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#40
by
Jim
on 22 Feb, 2013 02:03
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Would it be possible to attach 4 Atlas V cores to a Delta IV core with some modifications?
Anything is possible given enough money.
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#41
by
Ben the Space Brit
on 22 Feb, 2013 10:21
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Would it be possible to attach 4 Atlas V cores to a Delta IV core with some modifications?
Anything is possible given enough money.
Money also needs a reason to be spent. Without derailing this thread, I would remind everyone that there is currently an exploration launcher in development and I strongly suspect that there is no appetite to develop another, no matter how reasonable and potentially advantageous it is.
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#42
by
mmeijeri
on 22 Feb, 2013 10:35
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I suspect there is less elasticity there than we would hope. Put another way, buying a couple of extra rockets a year is not going to have much effect upon costs. The number would probably have to go up substantially before the costs come down even moderately. There's a lot of USAF money pumped into infrastructure support.
Total costs will likely only increase with launch rates for the foreseeable future, but
prices and costs per launch may come down, though only if the higher launch rates are combined with free, open, and ongoing multi-source competition. Currently ULA has to repay a percentage of the fixed costs that the DoD pays for whenever it sells a commercial EELV launch. Dividing those fixed costs over a higher number of launches will have an immediate and significant effect, precisely because the infrastructure spending is so high.
This is not a free market.
Competitive procurement is not inhibited by having a launch capability contract. You can open up the market without getting rid of the ELC, though in the long term it would be nice if it could be abolished because it was no longer necessary.
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#43
by
kevin-rf
on 22 Feb, 2013 13:37
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Would it be possible to attach 4 Atlas V cores to a Delta IV core with some modifications?
Anything is possible given enough money.
And a new pad.
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#44
by
LouScheffer
on 24 Feb, 2013 00:33
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Can't use planner's guide numbers for manned trajectories. The Atlas required either a structurally stable Centaur or a fairing that suspended the Centaur to take it out of the load path.
Is there a real technical objection, or does it just make people nervous? As I recall the Atlas the Mercury used was not structurally stable, but it sustained 8-9 G accelerations.
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#45
by
Danderman
on 24 Feb, 2013 00:37
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Would it be possible to attach 4 Atlas V cores to a Delta IV core with some modifications?
The better way to ask this question is: what are the requirements if you are crazy enough to want to attach 4 Atlas V cores to a Delta IV and get into orbit?
The best way is to ask: What is the optimal way to launch XX tons into orbit?
Jim is correct, asking if something is possible cannot be answered by "no".
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#46
by
RocketmanUS
on 24 Feb, 2013 02:24
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Would it be possible to attach 4 Atlas V cores to a Delta IV core with some modifications?
The better way to ask this question is: what are the requirements if you are crazy enough to want to attach 4 Atlas V cores to a Delta IV and get into orbit?
The best way is to ask: What is the optimal way to launch XX tons into orbit?
Jim is correct, asking if something is possible cannot be answered by "no".
Then need to read between the lines.
The goal with this would be heavy lift.
If I'm not mistaken the Altas cores would be better boosters and the Delta core a better core stage.
So for evolving the Delta IV for greater mass to LEO.
4 Atlas cores around a Delta core with payload on top ( with or with out an US ). This would not be human rated.
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#47
by
Jim
on 24 Feb, 2013 13:36
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Is there a real technical objection, or does it just make people nervous? As I recall the Atlas the Mercury used was not structurally stable, but it sustained 8-9 G accelerations.
That was for large manned spacecraft, and those managed by managed by NASA.
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#48
by
Lobo
on 24 Feb, 2013 19:24
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The better way to ask this question is: what are the requirements if you are crazy enough to want to attach 4 Atlas V cores to a Delta IV and get into orbit?
Nasa would be the only customer for such a configuration, but I bet it would be a pretty capable medium-heavy lifter. The only need for it would be in the absence of SLS. I wonder what its capabilities would be with the addition of an adequately sized 5m common centaur upper stage?
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#49
by
simonbp
on 24 Feb, 2013 19:34
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Would it be possible to attach 4 Atlas V cores to a Delta IV core with some modifications?
Anything is possible given enough money.
And a new pad.
And a couple of tanker trucks full of whiskey.
Seriously though, 4x Atlas boosters on a Delta core wouldn't have all that much better performance than 2x boosters, if they are all lit on the ground. If the Delta is air lit, it gets better, but RS-68 is not really air-lightable. So, replace it with a J-2X. That might be able to do 70-80 tonnes to LEO with the DCSS. But, it would be an almost entirely new vehicle.
