage was to be that launcher if it's existence could be justified as the LRB for SLS. That was Dynetics clear statement in their paper. Today that would take a political firestorm with ATK to make that happen but it is still an interesting thought.

So the question now becomes, staying on topic for this thread as TomH clearly wanted, can the SLS upper stage as currently configured, serve as a DUUS, be mounted on Pyrios and take Orion to LEO?

Hello Chuck,

Yea, dusting off some old discussions here.

First I think in the scope of 2013 when we were discussing this, SLS was going to be CLV.  There was not talk of a lander post CxP.  And the 1.5 architecture of CxP seemed to have been scrapped for a Shuttle Derived (using the term loosely) version of Saturn V.  SLS would evolve to a more capable LV than Saturn V with advances like the F-1/B powered Advanced boosters, and some sort of larger upper stage to replace the iCPS.

So that's probably why I said there was no reason for it...in that context. 

If there was to be some move back to to the 1.5 launch of CxP, and funding for a lunar lander, then yea, Pyrios would have been a better CLV than Ares 1.  If it could have used the SLS larger upper stage directly would be a matter of what size/capability that stage ended up being.  Had it been the plan from the start to use it for both SLS and Pyrios, then maybe it could have been designed with some ability to taylor it for one or the other in production.  Maybe a partial prop load and fewer engines for Pyrios, and then the full version for SLS?
DUUS and DUUS-Lite?

If there was a political push for a government run smaller CLV to compliment SLS...as well as additional funds for it...and for a lander that would necessitate a separate CaLV and CLV, then yea, I think it could work.

But today, with FH now flying and available, it would be able to launch the Orion CSM to LEO partially reusable.  It's going to be man-rated anyway.  So even with the government wanting to own and operate their own CLV as the premise, it's still pretty debatable that FH wouldn't get that job, and save NASA the cost of developing and operating Pyrios.  Plus FH launches from 39A, so it would be a good compliment to SLS launching from 39B for dual launch, able to launch both in quick succession.  Otherwise Pyrios needs to launch from 39B along with SLS, and then loiter time of the DUUS/EUS and lander would be an issue, and probably add additional cost to the DUUS/EUS for that.  So even with the way the government works, I think there'd be a big uphill battle to get funds to allocate for Pyrios right now.

Although Elon is wanting to replace SLS with BFR/BFS I'm sure, I also think he'd happily offer FH to NASA for this purpose on a CRS contract that would be cheaper than developing Pyrios, and use that revenue to help fund BFR/BFS.  It'd bring in money and ultimately give additional credibility to SpaceX for human space flight as they push forward with their Mars plans.





Offline Patchouli

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #59 on: 06/07/2018 12:13 AM »
There are some structural limitations on having FH launch a payload the mass of a fully fueled Orion so there Pyrios might still make some sense there and they probably could have even reused the Ares I upper stage though New Glenn could lift roughly the same payload.
« Last Edit: 06/07/2018 12:15 AM by Patchouli »

Offline Lobo

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #60 on: 06/07/2018 10:16 PM »
There are some structural limitations on having FH launch a payload the mass of a fully fueled Orion so there Pyrios might still make some sense there and they probably could have even reused the Ares I upper stage though New Glenn could lift roughly the same payload.
Not sure what limitations those would be.  The current version of Orion CSM is ~26mt.  FH has a much greater payload capability than that, and I'm assuming it can handle it's full expendable maximum payload capacity of 63mt+ (or else why advertise it?)
And the width of Orion isn't any wider than the PLF. 

Moreover the new crew access arm at 39A will be in the correct location for Orion, as it's going to be placed there for Dragon 2 on F9, which is the same height as FH.
Would be some costs to adapt the crew access arm to accommodate the hatch on Orion vs. Dragon 2, and some costs for the Orion to FUS adaptor, but those would be very minor compared to the development of Pyrios, even if the DUUS/EUS were designed to be compatible both it Pyros and SLS.

Now, if the SLS program were to get the F-1B LRB's rather than the Advanced Solids, and the DUUS/EUS were designed from the start to be compatible with the booster and SLS, then development costs would be greatly reduced, obviously.
However, I still the the case of that over FH would be very difficult for the remaining reasons.
1)  Pyrios would need another MLP, with connections specific to it.  It couldn't readily use the SLS MLP
2)  Even if it could launch off a side port of the SLS MLP, like Ares 1X did with the Shuttle MLP SRB side port, you wouldn't want to do that because you would be going back to the 1.5 launch scenario of CxP, so you'd want 2 MLP's, one for each, so you could launch them in as quick of succession as possible.   So you have the cost of a MLP for Pyrios.
3)  Pyrios still needs a new interstage adapter designed to mate the LRB with DUUS/EUS, as well as an adaptor to mate Orion with the EUS (similar to the adaptor FH would need to mate Orion with the FUS, this will be an expense whether Orion launches on SLS or Pyrios)
4)  It will always be faster to do a 1.5 launch when you can use both KSC pads, rather than just one for two launches.  Even with two MLP's, probably looking at a couple weeks between launches by the time they clear/inspect/repair the pad from the SLS launch, and roll Pryios/Orion out there and do all the preflight prior to launch.  By using both pads, the crew can literally go up the same day as SLS.

That could all be ignored and Pyrios built anyway...especially if the LRB's were going to be, or had been chosen over the Advanced Solids...but it's still a tough argument to make.  Others in Congress will argue against that extra development when there's a man rated, partially reusable LV with the capability to take Orion up already currently flying.
Since Advanced Solids seem to already be chosen as the SLS upgrade, the chance of Pyrios now is pretty much zero, IMO.


Offline envy887

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #61 on: 06/08/2018 12:43 AM »
There are some structural limitations on having FH launch a payload the mass of a fully fueled Orion so there Pyrios might still make some sense there and they probably could have even reused the Ares I upper stage though New Glenn could lift roughly the same payload.

Source? Capsules would not use the standard PAF. There is no such structural limitation to the upper stage AFAIK.

The is no valid reason for a USG operated medium/heavy (not super-heavy) launch vehicle.

Offline Khadgars

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Re: Common US: DUUS/Pyrios Single Stick
« Reply #62 on: 06/08/2018 04:14 PM »
I started this thread way back when Pyrios seemed a real possibility and reusable rockets were a pipe dream. Pyrios has long since died, F9 Block 5s are flying, Raptor has thousands of minutes testing, and there is a Mastadon sized elephant in the room ready to walk all over SLS.

If we are going to rehash this subject, let's all remember that it is purely an academic review of how things could have been different, and that it has no bearing on today's reality. Something infinitely more efficient will soon be flying and we're only debating what ifs of ancient history.

While I agree, if BFR does fly, everything currently flying or in-work become obsolete over night.  But imo I think we're well over a decade away before that becomes a reality.  A bird in hand is worth two in the bush applies here ;p

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