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#76 2005-03-07 15:40:32

LtlPhysics
Member
From: north of the equator
Registered: 2004-02-24
Posts: 76

Re: The Myth of Heavy Lift - (Let the fight begin...)

[color=#000000:post_uid0]I'm dropping into the middle of your conversations here. Cindy has already fired shots at me twice for asking questions that caused a topic to deviate from its course.

GC answered a question I had.and posted this:


No reuseable engines? http://www.pratt-whitney.com/prod_space_cobra.asp

I think this would do the trick... able to handle the requisit 50 flights before overhaul, and excelent reliability. At least some componets of it have been test fired.

http://www.pratt-whitney.com/prod_space_rlx.asp

Not sure about the fate of the RLX project, which may have gone out with SLI. It would also serve well for the application.

And make a reuseable version of this, http://www.space.com/busines....-1.html

Able to withstand at least 25 flights, and we'd be in business.


Cobra would be good for 50 flights? Ten flights out of any engine is mass transportation compared to any other engine being used today. But, maybe I'm wrong about that.

Say cobra engines are retired after 12 fights. I imagine NASA would pick apart the first one just because they are nervous (and rightly so). What can be done with cobra configurations and maybe some boosters?

It took five f-1 engines to get two men on and one circling the Moon. Chemistry being what it is, I doubt the combustion of h2 and o2 today is any different than it was in the days of Apollo. What about the today's technologies? Would a new moon mission weigh less? Would there be any merit in sending a fueled return vehicle on a prior launch?

This is from Pratt-Whitney:

Engine Characteristics

Thrust (vac): 200,000 - 1,000,000 lb
Dry weight (at 600k thrust): 8,000 lb
Specific impulse (vac): 455 sec
Cycle: Staged combustion
Propellants: Liquid hydrogen/liquid oxygen
Mixture ratio: 5.5:1 - 6.5:1
Shutdown reliability: 0.9995
Catastrophic reliability: 0.999995
Mission Life: > 100 missions
Time between overhauls: > 50 missions
Scheduled maintenance per flight: < 100 man-hr
Turnaround between flights: < 16 hr

Is that believable? How do they know what reliability it has? Is that too good to be true?[/color:post_uid0]

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#77 2005-03-07 18:09:47

Ad Astra
Member
Registered: 2003-02-02
Posts: 584

Re: The Myth of Heavy Lift - (Let the fight begin...)

[color=#000000:post_uid0]The RD-180 is also said to be reusable, but only for about four flights.  This is still better than the RS-68, which ablates and cannot be reused.  The industry has been building reusable rocket engines since the days of the X-15 and NF-104.  The difficult part will be re-flying the engine with a minimum of inspection between flights.  If we had to pull the jets off an airliner and swap them out after every flight, the airlines would be out of business.[/color:post_uid0]


Who needs Michael Griffin when you can have Peter Griffin?  Catch "Family Guy" Sunday nights on FOX.

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#78 2005-03-07 18:22:11

Ad Astra
Member
Registered: 2003-02-02
Posts: 584

Re: The Myth of Heavy Lift - (Let the fight begin...)

[color=#000000:post_uid0]I believe that an all-new modular rocket is the best way to attempt a clean-sheet HLLV.  Hypothetically, it would resemble a beefier Delta IV or Atlas V that could launch 20+ MT in its single-core version or 100+ MT in a triple-core form.

The reason for this is economics.  An HLLV may not make economic sense.  But if it can be built from components used in commercially-available (and commercially-successful) rockets, the costs can be shared with an economically-viable vehicle.

It's possible that SDV could actually make use of this modular approach.  The SRB could be the first stage for a smaller rocket, with the SDV and SRB-based rocket sharing a common LH2 upper stage.  If the ET engines are put on the bottom of the tank, the tank could be used without SRBs to launch lighter payloads.

I do believe it would be a mistake to use current boosters to make an HLLV.  The rocket would eventually become an entirely different animal, and would require new launch facilities.[/color:post_uid0]


Who needs Michael Griffin when you can have Peter Griffin?  Catch "Family Guy" Sunday nights on FOX.

