Lunar Scenario Study

[j05h]

<i>> Where does the H2 come from if not the poles? How definitive is the latest info indicating the poles are dry? </i><br /><br />There is confirmed hydrogen at both lunar poles, not water. What form that hydrogen takes is an unknown. It could be blue ice, it could be something clay-like or other. The assumption is that any hydrogen is worth extracting. I'm extremely skeptical of the polar-shadow working environment. We know there is water in the Mars system (either groundside or one of the moons) in a relatively easy-to-access form in the martian polar cap. I will stay on topic but think Luna is the wrong target for water-stations. Aluminum, titanium and radio silence? sure, the moon is great for those things. Water? More trouble than it's worth. Ship it from Earth for now, from Mars later.<br /><br />The mass found on Luna is in hydrogen, not H2O. What I would do if I were Mike Griffin and God would be use the lunar poles as a place to perfect tele-robotic mining. Don't bother with people at the poles, use human missions only for Mars and freefall. We have to be useful and inventive in freefall if that is where we're going to build new cities in space. <br /><br /><i>> If the poles are wet how hard is it to coordinate with an orbital re-prop station? Is that station in a polar orbit? Equatorial orbit? HEEO? HELO? L1? L5? </i><br /><br />Using something like the proposed Lockheed architecture with a prop depot, any lunar location can be accessed. I'm of the opinion that any propellant depot can be made to work. Pick an orbit and go with it. I'm a fan of HEEO for a NEO/Mars water return scheme that services an equatorial "office park" of various stations in LEO (remember BrazilTown?). Tugs fuelled from this common pool create a secondary leverage for your transportation system. EML1 might make more sense for Lunar materials, but whatever works. There is plenty of room for different systems. A huge leverage can be achieved by combining tankfarms and tugs. The smart <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[mdodson]

"Is that station in a polar orbit? Equatorial orbit? HEEO? HELO? L1? L5? "<br /><br />I vote for equatorial and HEEO. It requires lower launch delta V than the other suggestions, and most mission destinations are near the ecliptic.

 

[owenander]

Water doesn't hang around in space very long <br />where do the guys onboard the ISS get their water?

 

[rocketman5000]

resupplied from the space shuttle's fuel cell waste.

 

[mako71]

Hello,<br /><br />I have recently thought the space factories and the problems related to establish them (to Moon / asteroid) and this is something I could imagine as the first (and last?) step for building space infrastructures:<br /><br />PCR, Programmable Construction Robot<br /><br />The idea of an automatic factory (with self-repair / self-replication capabilities) in a distant body is - of course - not new, but digging the net didn't show me any far-going projects related to this. The thought is related to my SFWSB (Sci-Fi Writers Source Book, unfortunately written in Finnish) and the calculations and such made for that.<br /><br />My problem is that I'm not good in chemistry, so I can't give exact methods for soil processing and materials. PCR would need be constructed from the elements common in the distant body, i.e. mainly from iron and aluminium in the Moon. The lack of carbon and hydrogen makes it hard for me to think how it could process the soil and build e.g. gas lasers. If the PCR would use elements rare on the body, it could be very hard it to repair and extend itself.<br /><br />Currently I'm thinking if I could make a prototype of the automatic factory:<br /><br />PCR Prototype from LEGO bricks?<br /><br />..That is, how to build a robot from lego bricks, which can build a copy of itself when giving it a pile of lego bricks? Unfortunately I don't have enough money (and time) to buy enough LEGO bricks (those technical ones are expensive), but anyway that could be one way to study the problems in such factory.<br /><br />EDIT: Some additions; first, yes, I think that Luna/Moon is not a place for "Earth-like" chemistry (like water production). In overall, I think, these best locations of space factories (Moon and NEA) are problematic because they don't naturally have volatiles nor liquids (because they hasn't have mass enoug <div class="Discussion_UserSignature"> <p> </p><p>________________ </p><p>reaaliaika.net </p> </div>

 

[shadowsound]

