Author Topic: Alternative HLV Concepts  (Read 76075 times)

Online edkyle99

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Re: Pyrios Alternative HLV Concept
« Reply #40 on: 10/09/2013 07:52 pm »
But as to my previous quandry, can there simply be a scaled up Delta IV?  Rather than a 3-stage rocket?  Can you have a 10m core (or maybe 11 or 12m?) with seven RS-68A's (Assume for this they can be thermally protected enough to not fail), with say three or four RL-60's on an upper stage that also does a BLEO burn, just as the DCSS does on Delta IV now?  Or when the rocket is scaled up, does it need 3 stages?  I would think a single core Super-Delta would be more mass efficient than 7 Delta IV's, so it should at least be able to match the performance of 7 Delta IV's with just the two stages I would think.  (But I am no rocket engineer so I might be way off on that assumption.  :-)   )
I took a stab at this by starting with a six times scale up of Delta IV Medium.  I've assumed the Delta IV mass fractions (for the heavier RS-68A version), which is likely conservative.  The results provide a couple of clues for why I don't tend to end up with this result given the limitations of the VAB and the mission.

The six times scale up obviously needs six RS-68A first stage engines and six RL10B-2 second stage engines.  In reality, it isn't possible as I understand it to actually cluster that many RL10B-2 engines due to the size of the nozzle extensions, but lets not worry about that detail right away, shall we?  This gives us the Delta IV liftoff T/W ratio of a bit more than 1.2 with a second stage T/W ratio of about 0.42 at engine start. 

We get about 20 tonnes to escape velocity.  For LEO missions, second stage propellant must be offloaded to keep T/W2 >= 0.42, which is what also happens with Delta IV Medium.  This results in a 200 km x 28.7 deg payload of about 55 tonnes.  These payload numbers are also roughly six times larger than Delta IV Medium.  To get SLS Block 1 equivalent performance then would require a 10 times scale up of Delta IV Medium, which is going to present a size problem.

You are right that a 10 meter first stage is required to fit the thing in the VAB.

 - Ed Kyle
« Last Edit: 10/10/2013 06:29 pm by edkyle99 »

Offline Lobo

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Re: Pyrios Alternative HLV Concept
« Reply #41 on: 10/10/2013 12:44 am »
I took a stab at this by starting with a six times scale up of Delta IV Medium.  I've assumed the Delta IV mass fractions (for the heavier RS-68A version), which is likely conservative.  The results provide a couple of clues for why I don't tend to end up with this result given the limitations of the VAB and the mission.


Very interesting. thanks Ed.


The six times scale up obviously needs six RS-68A first stage engines and six RL10B-2 second stage engines.  In reality, it isn't possible as I understand it to actually cluster that many RL10B-2 engines due to the size of the nozzle extensions, but lets not worry about that detail right away, shall we?  This gives us the Delta IV liftoff T/W ratio of a bit more than 1.2 with a second stage T/W ratio of about 0.42 at engine start. 


I think we could assume a cluster of like three MB-60's to stand in for six RL-10B-2's.  As I understand, the MB-60 was designed by Boeing (in partnership with MHI) as a replacement engine for the RL-10 on the DCSS's?  Probably particularly on the 5m DCSS, and I think could boost D4H's performance if there was a single MB-60 with that higher thrust for the heavier paylaods after staging.  They are very similar in size and mass to the RL-10B, with the same extendable nozzles.
So, I think we could assume 3 of them to sub in for 6 RL-10B's, but using the DUUS as a model, probably two or four would fit better.  Two might be a little under powered, but four should be pretty useful.  Four could be used for the rest of the ascent, and then just two light for the EDS burn?
Does a cluster of four on the upper stage change the performance any?  Or will be be similar to six RL-10's, but would actually fit under the stage?