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#79 2005-03-08 00:56:04

Ad Astra
Member
Registered: 2003-02-02
Posts: 584

Re: The Myth of Heavy Lift - (Let the fight begin...)

[color=#000000:post_uid0]In response to the most recent comments:

1) Hydrogen engines aren't inherently inefficient at lower altitudes.  It's just a matter of what the exhaust pressure is and how closely it matches with the ambient temperature.  Extenable nozzles are a solution to the problem.

2) I never proposed reusing the RD-180; I was just making the point that it was possible in theory.  Bringing the engine back might make sense if it was part of a winged flyback booster.  Otherwise, you can forget about it.

3) When I say that we shouldn't modify existing boosters, I mean that we should not cobble rockets together out of existing stages.  For example, we shouldn't make a Delta IV-Atlas V Frankenstein or anything like that.  The parts may start off as "off the shelf," but they will evolve into totally different systems by the time the vehicle is integrated.  The Saturn I was originally a cluster of Redstone and Jupier missiles, but it looks totally different.

The best way to go about building a clean-sheet HLLV is to mate existing engines with new tankage.  The rocket should be designed around the available engines, not vice-versa.[/color:post_uid0]


Who needs Michael Griffin when you can have Peter Griffin?  Catch "Family Guy" Sunday nights on FOX.

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#80 2005-03-08 06:56:51

GCNRevenger
Member
From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: The Myth of Heavy Lift - (Let the fight begin...)

[color=#000000:post_uid0]Extendable nozzles are okay for small upper stage engines, but I have doubts about their practicality for large first-stage Hydrogen engines. An aerospike engine is probobly the only way of securing low-altitude efficency, and the cost of such an engine is probobly pretty high.

As nice as flyback boosters would be, unless Marshall or whoever building them can [i:post_uid0]prove[/i:post_uid0] they can do it cheaply and fly them cheaply, then no go. I would start with Shuttle SRBs as standard and consider flyback boosters as a future upgrade.

Side note: if flyback boosters are considerd, then side-mounting the payload is probobly out of the question due to the aerodynamics.

Yes, building a heavy lift rocket with exsisting medium lift stages is a bad idea. I don't know what Boeing is thinking with their seven-core monster.[/color:post_uid0]


"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw

The glass is at 50% of capacity

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#81 2005-03-17 23:27:19

LtlPhysics
Member
From: north of the equator
Registered: 2004-02-24
Posts: 76

Re: The Myth of Heavy Lift - (Let the fight begin...)

[color=#000000:post_uid0]Zubrin sent everyone this;

[i:post_uid0]Some people within the aerospace establishment understand that the development of a heavy lift vehicle is essential for a successful Lunar program, but wish to postpone consideration of the issue for political reasons. This is very unfortunate. One of the cheapest options to create an HLV is by converting the Shuttle.

[b:post_uid0]The Shuttle launch stack has the same takeoff thrust as a Saturn V, and if we delete the orbiter and add a hydrogen/oxygen upper stage, we can create a launch vehicle with similar capability.[/b:post_uid0]

However, under NASA's current plans, only about twenty-five more Shuttle launches are contemplated, and absent a plan for Shuttle conversion to an HLV, much of the industrial infrastructure for manufacturing key Shuttle system components (such as external tanks) will soon be dismantled. Recreating such capabilities after they have been lost will cost the taxpayers billions.[/i:post_uid0]

What's he talking about? The Shuttle stack has the same take off thrust as the Saturn V? How long can it maintain that thrust, or is that not a factor? Is lift equal to thrust X burn time?[/color:post_uid0]

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#82 2005-03-26 17:56:31

RobertDyck
Moderator
From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 6,445
Website

Re: The Myth of Heavy Lift - (Let the fight begin...)

