How long does the fuel last?

[Riftmaker]

Where can I find how long a given mech can last fuel wise?

[guardiandashi]

Where can I find how long a given mech can last fuel wise?

its usually in their discriptions at least for things like the protoculture power supplies etc.

in 1st edition the destroids had ~20 year power supplies, and the veritechs had 12 year nominal supplies, but constant and heavy use would drain them in ~6 years

3rd generation alphas betas and the like use protoculture batteries that when stored can last for years (indefinitely) but will power the mecha for about 1 month or in relatively low power mode they can operate for about 3 months on 1/2 their normal compliment of canisters (batteries) but their performance kind of sucks.

[Riftmaker]

Anything on the shadow chronicles era mecha?

[Alrik Vas]

It should say in the shadow chronicles book...right?

[glitterboy2098]

Alpha's have enough protoculture fuel (16 canisters) for 1 month (30 days) of operation.
Beta's use 32 canisters for the same duration.
Bioroid Interceptors, Condors, and conbats use a reactor. we don't know how long those last yet. (it wasn't listed in the shadow chronicles RPG main book)
Cyclones use 1 canister to get 1 month of operation (30 days), 2 weeks (14 days) if doing a lot of flying and heavy fighting.

invid mecha aren't specified.

Southern Cross era human Mecha use SLMH, stabilized liquid metallic hydrogen. this is basically hydrogen compressed so densely it's taken on some of the properties of a metal. they use fusion reactors for power. they carry a lot more fuel but also use it a lot faster so their durations are less.
the Logan, Ajax, and Spartas hovertank carry enough SLMH to power it for 7 days
the Myrmidon hover tank has 10 days.
ASC battloids carry enough fuel for 14 days (2 weeks)
the ASC powered armors use a SLMH fuelcell system that gives them 1 week (7 days) of power.

Robotech master's bioroids use "compressed protoculture fuel slugs", basically regular protoculture that has been compressed into something more liek a solid. we don't know how many canisters one slug equals.the hoversled, and pretty much all the bioroid mecha can run for 1 month (30 days) on a single slug.
the Terminator powered armor can operate for 2 years between refueling, but we do not know if it uses the slugs or not (probably)

Macross era human mecha also use SLMH.
the destroids are not listed how long they last.
the VF-1 Valkyrie has enough SLMH for 48 hours of operation.


Zentreadi mecha are powered by a micronized reflex furnace (basically a tiny copy of what powers the big starships), fueled by protoculture. sadly we are not given how long they last between refueling or how much fuel they require.

for the ones with no details you can pretty much decide for yourself at the moment.

[Seto Kaiba]

Where can I find how long a given mech can last fuel wise?

Depends what you mean by "fuel".

The RPG's stats only identify the endurance of a given mecha's power plant, which is not always equivalent to the actual fuel system endurance of the mecha itself. Many flight-capable mecha in the game make the engines and power plant separate systems, though invariably nothing is said about the fuel supply for the engines the power plant is powering. This is true for the New Generation and Shadow Chronicles mecha, the Zentradi, etc. Also missing is any indication as to the effective range of a craft in space, since nothing is said with respect to the amount of propellant (and/or rocket fuel) the craft can carry to produce thrust in space flight.

[Alrik Vas]

I always figured they turned PC into propellant "somehow."

[Seto Kaiba]

I always figured they turned PC into propellant "somehow."

Whether or not that's possible would be dependent on how, exactly, protoculture is actually used to generate power.

Harmony Gold's current creative staff haven't really put a new explanation out there in the wake of Robotech's reboot, they just quashed the various pseudo-magical baggage it'd accumulated via licensees and failed sequel attempts and established that it was an exotic but entirely mundane power source. Macek created an ex post facto explanation of protoculture in Robotech Art 1 that contradicted the show in numerous ways, and made it out that the energy protoculture was used to produce was life force rather than electricity or heat.

Most of the implementations that are talked about keep the protoculture self-contained and separate from the actual engines, usually as something analogous to fuel cells or batteries in human mecha and as "fuel slugs" for some kind of reactor that might be a cousin to pebble-bed fission reactors. Using protoculture itself as a propellant seems really unlikely to me. There just wouldn't be enough fluid volume in those protoculture cells to get you anywhere.

[The Artist Formerly]

I always figured they turned PC into propellant "somehow."

Whether or not that's possible would be dependent on how, exactly, protoculture is actually used to generate power.

