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Capacity of Delta IV growth options? Delta 4 medium+ 5,8?
by
Robotbeat
on 14 Mar, 2014 05:39
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I thought I remember hearing talking of a Delta IV Medium+ with 8 GEMs on it, bringing its capacity closer to the heaviest Atlas V configuration. What is the capacity of that option, and where's the source? My google-fu has failed me. I guess I was thinking about it because Delta IV supposedly was originally built with a capacity of 40 cores per year, and if you wanted to use ALL the cores, you'd maximize your performance if you had them flying with GEMs attached.
...Actually, here it is, page 264:
http://www.ulalaunch.com/site/docs/product_cards/guides/DeltaIVPayloadPlannersGuide2007.pdfEDIT:Or here p.246-247:
http://www.ulalaunch.com/site/docs/product_cards/guides/Delta%20IV%20Users%20Guide%20June%202013.pdfIt's about 17 tons to LEO (407km, 52deg), but probably more like 20 tons with upgraded RS-68A and lower altitude and lower inclination.
That's about 800 tons to LEO per year, assuming you can launch every 9 days (!).
Supposedly, the 8-GEM version of Delta IV Medium+ is available within 48 months of order.
...and add in an ACES upper stage and Al-Li, and you're probably in the 20-25 ton to LEO range.
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#1
by
MATTBLAK
on 14 Mar, 2014 06:29
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Sounds credible and sensible - and probably cheaper than Delta IV-Heavy. Although D-4H these days is supposed to lift about 27 tons to LEO. And it could lift a lot more with an upper stage upgrade (slight stretch, MB-60 engine) and switching to aluminium/lithium structures. Not to mention adding up to 6x GEMs...
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#2
by
baldusi
on 14 Mar, 2014 13:35
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The 2013 Paylaod Planner's Guide already has RS-68A performance included. M+(4,4) is not an issue and almost a given, because now they have a true Common Core from M to M+(5,4). So, doing (4,4) shouldn't be an issue. But doing M+(5,6) and specially M+(5,8) might require reinforcements that would mean a different core. That would significantly increase costs. Regrettably the Delta IV Common Core isn't. Heavy require three custom cores. And until the RS-68A so did each version.
And they got horizontal integration wrong. vehicle checkout is done on the pad vertical, instead of on the HIF. Thus, they get the cost of a VIF and a HIF with long pad times. Atlas V got it right for wholly vertical. We have to see, but I suspect SpaceX will get it right for mostly horizontal with vertical just for integration. The Soyuz at ELS seems a bit expensive with the mobile tower, but from an ops POV is done right.
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#3
by
Lobo
on 20 May, 2014 23:20
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This, along with some uncertainty in Atlas's future, and various discussions about if ULA could/would every down select to just Delta IV, as -supposedly- the two EELV's are redundant, made me think about this a little bit.
So, if we make a few assumptions (very big assumptions) that SLS survives long enough for NASA to fund RS-25E devepment. And -if- Atlas looses access to Russian RD-180's. And -if- a domestic replacement engine is not funded because USAF/DoD decides Delta IV and FH provide sufficient assured access to space.
If we were in such a scenario in say 2019, I was wonder if Delta IV could be streamlined a little to get it's costs down. A few thoughts.
1) Retire D4H. It's very expensive and doesn't fly much. And it needs 3 unique cores.
2) Modify the D4M+ core, to mount more than four GEM-60's, and to replace the RS-68A with one RS-25E, who's development would already be paid for by NASA, and annuals costs of it would then be shared.
Make Delta IV a single core only, with a true sustainer core. With perhaps 4-8 GEM-60's, and a long burning higher impulse core, the GTO and escape performance should be pretty good on the top end. (design to mount enough GEM-60's to replicate D4H's performance, however many that might be. Delta II seemed to work pretty good with 9 GEM's. Maybe 8, 9, or 10 would bee needed to replicate D4H performance?)
