The problem of Nitrogen on the Mun

[SingABrightSong]

I've been operating on the assumption that KSP LiquidFuel is simply LH2 by a simplified name. Would hydrogen be found on the Moon or Mun?

[kerbiloid]

7 minutes ago, FreeThinker said:

Building an entire space ship on the moon would be a lot more difficult in comparison then a operational Mine

I doubt a little that building a ship in L1 is easier than on Moon. Of course, zero-G instead of low-G, but no stable place, problems with waste, waste heat, storage and so on.

On Moon you can place reactors behind a mountain. at least.

Edited June 29, 2016 by kerbiloid

[FreeThinker]

3 minutes ago, kerbiloid said:

I doubt a little that building a ship in L1 is easier than on Moon. Of course, zero-G instead of low-G, but no stable place, problems with waste, waste heat, storage and so on.

Well perhaps building a Construction base on the Moon would be easier than in Orbit. But you are still going have to launch you interplanertary space ship into orbit. The cheepest way to do this would be with Aluminium+Oxygen Boosters.

Edited June 29, 2016 by FreeThinker

[kerbiloid]

1 minute ago, FreeThinker said:

The cheepest way to do this would be with Aluminium+Oxygen Boosters.

Once it's already build and equipped, I should prefer reusable nuke booster to lift its large parts.

[FreeThinker]

2 minutes ago, kerbiloid said:

Once it's already build and equipped, I should prefer reusable nuke booster to lift its large parts.

Idealy yes, but on the moon any Nuclear Propellant (like Hydrogen) would be expansive while Aluminium +Oxygen. would be very cheap. In the end it comes down to basic economics.

Edited June 29, 2016 by FreeThinker

[kerbiloid]

8 minutes ago, FreeThinker said:

Idealy yes, but on the moon any Nuclear Propellant (like Hydrogen) would be expansive while Aluminium +Oxygen. would be very cheap. In the end it comes down to basic economics.

And as you need several times less industrial facilities, it's probably cheaper to import (several hundred tons?) of hydrazine or hydrogen for your nukes.

Once the ship is assembled, you can attach the booster as its low thrust propulsion module.

Edited June 29, 2016 by kerbiloid

[FreeThinker]

24 minutes ago, SingABrightSong said:

I've been operating on the assumption that KSP LiquidFuel is simply LH2 by a simplified name. Would hydrogen be found on the Moon or Mun?

LiquidFuel + Oxidizer has about the density, performance, requirements and behavior  of a Hypergolic fuel. MMH + N2O4.

HYdrogen would give Higher performance, but is a lot more difficult to store.

Hydrogen is a more present on the moon then Nitrogen (either in the form of Ice in dark crater or in the top soil deposited by Solar Wind) but it would still be too scarce to waste as a rocket launch propellant 

6 minutes ago, kerbiloid said:

And as you need several times less industrial facilities, it's probably cheaper to import (several hundred?) of hydrazine or hydrogen for your nukes.

Once the ship is assembled, you can attach the booster as its low thrust propulsion module.

Well if your only goal would be to build a single planetary ship, perhaps, but our goal is to make a space economy, meaning we want to colonize the solar system the cheapest way we can so we can eventual build the Infrastructure  to go Interstellar (send ship to other stars).

Edited June 29, 2016 by FreeThinker

[kerbiloid]

10 minutes ago, FreeThinker said:

Well if your only goal would be to build a single planetary ship, perhaps, but our goal is to make a space economy, meaning we want to colonize the solar system the cheapest way we can so we can eventual build the nfrastructure  to go interstellar  (send ship to other stars).

Then we should select a proper place where ice, ammonia and stones are close to each other. Say, Joolpiter moons. And build on the Moon a ship to build a facility on, say, Ganymede, Then no problem with H,O,N,C,Al at all. Ideally, of course, near Titan.

(Just when I planned something similar, I just defined for myself that the aim of space program is colonization of Laythe to build there a complex facility).

Edited June 29, 2016 by kerbiloid

[FreeThinker]

2 minutes ago, kerbiloid said:

Then we should select a proper place where ice, ammonia and stones are close to each other. Say, Joolpiter moons. And build on the Moon a ship to build a facility on, say, Ganymede, Then no problem with H,O,N,C,Al at all.

