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#151 2006-08-12 14:49:11

RedStreak
Member
From: Illinois
Registered: 2006-05-12
Posts: 541

Re: Reusable LSAM

LOX production should be a priority indeed.  Its application to the RLSAM would be lowering the resupply mass by extracting it from lunar soil (or regolith if you want to be technical).  As I said in my big statement atop page 8 it should be considered since it will allow, for instance, more H2 to be imported, more base equiptment, ect.

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#152 2006-08-14 04:19:22

neviden
Member
Registered: 2004-05-06
Posts: 99

Re: Reusable LSAM

The russians think this could work:

http://www.energia.ru/english/energia/n … 07-01.html

But I would go one step futher.. they show you need only one propulsion stage to make lunar flyby, but two to go into LLO.. why not make lunar flyby that will go to L2.. it needs only extra 0,33 km/s delta-v to enter semi-stable (0,1 km/s delta-v stationkeeping a year) L2 helo orbit.. it will take you 8 days to go from LEO to L2.. you can return to earth with 0,33 km/s delta-v.. if 8 days is too long, you can go to  L2 directly with delta-v of TEI + 1,2 km/s.. and you will get there in 4 days..

http://www.nasaspaceflight.com/docs/hal … tation.pdf

Why L2? well.. you can reach any spot on moon from there.. and you can even use high inclanation earth orbits to get there (moon flyby saves you propelant) like ISS..

And when you are there.. you are already on Interplanetary Superhighway System.. you can go slowly with very little delta-v onto this highway, or you can go to mars the regular way.. you do lunar flyby (or if you want you can do moon-earth or even moon-earth-moon flybys) and off to mars you go.. you already have almost all the speed to do that.. you do need propelant to bring stuff from earth, but you would need all that propelant anyway to go to mars, and you can take your time.. combine all the parts for mars spaceship, test everything, send it to mars.. and on the way back use flybys to return to L2.. refit it, and reuse it..

http://www.cds.caltech.edu/~shane/paper … s_2001.pdf

the same way you could return material from asteoroids.. you need only TEI (which is basicly what you have in L1 or L2) + 0.06 km/s to get to or from 1982DB,.. and once you have this material in high earth orbit, you don't need to haul all that propelant from moon (well even if you dont find easy water you get lots of O2 on asteroids in oxides).. you just use moon, L1, L2, earth to change orbits.. and aerobraking (so you don't need to burn 3,1 km/s worth of propelant) of tugs to bring extracted O2 or water to LEO (so you can do 3,1 km/s TEI to reach any of those orbits from LEO)..

http://www.permanent.com/t-theory.htm

So, you get from 6x 20 MT launches to change crews (still cheaper than building 2 new rockets + everything else), to one soyuz/klipper launch to LEO, tug to lander changeover (either direct in HEEO, in LLO, L2 or via station in L2) Lander to moon.. with more propelant you could just combine tug and lander in one ship that can airbrake to LEO or land on moon.. they are quite similar (lander has bigger/more engines + legs - airbrake mass)... everything is reused, what is broken gets fixed either in LEO, L2 or moon, you send only spare parts (cheaper than new ships all the time), and each crew costs you - one soyuz/klipper to LEO costing 60 million $... dirt cheap compared to 2,5 billion $ pricetag for Ares V + Ares I...

And you also can build reusable mars ship, that you don't have to throw away because you need that much propelant that you must send from earth that it is just not worth it.. you build it in L1, L2, L5, HEEO.. in one safe orbit (so you don't have to wory about whole thing falling to earth like ISS would do if you would stop raising it's orbit), from wich you can do flybys to go to other places.. and since you can get material from asteoroids (they are just rocks that fly their own orbits around the sun) all you need to learn how to do is: make thick (1 cm? 10 cm? how much do you need?) sheats of metals (iron will do just fine), weald those pices together and you can make any large structure you need.. once you have airtight structures, you can fill it with air and make concrete 'walls' few m thick (protection against everything outside - radiaton, flairs, punctures).. from then on it's like building luxury cruise liner.. wheels (gravity = place to live, grow food, work), boxes (spacedock = place to work/fix on spaceships protected from radiation and with normal air.. no need to use spacesuits.. T-shirts would do just fine).. small, complicated things you get from LEO (ISS is 500 MT whole).. big things you build on site.. and from there on you can do anything..