The problem with most people considering access to space is that they consider whether it can withstand the high G force required to place an object into orbit.<br /><br />What about if you have a product that is not affected by it.<br /><br />What type of system given enough externally applied thrust can place an object into near Earth orbit minimizing solid recoverable boosters. Why does it have to be attached to the vehicle.<br />A system of applied pneumatics followed by maglev. followed by solid recoverable booster. With a final kicker motor to boost it to where you want it be it in LEO or LLO<br /><br />The launch platform doen't have to be above ground.<br /><br />A maglev launch system is restricted to 700 odd mph because of atmospheric drag. but given the that most of the cost of fuel for a launch is n the first hundred feet getting it moving you could convert most of that energy to Electrical using the maglev with recoverable solid booster kickers. and a final thruster like the space ship one for the boost to lunar orbit. Time doesn't matter since it is being prepositioned for later use . All you have to do is drift it to the lunar orbit over several months if need be.<br />Humans are another matter they require low G launch and resources to survive the trip, frozen water and other supplies do not.

 

[mrmorris]

<font color="yellow">"A maglev launch system is restricted to 700 odd mph because of atmospheric drag. but given the that most of the cost of fuel for a launch is n the first hundred feet getting it moving you could convert most of that energy to Electrical using the maglev with recoverable solid booster kickers. and a final thruster like the space ship one for the boost to lunar orbit. Time doesn't matter since it is being prepositioned for later use . All you have to do is drift it to the lunar orbit over several months if need be."</font><br /><br />No.<br /><br />The velocity required for a low-Earth orbit at 200km is 7.78 km/sec. 700 MPH equates to 0.313 km/sec. Put another way -- it is 4% of the velocity required to get into orbit. Accelerating something to that speed will not appreciably diminish the size of the booster required to get into LEO.<br /><br />As for getting to the moon -- the velocity required is generally *just* below that of Earth's escape velocity. I'm not going to look it up at the moment, but escape velocity for Earth is easy to find (11.2 km/sec). Given that -- your 700mph boost is only about 2.8% of the velocity required to get to the moon.<br /><br />'Time' isn't a factor in getting to the moon. Velocity is the factor. If you add enough velovity to your spacecaft to makeit it into a 5000km orbit... then you'll be orbiting at 5000 km essentially forever. The orbit isn't going to change over time simply because you'd like it to.<br /><br />SMART-1 took 18 months to get to the moon which might make someone umfamiliar with its functioning think that it was simply 'drifting' there. This is not the case. SMART-1 simply had a very low powered ion engine. It simply activated the drive once per orbit at (I believe) perihelion -- to raise its velocity (and thereby its orbit) gradually over the first 12 months plus. It wasn't travelling to the moon by a slow path -- it was simply orbiting the Earth further and further away until finally

 

[shadowsound]

Thank you for the link.<br /><br />The point I'm trying to make is that the overall cost to place something into orbit is a large majority of the fuel cost. That first inch of separation from the zero relative momentum to actual movement. the delta v that can be imparted at eh very first the less than overall cost in liquid or solid fuel. Take launching fighter off of a aircraft carrier.. The steam catapult impart an amount of to a craft to bring up to launch and operational velocity. by Using the catapult energy you save the reset for the crafts later operation.<br /><br />Also you need to preposition items like fuel and other supplies. In low earth orbit high earth orbit and in lunar orbit. newer thruster techniques will may be ready for use that will reduce the delta V change cost but we need to optimize use of these techniques where they have the best effect on operations. <br /><br />Bigalow has decided to place a larger module in orbit this next year. How can this mouse be used to further the placement of a space station in Lunar orbit.<br /><br />Can we attach several of these to a central stem, add a thruster assembly on one end and a linking module at the front boost it to lunar orbit. Carry spare fuel supplies. Maybe use the new lander on the front end and detach it when they get there, ready for when the astronauts and researcher. Maybe use something like it as a space going hotel that people would pay to go to. tourists or researchers.<br /><br />

 

[mrmorris]