We get about 20 tonnes to escape velocity.  For LEO missions, second stage propellant must be offloaded to keep T/W2 >= 0.42, which is what also happens with Delta IV Medium.  This results in a 200 km x 28.7 deg payload of about 55 tonnes.  These payload numbers are also roughly six times larger than Delta IV Medium.  To get SLS Block 1 equivalent performance then would require a 10 times scale up of Delta IV Medium, which is going to present a size problem.

You are right that a 10 meter first stage is required to fit the thing in the VAB.

 - Ed Kyle

For SLS Block 1B there will have to be propellant offload for LEO payloads too.  So that shouldn't be a problem. 

Yea, a 10X Delta IV would be a size problem. But, I'm thinking more of a two Medium-heavy class LV system.  Something more like 2X J-130.  Around 70mt to LEO each and like 25mt to escape.  55mt to LEO might be a little light for that.  Maybe a 7X Delta IV would fit, with four MB-60 engines on the upper stage?  Could we then make the upper stage 10m too?  so at least the LH2 tank can utilize the core tooling.  Maybe the LOX tank can use the 5m Delta IV tooling?
Assume the c7th and entral RS-68A on the core wouldn't melt for the sake of the excersize.
Or are we getting too tall?  Can we get the 10m core the same, add the 7th RS-68A, and make the upper stage a little bigger with four MB-60's?  Four MB-60's has the thrust of over 9 RL-10B's. 
We could add a 5th MB-60 on the upper stage, to account for the earlier staging with 7 RS-68A's.  But once in LEO, you can still do the EDS burn with just the central MB-60, or two opposite ones.  So as not to accelerate too fast if that was a problem.
The 5th MB-60 could require the LOX tank to be the same diameter as the core and LOX tank to fit 5 of them in a cross pattern.  Like the S-II.  Pretty sure you can't fit more than four of them on a 5 or 5.5m LOX tank.   Wouldn't have to be common bulkhead like the S-II, but two tanks of the same diameter with an intertank like the core, or like the Delta IV core.

I'm going to assume we'll have about the same performance with a 6X or 7X Atlas V?  Just might be able to have an 8.4m core with the denser kerolox?  Would that scale up with similar performance to our 6X Delta IV?







Offline TomH

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Re: Pyrios Alternative HLV Concept
« Reply #42 on: 10/10/2013 03:48 am »
Yout think the core needs strengthened, but why?  The 5-seg SRB will have about 3.5Mlbs of thrust at liftoff each.  How much will Pyrios have?  About 3.6Mlbs.  That's very similar.

But that's not what matters. The Pyrios will be much lighter and therefore have much more usable thrust, i.e. a higher thrust/weight ratio. Most of the thrust in that 5 segment will be just to lift its own self and not much more acceleration will be transferred to the core. The issue that comes out of this is something you did touch on further down in your post, that T/W means higher G loads on the core. In any case, however, these loads are applied at the thrust beam, so instead of buckling the core, they actually pull on the core and keep the cylindrical shape more true. Think about a thin Aluminum soda can. If you get the cylinder just a little out of true, you can easily crush it with your hands. OTOH, how likely is it you could take the two ends of that can in your hands and pull/rip it apart? You can't. A pulling force (which is what that thrust beam does to the core) must be much greater (for thin Aluminum at least)  than a pushing force to malform the cylinder. The tensile strength of the Al is greater than its resistance to flex or compression forces.
« Last Edit: 10/10/2013 03:55 am by TomH »

Offline Lobo

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Re: Pyrios Alternative HLV Concept
« Reply #43 on: 10/10/2013 05:00 am »
Yout think the core needs strengthened, but why?  The 5-seg SRB will have about 3.5Mlbs of thrust at liftoff each.  How much will Pyrios have?  About 3.6Mlbs.  That's very similar.

