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#60 by Downix on 23 Apr, 2013 06:29
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Actually no you don't. You need a new launch platform at SLC-6, but not a new launch pad itself.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.
Boeing studied a 7-core design (not a core w/ 6 boosters, 7 cores all bolted together, a la Saturn-IB style) and had SLC-6 w/ a new platform as the least expensive method to bring a system up to speed should a 90 metric ton payload be needed quickly. -
#61 by Lobo on 09 Jul, 2013 20:08
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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.
Anyway know what the BLEO performance of an upgraded D4H would be per the chart below that shows LEO performance upgrades? Current D4H can get over 1/2 of it's LEO capacity to GTO, would this 50+mt upgraded D4H put 25mt or better to GTO?
What about TLI?
And they show a new upper stage with RL-60. But would ACES with 2 or 4 RL-10's also get the performance there, with booster crossfeed and six GEM-60's?
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#62 by Antares on 10 Jul, 2013 14:42
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Wouldn't that be par for the course with the development of this kind of launch vehicle?
What does that mean? They should have planned a pad that accommodates a >3 core vehicle? How much would that have cost? Why would a cogent manager do that when there's no business case for it? No one in their right mind would spend that money. -
#63 by kevin-rf on 10 Jul, 2013 16:07
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Antares, Don't forget to mention they would also have to come up with a completely different system to hoist the rocket from Horizontal to Vertical. Three cores and you can lay them flat, other than really large flat packs, you would have to have some sort of cradle to support more than three cores for a market that did not exist when EELV's where designed.
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#64 by Star One on 10 Jul, 2013 17:52
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Wouldn't that be par for the course with the development of this kind of launch vehicle?
What does that mean? They should have planned a pad that accommodates a >3 core vehicle? How much would that have cost? Why would a cogent manager do that when there's no business case for it? No one in their right mind would spend that money.
It appears to have been considered?QuotePossible future upgrades for the Delta IV include adding extra strap-on solid motors to boost capacity, higher-thrust main engines, lighter materials, higher-thrust second stages, more (up to six) strap-on CBCs, and a cryogenic propellant cross feed from strap on boosters to the common core. These modifications could potentially increase the mass of the payload delivered to LEO to 100 tonnes.[21]
http://en.wikipedia.org/wiki/Delta_IV#Future_variants
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#65 by kevin-rf on 10 Jul, 2013 19:20
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That dates to a pre-ULA document on possible DeltaIV upgrades, I believe it was a wide (greater than 5m) Al-Li CBC that required an entirely new pad and someone to pay for it. The original .pdf is somewhere in the nsf threads. Maybe one of NSF's digital packrats could dig it up for you.
It never got beyond the power point stage. -
#66 by Antares on 10 Jul, 2013 21:23
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This is the space business. Everything has been considered. And then the real world intervenes. I choose not to waste processor cycles on the technically or financially impossible - though small scale R&D should be attacking both.
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#67 by Star One on 11 Jul, 2013 20:52
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That dates to a pre-ULA document on possible DeltaIV upgrades, I believe it was a wide (greater than 5m) Al-Li CBC that required an entirely new pad and someone to pay for it. The original .pdf is somewhere in the nsf threads. Maybe one of NSF's digital packrats could dig it up for you.
It never got beyond the power point stage.
Thanks for the clarification, makes me wonder then if it should still be in the page? -
#68 by kevin-rf on 12 Jul, 2013 02:34
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The thing is the historical section is littered with proposed vehicles... Some no more than studies, some that built hardware that never flew.