<font color="yellow">"The point I'm trying to make is that the overall cost to place something into orbit is a large majority of the fuel cost."</font><br /><br />This is true... and obvious.<br /><br /><font color="yellow">"That first inch of separation from the zero relative momentum to actual movement. the delta v that can be imparted at eh very first the less than overall cost in liquid or solid fuel. "</font><br /><br />This <b>might</b> be true, but is not guaranteed by any means. As I indicated in my reply -- given a boost of 700mph, the conventional chemical propulsion system still has to impart over 95% of the remaining velocity to orbit. This means the booster size and weight will be just *under* 95% of what it would have been *without* the maglev boost. In turn, <b>that</b> means that the maglev in question is having to accelerate one honking big mass. Generally, payloads are in the realm of 5% of the booster mass for GEO satellites. Let's assume that the maglev subtracts out 5% of that number (i.e. payload could be 10% of the booster mass). Mind you -- that's **horrible** math!!! The reality is that it would make more like a 1% or less difference... but we'll give this concept every break possible. Given that -- for a relatively small 2000kg payload, the maglev must boost a 20,000kg mass. This is simply not reasonable.<br /><br />Even if it <b>were</b> -- a booster would have to be built to handle the stresses of this maglev acceleration. These structural changes could easily more than make up for the modest 700mph boost that your original post used.<br /><br /><font color="yellow">" Take launching fighter off of a aircraft carrier.. The steam catapult impart an amount of to a craft to bring up to launch and operational velocity. by Using the catapult energy you save the reset for the crafts later operation."</font><br /><br />On landing, there's a 'catch-line' for decellerating the planes when landing on aircraft carriers.

 

[mako71]

<blockquote><font class="small">In reply to:</font><hr /><p><br />mrmorris: ...the conventional chemical propulsion system still has to impart over 95% of the remaining velocity to orbit. This means the booster size and weight will be just *under* 95% of what it would have been *without* the maglev boost.<br /><p><hr /></p></p></blockquote><br /><br />Is it so, since the propellant mass ratio is logarithmic function... Checking:<br /><br /><ul type="square"><li> 1000 kg to 150 km circular orbit, v = 7800 m/s, ve = 4500 m/s (LH2/LOX); computational propellant mass Mp = exp(7800/4500) * 1000 kg = 5,659 kg, full mass 6,659 kg.<br /><li> 1000 kg to 150 km circular orbit, v = 7800 m/s - 310 m/s (~700 mph), ve = 4500 m/s; computational propellant mass Mp = 5,282 kg, full mass 6,282 kg.<br /></li></li></ul><br /><br />Ratio: 6,282 / 6,659 = 94.3 %<br /><br />Result: Yes, you're right -- /> probably not worth of the technical problems and increased complexity, but you of course never know. <div class="Discussion_UserSignature"> <p> </p><p>________________ </p><p>reaaliaika.net </p> </div>

 

[j05h]

>> "The point I'm trying to make is that the overall cost to place something into orbit is a large majority of the fuel cost."<br /> /> This is true... and obvious. <br /><br />MrMorris, is he saying that fuel costs are a major part of the cost of space launch? Shadow's sentence is a little mangled, and I'm trying to figure it out. If so, it is incorrect, as fuel costs are generally only a few percent of the total cost of a launch, LOX and RP1 are cheap compared to labor, development, processing, insurance and other capital costs. <br /><br />Maglev and rocket-sled "half stages" have been discussed since the 60s. If they made any kind of sense for Earth launch, they would have been built already. <br /><br />Now, pre-positioning supplies and following a "base camp, first camp, second camp" policy, that makes sense. <br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[shadowsound]

Let's take this one at a time.<br />Lox and rp1:<br />With the reduction or removal of LOX and RP1 and replacing it with solid necessary fuel you reduce the overall complexity and weight of the craft, the safety procedures are reduced. Loading time requirements and loading time changes since the lox and the RP1 are no longer a factor you can pre-assemble and have the lower booster sections waiting for use with a standardized set of upper stages.<br /><br />labor read above.<br /><br />Development:<br />Amortized over the number of launches. and base cost per unit. Mass production. <br />Processing:<br />Using the same solid fuel as the Xprize Spaceship One the turnaround was a week.<br /><br />Insurance <br />much less stringent requirement for safety since there will never be any humans on these craft. they are strictly max dry/solid payload. Chance of blowup reduced. lower insurance rate.<br /><br />Other capital cost:<br />Of course. <br /><br />Since when did sense and politics ever mix.<br />

 

[mrmorris]