[color=#000000:post_uid0]Nope. If the cargo is truss segments, you don't need to make the fairing load bearing. The cargo [i:post_uid0]is[/i:post_uid0] structure. And the total of engine pod + cargo after the fairing is discarded has lower mass than the current shuttle + cargo, so current RCS thrusters are enough. In fact, the configuration I'm talking about includes the 2 aft RCS pods (one on each OMS pod) and doesn't include the nose RCS pod. That's only 2 out of 3; not enough to dock with ISS but certainly enough to rendezvous and stablize cargo while the orbiter picks segments off. The trick is to get rid of the orbiter.[/color:post_uid0]

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#83 2005-03-27 16:14:06

RobertDyck
Moderator
From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 6,445
Website

Re: The Myth of Heavy Lift - (Let the fight begin...)

[color=#000000:post_uid0]I looked at the cargo manifest again. STS-116 and STS-118 would carry SPACEHAB single modules, so a double module would be able to carry all their stuff. If an orbiter carries a SPACEHAB double module and external airlock with docking adapter, there's still room for unpressurized cargo. The Special Purpose Dexterous Manipulator (SPDM), nicknamed Dexter or "Canada Hand", could be included.

Shuttle-C would have so much lift mass remaining that the Cupola could be included, attached to Node 2 during launch. Dexter and the Cupola could aid assembly.[/color:post_uid0]

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#84 2005-03-31 21:19:18

GCNRevenger
Member
From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: The Myth of Heavy Lift - (Let the fight begin...)

[color=#000000:post_uid0]See, theres this great thing about message boards... the stuff that was written in the past [i:post_uid0]doesn't[/i:post_uid0] disapear into thin air. How awful it would be if you had to actually look for information...[/color:post_uid0]


"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw

The glass is at 50% of capacity

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#85 2005-03-31 21:21:09

Michael Bloxham
Member
From: Auckland, New Zealand
Registered: 2002-03-31
Posts: 426

Re: The Myth of Heavy Lift - (Let the fight begin...)

[color=#000000:post_uid0]No, I think you should re-type it all right here, [i:post_uid0]for your own benefit.[/i:post_uid0][/color:post_uid0]


- Mike,  Member of the Clean Slate Society

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#86 2005-03-31 21:29:57

GCNRevenger
Member
From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: The Myth of Heavy Lift - (Let the fight begin...)

[color=#000000:post_uid0]*shakes head* I've typed what I would like to see happen several times now, I don't feel like apeasing your condecending laziness by doing so again.

Hint: Search for posts I have written containing "strategy" and "reuseable."[/color:post_uid0]


"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw

The glass is at 50% of capacity

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#87 2005-04-01 04:25:27

Austin Stanley
Member
From: Texarkana, TX
Registered: 2002-03-18
Posts: 519
Website

Re: The Myth of Heavy Lift - (Let the fight begin...)

[color=#000000:post_uid0]

Oh not the "we have to flgiht test the LSS box!" argument again... Thats really getting kinda lame. Why exactly does a machine that handles gasses going to behave lots different with or without gravity?

If you absolutely had to flight-test it, it would probobly be easier to build a satelite and cram it in there with a CO2 & H2O tank to mimic human respiration products.[/quote:post_uid0]

Because you have to test things in the manner (or as close to the manner) you plan to use them, or it's realy rather pointless.  In the case of the Hab LSS system it has to function for two years without the possibility of major repair, in two very hostile enviroments and undergoing some of the most violent permutations (launch and re-entery) imaginable.  Testing the Hab in conditions as similar to these as possible is vital for a succesfull mission.

And the Hab LSS is more than just a simple machine that handles gasses.  Life support is interdepenat on virtualy every aspect of the hab, especialy the enviromental seal and the power systems.  Since one minor failure in one system can easily cause a major failure in another it is also critical to test all these systems together.

This is why I am in favor of doing a Moon "shakedown" using as much as the Mars mission technology as possible.  I guress this is kind of off-topica as the shakedown doesn't have to be launched immediatly, but the soon the better IMO.[/color:post_uid0]


He who refuses to do arithmetic is doomed to talk nonsense.

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#88 2005-04-01 06:52:51

GCNRevenger
Member
From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: The Myth of Heavy Lift - (Let the fight begin...)

[color=#000000:post_uid0]Sounds good to me. Test the LSS box on the Moon, not the ISS. You get extended zero-G and low-G testing with a nuclear-powerd EOR style mission.