While that would require a new modified core to mount more than four GEM's and an RS-25E instead of an RS-68A, but then that could be the -only- core ULA produces. A truely "common core". With a downselect to just the 5m DCSS as the only upper stage. RAC-3 looked at EELV configurations with a D4 sustainer core with RS-25, so while it wouldn't be without effort, I don't think it's unfeasible.
The drawback would be that this would need some GEM's to even get off the ground. I thought an original requirement of the EELV program was that the base EELV could launch without SRB's? But even if so, today's EELV's have been changed from the original requirements anyway, so I don't know if that would be much of a problem. And the Delta 4M+ (5,2) already needs two GEM's to get off the ground anyway with the 5m DCSS, and likey would with any sort of 5m Common Upper Stage like WBC or ACES. Also, looking back at the launch record, the last time a truely slick Delta 4M core was launched was 2006. So USAF/DoD apparently doesn't have much use for that configuration anyway.
Would this be a feasible evolution option to let ULA to lower costs and save money, and retain Delta IV as their only EELV? Seems like it could be.
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#4
by
Jim
on 21 May, 2014 01:56
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1) Retire D4H. It's very expensive and doesn't fly much. And it needs 3 unique cores.
There are payloads that need the Heavy
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#5
by
Jim
on 21 May, 2014 01:59
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2) Modify the D4M+ core, to mount more than four GEM-60's, and to replace the RS-68A with one RS-25E
Not feasible. Too low of thrust, no roll control. Too low performance for mission capture
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#6
by
edkyle99
on 21 May, 2014 03:07
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Rather than mess with the core or add more boosters, why not simply upgrade the boosters themselves? Atlas V already uses beefier solids than Delta IV. Wouldn't it be nifty if a common booster could be used to boost these common cores?
- Ed Kyle
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#7
by
Lobo
on 21 May, 2014 06:41
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2) Modify the D4M+ core, to mount more than four GEM-60's, and to replace the RS-68A with one RS-25E
Not feasible. Too low of thrust, no roll control. Too low performance for mission capture
Wouldn't the RS-25 provide the roll control, as the RS-68 does?
Also, 10 GEM-60's plus one RS-25E would have more thrust at lift off than three RS-68A's. There will be less thrust after SRB separation as the GEM's don't burn for nearly as long as the outboard D4H cores. Is that what you are referring to?
But the RS-25 would have significantly more ISP (over 40s more), and as they don't consume propellant as fast as the RS-68, they'd have a much longer burn time. Would the gravity losses be too great, or could that RS-25 core make up the performance with it's better efficiency and longer burn?
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#8
by
Lobo
on 21 May, 2014 06:47
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Rather than mess with the core or add more boosters, why not simply upgrade the boosters themselves? Atlas V already uses beefier solids than Delta IV. Wouldn't it be nifty if a common booster could be used to boost these common cores?
- Ed Kyle
Certainly. But I think the Delta IV cores would need to be messed with to mount the Atlas V SRB's. So a new core anyway. Perhaps Take my RS-25E core, and add 6-8 Atlas V SRB's? Each would produce about 100klbs more thrust per booster than GEM-60's. Eight of them along with the RS-25 would produce 2.7Mlbs of thrust.
As Jim says, it may not be feasible. Just trying to think of a way that Delta IV could be made cheaper and more competitive for ULA, especially if it were to be the only remaining EELV (hypothetically). Going from 4 cores to 1 in the production line would seem like a good place to start.
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#9
by
MATTBLAK
on 21 May, 2014 06:48
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While we are sort of playing rocket Legos (I love doing that) - RS-25E powered corestage, 4x Aerojet solids from Atlas V (modifying for 6x worth the cost?), 5 meter upper stage powered by MB-60 or RL-60 - what sort of performance are we talking about? Is J-2X feasible for a stretched 5 meter upper stage? An all-new Ares 1 type upper stage?
