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#1 2005-03-15 14:12:29

BWhite
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Re: Zubrin on Moon, then Mars - Three essays, one link

This space.com thread offers convenient links to Dr. Zubrin's three recent essays on lunar mission architecture.

Very interesting on the need for HLLV.


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#2 2005-03-15 14:37:01

GCNRevenger
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Re: Zubrin on Moon, then Mars - Three essays, one link

More interesting then you think...

...Because Bob is a liar in them


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

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#3 2005-03-15 14:46:20

BWhite
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Re: Zubrin on Moon, then Mars - Three essays, one link

Heh! I await the details.  :;):  ???

= = =

Another question. Suppose we have a quasi-permanent lunar base with launches leaving periodically and lift is powered by LH2/LOX or CH4/LOX or a mixture.

How much, if any, of the rocket exhaust combustion products would fall as water ice or CO2 ice within the close vicinity of the launch point? 

If we are scooping up regolith to process for O2, H2O or CH4 anyway, what about mining the regolith around your launch pad? Regolith that just got rained on with several tons of water and CO2 combustion products.


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#4 2005-03-15 15:18:16

John Creighton
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Re: Zubrin on Moon, then Mars - Three essays, one link

I will not speculate on whether or not Bob intended to mislead but what I will say is I agree with the big picture Bob presents but not the details. For instance his assignment that 4 EELV’s will be needed to launch the payload to the moon. If Boeing develops a variant of the delta that can lift 45 tons without SRB and 80 tons with solid rocket boosters then there are many possible configurations with one or two launches for launching mass to the moon. These include 80 tons launched in one launch, 90 tons launched in two launches 125 tons launched in two launches or 160 tons launched in two launches. It also gives the military a vehicle that can launch medium sized payloads and a launch option for heavier planetary probes like JIMO. If a vehicle of this size is needed extensively anyway for the military, planetary missions or crew rondaview with a SDV then it is not a waste but an important step forward for the united states in terms of launch capabilities. Moreover if the delta line is continued it may not mean starting from scratch again since much of the tools used to manufacture the upgraded EELV could conceivably used to manufacture an even more upgraded EELV. Still I am not saying a heavier lifting launch vehicle is a bad option. Perhaps two midsized payloads could be launched in one heavy lift launch vehicle just like to medium lift launch vehicles could be used to amass the payload of one heavy lift launch vehicle. It is all a matter of economics. The administration must ask what kind of payloads need to be delivered. Are the majority of the payloads better suited to medium sized launch vehicles or heavy lift launch vehicles. How much will each vehicle cost. What is the risk of each vehicle. I therefore leave it up to the engineers to determine what the most suitable launch vehicle is. These will include engineers working for NASA and the department of defense.

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#5 2005-03-15 15:22:40

BWhite
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Re: Zubrin on Moon, then Mars - Three essays, one link

Zubrin said (at a forum where I was present) that he is agnostic on the choice of HLLV.

Super-heavy Delta or Atlas are an option but would they need new launch facilities?

= = =

Add SRBs to an oversized Delta barrel with RS-68s and that starts looking a lot like an in-line SDV.

And some might say a 45 MT Delta IV is an HLLV.

Can you add SRBs to a triple barrel Delta IV?


Edited By BWhite on 1110921943


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#6 2005-03-15 15:47:03

John Creighton
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Re: Zubrin on Moon, then Mars - Three essays, one link

Zubrin said (at a forum where I was present) that he is agnostic on the choice of HLLV.

Super-heavy Delta or Atlas are an option but would they need new launch facilities?

= = =

Add SRBs to an oversized Delta barrel with RS-68s and that starts looking a lot like an in-line SDV.

Well, them maybe we are just arguing about what to call the thing?  Anyway, perhaps the best options is some amalgamation of all possibilities.

Can you add SRBs to a triple barrel Delta IV?

