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#101 2005-10-24 01:14:23

Martin_Tristar
Member
From: Earth, Region : Australia
Registered: 2004-12-07
Posts: 305

Re: NASA's Moon Mission

The current designs have alot of components that are left orbiting in space and when you have multiple trips going to the moon and if we do the same amount of trips that the shuttle has done already ( 100+) then we will have 100 stage two vehicles in space - rubbishing space. RECYCLE the name of the game and it should be NASA game as well.

The engine assemblies alone could be recycled, the fuel tanks as well  and outer shell of the modules for other spacecrafts or building other terrestial buildings like a fuel depot on the lunar surface or a water storage facility either.

I am not impressed with the scientists, and innovators of the NASA or it contractors if that is the only concept they could come up with.

:cry:  :cry:

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#102 2005-10-24 13:00:05

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

Re: NASA's Moon Mission

"RECYCLE the name of the game and it should be NASA game as well."

No

Why not? Simple, it would cost MORE to try and recycle parts in orbit then it would be to purpose-build and launch new ones. As counter-intuitive as it is, DOING anything in zero-G is so hard, that its just not worth it.


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

[i]The glass is at 50% of capacity[/i]

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#103 2005-10-24 16:06:13

Commodore
Member
From: Upstate NY, USA
Registered: 2004-07-25
Posts: 1,021

Re: NASA's Moon Mission

On the contrary, reuseability is going to be vital reducing per mission costs. Why launch a TLI stage every time when you can launch a reusable one and a fuel tanker capable of fueling 3 missions? Why launch a Accent stage when the CEV can do the same? Depending on how effective the new landing methods are, the service module could likely be equipped with a heat shield and reused as well.

Don't mistake Shuttle "reuseability" for VSE reusabilty. All of these components combined will have a tiny fraction of the complexity of the shuttle. With modern materials and technologies its highly unlikely that they would require anywheres near the level of rebuilding after every mission.


"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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#104 2005-10-24 17:49:43

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

Re: NASA's Moon Mission

On the contrary, reuseability is going to be vital reducing per mission costs. Why launch a TLI stage every time when you can launch a reusable one and a fuel tanker capable of fueling 3 missions? Why launch a Accent stage when the CEV can do the same? Depending on how effective the new landing methods are, the service module could likely be equipped with a heat shield and reused as well.

Don't mistake Shuttle "reuseability" for VSE reusabilty. All of these components combined will have a tiny fraction of the complexity of the shuttle. With modern materials and technologies its highly unlikely that they would require anywheres near the level of rebuilding after every mission.

You are simply incorrect, Commodore

That TLI stage on-orbit mass will be about eighty tonnes wet, which will be roughly sixty or seventy tonnes of fuel. So, even with the maximal 125MT heavy lifter, thats less then two loads of fuel each. If you include Earth-return fuel, thats only about one mission worth of fuel.

Now, under the current NASA plan, that TLI stage can be really dumb, that is, it doesn't have to be anything other then a gas tank with a rocket on the back. The Lunar lander will provide all the power, avionics, and maneuvering capabilities  so that the big rocket stage can be as simple as possible.

Simple and CHEAP... cheap enough to throw away

The fuel depot on the other hand, that will have to be carefully built... sturdy, space debries resistant tankage with long-term power supplies and cryogen coolers, docking "slips," and complex zero-G fuel transfer gear, and of course a big & flimsy sun shade.. Ships recieveing fuel will also need to be equipped with transfer gear too. The whole thing will be big, heavy, and expensive... but it just won't save much money.

Then there is getting fuel UP to it... the fuel tanker can't be a "dumb" tank either, the maximal HLLV doesn't come with an upper stage, so the TLI stage in the VSE plan actually doubles as both. So, your tanker will need a big engine too, unless you forgo the upper stage completly which decreases your payload by 1/3rd to 80MT.

And when it gets up there, you won't have a Lunar lander on the front to provide power and maneuvering, which will also have to be added, which will reduce your useful fuel mass by several tonnes. Developing the tanker will be on top of developing the fuel depot too; remember, development costs at a premium right now, even if that comes at the expense of higher operational costs later.