Eventualy Yes but  the Moon is a important stepping stone, essential to our road to the stars which can't just skip. We should use any tool in our box, an Aluminium+Oxygen is a usefull fuel we should not ignore

Edited June 29, 2016 by FreeThinker

[kunok]

2 hours ago, FreeThinker said:

Even if you have lot's of nuclear power, your still have to launch any minable resource (Titanium, Rare Earth Methals, Hydrogen, Argon, Neon Hellium4, Helium3)  into space somehow without expansive fuel  (which have to be hauled all the way from earth). Aluminium would be perfect as a cheap ISRU fuel to get into orbit. Once in orbit, you switch to Nuclear Hydrogen or electric propulsion for maximum Isp

What about a "simple" ore mass driver? If you have lots of electricity and access to lots of crap is a good option. You don't even really need to process the regolith, maybe just pelletize it.

[FreeThinker]

Just now, kunok said:

What about a "simple" ore mass driver? If you have lots of electricity and access to lots of crap is a good option. You don't even really need to process the regolith, maybe just pelletize it.

Of cource by the time we got this abilty, we certainly going to use it, until then Aluinium it the cheapest Ticket to get into space

[kerbiloid]

6 minutes ago, FreeThinker said:

Eventualy Yes but  the Moon is a stepping stone, essential to our road to the stars which can't just skip. We should use any tool in our box, an Aluminium+Oxygen is a usefull fuel we should not ignore

IRL (from ru.wiki) a production of 1 tonne of raw aluminium requires 2 t of alumina, 65 kg of cryolite, 35 kg of aluminium fluoride, 600 kg of graphite electrodes and 61 GJ of energy.

600 kg of graphite is also not very usual thing on Moon, but 61 GJ / t  = 11000 m/s if convert it to kinetic energy. Do you still want it?

Edited June 29, 2016 by kerbiloid

[kunok]

6 minutes ago, FreeThinker said:

Of cource by the time we got this abilty, we certainly going to use it, until then Aluinium it the cheapest Ticket to get into space

I feel really easier to do the mass driver part, than the industrialization of moon part. Look at the numbers of @kerbiloid

Edited June 29, 2016 by kunok

[FreeThinker]

6 minutes ago, kerbiloid said:

IRL (from ru.wiki) a production of 1 tonne of raw aluminium requires 2 t of alumina, 65 kg of cryolite, 35 kg of aluminium fluoride, 600 kg of graphite electrodes and 61 GJ of energy.

600 kg of graphite is also not very usual thing on Moon, but 61 GJ / t  = 11000 m/s if convert in to kinetical energy. Do you still want it?

I'm going to assume the electrodes can be maintained to continue to operate after the first ton of aluminium is produced (or at least be recycled into new ones). The same goes for cryolite and aluminium fluoride THe MJ  Power should be no problem, that's what Nuclear Power Reactor is for.

Edited June 29, 2016 by FreeThinker

[kerbiloid]

OK, let's forget about graphite and so on, maybe they use some beam devices splitting the alumina.

But 61 GJ/t won't disappear, it's an energy of chemical bounds — and alumina is one of the most tough substances in the Universe, planets are made of it.

So, you would spend 11 km/s of energy to get aluminium fuel with 2 km/s of ISP?
Probably you would better use railgun shooting with alumina balls.

Edited June 29, 2016 by kerbiloid

[PB666]

Don't put too much effort in responding to what Kerby says.

[kerbiloid]

Btw, that's a theme. That reusable booster can use ionized regolith dust. Again, not an aluminium chemical rocket.

[wumpus]

17 minutes ago, kerbiloid said:

So, you would spend 11 km/s of energy to get aluminium fuel with 2 km/s of ISP?
Probably you would better use railgun shooting with alumina balls.

Because your electrical propulsion system won't lift off of Mars?  Because solar power can be generated cheaply on a [dwarf] planet surface in ways not in other places in space (no wind bothering huge reflectors, ability to use the ground as a heat sink, no atmosphere interfering with the solar energy)?  Because you can't bottle up that solar power and send it to the asteroid belt?

No idea what the demand for aluminum as a structural metal would be (already in space), I suspect you can get high grade steel (expect to bring a few alloying metals, "starmetal" only was a great advantage vs. copper and bronze) from asteroids.  And you will almost certainly mine the asteroids first (and thus have the harder time disrupting the market for space metals).