Boeing has examined other Heavy unmanned cargo options using six solids to achieve in excess of 50 metric tons to orbit. Each GEM-60 has 191,000 lb. of liftoff thrust and, by mounting them all on the same side, the vehicle can still use Pad 37 without changes.

from:
Trial by fire

Also from the same article:

Boeing has also looked at other IV Heavy derivatives that would cluster 5-7 common cores with 5-7 RS-68 first-stage engines for 85-metric-ton Earth orbit payloads and 36-ton capability to Mars.
And it has considered increasing the diameter of the clustered cores from 16.1 ft. to 23 ft. for more propellant, giving the vehicle a payload capability comparable to the 7.5-million-lb.-thrust Saturn V. But the concepts with the multiple or enlarged cores would require new pad infrastructure and are not likely for any near-term mission options.

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#7 2005-03-15 15:53:29

GCNRevenger
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Re: Zubrin on Moon, then Mars - Three essays, one link

The tripple-core Delta using a cluster of GEM-60 solid rocket boosters (the little ones) and all the bells/whistles (Al-Li tankage, RS-68R, new fuel mix, ML-60 2nd stage) could hit the 40-45MT mark, which I believe can be built in bulk no more then $200M each when purchased in number.

Building a heavy-lift rocket based on clusters of EELV cores strikes me as a bad idea, that the inherint inefficency of such a system would probobly make a small clean-sheet launcher the superior option. Same deal for adding Shuttle SRBs to make Delta more powerful... could you? Probobly, but with all the changes involved (massive structural changes, all-new upper stage, new launch pad and VAB) you might as well do clean-sheet.


"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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#8 2005-03-15 16:04:17

BWhite
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Re: Zubrin on Moon, then Mars - Three essays, one link

The tripple-core Delta using a cluster of GEM-60 solid rocket boosters (the little ones) and all the bells/whistles (Al-Li tankage, RS-68R, new fuel mix, ML-60 2nd stage) could hit the 40-45MT mark, which I believe can be built in bulk no more then $200M each when purchased in number.

Building a heavy-lift rocket based on clusters of EELV cores strikes me as a bad idea, that the inherint inefficency of such a system would probobly make a small clean-sheet launcher the superior option. Same deal for adding Shuttle SRBs to make Delta more powerful... could you? Probobly, but with all the changes involved (massive structural changes, all-new upper stage, new launch pad and VAB) you might as well do clean-sheet.

Stick a cluster of RS-68s under a Michoud tank and what do you have?

Shuttle derived.  :;):

Can anyone make a big tank better or more efficiently than Michoud?

= = =

How do we move from 45 MT to 90 MT with Delta?

Edited By BWhite on 1110924623


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#9 2005-03-15 16:12:13

GCNRevenger
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Re: Zubrin on Moon, then Mars - Three essays, one link

The way Shuttle's tank is designed, it doesn't make sense to launc it without the boosters, it just doesn't have the thrust.

Take Delta from the 50MT intermediate catagory to the heavy 80MT+ range? You would have to use the seven-core megacluster, and a new massive upper stage. New launch pad/VAB too.


"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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#10 2005-03-15 16:34:59

BWhite
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Re: Zubrin on Moon, then Mars - Three essays, one link

Take Delta from the 50MT intermediate catagory to the heavy 80MT+ range? You would have to use the seven-core megacluster, and a new massive upper stage. New launch pad/VAB too.

Explain where I am wrong - -

The VAB, Pad 39 and the crawler give us heavy lift capability the Russians cannot dream of deploying without billions in infrastructure improvements, at a time when they are cash starved. Even Energia is smallish compared with big SDV.

We can make big tanks at Michoud. No one else in the world can do that.

For all my US bashing, I am gung-ho USA on this. Only the US can build genuine HLLV. Unless we throw that capability away.


Edited By BWhite on 1110926125


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#11 2005-03-15 16:47:02

GCNRevenger
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Re: Zubrin on Moon, then Mars - Three essays, one link

Well... no. Energia Vulkain would be aproximatly a match for even a "mega" SDV with RS-68R upper stage and five-segment SRBs. It would be  expensive to do though, given that the Vulkain varient was never built. Given the political problems, and the fact you would bascially have to "move" half of KSC to Russia, that ain't happening.

