Author Topic: Common US: DUUS/Pyrios Single Stick  (Read 34123 times)

Offline MATTBLAK

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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 »

Offline 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 »

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