Edited June 29, 2016 by wumpus
forgot that lifting off moon was the specific point of the quoted text.

[kerbiloid]

8 minutes ago, wumpus said:

Because your electrical propulsion system won't lift off of Mars?

(FreeThinker told about Moon, but OK), then just vapourize the alumina with this energy - and you get more ISP than if making a chemical fuel from it for the same spent energy.

8 minutes ago, wumpus said:

Because solar power can be generated cheaply on a [dwarf] planet surface in ways not in other places in space

Bring 10000 t of solar panels from Earth? Or melt 10000 t of alumina and silica to make solar panels, and anyway using nuclear reactor just to begin?

8 minutes ago, wumpus said:

Because you can't bottle up that solar power and send it to the asteroid belt?

Didn't understand. There are nukes, why to bottle solar power?

8 minutes ago, wumpus said:

No idea what the demand for aluminum as a structural metal would be (already in space)

Spacecrafts and rockets are made mostly of it.

Edited June 29, 2016 by kerbiloid

[wumpus]

32 minutes ago, kerbiloid said:

(FreeThinker told about Moon, but OK), then just vapourize the alumina with this energy - and you get more ISP than if making a chemical fuel from it for the same spent energy.

Bring 10000 t of solar panels from Earth? Or melt 10000 t of alumina and silica to make solar panels, and anyway using nuclear reactor just to begin?

Didn't understand. There are nukes, why to bottle solar power?

Spacecrafts and rockets are made mostly of it.

Why use solar panels?  You have low gravity, zero wind, and an available heatsink.  So concentrate the solar and use a heat engine.  How much solar can you get out of 1t of mylar?

Nukes in space don't have a great history.  Mostly because of the efficiency issues of NTGs.  I'd also really like to see how to build a fission [or fusion, for sufficiently far future] reactor with a heatsink that relies on blackbody radiation (nuclear thermal rockets were cooled by the fuel.  Making power without using *lots* of hydrogen is another story).  Building a nuclear reactor on the Moon might make sense, but I'd have to ask where all the current Earth tech is that is ready for such a leap*.

Spacecraft and rockets are made out of aluminum since they are made at the bottom of an 9km/s gravity well.  New designs are likely carbon fiber, and I'd expect more bits of titanium sooner or later.  Build outside of that well and cheap asteroid steel suddenly looks better than somewhat more expensive lunar aluminum (unless you really need to lose that dry weight.  Which might happen more often than you would think).

* I have this crazy vision of using comets to create a "cooling reservoir".  Basically the requirements would be to not boil it, and to be able to stabilize the reservoir's temperature to useful levels over the entire lunar day/month.  Possibly put the reservoir in a deep underground cavern carved by a nuclear explosion (how quickly would it evaporate in a crater?).  I suspect you need to want a *lot* of power before you will give up solar as the main source of space power, at least this side of Mars.

[passinglurker]

I think if we assume kerbals LF+O is one of the many classic hypergolic blends then we will have to endure some suspension of disbelief when it comes to our knowledge of extraterrestrial geology and the nitrogen content of the kerbal solar system. For all we know about our own moon maybe there are rocks with high nitrogen contents some where within 5 meters below the surface (I mean has anyone gone and really checked?  )

Saying the stock ISRU is unrealistic certainly isn't gonna convert enough people to the church of RO to make a more realistic model stock because after extensive modded gameplay experimentation by modders it was eventually found that most people don't actually like haveing a set of fuel tanks for each element on the periodic table. single resource mods proved to have a wider appeal due to the intuitiveness and lack of clutter resulting in a better game play experience for most. They might be considered spoiled by this but its a game they play for fun so let them be spoiled  

Any way all that being said I think we are overlooking one potential hypergolic blend that can break 300isp with absolutely no nitrogen needed.

Hydrogen Peroxide (just hydrogen and oxygen) + A wide variety of Hydrocarbons (just hydrogen and carbon)

it's surprising what a decomposed mixture of superheated steam and pure oxygen can combust with on contact  

[YNM]

IMHO if you got nukes in space better lugging them around than leaving it for the menial tasks. One can use NTRs or whatnot. Landings can still use the usual method - the fuel mass carried replaces the mass of ISRU tools you have to lug around.