Many of the proposed Delta IV growth options are like the many Saturn derivatives that where never built. They have a place, but are not viable options. No payload can afford, or currently needs the improvements you get with: Al-Li tanks, cross feed, sub-cooled LH, or a larger than 5m core. Someone will correct me if I am wrong, but I believe the Delta IV (and Atlas V) papers on growth options really came out as a counter to the Ares family of rockets. Kinda a yes we can. -
#69 by kevin-rf on 12 Jul, 2013 02:50
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Actually page 51 in this 2004 document has the slide with all the options.
http://www.boeing.com/defense-space/space/delta/kits/d310_d4heavy_demo.PDF
Notice the 7m core not only requires a new pad, but also a 'modified factory'. It also shows the proposed regenerative RS-68. They opted for the improved RS-68a with ablative nozzle instead.
Sorry I don't have a better link, but am on an obsolete HP webOS tablet that has limited capabilities. I just like it better than IOS, Android, Win 8, and OSX
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#70 by Lobo on 13 Jul, 2013 00:09
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Notice the 7m core not only requires a new pad, but also a 'modified factory'. It also shows the proposed regenerative RS-68. They opted for the improved RS-68a with ablative nozzle instead.
I'd guess the 5m tooling at Decatur can't be modified to go as wide as 7m, and a new 7m tooling production line would be needed? -
#71 by sdsds on 13 Jul, 2013 01:44
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They do some mysterious things in rocket factories! I think the factory in Decatur includes some giant chemical vats into which (I hypothesize) they dip barrel sections after they have been welded together. This hypothesis is based on some circumstantial evidence presented in an EPA report somewhere.... YMMV. But if true, then the size of the vat determines the maximum size of a barrel section. You wouldn't think building a bigger vat to accommodate 7m cores would be all that much of a challenge, but then there's that pesky EPA to deal with!
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#72 by Downix on 20 Jul, 2013 02:20
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They already did. That was part of how SLC-6 at VAFB was set up, if you checked the NTRS papers on it. Instead of modifying the pad structure, the decision was to use the existing pad structure (capable of handling a much larger vehicle than the Delta IV Heavy) and using a pad mount which could be replaced should a >3 core vehicle be approved. The anticipation being that should such a vehicle be needed, either a) it would be for polar use or b) should a more normal orbit be needed, they would use LC-39 and be assembled at the VAB.Wouldn't that be par for the course with the development of this kind of launch vehicle?
What does that mean? They should have planned a pad that accommodates a >3 core vehicle? How much would that have cost? Why would a cogent manager do that when there's no business case for it? No one in their right mind would spend that money.
Although this was part of an early proposal, one I still find fascinating to study from time to time. -
#73 by floss on 22 Aug, 2013 17:39
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Notice the 7m core not only requires a new pad, but also a 'modified factory'. It also shows the proposed regenerative RS-68. They opted for the improved RS-68a with ablative nozzle instead.
I'd guess the 5m tooling at Decatur can't be modified to go as wide as 7m, and a new 7m tooling production line would be needed?
I wish people would stop going on about cores greater than 5 meters diameter. The reason for 5 m is that it is the biggest that is easily road transportable. NASA can use wider cores because the built the rocket factory on the coast so no road transport . -
#74 by baldusi on 22 Aug, 2013 20:52
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What are you talking about? 3.7m is the road limit. ULA builds them in Decantur with river access and a custom built vessel. I think I heatd that the current bridges on the river limit maximum diameter to 6m and something. But that's at current factory. Also, the Atlas V core is 3.9m, which is designed to be transportable on an AN-124 (so is the Antares core). And Michoud is open to rent for zones, were you could do 8.4 to 10m depending on construction method.
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#75 by edkyle99 on 22 Aug, 2013 20:57
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I wish people would stop going on about cores greater than 5 meters diameter. The reason for 5 m is that it is the biggest that is easily road transportable. NASA can use wider cores because the built the rocket factory on the coast so no road transport .
Delta IV stages move the same way that SLS core will move - by river, canal, and/or sea. It only travels by road at Decatur and at its launch sites during transport to and from the Delta Mariner transport ship.