Harmony Gold's current creative staff haven't really put a new explanation out there in the wake of Robotech's reboot, they just quashed the various pseudo-magical baggage it'd accumulated via licensees and failed sequel attempts and established that it was an exotic but entirely mundane power source. Macek created an ex post facto explanation of protoculture in Robotech Art 1 that contradicted the show in numerous ways, and made it out that the energy protoculture was used to produce was life force rather than electricity or heat.

Most of the implementations that are talked about keep the protoculture self-contained and separate from the actual engines, usually as something analogous to fuel cells or batteries in human mecha and as "fuel slugs" for some kind of reactor that might be a cousin to pebble-bed fission reactors. Using protoculture itself as a propellant seems really unlikely to me. There just wouldn't be enough fluid volume in those protoculture cells to get you anywhere.

So then what does it use for reaction mass?

[Alrik Vas]

I think his point is that we don't know.

[glitterboy2098]

for the SLMH fusion powered ones, probably just SLMH.

for PC powered stuff.. probably just water. the RPG has most of the PC powered units using [url=https://en.wikipedia.org/wiki/Plasma_propulsion_engineplasma rockets[/url] for thrust so just about anything would work. Water would be an easily accessible material. they might still use SLMH though. any hydrogen rich liquid would suffice. SLMH though wouldn't be as easily replenished onboard a ship though. (needs special manufacturing using blky and power intensive gear. whereas water can be obtained pretty simply by diving into a gas giants atmosphere and using cooling systems to seperate out the materials.. or by loading snow from a comet or ice moon into a storagetank and letting it melt.)

[The Artist Formerly]

I think his point is that we don't know.

In the cat's eye recon episode, Ben was leaking 'fuel'. What that means, however is beyond me.

[The Artist Formerly]

for the SLMH fusion powered ones, probably just SLMH.

for PC powered stuff.. probably just water. the RPG has most of the PC powered units using [url=https://en.wikipedia.org/wiki/Plasma_propulsion_engineplasma rockets[/url] for thrust so just about anything would work. Water would be an easily accessible material. they might still use SLMH though. any hydrogen rich liquid would suffice. SLMH though wouldn't be as easily replenished onboard a ship though. (needs special manufacturing using blky and power intensive gear. whereas water can be obtained pretty simply by diving into a gas giants atmosphere and using cooling systems to seperate out the materials.. or by loading snow from a comet or ice moon into a storagetank and letting it melt.)

That seems reasonable.

[Seto Kaiba]

So then what does it use for reaction mass?

Thus far, it doesn't look like Robotech's creators really thought that far ahead when they invented Robotech's concept of protoculture on the fly during production.

The RT2E core book is mute on the subject, but from the Macross Saga book the protoculture power systems are usually powering a separate engine system that is almost invariably fusion-based. I'd assume, based on the rest of the RPG's fusion power systems, it would be using hydrogen in some form or another (possibly SLMH). Weirdly, only the VF-1's write-up treats the reactor as being an integral part of the engine, rather than simply powering the engine, on fusion-powered craft.

On reflection, that'd also explain the Alpha's backup fusion power system's fuel source... it would be tapping the propellant tanks to power the mecha.

for PC powered stuff.. probably just water. the RPG has most of the PC powered units using [url=https://en.wikipedia.org/wiki/Plasma_propulsion_engineplasma rockets[/url] for thrust so just about anything would work.

Source? The core book doesn't identify the engine type for anything using protoculture power, and the Macross Saga book makes it clear all the Zentradi ships and mecha are using fusion pulse-detonation engines. The only one mentioned as using a plasma engine that I can find on a quick skim is the Bioroid hoversled. Even the Bioroid dropship uses fusion engines.

[Seto Kaiba]

I think his point is that we don't know.

In the cat's eye recon episode, Ben was leaking 'fuel'. What that means, however is beyond me.

Yeah, can't help ya there... what Kakizaki's Valkyrie was leaking from its damage isn't specified in the original, but there are no fuel tanks in the VF-1's nose.

[The Artist Formerly]

So then what does it use for reaction mass?

Thus far, it doesn't look like Robotech's creators really thought that far ahead when they invented Robotech's concept of protoculture on the fly during production.

The RT2E core book is mute on the subject, but from the Macross Saga book the protoculture power systems are usually powering a separate engine system that is almost invariably fusion-based. I'd assume, based on the rest of the RPG's fusion power systems, it would be using hydrogen in some form or another (possibly SLMH). Weirdly, only the VF-1's write-up treats the reactor as being an integral part of the engine, rather than simply powering the engine, on fusion-powered craft.