oh, and when you reuse mars space ship, the price for one person to get to mars orbit is: 20 million per person + price of spare parts divided by number of persons.. (once you build this of course).. anyone interested? tongue

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#153 2006-08-14 07:21:30

neviden
Member
Registered: 2004-05-06
Posts: 99

Re: Reusable LSAM

Zero-gravity ship building is a pipe dream too for the next half century at least. This is so far away that there is no sense in discussing it. Mining base metals or propellant from the Moon/asteroids is again a thing of a dreamy far future, its just so hard to do that its not easier than Earth launch.

We must learn how to seperate Oxygen from metal oxides.. we know how to do this on earth.. We must learn how to weld metals together.. we know how to do this on earth.. if zero-g causes you problems, then you just build first smelter that spins enough, so it works.. and once you weld your first wheel together, fill it with air, spin.. from then on it's just like earth.. you don't even need to research anything new.. only use what you use on earth..

This is the wrong way of thinking.

NASA plans to spend 2,5 billion dollars each time to send 4 people to moon for 6 months (not even to mars).. build everything each time, and throw it away.. and you think my way of thinking is wrong?  roll

Space construction, operation, etc are all very expensive endeavours and their cost must be weighed against just building it here where we have all the food, water, and energy in abundance and just launch it.

Yes.. space construction.. but if you are working in 1 G environment, protected by few m of concrete from space, its like working on ship on earth.. and since have all the energy that you need (sun shines 24 hours a day, 365 days a year), you can light up your greenhouse, that will give you food and recycle water..

you know.. like those greenhouses that produce food when there is - 70 degress celsius outside.. on earth south pole.. http://www.antarctichydroponics.com/international.htm

I am not just talking in the short term but the long term as well, that the initial costs are so massive and the operations cost still so high by virtue of its difficulty that competing with Earth will be difficult. For instance, Lunar mining/smelting and factories to build anything of useful scale would be very large, as would factories and support. Can this really be cheaper than just building on Earth and flying from here? Not just now, not just in the short term, but ever.

You just need to build 'factory' that can melt iron oxides (mirrors and sun?) insert CO or H to remove Oxygen from it, recycle gass, and form this iron into sheets. Repeat. Weld sheets together and.. you have your 1 G spacestation.. how much would this weigh? 10-100 MT? You send it once.. complicated parts? Rapid manufacturing...

http://en.wikipedia.org/wiki/Rapid_prototyping

Again, reuseability is not always the cheaper option. A tug or lander will have to fire its main engine four times for each trip, and so to even last ten trips you'd need an engine with four times the service life of the best engine, the RL-10. If the lander or tug can't make many missions, then there is no point in bothering with them at all, particularly when they have to be big enough and have enough thrust to move 100's of tonnes of payload.

Then we will just have to build better engines.. if they are made to last 10 times they can be inproved.. to 20.. to 50.. and more.. and make them easy to repleace/fix.. then send one container full of engine parts to LEO and that should cover it.. you don't dump whole car when it's tires wear out..

Oh, tugs/landers WOULD make many missions.. there is all that O2 or watter to move around and containers to be delivered.. especialy if that costs you nothing extra to launch them.. it's not like they have to be rebuilt every time because they must do 10 km/s to get to LEO and airbrake back in one big fireball..

No! You make it sound like building these big ships will be cheap and their cost negligible, this is not only untrue, but frankly its misleading. If these vehicles cost anything like what I expect (say $500M each) then building 100 each is one hundred billion dollars.

since we are talking about something like ATV or progess.. ATV costs 70 million euros, progress is even cheaper (30 million $?).. but even it costs 500M each.. NASA is planing on building/designing all those things anyway.. so how is 500M reusable lander different than 500M expendable lander? It's the same thing.. reusable lander only has bigger tanker and more/better engines..

and since you reuse them.. you only build them once.. NASA has 15 billions to spend each year.. thats 15 landers/tugs that will last you looong time (you fix them, remember).. costs fall once you don't have to send all that propelant from earth.. and once everything is built, delivered and works.. then you send ocasional new lander/tug, spare parts and lots of payloads.. 20 MT to LEO costs you 100 million $.. Ares V + Ares I + EDS + lander that does the same job (deliveres 20 MT to moon) costs 2,5 billion.. and nothing even exists..


