Author Topic: Common US: DUUS/Pyrios Single Stick  (Read 25540 times)

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.

Offline Lobo

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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 »

Offline sdsds

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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 »

Offline edkyle99

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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...

Offline sdsds

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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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Online 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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Offline edkyle99

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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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Offline MATTBLAK

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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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