On reflection, that'd also explain the Alpha's backup fusion power system's fuel source... it would be tapping the propellant tanks to power the mecha.

for PC powered stuff.. probably just water. the RPG has most of the PC powered units using [url=https://en.wikipedia.org/wiki/Plasma_propulsion_engineplasma rockets[/url] for thrust so just about anything would work.

Source? The core book doesn't identify the engine type for anything using protoculture power, and the Macross Saga book makes it clear all the Zentradi ships and mecha are using fusion pulse-detonation engines. The only one mentioned as using a plasma engine that I can find on a quick skim is the Bioroid hoversled. Even the Bioroid dropship uses fusion engines.

You're right.

But it's important to remember that Scifi-cartoon writers from the late 70s and early 80s aren't all that well versed in real physics. So "protoculture" was just the handwavium/magic that they made up to explain everything that was impossible.

[The Artist Formerly]

I think his point is that we don't know.

In the cat's eye recon episode, Ben was leaking 'fuel'. What that means, however is beyond me.

Yeah, can't help ya there... what Kakizaki's Valkyrie was leaking from its damage isn't specified in the original, but there are no fuel tanks in the VF-1's nose.

Same episode in which red-shirt recon pilot is able to talk via Ben's mouth, so... Magic.

[Alrik Vas]

Editing win of the 80s.

[Seto Kaiba]

You're right.

But it's important to remember that Scifi-cartoon writers from the late 70s and early 80s aren't all that well versed in real physics. So "protoculture" was just the handwavium/magic that they made up to explain everything that was impossible.

Oh, I'm sure many of the writers from the period weren't too good on the physics front... but the original creators of Macross and MOSPEADA had an excellent grasp of a lot of the hard science behind the advanced technologies they were using. Robotech's writers could probably have come up with something a bit more coherent if they hadn't been on such a tight schedule... there were at least a few fans of harder, more scientifically sound SF on the staff.

The OSM design art and descriptions for how the VF-1's engines work from '82-'83 is very close to what NASA came out with for a fusion turbine in April 2005.

Same episode in which red-shirt recon pilot is able to talk via Ben's mouth, so... Magic.

... Macek's explanation of protoculture being what it is, we could've taken that as an entirely unironic answer until the Macross Saga sourcebook came out and announced the VF-1 ran on fusion.

[The Artist Formerly]

Oh, I'm sure many of the writers from the period weren't too good on the physics front... but the original creators of Macross and MOSPEADA had an excellent grasp of a lot of the hard science behind the advanced technologies they were using. Robotech's writers could probably have come up with something a bit more coherent if they hadn't been on such a tight schedule... there were at least a few fans of harder, more scientifically sound SF on the staff.

The OSM design art and descriptions for how the VF-1's engines work from '82-'83 is very close to what NASA came out with for a fusion turbine in April 2005.

... Macek's explanation of protoculture being what it is, we could've taken that as an entirely unironic answer until the Macross Saga sourcebook came out and announced the VF-1 ran on fusion.

Yeah...no. If we're using fusion then the flower of life is moot and all of the Invid stuff can go away. Helium 3 would cover our needs and problem solved. Magic space plant making Plasma is just fine. We've solved the problem.

[glitterboy2098]

not really. having to move a hundred tons of lunar regolith to get a gram of helium 3 means its a non-starter. you expend more energy obtaining it than you obtain from fusing it.

and the magic space plant is an issue in macross because we know earth was in the dark about the factory on board until after the war.

if the tanks of PC on the SDF-1 start producing more fuel than they can possibly hold someone would have figured out the factory was there before the zentreadi told them.

an when you've got only one small finite source (which remember, is also needed to run that ships weapons and drives, which are needed to defend earth) your not going to be using it for much.

certainly not to fuel the millions of mecha you'd need to defend earth. or to build the hundreds of ships needed.

and how long do you have to defend? earth didn't know when more aliens might come. so its not like they could just say "oh we need it for a year". they were looking at potentially decades, centuries of waiting. sure they'd expect that eventualyl they'd improve their tech, maybe figure that weird green fuel out. but its not like they knew when that would happen.

from a storytelling standpoint fusion works. its something that the alien tech could enable but which could be fueled with something fairly common.. hydrogen. the RPG's use of SLMH was just a clever way to keep fusion from being too powerful. not only is metallic hydrogen a darn good fuel to justify the kinds of performance you see in the show, but it also is an exotic material.. not something you could whip up without major infrastructure. which keeps warlords in the reconstruction and resistance fighters under the invid from just refilling their 1st war VF's off a convenient lake.

and it makes the macross era's military projects plausible.

