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Check of HLLVs because of (severe) doubts

Posted by: Ekkehard Augustin - Sun Jan 07, 2007 11:25 am
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Check of HLLVs because of (severe) doubts 
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Post    Posted on: Fri Mar 02, 2007 3:04 am
They did launch it directly to solar escape velocity.

And , Publiusr, Atlas V 552 can put 20,500 kg in LEO. Way more than any Delta IV, except the heavy.


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Post    Posted on: Fri Mar 02, 2007 10:26 pm
I see the 551 on M Wade now...It seems that single core really needs some mods. They still want the three CCb though for some margin...


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Post    Posted on: Sat Mar 03, 2007 8:07 am
An additional source is contributing to my doubts. The source doesn't have to do with vehicles to be launched from teh earthian surface but provides a hinbt to what I have in mind nonetheless for the future: The detailed data liested under www.astronautix.com about vehicles that orbited the Moon are all on one straight line when a regressional function is derived from them. This I did in the Lunar Soyuz-thred in the Financial Barriers section. The degree of determination is extremely close to 100%.

The function describing the line mathematically is linear - and this means that there was not a single advantage of heavier vehicles over lightervehicles.

This holds also, if all the different propellants are calculated into one standard propellant.

If heavier vehicles would have an advantage of lighter ones they wouldn't be in one straight line with them like the one found but they would be above such a line - meaning that there would be a curvature.

Please note - I explicitly and consciously call this a source of doubts but NOT a fact that can be used as argument. It only means that regressions and such functions are of meaning here and that it will be interesting what are the causes behind such functions. May be that the vehicles are optimized - then the function could be an argument - may be instead that the vehicles are NOT optimized - then more detailed looks are required into several details.

I have in mind that the vehicles used to get those function are from different years - this makes me think of the possibility that the earlier ones aren't that optimized as the later ones.

May be that the later ones already involve weight savings not involved in the earlier ones - but this would mean an evolution toward lighter vehicles and an advantage of lighter vehicles.

All in all my severe doubts are increased a bit for now and there will be more checks of the rockets and vehicles to be launched from the earthian ground.



Dipl.-Volkswirt (bdvb) Augustin (Political Economiist)


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Post    Posted on: Sat Mar 03, 2007 3:12 pm
publiusr wrote:
I see the 551 on M Wade now...It seems that single core really needs some mods. They still want the three CCb though for some margin...


You need the 2 engine Centaur for LEO, the heavier payloads need more thrust. But I agree the 3 CCB Heavy would be needed for a full Orion (CEV) as currently designed. Makes me wonder if Orion is deliberately just too large for an EELV.

But 20,500 kg is plenty for a manned taxi to LEO. In fact the 402 at 12,500 kg is plenty as the Bigelow - LockMart discussions show. With no SRB's and no LH2.

Makes me wonder if LockMart think the Ares I may be killed by Congress, and want to be ready to step in with an alternative to the COTS vehicles.


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Post Couplings Exist?   Posted on: Wed Mar 28, 2007 1:04 am
I was pondering HLLV while waiting at a railroad crossing. Launch complexes are expensive ($500 Million to add Soyuz capability near Ariane complex) ANY HLLV launch complex would cost more – a lot more. A cluster of seven Delta IV cores might not be very expensive to develop (actually labeled the Delta IV 94t), but would add the launch complex cost before first flight. What are the options for heavier payloads too big for the Dealt IV Heavy (>56,800 pounds)?

We have been entertained with “TinkerToyâ€


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Post Re: Couplings Exist?   Posted on: Wed Mar 28, 2007 1:08 pm
rpspeck wrote:
Can fuel be transferred in a dynamic environment? Not the inches per minute differential velocity normal for ISS docking in vacuum, but with significant velocities and unpredictable forces?


Docking at high differential velocities is never a good idea. Even railroad "dockings" take place at low differential velocities. But your main point, that most of the mass needed for space flight is propellant, is right on target. NASA and a number of private companies are thinking about orbital propellant depots. I think we may see some hardware within 5 years. Then the vehicles can be launched dry and refueled in space. :idea: Maybe we need a new thread on orbital propellant depots.


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Post    Posted on: Sun Jun 24, 2007 4:20 pm
I in between was thinking more about the straight line I found which accords to a linear function.

The point seems to be that the probes all had to enter an orbit from space - and I suspect that they all have been designed so that they are optimized. In so far the linear funtion represents the family of optimal probes. This means that there is no advantage of HLLVs entering an orbit from space.

This leads to the question if the might be such an advantage if the probes are launched from ground.

The rockets applied to launch those probes from earthian ground no way fit into any function. This may be a first sign that no advantage may exist. Even heavy probes seem to have been launched by lighter vehicles and lighter ones by heavy lifters.

The data seem to show that the rockets choosen simply weren't selected so that they are just sufficient for the weights of those probes. This has to be checked yet.

But the thoughts about the probes themselves merely assist my doubts about HLLVs.



Dipl.-Volkswirt (bdvb) Augustin (Political Economist)


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Post    Posted on: Mon May 19, 2008 8:58 pm
You should have no doubts about them

Here's why
http://trs-new.jpl.nasa.gov/dspace/bits ... 8-03_A.pdf


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