- Ed Kyle -
#76 by floss on 23 Aug, 2013 15:54
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What are you talking about? 3.7m is the road limit. ULA builds them in Decantur with river access and a custom built vessel. I think I heatd that the current bridges on the river limit maximum diameter to 6m and something. But that's at current factory. Also, the Atlas V core is 3.9m, which is designed to be transportable on an AN-124 (so is the Antares core). And Michoud is open to rent for zones, were you could do 8.4 to 10m depending on construction method.
I know that road limit is 3.9 but you can push it to 5m wide without too much trouble after that you have to start modifying bridges etc.Who ever picked the site for Michoud was a very clever man indeed. -
#77 by Jim on 23 Aug, 2013 15:59
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I know that road limit is 3.9 but you can push it to 5m wide without too much trouble after that you have to start modifying bridges etc.Who ever picked the site for Michoud was a very clever man indeed.
It was a originally a Liberty ship building facility -
#78 by floss on 23 Aug, 2013 16:06
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I know that road limit is 3.9 but you can push it to 5m wide without too much trouble after that you have to start modifying bridges etc.Who ever picked the site for Michoud was a very clever man indeed.
It was a originally a Liberty ship building facility
Class I wish I had access to the history of us space centers . -
#79 by baldusi on 23 Aug, 2013 18:15
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What are you talking about? 3.7m is the road limit. ULA builds them in Decantur with river access and a custom built vessel. I think I heatd that the current bridges on the river limit maximum diameter to 6m and something. But that's at current factory. Also, the Atlas V core is 3.9m, which is designed to be transportable on an AN-124 (so is the Antares core). And Michoud is open to rent for zones, were you could do 8.4 to 10m depending on construction method.
I know that road limit is 3.9 but you can push it to 5m wide without too much trouble after that you have to start modifying bridges etc.Who ever picked the site for Michoud was a very clever man indeed.
I can't recall exactly what the total height limit is, but I guess it's close to 4.2m. But that's the top dynamic height for the whole transport. Once you take into consideration the support structure, the environmental protection, the clearance to the road plus the possible vertical curvature of the road and all such you arrive to an effective maximum height for your delicate cargo of around 3.7m (plus or minus a bit). You can do wider reasonably easy, but rocket cores are cylinders.
You can go a bit higher if you study the road, but ten you have to get a permit per each state you cross. And if you go higher you have to get a permit per county! Thus, 3.7m is sort of the maximum width that you could transport easily. Let's say that you want to transport a fairing that's 7m wide, but each half is 3.5m, you might do it cheaply. Or just look at the drawing of the Rocketdyne's F-1 transport rig.
Yet, water or even road transport are not always the cheapest way. Say, for example, that you do have a port, but it's on a shallow water way, or is very far from major traffic lanes, then it might cost you more than do a straight airlift. Ditto for very far places. Sometimes train is cheaper.
For some reason LM decided that 3.9m air lifted was better than 3.7m road transported. Now that they are unified on ULA, they ship it by water if they can consolidate it with some extra cargo, but if they only have to ship a single Atlas V core, they still send it by An-124. The US is a great place to move things around, all the logistics are reasonably optimized. Thus, airlift can be cheaper than even road transport for certain cases.
The reason MD/Boeing chose the wider core for Delta IV was because they chose H2 as core fuel. And because they expected to make tens of launches per year. At that rate, having a ship that can transport 3 cores per trip might well be cost effective vis-a-vis even road transport. Currently it's not. But they don't have that option.
Now, let's say that ULA can transport the wide cores and even a 10m fairing, if so they chose (which they can). Never forget that rockets are a mean to transport payloads, not an end in themselves. What there's a total scarcity, is of all the support structure for bigger than 4.6m payloads. Think about transporting those, about anechoic chambers, environmental testing chambers, shakers, clean rooms, etc. I would recommend that you look up videos about the ATV's processing. They clearance above and on the sides when entering a clean room is around 10cm. And all the things I've mentioned are cubically more expensive with scale. Thus, if you have a clean room that could fit a 6m payload, you would have to charge about twice for your services than a 4.6m one. How many clients would you expect?