Again, nobody knows that SDV will be cheap enough to fly... not you&me, not NASA, and definatly not Bob Zubrin (despite his bogus assertions to the contrary).


"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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#12 2005-03-15 16:56:43

BWhite
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Re: Zubrin on Moon, then Mars - Three essays, one link

Well... no. Energia Vulkain would be aproximatly a match for even a "mega" SDV with RS-68R upper stage and five-segment SRBs. It would be  expensive to do though, given that the Vulkain varient was never built. Given the political problems, and the fact you would bascially have to "move" half of KSC to Russia, that ain't happening.

Again, nobody knows that SDV will be cheap enough to fly... not you&me, not NASA, and definatly not Bob Zubrin (despite his bogus assertions to the contrary).

I can agree with this, but

No one knows if we can sustain a lunar presence with 40-45 MT per launch and we sure as heck are not going to Mars with a 45 MT launcher as our biggest and

if Boeing needs a new VAB and pad for the 7 core Delta, will we need to re-hire that standing army anyway?


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#13 2005-03-15 17:06:54

John Creighton
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Re: Zubrin on Moon, then Mars - Three essays, one link

If I understand the difference between a shuttle derived and an EELV is that the EELV has more thrust per weight at its core. Would it be easy to find some intermediate options by varying the number of engines on the main tank of the shuttle? Thus perhaps a shuttle derived that would have the options of launching without any solid rocket boosters for intermediate payloads or human flights.

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#14 2005-03-15 17:09:00

GCNRevenger
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Re: Zubrin on Moon, then Mars - Three essays, one link

I am saying that we DON'T need a launcher bigger then ~45MT to maintain a Lunar base, we do not need it.

No concieveable varient of SDV will possibly cost less then a few hundreds of millions of dollars without a truely radical reduction in KSC staff or massive design changes, which I don't think will happen.

The basic version of SDV will never be able to lift more then 100MT without an expensive mega upper stage.

I don't think that it is realistic to peg a Delta-IV HLV shot at more then ~$200M with modifications, if they were built in number.

SDV will not have an upper stage persay, so whatever Lunar payload will be mated to a TLI stage, each of aproximatly equal mass...

So, I am stating that SDV will not be able to offer a radically cheaper solution to Delta-IV superheavy without massive (like flyback liquid boosters) and expensive alteration.

For Mars, yes, we will absolutely require bigger payloads. For the Moon though, we don't.

...In theory, the huge "mega Delta-VII" wouldn't need a much bigger crew then the tripple-barrel one. Much of Delta's assembly is automated (laser-guided robot arms) at the VAB, it would just have a lower flight rate.

The problem with launching Shuttle with only the main tank is that it would require too many engines (in my opinion) to have enough thrust to get off the ground. The RS-68 is a large (by volume) engine, and I don't think you could fit many of them under it. The large diamater's drag also demands high thrust.

It would also require signifigant pad operations & modifications.


"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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#15 2005-03-15 18:05:56

Michael Bloxham
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Re: Zubrin on Moon, then Mars - Three essays, one link

Err, wouldn't that then be a single stage system? I'm skeptical of any Medium-lift solution: Yes, the cost per pound may be a lot cheaper than any SDV can deliver, but the actual space program based on an HLLV will be much much cheaper overall (Reduced complexity, etc.). Maybe we're focusing too much on launch costs, and forgetting to look at the effects on the overall program costs.

-Mike


- Mike,  Member of the Clean Slate Society

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#16 2005-03-15 19:13:49

Ian Flint
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Re: Zubrin on Moon, then Mars - Three essays, one link

I am saying that we DON'T need a launcher bigger then ~45MT to maintain a Lunar base, we do not need it.
.......
For Mars, yes, we will absolutely require bigger payloads. For the Moon though, we don't.