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#10
by
hkultala
on 21 May, 2014 09:02
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2) Modify the D4M+ core, to mount more than four GEM-60's, and to replace the RS-68A with one RS-25E
Not feasible. Too low of thrust, no roll control. Too low performance for mission capture
Wouldn't the RS-25 provide the roll control, as the RS-68 does?
No. RS-68 can do roll control because it has separate roll control nozzle which is fed from the exhaust of the gas generator.
In RS-25 everything is coming out of the one main nozzle, because it's staged cycle engine. There is no roll control nozzle, and no possibility to add that roll control nozzle.
Some russian rocket stages have small dedicated multi-hamber control thruster engine to allow roll control with single-chamber closed cycle main engine.
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#11
by
Jim
on 21 May, 2014 11:03
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Also, 10 GEM-60's plus one RS-25E would have more thrust at lift off than three RS-68A's.
10 GEM's won't fit on the vehicle. The TSM's would get in the way
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#12
by
clongton
on 21 May, 2014 11:27
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Have you thought about the TR-106? That LOX/LH2 engine was actually completed, built and tested at Stennis in 2000 thru its full range from max 108% to throttle down to 65%. The TR-106 has about 650,000 lbsf/sl thrust and was designed to be inexpensive. It is a sweet engine and would easily fit under the existing Delta core. The RS-25e will have about 520,000 lbsf/sl thrust and be an expensive engine.
Tom Mueller was a lead engineer for development of the TR-106 and became TRW vice president of propulsion. In 2002, Elon Musk asked Mueller to join him as a founding member of SpaceX becoming its head of propulsion, along with other TRW staffers. Technology lessons from the Low Cost Pintle Engine project were used in the development of the SpaceX Merlin engine.
If you're looking to upgrade the Delta-IV with an engine change, forget the expensive RS-25e and the RS-68A. Do something real and go to the TR-106. More powerful, less expensive, better throttle range, potentially reusable should ULA want to consider that route.
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#13
by
MATTBLAK
on 21 May, 2014 12:03
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What Chuck said! And about those 4x Aerojet solids and the MB-60...
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#14
by
baldusi
on 21 May, 2014 14:15
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What you are talking about would be a Delta V. Why not go all the way and use the 5.5m composite tooling on a new core. You could put 2 RS-25E and design to take upto 8 Atlas SRB. You'd of course be talking about a new vehicle, anyways. Same technology for the Upper Stage, while still using the RL-10C-2, with option of dual RL-10C-1 for LEO.
Regarding any TRW engine, I understand the engineering team was disbanded. And many are working for the competition. In fact, it would be easier for TRW to license the technology of the TR-106 to AeroJet.
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#15
by
TrueGrit
on 21 May, 2014 16:35
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Once again from my real world experience... The logic of the expendable SSME (RS25E) has always escaped me. The RS25 has ~5x the number of parts and ~2x the amount of labor hours to build compared to an RS68. For NASA to say the RS25E is going to be cheaper just doesn't pass the smell test... When has NASA ever been right on program costs? But let’s just say they do the impossible... For the RS25E to work on a Delta IV you would need 2 of them, to get the thrust or you can get off the ground. This solves the roll control issue, but do any of you believe the RS25E will be half the cost of an RS68? And I haven't begun to talk about the costs of a completely new aft structural section and new propellant feedsystem that has to be designed, built, and qualified.
As for the Atlas solids... The differences have some hidden integration costs and don't provide that much of a performance improvement. The Delta solid thrust profile was tuned specifically to manage the Delta loads, while the same was done for Atlas. There is a great potential of problems mixing and matching, which means a full up development loads cycle for the whole "mission box". This potentially could result in a need to pour the solid differently, or cause major redesign in the interstage or other structural areas. And I haven't begun to address the other integration problems: the Atlas solids are longer which results in major changes to the Delta tank and manufacturing tooling, the Atlas solids electrical connection and attach configuration is different and has some incompatibilities, the Atlas solids need to gain and be qualified for gimbal capability, the Atlas solids would impact liftoff acoustics and IOP, and more.