Since you have to send up a whole HLLV worth of fuel for just ONE trip to the Moon, maybe one-and-a-third, then whats the point? Now you have to pay to develop the fuel depot, you have to pay to develop the fuel tanker, and you have to build a brand new smart, powerd, maneuverable tanker every time you want to refuel for one (to 1.33) trips.

Or, you can just launch the dumb expendable TLI stage one time and be done with it.

And this business about "the CEV can do the same," again no! NO direct-return trajectory: direct return costs much more fuel then Lunar orbit rendezvous even with the seperate acent vehicle! You would be hard pressed to even get the full-size "big" CEV up and down, much less with payload. The problem is that you have to lift the Earth-return fuel from the Lunar surface to Lunar orbit, which itself takes lots of fuel. Since CEV weighs about 25MT, we're talking alot of fuel! The acent stage will be light weight, and will require much less, plus adds a backup "lifeboat" ability (like Apollo 13) and increases living space for the trip out.

I reiterate, that it is absolutely vital that the manned Lunar lander carry at least some payload with it. Otherwise, they are doomed to just be a repeat of Apollo and will increase the logistics cost of a Moon base. Several tonnes at least, enough for a prospecting drill or supplies for a six-month crew rotation or whatnot... otherwise you're just not going to do anything useful.

It will be very hard to try and save the service module too: you don't understand how hard it is to make a vehicle survive reentry from Lunar velocities, that even the current model of the Soyuz capsule would be reduced to a cinder without modification. The aerodynamics are very demanding, and the conical shape of the Apollo and CEV capsules are practical because their sides are sharply canted away from the heat shield, and hence are protected from the firey gasses. The service module, on the other hand, has straight walls even if did have a heat shield of its own (which would add a dozen tonnes total stack mass!), which would make it melt. The only solution is to have a very big heat shield or heat-proof walls, which wouldn't fit on the CEV rocket at all and weigh even more. The service module is also going to be very light, and as such, could be subjected to even higher G-forces then a CEV capsule, which would require signifigant structural stiffening... Its not happening.


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

[i]The glass is at 50% of capacity[/i]

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#105 2005-10-24 17:54:05

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

Re: NASA's Moon Mission

On the contrary, reuseability is going to be vital reducing per mission costs. Why launch a TLI stage every time when you can launch a reusable one and a fuel tanker capable of fueling 3 missions? Why launch a Accent stage when the CEV can do the same? Depending on how effective the new landing methods are, the service module could likely be equipped with a heat shield and reused as well.

Don't mistake Shuttle "reuseability" for VSE reusabilty. All of these components combined will have a tiny fraction of the complexity of the shuttle. With modern materials and technologies its highly unlikely that they would require anywheres near the level of rebuilding after every mission.

I agree with GCNRevenger on this one. It would be questionable whether we could re-use some of our space craft that land on the Earth and whether they could be clean up  well enough so we could  fire them back up as space craft again. Let take the moon as an example of neither retrofitting old hardware for a new job being done right off the bat. Some one mentioned that we could use the old lunar lander as a bases to build a permanent habitat.  So we are going to make six moon landing for 7 days stay apiece at the same location. We will be on the moon for 42 days over a three year period. We going to have to build 12 rockets and we will leave six lunar lander pods at the same location. So we say let transform those six lander pods into a permanent habitat. It sound like a good idea everybody. But, before we get started some says, let build five rocket and instead of spending 42 day on the moon in the same place over three year period, let spend 365 day there over a one year period. We build our two space ship that will be sent up six month apart, but that fifth is rocket going to be caring a Bigelow habitat that can sustain people for six month or longer of period. It will have sleeping quarter, food galley, a small laboratory and entrance to clean the lunar dust of your space suits and a service area for lunar buggies. Instead of having 42 day of trying to patch something together to gather to get a permanent moon habitat, we have a full blown lunar base working with sleeping quarter labs, power station, etc., that we can use 365 day a year.