But that's not what matters. The Pyrios will be much lighter and therefore have much more usable thrust, i.e. a higher thrust/weight ratio. Most of the thrust in that 5 segment will be just to lift its own self and not much more acceleration will be transferred to the core. The issue that comes out of this is something you did touch on further down in your post, that T/W means higher G loads on the core. In any case, however, these loads are applied at the thrust beam, so instead of buckling the core, they actually pull on the core and keep the cylindrical shape more true. Think about a thin Aluminum soda can. If you get the cylinder just a little out of true, you can easily crush it with your hands. OTOH, how likely is it you could take the two ends of that can in your hands and pull/rip it apart? You can't. A pulling force (which is what that thrust beam does to the core) must be much greater (for thin Aluminum at least)  than a pushing force to malform the cylinder. The tensile strength of the Al is greater than its resistance to flex or compression forces.

True.

We discussed this with Starlab and some others on an L2 SLS thread awhile back.  I'd thought the same thing, the boosters might actually lift the core up and put it in tension rather than compression.  Someone wondered if the core -could- withstand being in tension?  Never got a good answer to that though.  Seems like it should be ok, but rocket cores aren't soda cans (even though they are both aluminum).  It might not be designed for tensile forces...or at least not for both tensile (during booster phase) and compression (after booster separation). I can't remember for sure, but I think I or someone else estimated the rough mass of the core from the intertank/thrust beam on down, and I think it was less mass than the four RS-25's would put out.  So I think there's enough thrust pushing on the bottom that will keep the core in at least some compressions during liftoff.
Obviously, it would seem the maximum bending loads on the core will be after booster separation, when the core is in compression over it's entire length.  And this is where a taller stack for some of the Block II options could result in a full core redesign, because with height added to the stack, that increases those bending loads both from the additional stack height, but from a 5th RS-25 on the bottom.
Where if you add different boosters, the booster interfaces will need to be modified, but the core itself may not be.
(Titan IV didn't even light the core until booster separation, but the Titan SRB's lifted from the bottom, not the top, so the core was still in compression).

Which takes us back to your first point about Pyrios bosoters being lighter so they have better T/W ratio than 5-seg's.  And that's true.  We'd have to see some numbers for the weight of a fully fueled Pyrios vs. a 5-seg to see how much that difference would really be.
But...I don't know what it really matters.  I was just pointing out that the LRB's might not really be much more "powerful" in thrust than the Solids.  But they will burn longer and have better ISP than solids, thus improving overall performance. 
And since SLS will be a man-rated LV, they'll be tailoring it's ascent profile to keep g-loads below a maximum (4g's I think?)  So even if Pyrios boosters were -able- to put a lot greater loads on the core, wouldn't they have a process of combining core throttle down with boosters throttle down to keep those g-loads under 4g's?  I think the 5-seg SRB's will be designed to self throttle to keep the loads down as the 4-seg STS boosters were.  And if the ATK paper is accurate, the Dark Knights would have 4.5Mlbs of thrust -and- be lighter than the 5-seg.  SO they could be the most powerful boosters.  however, again, NASA will have g-load limits so while they might have that at lift off and shortly there after to get the stack off the pad and accelerating, they'd be tapered to start reducing thrust as it accelerates to keep loads moderated.

Or am I misunderstanding how that works?  I understand it to usually only needing that max thrust to break the inertia of sitting on the pad and overcome those initial gravity losses.  But as it gets moving, it needs less and less thrust to keep accelerating.  And thus many rockets have boosters and extra engines shedding off, and engines throttling down and/or shutting off.

So...that brings us back to the question of if the core itself will need to be strengthened to accommodate Block II, if Block II is Block 2B, and thus no taller than Block 1B, and with the same number of engines on the core?  Will it need more than new boosters interfaces?

That's how I understood it on the L2 SLS discussion anyway.  I think Starlab said something to that effect.  And that making the stack taller in block 2 by having the larger-than-DUUS J2X upper stage, and a CPS, with the 5th engine on the core, would likely need core strengthening.