That is basically Zubrin's point.  We don't technically need HLLV for the Moon, but if we are looking at a Moon/Mars vision we will eventually need the HLLV.  So why should we waste our time on EELVs when we will have to build the darned HLLV anyway.  If the Moon doesn't need all that capacity it can simply have a slower launch rate.

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#17 2005-03-15 19:29:40

Grypd
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Re: Zubrin on Moon, then Mars - Three essays, one link

Err, wouldn't that then be a single stage system? I'm skeptical of any Medium-lift solution: Yes, the cost per pound may be a lot cheaper than any SDV can deliver, but the actual space program based on an HLLV will be much much cheaper overall (Reduced complexity, etc.). Maybe we're focusing too much on launch costs, and forgetting to look at the effects on the overall program costs.

-Mike

Good call, but on a related matter

Assuming that shortly after we have the current shuttle flying again there will be an exact request for a replacement for the shuttle from Nasa. Im still not sure that a good part of the Shuttles army of ground support will not simply be added to this the next generation launcher.

Do we have a figure as to how many are in this ground staff and there exact job descriptions. We will have to accepth that we will get a cross over from the Shuttle to this new launcher/s of a good majority of this ground army.

And we are talking about everybody from the Mission controller down to the people who clean up. There are a lot of important jobs that go with space launches and these we are not costing into any of these systems.

Oh there is fat that can be cut but how much is difficult. Nasa is a goverment agency and has a well padded out structure. This can be deflated a bit but in this it is the little guy who seems to go first and this actually effects efficiency on the ground.

So the arquement really should come down to this which system or combination will give the most value per dollar spent and value must include launch rate, science, efficiency, capacity and also how big a standing army it needs to actually operate.


Chan eil mi aig a bheil ùidh ann an gleidheadh an status quo; Tha mi airson cur às e.

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#18 2005-03-15 20:24:57

Commodore
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Re: Zubrin on Moon, then Mars - Three essays, one link

Its never been all that clear what exactly is ment by the "Shuttle Army". If we use a SDV, then we have a well trained and proven workforce already in place, along with all their equipment.

Sounds to me like an advantage.


"Yes, I was going to give this astronaut selection my best shot, I was determined when the NASA proctologist looked up my ass, he would see pipes so dazzling he would ask the nurse to get his sunglasses."
---Shuttle Astronaut Mike Mullane

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#19 2005-03-15 22:32:17

Michael Bloxham
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Re: Zubrin on Moon, then Mars - Three essays, one link

Why not an architecture which uses both medium and heavy lift? A hybrid of sorts; it could utilize the best attributes from both. Maybe a cargo only SDV for heavy lift items like the hab, then send the crew up for rendezvous on a man-rated CEV/MLV... Or keep the SDV man-rated, launched with a crewed hab, and send the other bits and pieces on a conventional MLV. Mars Direct might also benefit from a similar architecture. Sending small stuff like science equipment, rovers, supplies etc. on an MLV might give you a little extra mass to play with.  :;):


- Mike,  Member of the Clean Slate Society

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#20 2005-03-15 23:25:38

GCNRevenger
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Re: Zubrin on Moon, then Mars - Three essays, one link

I am saying that we DON'T need a launcher bigger then ~45MT to maintain a Lunar base, we do not need it.
.......
For Mars, yes, we will absolutely require bigger payloads. For the Moon though, we don't.

That is basically Zubrin's point.  We don't technically need HLLV for the Moon, but if we are looking at a Moon/Mars vision we will eventually need the HLLV.  So why should we waste our time on EELVs when we will have to build the darned HLLV anyway.  If the Moon doesn't need all that capacity it can simply have a slower launch rate.

No it isn't, you are just trying to ignore Bob's deceptive smear attack against the EELV route. How could you possibly read his essays and come to the conclusion that he thinks EELV would be practical?

Mars is a long way off, far enough off that a few years spent developing a new HLLV is not a big deal. It is also far enough off, and NASA's current budget so tight, that whatever option we pick for the Moon should be the best option only for the Moon and our current dollar... if it helps for Mars later, great, but there is no time nor money to absorb the additional cost in fiscal and political capital to do otherwise.