Bottled gasses for the whole round trip would be practical if it were to fail. Leave room in the back seat of the CEV capsule to unplug the thing and bring it home for study. Lunar oxygen is handy too if ISRU is available.[/color:post_uid0]


"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw

The glass is at 50% of capacity

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#89 2005-04-01 09:59:00

GCNRevenger
Member
From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: The Myth of Heavy Lift - (Let the fight begin...)

[color=#000000:post_uid0]Oh here Michael, I'll even find the thread where I was talking about my desired strategy last...

"Zubrin on Moon, then Mars" Page 6.[/color:post_uid0]


"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw

The glass is at 50% of capacity

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#90 2005-04-02 02:53:48

Michael Bloxham
Member
From: Auckland, New Zealand
Registered: 2002-03-31
Posts: 426

Re: The Myth of Heavy Lift - (Let the fight begin...)

[color=#000000:post_uid0]GCNR, what I am trying to do is to get you to compare what it is you want with what NASA is likely to do. Yes, we [i:post_uid0]should[/i:post_uid0] have cheap rockets and efficient RLV's and such before we start, and we [i:post_uid0]should[/i:post_uid0] look into mining the moon as a profitable enterprise; But sadly, it's just not going to happen. Right now there isn't a demand for lunar resources like He3 or PGM's, and any water found on the lunar surface will only be beneficial to astronauts living [i:post_uid0]on the lunar surface[/i:post_uid0]. It is pointless to return to the moon simply because, 45 years later, it will be *easier*. I don't care what others will have you believe: Right now it is either the Moon or Mars; [b:post_uid0]NASA cannot afford both.[/b:post_uid0][/color:post_uid0]


- Mike,  Member of the Clean Slate Society

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#91 2005-04-02 03:51:23

RobertDyck
Moderator
From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 6,445
Website

Re: The Myth of Heavy Lift - (Let the fight begin...)

[color=#000000:post_uid0]In general I agree with you Michael, but you mentioned He3. It's been a while since I posted "debunking He3". Right now we don't have a viable nuclear fusion reactor, which is the first reason not to pin economic development to it. However, once we develop a commercial fusion reactor we will be able to use deuterium alone as the fuel. Once you take into account all the secondary reactions, the energy yield from a D-D reactor is roughly 90% that of D-He3. Deuterium comes from heavy water, which is distilled from tap water. The additional energy from He3 will never justify the expense of mining the Moon.

That said, there are reasons to mine the Moon or asteroids. M-type (metal) asteroids do contain a lot of PGM, and C-type (carbonaceous) asteroids contain water that can be made into rocket fuel. If you want to build really big things in space, like a ship to carry settlers to Mars, then you need in-space materials. M-type asteroids have iron and nickel, C-type have carbon. Iron & carbon make steel. There's also all the industrial metals for stainless steel alloy. Nickel and those industrial metals make Inconel. The Moon has titanium and aluminum. There should be some S-type (stony) asteroids that also contain aluminum. Most S-type asteroids have too little aluminum for viable mining, but 4% of asteroids are M-type and they came from the core of a large asteroid or small moon that broke up; the surface should also be out there. Those S-type asteroids from the surface should have as much aluminum as Earth's moon, and about as many as from the core.

But, yea, all that is long term. NASA has a mandate from George W. Bush to go to the Moon. I'ld like to go directly to Mars and skip the Moon, but George W. said "Moon".[/color:post_uid0]

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#92 2005-04-02 10:37:16

GCNRevenger
Member
From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: The Myth of Heavy Lift - (Let the fight begin...)

[color=#000000:post_uid0][i:post_uid0]"I don't care what others will have you believe"[/i:post_uid0]

Then you are being irrational and are just parroting what you think, not debating.

[i:post_uid0]"Right now it is either the Moon or Mars; NASA cannot afford both."[/i:post_uid0]

Says you... NASA can afford lots of things if it has time to take it slow. $15Bn a year turns into $150Bn if you wait a while (a figure ten times what Shuttle-II would cost). I am thinking on the timescale of decades, the next fifty years, not the next ten or twenty. So no, NASA can't do both [i:post_uid0]right now[/i:post_uid0], but they can do them both.