[The Artist Formerly]

not really. having to move a hundred tons of lunar regolith to get a gram of helium 3 means its a non-starter. you expend more energy obtaining it than you obtain from fusing it.

Chinese don't think so.

and the magic space plant is an issue in macross because we know earth was in the dark about the factory on board until after the war.

if the tanks of PC on the SDF-1 start producing more fuel than they can possibly hold someone would have figured out the factory was there before the zentreadi told them.

an when you've got only one small finite source (which remember, is also needed to run that ships weapons and drives, which are needed to defend earth) your not going to be using it for much.

certainly not to fuel the millions of mecha you'd need to defend earth. or to build the hundreds of ships needed.

and how long do you have to defend? earth didn't know when more aliens might come. so its not like they could just say "oh we need it for a year". they were looking at potentially decades, centuries of waiting. sure they'd expect that eventualyl they'd improve their tech, maybe figure that weird green fuel out. but its not like they knew when that would happen.

from a storytelling standpoint fusion works. its something that the alien tech could enable but which could be fueled with something fairly common.. hydrogen. the RPG's use of SLMH was just a clever way to keep fusion from being too powerful. not only is metallic hydrogen a darn good fuel to justify the kinds of performance you see in the show, but it also is an exotic material.. not something you could whip up without major infrastructure. which keeps warlords in the reconstruction and resistance fighters under the invid from just refilling their 1st war VF's off a convenient lake.

and it makes the macross era's military projects plausible.

GB, you're trying too hard. Magic space plant energy works. This is science fiction. It doesn't need to be anything more then that. Space plant makes Plasma, plasma makes reaction mass. We're good. Inject too much realism and this whole thing falls apart. I don't worry about how a light saber works, or how massive robots aren't crushed under their own weight or how black hole jump drives function. We have just enough science to drive our fiction. We're good my brother. Magic space plant.

[Seto Kaiba]

Yeah...no. If we're using fusion then the flower of life is moot and all of the Invid stuff can go away. Helium 3 would cover our needs and problem solved. Magic space plant making Plasma is just fine. We've solved the problem.

Well, yeah... the idea that you can power huge spaceships and fighters just as effectively with nuclear fusion kind of digs a colossal hole in the "protoculture is essential for robotechnology" thing.

As far as Helium-3 goes, it's worth noting that in the Macross and MOSPEADA OSM they're actually using hydrogen as the fuel of choice rather than Gundam's favored Deuterium Helium-3 mix. Macross's mecha use hydrogen slush as their fuel of choice (though the thermonuclear reaction overtechnology in that setting is more "like fusion but"[sup]1[/sup]), and MOSPEADA's mecha use hydrogen fuel cells and their ships use hydrogen fusion reactors and fusion rocket engines. Robotech's official canon says nothing about the material they're using as fuel for fusion reactors, "stabilized liquid metallic hydrogen" is purely a RPG thing, and that's just a denser form of elemental hydrogen.

GB, you're trying too hard. Magic space plant energy works. This is science fiction. It doesn't need to be anything more then that. Space plant makes Plasma, plasma makes reaction mass. We're good. Inject too much realism and this whole thing falls apart.

Really, it falls apart way, WAY before we could get to the point of injecting realism... the whole protoculture thing in Robotech was made up on the fly by its writers, so there are a lot of inconsistencies.

The way it's written up in RT now, it's "Magic space plant releases non-specific energy. Non-specific energy is converted into high-voltage electricity somehow. High voltage electricity is used to power fusion engines and electric motors. What exactly are those fusion engines fusing?"



1. Macross's thermonuclear reaction overtechnology is "like fusion but" in the sense that the reaction is still fusing elemental hydrogen, but the reaction is sustained, controlled, and catalyzed by the application of higher-dimension physics.

[ShadowLogan]

I always figured they turned PC into propellant "somehow."

I've said this before, but the amount of PC carried in the Alpha is unsustainable for thrust operations since it requires the mass to be expelled at velocities faster than the speed of light to maintain maximum thrust (4 main engines) for the entire heavy activity period listed in the 2E RPG (never mind the 1E RPG).