« Last Edit: 10/10/2013 05:04 am by Lobo »

Online edkyle99

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Re: Pyrios Alternative HLV Concept
« Reply #44 on: 10/10/2013 05:16 pm »
Ed,

There's a Boeing AIAA paper out as of about a month ago.
"The Space Launch System Capabilities with a New Large Upper Stage"
I can't post it as it was shared with be with the instructions not to post it.
But, I did list some performances above (I'm hoping that is ok.  :-)  )

It lists performance for Block 1, and the three Block 1B configurations, four RL-10's, two MB-60's, and one J2X.
I notice your numbers for Block 1, and Block 1B with four RL-10's to LEO and escape in your drawing.
Per the Boeing paper?

LEO: 
Block 1:  LEO:  70mt
              TLI:  24mt

Block 1B (with four RL-10's)
LEO:  93.1mt
TLI:  39.1mt

Those are a little less than you are showing for Block 1 and 1B to LEO and Escape. I think Escape is usually less mass than TLI?

Just just thought I'd mention that.  Are your numbers for Block 1 and 1B a little high? (I have no idea myself)
My drawing showed a high number for Block 1/ICPS Escape.  I've now retroactively fixed that.  The higher number was likely for a different stage, ICPS obviously being the limiting factor.  Block 1B performance depends on the size of the second stage, which varies from Boeing paper to Boeing paper.  My numbers came from last year's Boeing paper!  Pardon my skepticism, but since this paper presumably supports a J-2X powered Large Upper Stage, the authors would have no incentive to show the maximum possible for a DUUS.  ;)

Block 1 LEO is given as 70 tonnes in the contract, so that's simply the end of the discussion even though much more is possible.  (That Boeing paper looks like a managerial level overview, so it'll show the contract number.)  The fact is that Block 1 will during its brief life never lift even 70 tonnes and never to LEO.  It is going to fly twice on cis-lunar tests with a 31+tonne ICPS and a 24.2-ish something tonne MPCV.  They will be injected initially into an elliptical orbit, so LEO specifically is a useless number for this configuration.

 - Ed Kyle
« Last Edit: 10/10/2013 06:39 pm by edkyle99 »

Offline Lobo

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Re: Pyrios Alternative HLV Concept
« Reply #45 on: 10/11/2013 04:52 am »
My drawing showed a high number for Block 1/ICPS Escape.  I've now retroactively fixed that.  The higher number was likely for a different stage, ICPS obviously being the limiting factor.  Block 1B performance depends on the size of the second stage, which varies from Boeing paper to Boeing paper.  My numbers came from last year's Boeing paper!  Pardon my skepticism, but since this paper presumably supports a J-2X powered Large Upper Stage, the authors would have no incentive to show the maximum possible for a DUUS.  ;)


Here's the paper right here.  Unfortunately it's paywalled.  I'd love to post it but was asked not it so I want to respect it.  I'm sure it'll get here sooner or later.  :-)

http://arc.aiaa.org/doi/abs/10.2514/6.2013-5421

And it actually completely about Block 1 and Block 1B.  No mention of any Block 2 variant.  It gives data on Block 1, and then the 3 different engine versions of the DUUS (they refer to it as "Large Upper Stage").   But they list all the cores as having 4 RS-25's, not 5, so this isn't looking at one of the optional upgrades which have a J2X larger upper stage on a 5 engine core.  It's Block 1B.

And it doesn't really "support" any engine, just gives performance information for each, as well as some cool CG art showing the RL-10 version and the J2X version (and the MB-60 version stacked, so it's harder to see the engines).  It also gets into possible missions for it like a Uranus probe, a solar probe, a BA-2200 like inflatable station module, and the ATLAST telescope.  And how block 1B SLS would make these different missions possible.

It also gives a full loaded mass for the DUUS at about 120mt, with 105mt usable propellant load.

The J2X version allows for less propellant offload for LEO payloads and about 105mt to LEO.
The RL-10 version and MB-60 version are 93 and 97mt respectively with more propellant offload.
But the RL-10 and MB-60 have better BLEO performance, and it gets more pronounced the farther away from LEO you go.  TLI, TMI, Europa, Titan, and Uranus.    It gives performances for all of those trajectories for the Block 1 and three block 1B DUUS engine variants.