Now what is a valid argument is that it will be a while, a couple of decades perhaps, before Lunar reasources become needed to Earthlings. I am not wholey convinced that He3 is worthless, since it would produce less (or even none?) neutron radiation (which could be a problem). If it is easy to dig up in a few decades from now and ship back to Earth technologically, then the extra 5-10% efficency and reduced radiation could be worthwhile.

And, eventually the PGM supply on Earth will run out. In fact, its arguable if it is economical enough right now for large-scale fuel cell production. We aren't likly to come up with anything as an alternative, since as far as we know, Platinum and the neighboring groups metals are the only ones that can break down Hydrogen bonds the way they do.

My response is, that we can get these materials sooner if we preposition some of the infrastructure and develop many of the Lunar technologies before the enabling technologies - fusion power and [i:post_uid0]real[/i:post_uid0] "no really!" cheap access to LEO - are available. The economic, environmental, and political penalties of using oil for power will continue to grow as world demand increases, and so I think it a good idea to speed up building the groundwork for the enabling infrastructure for technologies to alieviate this problem.

I think that asteroid mining is inherintly going to be harder then Lunar mining. The biggest problem is the lack of gravity, which I think will make building/digging/etc on the Moon easier then asteroids sufficently that the additional trouble of defeating Lunar gravity is a worthwhile tradeoff. Being close to Earth is kinda nice too, since long-term perminant habitation wouldn't be nessesarry, since you could rotate crews like on oil derricks.
---------------------------------------------------------------------

All that said, I do agree that NASA can only afford to lay down infrastructure for Lunar mining [i:post_uid0]OR[/i:post_uid0] go to Mars over a span of some years. I am undecided which should come first... it mainly depends on how badly we need the Moon's unique reasources.

[i:post_uid0]BUT[/i:post_uid0], I do think we should go back to the Moon on a reasonably small scale (like EELV+ scale) first. This is, simply, easier to do then going to Mars. NASA needs a project that can be done relativly easily to regain experience, develop technologies, and convince Congress (and themselves!) that they are competant and a worthwhile investment... The development cost (EELV+ vs New HLLV, capsule vs crew taxi) is really paramount, that if the barrier for results must be as low as possible given NASA's current state.

[i:post_uid0]Any[/i:post_uid0] project to either body gets us out of LEO is a good thing, and we can start some worthwhile prepatory work on the Moon for both a Lunar mining base or for some Mars technology testing, but since it is relativly small scale then it is easier to scale back (or even postpone) while we focus on Mars.[/color:post_uid0]


"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw

The glass is at 50% of capacity

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#93 2005-04-05 08:30:45

BWhite
Member
From: Chicago, Illinois
Registered: 2004-06-16
Posts: 2,635

Re: The Myth of Heavy Lift - (Let the fight begin...)

[color=#000000:post_uid0]

We are all under false hope if we think that if we save the yearly budget over a period of time that we can do anything.

But the facts of the past have been that as each year were to go by that the congress would cut the budgets of nasa as for it would be seeing nothing has come from the money given there reaction would be to continue lowering it as each year progressed until we have no space programs at all.

So we can not wait to accumilate the funds before investing them into designing of what we need for the moon or mars or for that fact into colonization of space.[/quote:post_uid0]
And you put your finger on the problem and in a nutshell. So we need either a short range goal that congress can see the accomplishment of the NASA projects or we need a new mission goal of what we want to do in space and then go after it. Within the budget we got, that would leave Mars out and even going back to the moon might be a problem. Then we need to start peddling the idea that we need the Helium 3 as a replacement power source for oil to push new moon mission to the moon.

Larry,[/color:post_uid0][/quote:post_uid0]
[color=#000000:post_uid0]Platinum for lower cost fuel cells in order to stretch our current energy sourecs further can be deployed today without fusion breakthroughs.

That said, He3 does have commercial value other than fusion and to harvest it also while mining platinum is an obvious possibility.