<font color="yellow">"If so, it is incorrect, as fuel costs are generally only a few percent of the total cost of a launch..."</font><br /><br />I wasn't really reading it that way. It's certainly possible that I was reading wrongly -- or simply reading too much into it. I was thinking in terms of the energy being the primary problem -- not fuel in particular or even dollar amounts. The primary problem with getting into orbit is that it simply takes so much flipping energy. If there were an easier/better way to add energy (velocity) to objects we want to put in orbit -- much of the difficulty would go away. This is the basic impetus behind people looking for railgun launchers, space elevators, flyback boosters, SSTOs and other (currently) mythical creatures. <img src="/images/icons/smile.gif" />

 

[spacester]

Ah, thanks for the clarification, I was confused as well. The issue of "fuel cost" is an old dragon we've slain over and over again, so there is a knee-jerk reaction for some of us.<br /><br />A calc I did once came out to $15 per pound to LEO using LH2/LOX.<br /><br />But the point made here is very well taken. What if we redefine "fuel costs" in a way that resembles what we would consider a "common public misconception"? Perhaps there is some utility in exploring things from that perspective.<br /><br />One of the reasons many of us pin such high hopes on Space X is that we railed for years that what was important wasn't just flight rate, but operational costs, and Elon is not going to need a standing army to get stuff up there.<br /><br />So what do things look like if we analyze our operational costs in terms of "fuel handling" - all the activities associated with getting the propellant loaded, from a broad perspective? Certainly, for Earth launch, these issues have been investigated to a great depth.<br /><br />But what about the thread topic? If we're talking about moving water around in cis-lunar space, would we be well advised to focus our architecture design around a focus on the costs associated with "fuel handling"?<br /><br />Certainly, cryogenic liquids are difficult to handle when compared to solid propellants.<br /><br />Is it possible that we are making a poor assumption that since we are moving around water, that our rocket propellants are LOX/LH2? <br /><br />I'm thinking that stockpiling hybrid rocket motors might make more sense than stockpiling LH2. Then you would just use LUNOX to get around, maybe use the spent motor casings for something else. It's not like you're going to be able to recycle the fuel anyway, whether it's rubber or LH2. <div class="Discussion_UserSignature"> </div>

 

[j05h]

Shadow- <br />there are handling issues with most fuel/rocket types. I thought you were talking about the ARES I, not a generic solid rocket. The Shuttle SRB (and ARES) uses a much different fuel than SpaceShipOne. <br /><br />Josh <div class="Discussion_UserSignature"> <div align="center"><em>We need a first generation of pioneers.</em><br /></div> </div>

 

[scottb50]

A calc I did once came out to $15 per pound to LEO using LH2/LOX....<br /><br />Which, as you know has always been my point. Some extra help getting off the ground would be helpful, hybrid solids and such, but everything else could be handled using LH2/LOX. <br /><br />This leads to the requirement to place water in orbit and produce the LH2/LOX there instead of taking it to orbit, which leads to much simpler launchers if all you have to put into orbit is water. Add the fact when we include people in the equation we have to have water anyway it only makes sense.<br /><br />I'm thinking that stockpiling hybrid rocket motors might make more sense than stockpiling LH2. Then you would just use LUNOX to get around, maybe use the spent motor casings for something else....<br /><br />LUNOX might be available, but then you need to find it, exploit it, handle it and store it. Look at a mission to an asteroid as an example; you would have continuous solar power available so you could produce Hydrogen and Oxygen as you need it. Thrusters could use easily stored gas and liquids needed for major events could be produced as needed reducing storage times. There seems to be huge concerns for radiation protection and water provides probably the best option, so it would be an advantage to carry a lot anyway. It then becomes a choice of putting solid fuels into orbit as well as oxidizers, solid fuels into orbit and finding oxidizers on the moon or putting water into orbit.<br /><br />If you look at the ISP available from rubber, wax or other fuels and LOX compared to LH2/LOX water makes a lot of sense. <div class="Discussion_UserSignature"> </div>

 

[shadowsound]

Now you have the idea.<br />Keep things in the most controllable state.<br />After insertion to orbit apply the energy needed to converted it back to the product you need whether it is water, oxygen, Hydrogen. Create solid mixture that when heated by electrical current, sunlight, or heat is applied will change to the liquid, gas, or base components needed. <br /><br />Insurance Why? just liability. what else do you need. <br />KIS principle.