Block 1 LEO is given as 70 tonnes in the contract, so that's simply the end of the discussion even though much more is possible.  (That Boeing paper looks like a managerial level overview, so it'll show the contract number.)  The fact is that Block 1 will during its brief life never lift even 70 tonnes and never to LEO.  It is going to fly twice on cis-lunar tests with a 31+tonne ICPS and a 24.2-ish something tonne MPCV.  They will be injected initially into an elliptical orbit, so LEO specifically is a useless number for this configuration.

 - Ed Kyle

I have a post about this here:

http://forum.nasaspaceflight.com/index.php?topic=32035.msg1106630#msg1106630

Up until now I'd always thought that 70mt number for Block 1 was just a political number.  NAA2010 required it for the first iteration of the SLS and NASA said, "Sure, our first version will do that". 

But...maybe that's actually going to be the Block 1 number?  It seemed implausible for the reasons I mention in that post, but maybe it's accurate?  I'd always kinda thought Block 1 would be closer to the LV 26/27 form ESAS, of performance in the mid 90mt range with no upper stage.
Maybe it's accurate, especially if the Block 1B numbers are 93, 97, and 105mt tons depending on engine.

But like you said, Block 1 will never be putting 70mt in LEO.  And while block 1B can put 93-105mt to LEO depending on engine, that's with propellant offload, and that payload isn't going any further than LEO once it does it.  otherwise it'll have a full DUUS and a smaller payload, and then push right on through BLEO.

(That, according to the new Boeing paper anyway).


Online edkyle99

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Re: Pyrios Alternative HLV Concept
« Reply #46 on: 10/11/2013 03:10 pm »
And finally here is an F-1B based core option.  Again I've optimized these for Escape missions and made them with only two stages, EELV style.  A two-stage core can roughly do the SLS Block 1 mission.  Switching to an RP core solves the VAB height constraint.  Adding F-1B boosters gets the machine to Block 2 capability.  As far as I'm concerned, the Block 1 rocket could run any space program.

 - Ed Kyle
« Last Edit: 10/11/2013 03:11 pm by edkyle99 »

Offline Lobo

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Re: Pyrios Alternative HLV Concept
« Reply #47 on: 10/11/2013 04:17 pm »
And finally here is an F-1B based core option.  Again I've optimized these for Escape missions and made them with only two stages, EELV style.  A two-stage core can roughly do the SLS Block 1 mission.  Switching to an RP core solves the VAB height constraint.  Adding F-1B boosters gets the machine to Block 2 capability.  As far as I'm concerned, the Block 1 rocket could run any space program.

 - Ed Kyle

Winner, winner, chicken dinner!

That's exactly what I was looking for.  And I agree, the Block 1 would be just fine for a two launch architecture.  Block 2 could be developed later if it was deemed needed for like a Mars mission or something.
I think it would nicely hit that "larger than the EELV-class fleet", but "not such a huge BFR"

Two stages which share common tooling and would be made right next to each other at MAF.  Two engines only.  One is an updated version of an older engine that few.  The other was 90% finished by the time of ESAS.  No J2X "mostly from scratch" program.  And RL-60 could be shared with EELV's, as it was intended to replace RL-10 as I understand.
No new 5.5m ARes 1 upper stage.  No 5-seg SRB develop.  No new Advanced booster program (unless they want block 2 later, but then it shares the same engine as the core). 

By NAA2010, I don't know this would have saved any development money over Block 1B SLS.  There's still a core and an upper stage to develop, and much 5-seg money was already spent, left over from CxP.
However, this would reduce overhead by eliminating support of a booster.  Be that 5-seg or some advanced booster.  But back during ESAS this would have been a very nice 2-launch LV. 