Do not harvest one lunar resouce. Harvest them all.

LOX for spaceflight applications;
PGMs & He3 for export to Earth; and
Lunar tourism and "pay to study" university led research missions

etc. . .

Its not an either/or situation[/color:post_uid0]


Give someone a sufficient why and they can endure just about any how

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#94 2005-04-05 09:46:55

Martian Republic
Member
From: Haltom City- Dallas/Fort Worth
Registered: 2004-06-13
Posts: 855

Re: The Myth of Heavy Lift - (Let the fight begin...)

[color=#000000:post_uid0]

We are all under false hope if we think that if we save the yearly budget over a period of time that we can do anything.

But the facts of the past have been that as each year were to go by that the congress would cut the budgets of nasa as for it would be seeing nothing has come from the money given there reaction would be to continue lowering it as each year progressed until we have no space programs at all.

So we can not wait to accumilate the funds before investing them into designing of what we need for the moon or mars or for that fact into colonization of space.[/quote:post_uid0]
And you put your finger on the problem and in a nutshell. So we need either a short range goal that congress can see the accomplishment of the NASA projects or we need a new mission goal of what we want to do in space and then go after it. Within the budget we got, that would leave Mars out and even going back to the moon might be a problem. Then we need to start peddling the idea that we need the Helium 3 as a replacement power source for oil to push new moon mission to the moon.

Larry,[/quote:post_uid0]
Platinum for lower cost fuel cells in order to stretch our current energy sourecs further can be deployed today without fusion breakthroughs.

That said, He3 does have commercial value other than fusion and to harvest it also while mining platinum is an obvious possibility.

Do not harvest one lunar resouce. Harvest them all.

LOX for spaceflight applications;
PGMs & He3 for export to Earth; and
Lunar tourism and "pay to study" university led research missions

etc. . .

Its not an either/or situation[/color:post_uid0][/quote:post_uid0]
[color=#000000:post_uid0]I agree! There no point in going to the moon to harvest one resource, while we are there. We need to make it a point to harvest what ever resources are on the moon whether it be water, helium, platinum, aluminum, iron, silicone, glass, etc. Since it easier to refine those metal on the moon than trying to bring that ore back to the Earth to refine it, we need to develop a foundry on the moon to refine it too. Once we have a foundry on the moon to refine it, then we need to setup manufacturing system to make something out of those metals that could be marketed for sale or there no point in doing it either.

But, all that would be contingent on having new shuttle for the earth and a shuttle for the moon and transportation between those two points too, because we have to be able to get to  moon and from the moon in a cost efficient manner and with a regular schedule or it will not happen, because it too expensive and we won’t have access to it.

So we have to assume that it has to be an all or nothing deal, don’t we?

Of course if we can get it this far, we not going to stop here either, but it a good thing to shoot for though.

Larry,[/color:post_uid0]

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#95 2005-04-05 19:57:04

LtlPhysics
Member
From: north of the equator
Registered: 2004-02-24
Posts: 76

Re: The Myth of Heavy Lift - (Let the fight begin...)

[color=#000000:post_uid0][b:post_uid0]I agree! There no point in going to the moon to harvest one resource, while we are there. We need to make it a point to harvest what ever resources are on the moon whether it be water, helium, platinum, aluminum, iron, silicone, glass, etc. Since it easier to refine those metal on the moon than trying to bring that ore back to the Earth to refine it, we need to develop a foundry on the moon to refine it too. Once we have a foundry on the moon to refine it, then we need to setup manufacturing system to make something out of those metals that could be marketed for sale or there no point in doing it either.[/b:post_uid0]

Infrastructure, infrastructure, where to begin? Were NASA to be granted an extra $10 billion, would they know what to do with it?[/color:post_uid0]

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#96 2005-04-08 13:47:23

publiusr
Member
From: Alabama
Registered: 2005-02-24
Posts: 682

Re: The Myth of Heavy Lift - (Let the fight begin...)

[color=#000000:post_uid0]

I'm sorry, I can't follow your ranting...