Building a vehicle to last 15 years without expensive servicing (eg new engines) will be a tall order, and will add to the cost of each unit built substantially.

Russian Parom is supposed to have 15 years on orbit life with servicing.. and if you design engines to be easily fixed in orbit, then you only replace engines.. or even only parts that get worn out..


Furthermore, fuel boiloff really is critical for such a scheme, that if travel times are slow or the vehicles have to wait in orbit alot of that fuel is going to be lost.

Most of the fuel will be in LEO station (where you convert water or store O2 and H2) lunar orbit/L2 and on moon .. they will not move, so you can aford to reliquify boiloff + chill everything realy good.. that fuel will get transfered to tugs/landers right before they go.. that means it will be there for few days.. only exception would be tug that slowly aerobrakes back to LEO.. but it can cary water, so you don't have boiloff problem.. or O2, but O2 does not boil off that fast.. plus, if you keep your tanks in shade they will be cold..

in a ways ships and spaceships are the best comparisson

But they aren't, that was my whole point. Your comparison is wrong because they are nothing at all alike.

But they should be... we build them out of steel.. we build them big.. we build lots of them.. and we build them simple.. we keep them in the water but load them with cranes/boats in harbors (only use drydocks to fix them).. hell, we even make ships that cary cryogenic fuel on warm see with capacities of up to 200,000 m3 (LGC).. and that ship has to survive large waves, corosion and storms.. and they cost in millions not BILLIONS..

There is no future in this massive base idea if it is just to extract fuel from the Moon.

if you plan on building moon base, you might just ass well build something that's not complete waste of money.. and when you have base that is CHEAP TO RUN it will not end up like Appolo...

a mirror big enough to reflect enough sunlight to heat literally millions of tonnes dust anually is not happening. No, there are not lots of ways.

who said anything about ONE mirror.. you put LOTS of simple mirrors on the tops of mountains and point them all to one big black box below.. then just throw dirt in it, and move mirrors a little..

like this, only upside down.. http://en.wikipedia.org/wiki/Solar_thermal_energy..

Things are NOT simpler for smaller asteroids, because it takes the same amount of fuel per tonne of asteroid to stop their spinning reguardless how big they are.

It's spinning? well.. unless it's tumbling horibly then you land on it's axis (like you would on north/south pole on earth).. if it's tumbling then you can use something that would look like a spider and try to grab it.. if rock is strong enough you would be basicly hanging upside down from it.. and you basicly landed on asteoroid and you can start pickin up/minning.. if that part that you grabed brakes off, well.. congratulation - you just picked up part of asteoroid.. put that part to tug, and repeat.. when tug is full start engines to meet with earth, do lunar flyby and you are in earth orbit..

A small asteroid might be easier, but its also worth much less.

it doesn't matter how big asteroid is.. it matters how much can you get to earth orbit.. even 10m wide would need a lot of propelant.. but if it's delta-v to earth is small enough to get it.. it will be done.. 1982DB needs just 0.06 km/s..

The fuel to get to multiple smaller asteroids will also be larger than one central asteroid.

well.. since you must process asteoroids in HEEO, L5, L1, L2, werever.. you will have lots of fuel.. and since you already have almost all the speed that you need... the easy to reach small asteorids will get picked up/mined first.. but once you have few that have water/H2/O2 in them around orbit, you will have more than enough fuel to go to harder ones..

You simply not caring how its done doesn't make the problem go away; there is a principle in applying quantum mechanics to real-world situations that is apt here, that if something is very very unlikely then it is for all intents impossible.

No, I am saying that I don't care what is the best way.. even I can find some ineficient easy ways to get things done.. what it the optimal way is for someone else to find out (remember those billions that will cost to design things)..

And if you see problems that are fundamentaly showstopers, then point them out..