Once we have our Moon base and you want to recycle some thing to save money then, more power to you and your idea might work then. But, this side of having permanent lunar base that we can work from, then no, your idea will be more expensive and use up more resources then going with a one use design policy. Your trying to recycle 12 rockets and we are going for single use of our rocket for 5 rockets and we can get more done than you can.

Larry,

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#106 2005-10-24 20:27:23

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,747

Re: NASA's Moon Mission

GCNRevenger post was geared at exploration an not expected to visit the same location while sacrificing all but the CEV capsule. While Martian Republic I think is expressing striving for setting up some roots of colonization with each exploration step. While Commodore is looking past both to set up some infractruture from what others would throw away.

GCNRevenger would throw away the TLI stage while needing expensive lander electronics. But the lunar lander is also expendable which makes it very costly.
The cost of 12 rockets or 6 pairs is at the same level of cost as if we were flying 9 shuttle missions at least from the number of SRB's and ET's that will be used.

What is not known at this time will be the refurb costs for the CEV capsule. Which is designed for all these missions to use.

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#107 2005-10-24 20:48:18

John Creighton
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From: Nova Scotia, Canada
Registered: 2001-09-04
Posts: 2,401
Website

Re: NASA's Moon Mission

I am not sure about weight here but if we have a reusable lunar Lander could everything be launched on the SDV instead of using it and the stick. I realize this would sacrifice safety so another use maybe be chosen for the extra payload capacity.

Now about the reusable Lander. It would require of course ISRU oxygen production. If we are on the exploration stage it would have to refuel somewhere else so it would have to do 2 landings and two takeoffs between each refuel. But if we are at the base stage it would only have to do one landing and one takeoff between refueling. I don’t think it is unreasonable to do 2 landings and two takeoffs between refueling because I think that is considerably less deltaV then taking off from earth.

Anyway my point is if A is true it means one less CLV per mission which is a very real savings. I don’t think that A is true so the significance wouldn’t be as significant but I think it is worth trying to incorporate more reusability into the architecture later on.


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#108 2005-10-24 21:07:37

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

Re: NASA's Moon Mission

What we do on the Moon is one thing, I am more addressing how we get there. My basic points are, that because the majority of the total mission mass will be rocket fuel (~90MT or so, give or tank for tankage), and because there is no super-cheap way to launch just fuel, and because of the large amount of fuel needed per-sortie makes the current NASA plan the best one.

You eliminate the need for a seperate upper stage or any tankers by making the TLI stage double as both and you minimize the complexity of the TLI stage by launching it with the powerd/maneuverable Lunar, which will be expendable anyway. The Lunar-rendezvous mission arcitecture is a given, since it maximizes payload; it would be difficult to launch the big CEV and its Methane fuel back to Earth from the Lunar surface at all even on a rocket as big as the Magnum HLLV, and would eliminate any extra payload completly.

This extra payload makes all the difference, since you need equipment to do anything on the Moon exploration wise other then repeat Apollo, and for base crew rotations they could carry all their supplies with them, eliminating the need for a seperate but expensive light cargo launch.

Don't get me wrong, reuseability will eventually be needed, but it just doesn't make sense right now: for reuseability to make any difference, the fuel situation just simply has to change. First, LOX (and maybe even Hydrogen) will have to be produced in quantity on the Moon, which will require some modest infrastructure. The best way to set up this infrastructure is with big expendable rockets and landers. Secondly, you will need a way to get fuel from Earth into Earth orbit much cheaper then even a big HLLV can deliver, which probobly means either Elon Musk's Falcon-IX or a private light RLV, neither of which will exsist for a while.

THEN we can start talking about reuseable Lunar vehicles, and not one day before.


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

[i]The glass is at 50% of capacity[/i]

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#109 2005-10-24 21:12:21

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

Re: NASA's Moon Mission

I am not sure about weight here but if we have a reusable lunar Lander could everything be launched on the SDV instead of using it and the stick. I realize this would sacrifice safety so another use maybe be chosen for the extra payload capacity.