They kinda looked at that with the Atlas X concept, although their concept was a little small perhaps. 5 RD-180's and 4 J2S's.   Which then bring me to a last LV concept question.  What performance would an RD-180 equivalent of this Block 1 LV be like?  THey existed and EELV's were already using them.  Rocketdyne has the rights to build a US-version if need be, if there was any inturruption in Russian supply.
I know the big GG F-1's would be simple and reliable, but RD-180's were already rolling off the assembly line and being used by another US launcher.  And seemed to have a pretty good reliability track record.   So there could be an argument to use them rather than develop the updated F-1.  Could you check those numbers to see how they compare to this Block 1?  Maybe 7 of them? or 8?  Two are needed to replace F-1B in thrust but they have better ISP, so I'm not sure what's optimum.

And one last question if I may.  This Block 1 has 27mt to escape.  (and that's a great point optimizing for BLEO).  What's it's TLI number?  Would that be around 33mt or something?  And could this upper stage be used like the DUUS in that, could it go along with Orion or a lunar lander, and perform the LOI burn?  Especially with those four RL/MB-60's.  You could light just two of them to do the LOI burn for a more gentle braking, then like a single J2X might do. 

I like those RL/MB-60's.  Great engines for this type of thing.  Awesome ISP and enough thrust that they can be used on anything from EELV medium class up to heavy lift (as long as it wasn't staging too early, like the S-1C).

 
« Last Edit: 10/11/2013 04:18 pm by Lobo »

Offline M129K

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Re: Pyrios Alternative HLV Concept
« Reply #48 on: 10/12/2013 09:46 am »
Lobo, could you post the exact specifications from the document about burnout mass and propellant mass for the SLS core? Knowing that would be a great help in the payload to LEO discussion.

Edit: Also, this thread has turned into a bit of a "show off your concepts" thread. I suck at paint, are pencil drawings allowed too?
« Last Edit: 10/12/2013 03:13 pm by M129K »

Offline Lobo

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Re: Pyrios Alternative HLV Concept
« Reply #49 on: 10/13/2013 04:51 am »
Lobo, could you post the exact specifications from the document about burnout mass and propellant mass for the SLS core? Knowing that would be a great help in the payload to LEO discussion.

Edit: Also, this thread has turned into a bit of a "show off your concepts" thread. I suck at paint, are pencil drawings allowed too?

m129K,
Sure, when I get a chance I'll post that.

Also, good point on the thread topic.  I changed the thread title accordingly to account for the HLV alternative concepts that have been discussed other than just the Pyrios based ones.

And yes, include pencil drawings.  I suck at Paint too.

:-)

Offline M129K

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Re: Alternative HLV Concepts
« Reply #50 on: 10/13/2013 05:17 pm »
Well, if I can...

The core would be 8.4m in diameter and about 50 meters high. It carries 1785.6 tons of propellant and has an empty mass of 134.4 tons, with a PMF of 0.93. Instead of F-1, I thought it would be a better idea to fuel it with something similar to the AJ-1E6, because of higher efficiency. It uses 5 of them. It can use large strap on boosters which use 3 AJ-1E6 engines, carry 742 tons of propellant and have a burnout mass of 76 tons. The second stage is based on the Boeing proposed LUS designed for SLS, but uses an RS-68A instead of J-2X, for lower cost and higher thrust. It can also use a modified DUUS, with 2 or 4 RL-60 engines, either for BEO missions or some extra oompf for LEO. The base vehicle without boosters or DUUS can bring 70 tons into LEO, the complete vehicle with boosters and DUUS can lift 150 tons to LEO.

Included is a quick sketch.... Sorry for the poor quality, I don't have a scanner on me here.
« Last Edit: 10/13/2013 05:20 pm by M129K »

Offline Zed_Noir

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Re: Alternative HLV Concepts
« Reply #51 on: 10/14/2013 06:26 am »
The core would be 8.4m in diameter and about 50 meters high. It carries 1785.6 tons of propellant and has an empty mass of 134.4 tons, with a PMF of 0.93. Instead of F-1, I thought it would be a better idea to fuel it with something similar to the AJ-1E6, because of higher efficiency. It uses 5 of them. It can use large strap on boosters which use 3 AJ-1E6 engines, carry 742 tons of propellant and have a burnout mass of 76 tons. The second stage is based on the Boeing proposed LUS designed for SLS, but uses an RS-68A instead of J-2X, for lower cost and higher thrust. It can also use a modified DUUS, with 2 or 4 RL-60 engines, either for BEO missions or some extra oompf for LEO. The base vehicle without boosters or DUUS can bring 70 tons into LEO, the complete vehicle with boosters and DUUS can lift 150 tons to LEO.