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#50
by
deltaV
on 07 Apr, 2013 17:33
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How far could the Delta IV's mass to LEO be improved for around $500 million of development costs? Could e.g. Delta IV Heavy + solids + crossfeed be developed for that amount? The ULA phase 2 paper (
http://www.ulalaunch.com/site/docs/publications/EELVPhase2_2010.pdf) gives an (outdated) estimate of $2.3 billion for phase 2, but no estimate for phase 1.
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#51
by
Ben the Space Brit
on 07 Apr, 2013 18:31
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@ deltaV,
I don't know if it would cost $500M or less but my shopping list for Delta-IV is:
* Common Centaur upper stage (up to 4 x RL-10B-2);
* Propellent cross-feed between cores;
* GEM solid rockets on Heavy tri-core variant (maximum of 8, four on central, two each on outboards).
This is my interpretation of the EELV Phase 1 and it would be the Cargo Launch Vehicle (CaLV) to the Atlas-V Heavy's Crew Launch Vehicle (CLV).
Optional Extras:
* Propellent Densification
* 5 x core configuration with crossfeed and/or thrust augmentation on outboards
I figure these latter options would push past the spending limit and that Phase-2 (2 x RD-180 replacement core) would be cheaper.
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#52
by
deltaV
on 07 Apr, 2013 18:49
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Ben: do you mean Common Centaur or ACES? They are distinct proposals; the former is an adaptation of the existing two-engine Centaur stage and the latter is a new four-engine stage. See page 4 of the EELV Phase 2 paper.
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#53
by
Ben the Space Brit
on 07 Apr, 2013 19:23
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Ben: do you mean Common Centaur or ACES? They are distinct proposals; the former is an adaptation of the existing two-engine Centaur stage and the latter is a new four-engine stage. See page 4 of the EELV Phase 2 paper.
I'm wary about saying 'ACES' - It's virtually a spacecraft in its own right with ZBO technology and a long-duration on-board power generation.
I'm thinking specifically of a 5.1m (Delta-IV core diameter) upper stage using Centaur technology and suitable for 1, 2 or 4 RL-10B-2 engines, which is what I thought was the Common Centaur. It would be cheaper than ACES and quicker to deploy. ACES can come later when it's needed for longer-duration missions (basically, this system's equivalent of aCPS). As an EDS or an ETO upper stage, Common Centaur does fine.
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#54
by
RocketmanUS
on 07 Apr, 2013 19:44
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How far could the Delta IV's mass to LEO be improved for around $500 million of development costs? Could e.g. Delta IV Heavy + solids + crossfeed be developed for that amount? The ULA phase 2 paper (http://www.ulalaunch.com/site/docs/publications/EELVPhase2_2010.pdf) gives an (outdated) estimate of $2.3 billion for phase 2, but no estimate for phase 1.
Cross feeding is unknown, has not been done yet to my knowledge.
So not sure just how much that could cost.
It would be best if they just developed the phase II Atlas with a 5m US ( 1 to 4 engine capable ). And as stated above add the ACES ( what ever it will end up being ) US later when it is available. From what I was reading on that PDF it doesn't look like there is cross feeding for the 70mt version.
An US for phase II would be cheaper than trying to make it for Atlas V and Delta IV also. That might fit the estimated $2.3B cost for an Atlas phase II.
Phase II with the stumpy version would give them plenty of options. There are some hint out there that there could be work already being done for phase II. There would need to be a commercial business case for this to happen. There just is to much uncertainty what NASA will end up needing in the future ( authorized to do ).
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#55
by
simonbp
on 09 Apr, 2013 00:47
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I wonder what performance a first stage with Delta CBC-derived tanks and an F-1B would have? Not as much as Phase II, but not bad.
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#56
by
RocketmanUS
on 09 Apr, 2013 01:47
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I wonder what performance a first stage with Delta CBC-derived tanks and an F-1B would have? Not as much as Phase II, but not bad.
Might give around 150 second of burn time.
Cluster of 5 cores would most likely have a little more dry mass than a Saturn V 1st stage. However it could shed mass by dropping cores and using cross feed. US with (4) J-2X's should be around an INT-21. Don't know if this configuration could be done. A three core might be able to be done with a RL-10 or NGE upper stage, similar to the Atlas phase II. I don't know how that with a single core would work with lite payloads.
Would Boeing want to go with an RP-1/LOX 1st stage?
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#57
by
Star One
on 10 Apr, 2013 19:31
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The D4H is three cores combined, how many more cores could be combined before it became unworkable?
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#58
by
kevin-rf
on 10 Apr, 2013 21:03
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The D4H is three cores combined, how many more cores could be combined before it became unworkable?
More than three and you need a new launch pad.
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#59
by
Star One
on 12 Apr, 2013 19:39
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The D4H is three cores combined, how many more cores could be combined before it became unworkable?
More than three and you need a new launch pad.
Wouldn't that be par for the course with the development of this kind of launch vehicle?