Now about the reusable Lander. It would require of course ISRU oxygen production. If we are on the exploration stage it would have to refuel somewhere else so it would have to do 2 landings and two takeoffs between each refuel. But if we are at the base stage it would only have to do one landing and one takeoff between refueling. I don’t think it is unreasonable to do 2 landings and two takeoffs between refueling because I think that is considerably less deltaV then taking off from earth.

Anyway my point is if A is true it means one less CLV per mission which is a very real savings. I don’t think that A is true so the significance wouldn’t be as significant but I think it is worth trying to incorporate more reusability into the architecture later on.

Even with a 100% reuseable lander powerd by LOX, you'll need to get Hydrogen or Methane for it on a pretty regular basis. You might eliminate the need for a seperate CEV launch on TheStick by replacing the Lunar lander with the capsule on the HLLV, but you will have to trade the savings of several Sticks' for one big HLLV with fuel now and then. A good start, but only one leg of the trip. It will only pay big dividends when both ends have a cheap supply of fuel.


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

[i]The glass is at 50% of capacity[/i]

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#110 2005-10-25 06:17:49

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,747

Re: NASA's Moon Mission

Don't get me wrong, reuseability will eventually be needed, but it just doesn't make sense right now: for reuseability to make any difference, the fuel situation just simply has to change. First, LOX (and maybe even Hydrogen) will have to be produced in quantity on the Moon, which will require some modest infrastructure. The best way to set up this infrastructure is with big expendable rockets and landers. Secondly, you will need a way to get fuel from Earth into Earth orbit much cheaper then even a big HLLV can deliver, which probobly means either Elon Musk's Falcon-IX or a private light RLV, neither of which will exsist for a while.

THEN we can start talking about reuseable Lunar vehicles, and not one day before.

So how soon GCNRevenger do you think before we can switch into this mode, for this is the transition from exploration to colonization.

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#111 2005-10-25 08:54:01

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

Re: NASA's Moon Mission

That depends... first, how many exploration missions will NASA fly and how many for base building? If they fly lots of base building, then we could have LOX supplies sooner.

Second, how soon can private industry get its act together? Elon Musk's Falcon-IX rocket with a private-built tanker is probobly the best bet for reasonably cheap fuel, but otherwise who knows, it depends on when somebody actually comes up with a cheap means of launch.


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

[i]The glass is at 50% of capacity[/i]

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#112 2005-10-25 09:23:54

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,747

Re: NASA's Moon Mission

In addition to the building of the much needed infrastuture on the surface of the moon there will also be the need for enhancing communications as well.
Creating a better transmission system for deep-space applications

Recent advances in wireless computing technology could improve deep-space missions like asteroid research and remote spacecraft operations by changing the way signals are sent from Earth. A new method designed to effectively deliver commands and instructions using hundreds of millions of tiny transmitters linked together could also free the giant satellite dishes currently used to send and receive the long-range information for other applications principle known as a phased array, a method to align a number of mini-transmitters alongside one another and direct their combined beam into the sky

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#113 2005-10-25 20:55:42

RobS
Banned
From: South Bend, IN
Registered: 2002-01-15
Posts: 1,701
Website

Re: NASA's Moon Mission

The LSAM they are planning to build could provide a good start toward a reusable lunar shuttle anyway. The vehicle has two stages, the first being hydrogen-oxygen and able to land a pretty significant mass on the moon (a 25 tonne CEV plus maybe a 10-tonne methane-oxygen ascent stage, if I have the masses right). If you are producing lunar hydrogen-oxygen fuel and can upgrade the first stage of the LSAM so that its engines can be reused a half dozen times, it would have enough fuel to launch 35 tonnes back into lunar orbit. That's just about enough to launch a 25-tonne CEV to orbit and return itself back to the surface of the moon for refueling. It may even be close to enough to launch itself fully fueled to lunar orbit and return to the surface with a light CEV or a load of cargo. If the fuel masses are not enough, an enlarged single-stage LSAM could be developed that would do the trick.