IIRC the RS-68A can not be air-started now.

Offline M129K

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Re: Alternative HLV Concepts
« Reply #52 on: 10/14/2013 01:22 pm »
I think that would be the least of our concerns in the development of such a vehicle. It could probably be modified to be air-started fairly easily.

Offline Lars_J

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Re: Alternative HLV Concepts
« Reply #53 on: 10/14/2013 03:43 pm »
I think that would be the least of our concerns in the development of such a vehicle. It could probably be modified to be air-started fairly easily.

Do you think so? The RS-68 appears to need a lot of ground equipment to start.

Offline Lobo

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Re: Pyrios Alternative HLV Concept
« Reply #54 on: 10/14/2013 04:17 pm »
Lobo, could you post the exact specifications from the document about burnout mass and propellant mass for the SLS core? Knowing that would be a great help in the payload to LEO discussion.


I posted some info here on it.

http://forum.nasaspaceflight.com/index.php?topic=32035.msg1108031#msg1108031

Block 1 core at 220.6klbs (100.062mt) and Block 1B core at 222.0klbs (100.7mt)
So almost idenitcal for the.  Unfortunatley it doesn't list the burnout mass, just the dry mass.  Although it also gives the following:

Usable prop:  2116.9klbs
startup prop 18.6klbs
non-usable:  30.9klbs

So maybe burnout is dry mass plus non-usable?

The DUUS info here:

they list the DUUS (they call the LUS) total mass of 264.2klbs (119.8mt), with 231.5klbs (105mt) of usable propellant, and a dry mass of 27.6klbs (12.5mt).  That dry mass is with the single J2X version of the DUUS. 
The J2X weighs 5,450lbs
The RL-10 weighs 664lbs each (2,656lbs for four)
So that DUUS weighs 262.75klbs fully fueled.

I thinkt he MB-60's weigh about 1300klbs, so two of them weight about the same as four RL-10's, give or take.   

Edit:  1300lbs, not kilns
« Last Edit: 10/15/2013 03:54 am by Lobo »

Offline M129K

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Re: Alternative HLV Concepts
« Reply #55 on: 10/14/2013 06:41 pm »
I posted some info here on it.

http://forum.nasaspaceflight.com/index.php?topic=32035.msg1108031#msg1108031

Block 1 core at 220.6klbs (100.062mt) and Block 1B core at 222.0klbs (100.7mt)
So almost idenitcal for the.  Unfortunatley it doesn't list the burnout mass, just the dry mass.  Although it also gives the following:

Usable prop:  2116.9klbs
startup prop 18.6klbs
non-usable:  30.9klbs

So maybe burnout is dry mass plus non-usable?

The DUUS info here:

they list the DUUS (they call the LUS) total mass of 264.2klbs (119.8mt), with 231.5klbs (105mt) of usable propellant, and a dry mass of 27.6klbs (12.5mt).  That dry mass is with the single J2X version of the DUUS. 
The J2X weighs 5,450lbs
The RL-10 weighs 664lbs each (2,656lbs for four)
So that DUUS weighs 262.75klbs fully fueled.

I thinkt he MB-60's weigh about 1300klbs, so two of them weight about the same as four RL-10's, give or take.   