The Shuttle Army (and the ISS Brigades by extension) is largely responsable for taking up so much of NASA's money, that they have nothing left to do anything but go in circles. About 3/4ths to 4/5ths of NASA's manned spaceflight budget goes into paying The Army, which amounts to around $4.5-5.0Bn per year.

NASA cannot survive to execute VSE so long as it is paying this huge cost, NASA simply can't afford to go to the Moon unless it can use this money. Since NASA doesn't need The Army if it uses EELV, then Congress will point out this fact if NASA came begging for a big budget hike to pay for VSE + The Army, and refuse.

In order to make SDV affordable (under $400M/each if current hardware prices carry over to SDV), about 50% to ~66%, perhaps a little more, of The Army would just have to go. I don't think we can trust NASA to do this, not yet.


"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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#21 2005-03-16 06:35:40

SpaceNut
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Re: Zubrin on Moon, then Mars - Three essays, one link

So the moon and mars programs are so far off that developing Heavy lift will be on the shelf for a while. ???

Developing a new heavy lift rocket needs what type of research to make it not be an off the shelf configuration of what is available today in parts or pieces, am I correct.

So last I knew all new engine developement had been cancelled that was part of OSP and next generation. I seem to recall a Kerosene lox engine simular to the F1 was under developement.

So again what new technology must be researched? IMO it is non and that all the time is in engineers drafting up a structural design and protoype build of it, be it manned or otherwise.

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#22 2005-03-16 07:08:08

GCNRevenger
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Re: Zubrin on Moon, then Mars - Three essays, one link

Addendum: Actually NASA did look into making a launch vehicle based on the Shuttle tankage that would not have needed boosters to reach orbit (see National Launch System), but the tank  and pad would have to be so modified that it would basically be a clean-sheet rocket... It would also be of the appropriate size, able to lift 40MT and 80MT payloads with optional Shuttle SRBs. It would definatly require uprated "super" RS-68R engines to make it economical though.

As far as building a heavy lift vehicle, if we are satisfied by throwing away the whole thing, then we don't need much new technology at all. Shuttle SRBs and RD-170 engines would provide plenty of thrust (and perhaps limited reuseability), it would mainly be a question of the upper stage engine choice. SSME is too expensive, RS-68 is awfully big (but could serve), clusters of RL-60's would do but would be alot of trouble and limit performance, and the RD-0120 isn't clearly a viable option.

If we want to get some of the rocket BACK to save on money, then building a core vehicle with improved RS-68R engines and 2-3 flyback boosters with a big reuseable Kerosene engine (like the RS-86 you refer to SpaceNut) with optional upper stage would be ideal.


"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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#23 2005-03-16 09:03:55

BWhite
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Re: Zubrin on Moon, then Mars - Three essays, one link

What about the other aspects of Zubinr's missive, lunar orbit rendevouz or direct flight?


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#24 2005-03-16 09:31:03

GCNRevenger
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Re: Zubrin on Moon, then Mars - Three essays, one link

Zubrin arbitrarily assumes things that make the EELV route look bad, like assuming the LSAM will use Hydrogen for the decent stage, which is silly... He also assumes the EELVs are limited to only a tiny 10% improvement over Delta-IV HLV, when infact a larger increase is obviously possible.

So I think he is also inflating the risks involved with relativly simple space maneuvers and operation, which when aggregated a small bias makes a big scarry number that fits his thesis that EELV is a bad idea.

Direct flight makes no sense until we have signifigant ISRU capacity. It should be a major goal, but not a life/death prospect for early missions.

Bob hates EELV because it isn't a step to his Mars rocket.

If 100MT is enough for a Lunar expedition, then you would only need three launches, two for 40MT class Delta-IV HLVs to lift the LSAM & EDS, and a third 20MT class flight for the CEV & TEI stage.


"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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#25 2005-03-16 09:35:57

BWhite
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Re: Zubrin on Moon, then Mars - Three essays, one link

Then it is false advertising to call it Moon-Mars?


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