                         -- RobS

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#114 2005-10-25 22:33:34

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

Re: NASA's Moon Mission

The Lunar lander isn't quite that powerful: remember that the lander does not land the CEV capsule on the surface, only the ~15MT acent stage and a 2-3MT of ancillary payload for a total of around 20MT. It takes an awful lot of fuel to go from Lunar orbit to the surface, at least considering whats economical to bring from Earth. An acent rocket capable of blasting the CEV capsule and service module off the Lunar surface would require buckets of fuel.

Taking the Lunar lander decent stage and putting on a light weight crew cabin with a "luggage rack" or a cargo attach point and making it into a Lunar SSTO makes sense though, so NASA could send a crew or ~20MT of cargo to the Moon with a pair of "Sticks" instead of one stick and a big Magnum HLLV if the lander and its fuel were provided for.

I was under the impression that the NASA Lunar "stack" went something like this:
-25MT CEV with service module and fuel to get from LLO to Earth
-40MT Lunar lander, about half of which is decent stage and half payload
-75MT EDS stage (on orbit mass) to push the stack to the Moon

If you could eliminate the need for the Lunar lander, that would obviously make a big difference... I do wonder how much payload you could deliver fully expendable with one shot of the HLLV though, if you skipped the CEV and stretched the decent stage fuel tanks.


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

[i]The glass is at 50% of capacity[/i]

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#115 2005-10-25 23:23:07

DigitalMan
Member
Registered: 2005-10-25
Posts: 3

Re: NASA's Moon Mission

Perhaps it would require a 'Crater' of fuel :-)

the architecture docs at nasa's exploration site indicate a plan for 21 MT of cargo to the moon, but don't indicate how they plan to do that.  Seems like it would be reasonable to have a simpler stage for a cargo drop than manned.  We shall see.

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#116 2005-10-26 01:38:50

TwinBeam
Member
From: Chandler, AZ
Registered: 2004-01-14
Posts: 144

Re: NASA's Moon Mission

Speaking of re-useablility - how much of the lunar descent components could be re-used locally, and how?

Offhand :
- the fuel tanks could be used for storage tanks in a prototype O2 production facility.  Longer term, maybe re-use locally filled tanks directly, attaching them to ascent stages.

- since you'd want to land with some excess fuel (a safety margin), left-over methane could be used to provide H2 for O2 extraction.

- Landing struts might be designed to form the frame of a shelter - drape it with a "tent" and bury it with lunar soil.  Line up several to make a larger shelter.  Ideally figure out a way to do that with the lander you came down on - but that means figuring out how to safely remove them and still be able to launch the ascent stage.  If we can't get that clever, use the struts from a previous lander.

- Struts might also be used as supports for a drill.

- foil shielding could be used in a solar concentrator, to double or triple solar collector energy production.

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#117 2005-10-26 10:52:40

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,747

Re: NASA's Moon Mission

Well I think you have hit on something with regards to reusuability of what gets left behind. I have also been wondering about other senerios with the LSAM moon lander. Since we leave the descent stage on the moon but return to lunar orbit with the crew ascent stage. The question I have is could we bring the fuel for the ascent stage and just a new descent stage for each repeat mission if the LSAM could be placed into a high enough orbit to keep it safe until we returned weeks, months or possibly a year later.

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#118 2005-10-26 11:07:09

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

Re: NASA's Moon Mission

Speaking of re-useablility - how much of the lunar descent components could be re-used locally, and how?

Offhand :
- the fuel tanks could be used for storage tanks in a prototype O2 production facility.  Longer term, maybe re-use locally filled tanks directly, attaching them to ascent stages.

- since you'd want to land with some excess fuel (a safety margin), left-over methane could be used to provide H2 for O2 extraction.

- Landing struts might be designed to form the frame of a shelter - drape it with a "tent" and bury it with lunar soil.  Line up several to make a larger shelter.  Ideally figure out a way to do that with the lander you came down on - but that means figuring out how to safely remove them and still be able to launch the ascent stage.  If we can't get that clever, use the struts from a previous lander.