Do you mean to state that modifications to Delta-IV HLV will be [i:post_uid0][u:post_uid0]more[/u:post_uid0][/i:post_uid0] expensive then building SDV?

Lets see here...
-Addition of regenerative nozzles on RS-68, a few small upgrades
-Swapping out RL-10 for new RL-60, which is planned anyway
-Add 4-6 GEM-60 SRMs to the central CBC, prexsisting engines
-Widen portion of central launch pad flame pit to accomodate SRM exhausts.

Versus
-Building and programming avionics from scratch
-Also modifying RS-68 (SAME COST DOLT!)
-Heavy modification to external tank (AS OPPOSED TO HEAVY MODS FOR WIDE BODY DELTA'S)
-Addition of new engine section under the ET(AS OPPOSED TO CROSS-FEEDED?)
-Development of new 8.4m+ kick-stage
-Development of new superheavy upper stage (optional)
-Redo all the aerodynamics
-Redo the mobile transporter launch table
-Redo Pad-39 flame trenches, umbilicals, etc
-New SRB handling and mounting procedures

AS OPPOSED TO REDOING THE DELTA PADS TO GET LESS PER FLIGHT?

...basically, building a new rocket using exsisting engines and a similar fuel tank. I know which one will cost less to develop.

And SDV can be improved to have a massive payload beyond 120MT huh? How would you do that? Simply slapping on more boosters will quickly yeild performance diminishing returns.
WHICH IS EVEN MORE TRUE WITH DELTA IV

Will the modications and the extra $60M for boosters be worth another 10-15MT? I doubt it.

[i:post_uid0]"HLLV's allow outsized craft less cramped conditions than more narrow enclosures."[/i:post_uid0]

Which are unnessesarry for the Moon, as putting crew in a cramped capsule is not a problem for a 2-3 day trip.[/quote:post_uid0]
We are talking more than a two day trip--HLLV will be better for Mars missions than fifty-elleven EELV dock 10 times and touch your nose nonsense. Buckling down for ONE SDV HLLV IS cheaper than the whole list Boeing has presented--remember the graph?

To start with, how 'bout the cross-feeding plan--or the modifications to the Delta IV launch pad for extra-cores? or the wide-body designs they have. Look at their whole development run and the graphs they have--and you will see more money wasted there using multiple engines and pad time per 100 tons. If you weren't such an EELV apologist you would admit this. Or does Mike Griffen know less than you--?

You have convieniantly left out all the pad mods to Delta IV's with extra CBCs, haven't you? Ot the cost of multiple upper stages?

If you want a robust space program--you will support Robust HLLV infrastructure than will shine for both Moon & Mars exploration, not this stupid EELV crap you keep spouting.[/color:post_uid0]

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#97 2005-04-09 16:48:28

GCNRevenger
Member
From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: The Myth of Heavy Lift - (Let the fight begin...)

[color=#000000:post_uid0]As nice as redundancy would be, I don't think its worth the cost. Whatever system we use will cost money to qualify and/or modify, and unless Boeing or LockMart are willing to pick up the tab, then that is money that could go to better use elsewhere. Only one system... Delta, Atlas, or SDV, is really needed. If there is a problem, then VSE will simply have to be delayed. Insurance for such an event isn't worth it.[/color:post_uid0]


"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw

The glass is at 50% of capacity

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#98 2005-04-15 14:53:13

publiusr
Member
From: Alabama
Registered: 2005-02-24
Posts: 682

Re: The Myth of Heavy Lift - (Let the fight begin...)

[color=#000000:post_uid0]

Michael Griffin gave a guest lecture at U of W.

He concluded (see page 30 of the pdf) that HLLV is better for a low flight rate return to the moon defined as less than 20 flights per year and that a genuine RLV is better at higher annual flight rates.[/quote:post_uid0]
I agree with Griff'. I guess us 'ranter's just don't know when to give up.

Here is what I want to see:
http://www.atk.com/images_photogallery/ … atives.jpg

If Delta IV needs more thrust--then the three-barrel 50 ton to LEO Delta is just not credible. I don't know that Delta IV 'heavy" can put 30 tons up there in any config with less volume than an ET.