And before you talk about what Delta got wrong about horizontal integration… Get some historical perspective and bother to do some research. The HIF was designed from the start to be capable of doing stage integration testing. But the launch rate collapsed before they ever got to fitting it all out. Delta abandoned it in place, unfinished because there is no need with a launch rate of 6 week centers or longer. The biggest difference between Delta processing and Atlas processing is that Atlas has eliminated WDRs. If Delta did the same it would eliminate 2+ weeks from the processing schedule, prep for and recovery from the WDR, putting it on par with Atlas. That also was in the inital Delta planning aswell, but hasn't been done... At least not yet.
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#16
by
Jim
on 21 May, 2014 17:34
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Delta abandoned it in place, unfinished because there is no need with a launch rate of 6 week centers or longer.
The pad ops are still longer than Atlas VIF ops with removing the WDR (which is only a week hit for Atlas). Atlas reduces some time with ASOC testing.
There are no get ahead tasks available in the HIF after the vehicle is assembled.
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#17
by
Lobo
on 21 May, 2014 19:40
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2) Modify the D4M+ core, to mount more than four GEM-60's, and to replace the RS-68A with one RS-25E
Not feasible. Too low of thrust, no roll control. Too low performance for mission capture
Wouldn't the RS-25 provide the roll control, as the RS-68 does?
No. RS-68 can do roll control because it has separate roll control nozzle which is fed from the exhaust of the gas generator.
In RS-25 everything is coming out of the one main nozzle, because it's staged cycle engine. There is no roll control nozzle, and no possibility to add that roll control nozzle.
Some russian rocket stages have small dedicated multi-hamber control thruster engine to allow roll control with single-chamber closed cycle main engine.
Ok, thanks for that.
Then how did STS provide roll control? How will SLS? How could Jupiter 130 have done it? The SRB nozzles?
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#18
by
Lobo
on 21 May, 2014 19:50
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Have you thought about the TR-106? That LOX/LH2 engine was actually completed, built and tested at Stennis in 2000 thru its full range from max 108% to throttle down to 65%. The TR-106 has about 650,000 lbsf/sl thrust and was designed to be inexpensive. It is a sweet engine and would easily fit under the existing Delta core. The RS-25e will have about 520,000 lbsf/sl thrust and be an expensive engine.
Tom Mueller was a lead engineer for development of the TR-106 and became TRW vice president of propulsion. In 2002, Elon Musk asked Mueller to join him as a founding member of SpaceX becoming its head of propulsion, along with other TRW staffers. Technology lessons from the Low Cost Pintle Engine project were used in the development of the SpaceX Merlin engine.
If you're looking to upgrade the Delta-IV with an engine change, forget the expensive RS-25e and the RS-68A. Do something real and go to the TR-106. More powerful, less expensive, better throttle range, potentially reusable should ULA want to consider that route.
TR-106 was a pretty cool engine from what I've read on it. Just like it's cousin, the TR-107. But my main reason for even bringing this up was not so much to play legos with Rockets (although I do love to do that), but for two reasons.
1) Eliminate the D4H but replicate it's capability with a cheaper variant.
2) Use an engine that will already be developed and paid for by NASA.
3) Keep modifications down as much as possible.
TR-106 Would work, but it'd have a ways to go to bring it back at this point I think. Not as much as a new engine from scratch, but enough that it might be hard to justify over RS-25e which would already be rolling off the assembly line for SLS. Now, if NASA were developing TR-106 for SLS, then that would be the way to go. Too bad things didn't work out that way. So reason #2 goes away.
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#19
by
Jim
on 21 May, 2014 19:53
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Then how did STS provide roll control? How will SLS? How could Jupiter 130 have done it?
They had more than one engine.