- Struts might also be used as supports for a drill.

- foil shielding could be used in a solar concentrator, to double or triple solar collector energy production.

After you had a semi permanent base that your going to be staying in on a regular bases over year or so, is when your would start raiding those old landers and see what you could salvage out of it. You may find an air lock here. A tank over there. But, in the beginning it will be primarily just off time toying around with the old equipment to see what there and then seeing something that you can build out of it. It will basically just be a stroll through the lunar junkyard, until we have enough stuff to work with like digger or cranes or thins like that.

But, answer you question, it would be slow process and it would probably be a year or two after we dropped a semi permanent base there, because you would be doing too many other things to make it  possible for doing something like that possible. Your going to be unpacking the base camp, setting us the communication towers, powers station, setting up a hydroponics garden, looking for resource to make your base more self-sustainable hydrogen, oxygen or water, etc. After you have unpacked the plug and play stuff from earth and put it together, then you might look at the old junk that been sitting there for two or three years by that time. Right around that time is where you would start fiddling around with it.

Larry,

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#119 2005-10-31 23:44:45

idiom
Member
From: New Zealand
Registered: 2004-04-21
Posts: 312

Re: NASA's Moon Mission

On getting fuel into orbit... It takes about 15 litres of fuel or so to be expended to get each litre into orbit right?

How hard is it to mount an interchangeable gas tank? That is instead of pumping the fuel across, physically swapping out the fuel tanks?

How much fuel could a fuel pump pump if a fuel pump could pump fuel up the inside of a space elevator? What if it was only just boiled and easy to reliquify at the top? It would take a while right?


Come on to the Future

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#120 2005-10-31 23:49:29

DigitalMan
Member
Registered: 2005-10-25
Posts: 3

Re: NASA's Moon Mission

It seems to me it would be easier to build a space elevator on the moon if only to make it more reasonable to transport manufactured fuel / other items.  I wonder if anyone has considered this ?  (anyone at NASA that is)

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#121 2005-10-31 23:55:43

John Creighton
Member
From: Nova Scotia, Canada
Registered: 2001-09-04
Posts: 2,401
Website

Re: NASA's Moon Mission

It seems to me it would be easier to build a space elevator on the moon if only to make it more reasonable to transport manufactured fuel / other items.  I wonder if anyone has considered this ?

Yes, it is considered and when the time is right will probably be eventually built.


Dig into the [url=http://child-civilization.blogspot.com/2006/12/political-grab-bag.html]political grab bag[/url] at [url=http://child-civilization.blogspot.com/]Child Civilization[/url]

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#122 2005-11-01 19:24:03

Commodore
Member
From: Upstate NY, USA
Registered: 2004-07-25
Posts: 1,021

Re: NASA's Moon Mission

Well I think you have hit on something with regards to reusuability of what gets left behind. I have also been wondering about other senerios with the LSAM moon lander. Since we leave the descent stage on the moon but return to lunar orbit with the crew ascent stage. The question I have is could we bring the fuel for the ascent stage and just a new descent stage for each repeat mission if the LSAM could be placed into a high enough orbit to keep it safe until we returned weeks, months or possibly a year later.

The accent stage at this point is probably not going to be built to last longer than the 2 weeks out, there, and back. The CEV can apparently stay in lunar orbit for 6 months, but I think that’s mostly a fuel issue.

I would love to see any number of steps taken to reduce the per mission costs of early missions. We are going to have the CEV by 2012, and at the rate the Shuttle is going the HLLV before that. We should take the time in the time in the intervening years leading up to 2018 to set the infrastructure in place to allow a sustained lunar campaign. Its only a matter of time before some Senator decides the current plan is too much like Apollo.