Putting two more strap-ons North south will cost money, as will Boeing's chart if we follow the whole path they lay out. If we want to go to Mars, buckle down and build the HLLV now and keep the Delta IV as it is.--and nix Atlas V's public funding so they will be forced to keep Michold--rather than cutting their heads off.

Here is the chart of what Boeing wants.

http://www.spacecongress.org/2004/Panel-4/2Collins.pdf
skip down showing the graph of all the Delta iterations.

Don't tell me all that will cost less than SDV--please.

If we are going to Mars--which this forum is supposed to be about--build to ATK's needs and not Boeing's wants. You will spend better money that way. I have heard about UR-700 cross-feeds--and without regard as to wheter they do them or not--putting three SSME/RS-68 engines on one ET-based design throws away fewer engines than the larger concepts at the end of the chart.

50-to to LEO Delta IV my eye.

I stick with what NASA's new boss said:

http://www.space.com/spacenews/business … 40412.html

He "wrote the book" as it were:

http://www.aiaa.org/content.cfm?pageid=360&id=1107

I'll defere to his pro-HLLV NOW wisdom. Not hand-waving EELV supporters who want to put an Albatross around my neck because they are having trouble with sales. Two EELVs we don't need. ONE EELV and ONE HLLV is just fine.

I think Mike would agree.[/color:post_uid0]

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#99 2005-04-15 15:35:36

GCNRevenger
Member
From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: The Myth of Heavy Lift - (Let the fight begin...)

[color=#000000:post_uid0][i:post_uid0]"Don't tell me all that will cost less than SDV"[/i:post_uid0]

Too bad: a pair of modified Delta-IV HLVs will cost less (in bulk) then SDV will. Maybe if you didn't have a reading comprihension level of a rock or the memory of your average cave cricket, you would have rememberd that I [i:post_uid0][u:post_uid0][b:post_uid0]specifically[/b:post_uid0] said that the multi (4+) core rockets were a bad idea[/u:post_uid0].[/i:post_uid0]

Okay, see that nice graph you are referencing? I am talking about the 11th vehicle idea, the next-to-last one in the green box. As you can read from the label, the regular Delta-IV tripple-barrel equipped with improved engines and some cheap SRMs can hit ~45MT, and probobly about 50MT with improved "high octane" fuel. [b:post_uid0]The same exact rocket[/b:post_uid0] as the one Boeing flew this year, except with improved engines (the same number even) and some cheap small SRMs.

If each regular "basic" Delta-IV costs $180M each, then I think these upgrades can be added for no more then ~$20M. And thats for only a few a year, the price would drop signifigantly if you bought a dozen anually. Each SDV shot will cost a bit under $200M just for the hardware.

And you know those big white reuseable SRBs you like so much? Guess what genius? They cost about $25-30M apiece to refurbish... double the cost of a brand new RS-86.

NO crossfeed system
NO lithium alloy tankage
NO signifigant CBC structural or electronic modifications
NO signifigant launch pad modifications
NO factory modifications
NO payload faring modifications required
NO brand new engines

Fifty metric tonnes to low Earth orbit

[i:post_uid0]"If Delta IV needs more thrust--then the three-barrel 50 ton to LEO Delta is just not credible."[/i:post_uid0]

Why not? Please state the reasons that the D-IV HLV is "not credible" because it needs more thrust? All cryogenic rockets suffer in performance at low altitudes and in thrust, including SDV. Why is adding solid rockets, like Shuttle, Ariane, Titan-IV, Delta-II, and H-2A somehow "not credible?"[/color:post_uid0]


"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw

The glass is at 50% of capacity

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#100 2005-04-21 21:14:16

GCNRevenger
Member
From: Earth
Registered: 2003-10-14
Posts: 6,056

Re: The Myth of Heavy Lift - (Let the fight begin...)

[color=#000000:post_uid0]If a little under a billion dollars goes into buying SDV hardware (including SRB refurbishing staff pay), then thats still a billion dollars too much.[/color:post_uid0]


"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw

The glass is at 50% of capacity

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