But its not just "unfortunate," its a show-stopper. It stops your plan completly. If you have to bring Hydrogen from Earth, then there is no point bothering to lug Oxygen from the Moon to mix with it, it would be better just to bring the Oxygen from Earth too for everything except landing. The Moon, as mentioned, even if it does have ice it won't be practical to extract Hydrogen in quantity,

Lander that is reusable can be built. O2 can be extracted on moon. H2 could be sent from earth (even you think this is good idea). IF there is ice on moon you could export it all the way to LEO. If it's not.. well O2 is 90% by weight, so you need to bring only 10% H2 from earth.. but, as I said.. we should send something to check if there is ice.. and if there is, it would be easy to get it (just heat the soil and you have steam).. there is nothing complicated with mirrors and boxes..

and comets require much more fuel to reach plus spin just like asteroids do. Not to mention the whole random surface explosion bit.

Actually.. 10% of know asteroids need less delta-v than to land on moon.. as for 'random sufrace explosions'.. it's not like you work on atomic bomb.. if you have problems with sun heating surface, then just block the sun with some simple deployable sunshade..

To do so in any reasonably amount of time before the cargo of rocket fuel boiled off would need a heat shield, which would weigh about as much as boiloff condensing equipment or extended tankage I bet. This saves little versus powerd braking I bet.

It depens what you are transporting.. if you airbrake 100 MT of water into LEO then you get 100 MT of water.. you burn all needed fuel to bring water from moon to LLO/L2, after that tug aerobrakes slowly to LEO.. if O2.. well.. you would need boiloff condensing.. but most of the figures i have seen point to few percent boiloff a month.. so instead of 100 MT of O2 you get 90 MT after a month or two in LEO.. not realy big deal.. the only unknown is heat shield.. but if you made it big enough and did not went to low it would not heat that much so it would not have to be all that strong/heavy..

This is something small, but you can make it bigger.. or hotter.. or slower.. http://aria.seas.wustl.edu/SSC01/papers/11-8.pdf

Not true, your tugs will have to wait at least some in Lunar orbit for return fuel, and I doubt that you can leave for Earth any time you want from polar orbit without incuring a large fuel penalty.

good point, but you could go to/from polar orbit and L2 at any time.. and lunar orbit would be good for about 4 months before you crased.. enough to refuel and split before you ended on moon..

Which requires an orbital water cracking/cryogen liquifying station with tank farms, which will cost money. Lots of money if ISS construction is any guide. You keep on adding and stacking up these ten digit infrastructure expenses, and it just can't compete with less reuseable arcitectures.

Yes you would need liquifying station with tank farms.. but, what is so complicated about them that they would need tens of billions of dollars? They are tanks for O2, H2, H2O, cracking plant (basic electolisis - we do this on earth), liquifying (compress, remove heat, expand - liquid) and cooling.. oh and pumping.. and that's it.. it's not like we don't know how to do this things on earth some 100 years.. but even if it does cost a lot of money to develop this thing.. once you developed them you don't have to develop them again.. just build few of them and you are set..

but one has legs (lander), other has big panels to airbrake with (tug)

So you want to go through all this trouble to develop a different vehicle that trades thrust and a little structure for an aerobrake shield and boiloff condenser? Why? Just use the lander and powerd braking, skip the tug alltogether.

Aerobrake alows you to return from moon with propelant for FREE (propelant wise).. you pay the price with shield and boiloff condenser.. but if you can return more of it to LEO than you need to get tug back to LLO, than it's worth it..

you split it, because you don't need shield, condenser an solar panels on moon (not to launch with them anyway) and you don't need legs on tug, you get two different ships.. but if you didn't need lot of mass to aerobrake, you could just make one.. in any way they would use same engines, electronics, docking/refueling, navigaton.. so actually they are not all that different and most of the things would have to be developed only once..

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#154 2006-08-15 20:47:12

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 15,791

Re: Reusable LSAM

Any of the thoughts for creating fuel and oxygen from lunar soil can all be tried out in advance on the ISS and a plus is that every now and then you could send a progress to lunar orbit. There is so much waste on the ISS from only a 2 person crew that the more that there are in orbit the more we must learn how to reuse our own waste.
The current cracking of water whether it be from waste or from a clean source produces waste hydrogen that is vented out of the station. Send up a little lunar simulant and try every thing that would lead to cheaper efforts to get more of us to our dreams.