Thanks. If the "unusable" propellant is the stage's burnout mass, those numbers definitely seems to suggest a payload in the mid-80 metric ton range. The problem with the SLS payload discussion is the lack of consistent figures available. A different Boeing document on L2 claims an empty mass of 115 tons with 966 tons of usable propellant (which suggests a 20 ton payload), while info from a GSDO document claims 988 tons of propellant and 95 ton empty mass, which suggests a payload of over 90 tons, and then there's a NASA fact sheet claiming 85 tons empty mass, which according to NASAJim is the contracted value and not the real one, which is 102 tons. Ed's estimates of 95 tons are obviously based on the more "optimistic" values.

I think the numbers from your Boeing paper are close to reality, but I think the payload is closer to 80-85 tons than 70 tons. 70 tons is the contracted value, like Ed said, so I think that's why they claim it. The DUUS payloads do seem accurate though.

Offline Lobo

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Re: Pyrios Alternative HLV Concept
« Reply #56 on: 10/16/2013 06:58 pm »
And finally here is an F-1B based core option.  Again I've optimized these for Escape missions and made them with only two stages, EELV style.  A two-stage core can roughly do the SLS Block 1 mission.  Switching to an RP core solves the VAB height constraint.  Adding F-1B boosters gets the machine to Block 2 capability.  As far as I'm concerned, the Block 1 rocket could run any space program.

 - Ed Kyle

Ed,

Any chance of you running the numbers for a compartive LV using like 7 or 8 RD-180's instead of the four F-1's?
Then with RL/MB-60 upper stage engines as well as your concept above?

Online edkyle99

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Re: Alternative HLV Concepts
« Reply #57 on: 10/16/2013 08:56 pm »
Ed,

Any chance of you running the numbers for a compartive LV using like 7 or 8 RD-180's instead of the four F-1's?
Then with RL/MB-60 upper stage engines as well as your concept above?
Sure.  Give me a day or so.  In the mean time I can point to ESAS 5.1 "Evolved Atlas", which was an 8.4 meter diameter two-stager powered by five RD-180s and four J-2S second stage engines listed for 78 tonnes to a 28.5 deg LEO.  ESAS rules seem to have required higher second stage T/W than we've seen in subsequent studies, likely for crew escape requirements.

 - Ed Kyle
« Last Edit: 10/16/2013 11:45 pm by edkyle99 »

Offline Lobo

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Re: Alternative HLV Concepts
« Reply #58 on: 10/17/2013 04:34 am »
Ed,

Any chance of you running the numbers for a compartive LV using like 7 or 8 RD-180's instead of the four F-1's?
Then with RL/MB-60 upper stage engines as well as your concept above?
Sure.  Give me a day or so.  In the mean time I can point to ESAS 5.1 "Evolved Atlas", which was an 8.4 meter diameter two-stager powered by five RD-180s and four J-2S second stage engines listed for 78 tonnes to a 28.5 deg LEO.  ESAS rules seem to have required higher second stage T/W than we've seen in subsequent studies, likely for crew escape requirements.

 - Ed Kyle

Yea, I noticed that. I thought it odd the upper stage had so much power.  Seemed like an LV totally optimised for LEO.  and with only five RD-180's, seems like the 1st stage maybe burned out fast and staged early more like a Saturn 1b or Saturn INT-21 rather than a scaled up EELV like Atlas Phase 2or something.
So I wasn't sure if it was a very accurate representation of a two stage BLEO optimized scaled up EELV like we are looking at here.  Seems like it might have needed a 3rd stage to get out of LEO with as powerful as that upper stage was.

I'm wondering more like a few more RD-180's on the booster with a longer burn, and a cluster of 4 or 5 RD/MD-60's on a dual use upper stage like your F-1b concept.  :-)

Offline Lobo

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Re: Alternative HLV Concepts
« Reply #59 on: 10/17/2013 04:41 am »
And it's a little off topic I suppose, but I've been wondering what an EELV class core with a single F-1B on it...maybe 5 or 6m wide...and a dual use upper stage with either a single or pair of RL/MB-60's would to to LEO, GTO, and escape.

So if you are ever board and looking for something to do some time, I'd be curious about something like that.

:-)

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