For continued presence ? Use the NTR. Why do you think the most long-lasting subs and ships today are nuclear powered instead of powered by anything else ?

[kerbiloid]

12 hours ago, wumpus said:

Spacecraft and rockets are made out of aluminum since they are made at the bottom of an 9km/s gravity well.  New designs are likely carbon fiber, and I'd expect more bits of titanium sooner or later.

There's a lot of alumina on the Moon, but lunar carbon?
OP's intention is to use local materials (especially alumina) as wide as possible.

12 hours ago, wumpus said:

So concentrate the solar and use a heat engine.  How much solar can you get out of 1t of mylar?

Nukes in space don't have a great history.

Well, the space history of the industrial sun concentrators is even shorter. At least, several dozens of small (several kW) reactors were successfully working on orbit in 1970-80s.

12 hours ago, wumpus said:

but I'd have to ask where all the current Earth tech is that is ready for such a leap

Current Earth tech still doesn't mine ore on the Moon.

[FreeThinker]

18 hours ago, passinglurker said:

I think if we assume kerbals LF+O is one of the many classic hypergolic blends then we will have to endure some suspension of disbelief when it comes to our knowledge of extraterrestrial geology and the nitrogen content of the kerbal solar system. For all we know about our own moon maybe there are rocks with high nitrogen contents some where within 5 meters below the surface (I mean has anyone gone and really checked?  )

Saying the stock ISRU is unrealistic certainly isn't gonna convert enough people to the church of RO to make a more realistic model stock because after extensive modded gameplay experimentation by modders it was eventually found that most people don't actually like haveing a set of fuel tanks for each element on the periodic table. single resource mods proved to have a wider appeal due to the intuitiveness and lack of clutter resulting in a better game play experience for most. They might be considered spoiled by this but its a game they play for fun so let them be spoiled  

Any way all that being said I think we are overlooking one potential hypergolic blend that can break 300isp with absolutely no nitrogen needed.

Hydrogen Peroxide (just hydrogen and oxygen) + A wide variety of Hydrocarbons (just hydrogen and carbon)

it's surprising what a decomposed mixture of superheated steam and pure oxygen can combust with on contact  

Although, carbon would be an alternative, Carbon is just as difficult to find as Nitrogen. At least Carbon has the big advantage that it is much easier to store than Cryogenic Nitrogen. If brough with us from earth, we could use it to create Methane + HTP.

But what other Fuels that use neither Nitrogen or Carbon like like Diborane ,  Lithium Hydrate  or  Beryllium Hydride which could be created from local resources. Especial lithium Hydrate as a fuel is interesting as there is a surprising amount of lithium in the moon dirt and it could also be used as a thermal nuclear propellant

Understand my main problem with Stock ISRU is that it gives players the wrong impression that it is easy to manufacture fuel from local resources similarly we would use for standard rocketry, which it is clearly not the case. It's simply bad science education.

Edited June 30, 2016 by FreeThinker

[passinglurker]

2 hours ago, FreeThinker said:

Understand my main problem with Stock ISRU is that it gives players the wrong impression that it is easy to manufacture fuel from local resources similarly we would use for standard rocketry, which it is clearly not the case. It's simply bad science education.

Actually in the stock solar system it can be made to make sense. The outer solar system is a lot smaller and emptier than our own. also a frosty objects like minmus are found in the inner solar system as well. It's possible that the kerbol system formed in such a way that nitrogen was not pushed out to the far edge and so nitrogen ores are much more prevalent through out based on the simple evidence of how the kerbol system is put together.

Now if a player was playing with a replica of the sol system then the thing to do is make stock ore very rare in the inner solar system and more common in the outer solar system because as you have pointed out nitrogen isn't easy to find in our solar system because it was pushed out by solar wind.

Either way I don't see stock giving that deep of an education. If you want to popularize a more in depth isru system among the common user then you need to find a way to cut the part bloat of having converters for every planet and tanks for every element on the periodic table. (Maybe a part with a "big pharma" style mini game inside? I dunno)

2 hours ago, FreeThinker said:

Although, carbon would be an alternative, Carbon is just as difficult to find as Nitrogen. At least Carbon has the big advantage that it is much easier to store than Cryogenic Nitrogen. If brough with us from earth, we could use it to create Methane + HTP.

Oh missed this at first. But there is plenty of carbon on venus and mars