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#155 2006-08-17 10:57:54

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

Re: Reusable LSAM

We do not need to use the failed ISS assembly method to build moonships.

Russian needs to either bring back Energiya or stick to comsat launches.

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#156 2006-08-17 13:17:59

neviden
Member
Registered: 2004-05-06
Posts: 99

Re: Reusable LSAM

We do not need to use the failed ISS assembly method to build moonships.

It's a question of money.. Mir was assembled in space and it did quite ok.. ISS would to, if it didn't use Space shuttle to deliver 20 MT payloads at the price of 1000 - 500 M$ per launch..

Russian needs to either bring back Energiya or stick to comsat launches.

Russians have Proton/Angara, ESA has Ariane 5, China will have Chang Zheng 5, USA has Delta IV/Atlas V/Falcon 9.. they are all in the 25 MT to LEO range.. they cost around 100 M$ to launch and all are in production/design.. and ALL are underutilized (they would cost less if you launched more of them).. you can do the same thing (20 MT to lunar surface) with 6 launches (1x lander, 1x cargo, 1x manned, 3x booster stages to LLO) or even 4 launches (1x lander, 1x manned, 2x booster to LLO) compared to 2 launches (Ares I, Ares V).. it even costs the same (or less), with the exception that you don't need to develop new rockets..

therefore, I don't think russians, europeans or even chinese will build 100+ MT to LEO ship anytime soon.. they can save all that development/infrastucture building money and just increase launch rate.. russians don't have a luxury of throwing money at problems.. they only have 10% of NASA's budget.. they have to be creative..

NASA will scrap Shuttle.. and since it has no operational manned rocket anymore it will need to develop new rockets.. and since it has 15 B$ it can build 100+ MT rocket.. it will help it to save all those workers (and votes in congress) in Florida and elsewhere.. it will still cost NASA (remember those workers?) 500 M$ to launch, but this time they will get 5x MT to LEO (compared to Shuttle).. and those big rockets will be very usefull once you go to Mars.. others will have to do space assembly/refuelling/docking/stacking things, while NASA will go direct (or if NASA will launch big stuff on Ares V for them, but that's a matter of politics/pride)..

The problem I see is.. If you can launch 5x 120 MT to LEO to build Mars ship.. why bother with developing space utilisation.. it costs a lot of money, it's risky.. just build rockets for a low, low price of 500 M$ and forget about all that development.. but that way they will never develop and use anything that would be sustainable in the long run.. estimated 2,5 B$ to change crews on moon? What are they thinking...

think of what russians could do if they had NASA's money, but still had to be 'creative'.. my guess is.. russians/europeans/chinese will manage quite well, only with 1/5 of the money NASA spends + they will have to USE new technologies (they will not have luxury of 120+ MT LEO NASA has).. which will eventualy open space beyond LEO (and then SSTO will make sense)...

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#157 2006-08-22 17:43:30

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

Re: Reusable LSAM

We do not need to use the failed ISS assembly method to build moonships.

It's a question of money.. Mir was assembled in space and it did quite ok.. ...

No--it was cramped, and was to be replaced by Polyus style Mir 2 modules-- 80-90 tons each)--abandoned because they invaded a muslim country and became overextended. And they took it out on their space efforts

Sound familiar?

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#158 2019-01-01 16:38:45

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 15,791

Re: Reusable LSAM

Vintage topic but on point with the topic title of what we land in on the moon needs to be reuseable..

The Zubrin plan of the cover page is using insitu water ice mining for refueling the LEV aka apollo stye LEM...

A Falcon Heavy is used to deliver another cargo lander to orbit, whose payload consists of a fully fueled Lunar Excursion Vehicle (LEV). This craft consists of a two-ton cabin like that used by the Apollo-era Lunar Excursion Module mounted on a one-ton hydrogen/oxygen propulsion system filled with nine tons of propellant, capable of delivering it from the lunar surface to Earth orbit.

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