A reusable accent stage would free us from a massive HLLV launch every time we go. Decent stages could be launched 3-4(assuming 25 tons each and another 25 tons of supporting systems) at a time, completely fueled, in a shielded "magazine" module in lunar orbit at the cost of two launches (the magazine, and the tug to get them there). Plus both the tug, and the empty magazine could be used later. The accent stage could be stored in LEO.

The "trouble" is the service module can't take itself to lunar orbit as is, much less with the AM in tow. A tug, or TLI stage will still be needed, but since it no longer needs to haul as much cargo its weight and the fuel weight will be much lower. This will make a reusable TLI and fuel depot much more practical. Your moving 30-35tons (20ton CEV/SM + guestamated 10ton AM) per go instead of over 70. Now you get 3-4 missions for every fuel launch. So while your technically only down to .75 HLLV launches per mission, the work put into developing the side systems is well worth it. In fact in reality your probably only developing one system, the LEO fuel depot module. Its a huge empty tank with significant insulation and shielding to prevent boil off, along with some side tanks for recirculation what does. It’s also the ideal place to store your AM.

But you ask "what about the "magazine"? It's just Decent modules stacked on top of each other, with significant insulation and shielding to keep the fueled decent modules fueled. The very same significant insulation and shielding found on the LEO fuel depot module.

But you ask "what about the refueling tank for the fuel depot"? That’s just the huge empty tank gutted to last just long enough to get the fuel in the depot. The same one you made for the fuel depot, sans the significant insulation and shielding.

And I ask what was Skylab? A big empty fuel tank with significant insulation and shielding, and life support. The fuel depot module with added life support can be a huge solid hab, in LEO, on the moon, on the way to Mars, on Mars, ect.

I present a fourer.

Now if only we could design the decent module so they not destroyed when the AM takes off.


"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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#123 2005-11-01 20:21:31

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,747

Re: NASA's Moon Mission

Well if one of the items happens to be a crane maybe even the Canadian arm that is on the ISS would do. That gets delivered on a cargo descent module, then one can simply seperate the unit and place it onto a new launching location. Then move the descent stage and have some real fun in having it to reuse over and over again until the engines and other parts no longer can take the wear and tear.

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#124 2005-11-01 21:07:54

Commodore
Member
From: Upstate NY, USA
Registered: 2004-07-25
Posts: 1,021

Re: NASA's Moon Mission

The legs could be designed to let the DM "hang" off them, allowing the hab part could be dropped off and dragged/rolled to the side, leaving just the AM propped up on the legs with a ladder going up.


"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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#125 2005-11-07 11:06:22

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 28,747

Re: NASA's Moon Mission

I have asked before how soon can we go from the exploration phase to setting up a base.

As part of a new Nasa challenge,
sponsored xcup style contests for prizes are definetly a possibility.


Could the X Prize Cup help NASA develop a Lunar RLV?

When would we need such a Reusuable Lunar lander?

If NASA keeps to its current plan, they will fly the first “Outpost Mission” in 2022 or 2023. These are by far the most important NASA missions of the first half of the 21st century. The goal is to begin work on what will become a permanent base on the Moon. In time this will evolve into the starting point for lunar colonization and development. To accomplish this NASA hopes to show that it can “live off the land” using In Situ Resource Utilization (ISRU) technology, especially to provide the Moon base with a source of rocket fuel.

Of course where is the payoff, then again were should they start looking for design references since we only have the LM?

On the Moon things are different. The ascent stage of the Apollo-era Lunar Excursion Module (LEM) weighed about 4,500 kg and its fuel weighed about 2,300 kg, i.e. a mass fraction of about 50%. This is far more manageable than the 90% needed to escape from Earth’s gravity. The designers of a Lunar RLV will have more available mass for the vehicle’s structure and payload than those working on its terrestrial equivalent.

So we will be using the LSAM for exploration but when it comes to going forward we want the private industry to go it.

Moving from the LSAM to the Lunar RLV will take a positive decision by NASA and by the White House and Congress. The plan, as its stands now, is for the LSAM to be developed between the years 2010 and 2018. It would seem natural that Lunar RLV development begin immediately after the LSAM becomes operational.

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