Rand (2E NG SB gives him a PS of 13) is shown carrying SEVEN full four pack carriers of PC canisters (28 in total) in the animation. We also know the heavy activity period in the 2E RPG (2weeks). We also know from the OSM what the thrust levels are (4800kg each). When you do the real world math, and lets just say Rand's full PS of 13 went into transporting 16 canisters worth of PC for simplicity: the PC would be exiting at something like ~12.9x the speed of light. Which is impossible.

To lower the speed to a realistic value, would require that the 16 PC canisters to have much more mass (over x10 more massive), so the "propellant" has to come from somewhere else (air, storage tanks). Alternatively, the operational time has to come down from constant activity.

Bioroid Interceptors, Condors, and conbats use a reactor. we don't know how long those last yet. (it wasn't listed in the shadow chronicles RPG main book)

As their standard equipment is taken from the Alpha or Beta, I would use that for the reactor endurance.

Southern Cross era human Mecha use SLMH, stabilized liquid metallic hydrogen. this is basically hydrogen compressed so densely it's taken on some of the properties of a metal. they use fusion reactors for power. they carry a lot more fuel but also use it a lot faster so their durations are less.

I will only add that the TRM saga SB introduces different grades of SLMH in addition to the normal SLMH:
non-transformable battloids all use SLMH/B (pg106)
Veritechs (VFs and VHTs) all use SLMH-V (pg82/88/96/103)

not really. having to move a hundred tons of lunar regolith to get a gram of helium 3 means its a non-starter. you expend more energy obtaining it than you obtain from fusing it.

That assumes that you are only interested in the He-3 from the regolith, and not other materials that could be just as useful like the Oxygen, silicon, iron, and titanium. From an energy standpoint, you are able to capitalize on the investment since you can get more than He-3 out of it.

Source? The core book doesn't identify the engine type for anything using protoculture power, and the Macross Saga book makes it clear all the Zentradi ships and mecha are using fusion pulse-detonation engines. The only one mentioned as using a plasma engine that I can find on a quick skim is the Bioroid hoversled. Even the Bioroid dropship uses fusion engines.

Fusion pulse-detonation engines would qualify as a type of plasma engine.

[Seto Kaiba]

I've said this before, but the amount of PC carried in the Alpha is unsustainable for thrust operations since it requires the mass to be expelled at velocities faster than the speed of light to maintain maximum thrust (4 main engines) for the entire heavy activity period listed in the 2E RPG (never mind the 1E RPG).

Quite frankly, it's doubtful that the fluid volume of sixteen cells would be sufficient to provide sustainable thrust for more than a few seconds at high output. The HBT cells in MOSPEADA are about the size of an old 1 quart oil can... four US gallons of fuel (15L) won't get you very far in space.

To lower the speed to a realistic value, would require that the 16 PC canisters to have much more mass (over x10 more massive), so the "propellant" has to come from somewhere else (air, storage tanks). Alternatively, the operational time has to come down from constant activity.

Yep... and based on the official cutaways from the original creators, we can take a pretty good guess as to where the "Alpha" has been keeping its propellant and how much it'd actually be carrying. Kind of a slam dunk, really, since the Alpha's internal spaces were packed full of equipment to the extent that the only free space is in the center of the wings. Rough order estimate, that's a space that'll get you about 300-400L of fuel slush, which is more respectable.

Source? The core book doesn't identify the engine type for anything using protoculture power, and the Macross Saga book makes it clear all the Zentradi ships and mecha are using fusion pulse-detonation engines. The only one mentioned as using a plasma engine that I can find on a quick skim is the Bioroid hoversled. Even the Bioroid dropship uses fusion engines.

Fusion pulse-detonation engines would qualify as a type of plasma engine.

But not the type previously described... those are all variations on plasma ion engines, but what's described in the books is a pulse-detonation fusion engine... essentially a fusion rocket.

[The Artist Formerly]

Well, yeah... the idea that you can power huge spaceships and fighters just as effectively with nuclear fusion kind of digs a colossal hole in the "protoculture is essential for robotechnology" thing.

As far as Helium-3 goes, it's worth noting that in the Macross and MOSPEADA OSM they're actually using hydrogen as the fuel of choice rather than Gundam's favored Deuterium Helium-3 mix. Macross's mecha use hydrogen slush as their fuel of choice (though the thermonuclear reaction overtechnology in that setting is more "like fusion but"[sup]1[/sup]), and MOSPEADA's mecha use hydrogen fuel cells and their ships use hydrogen fusion reactors and fusion rocket engines. Robotech's official canon says nothing about the material they're using as fuel for fusion reactors, "stabilized liquid metallic hydrogen" is purely a RPG thing, and that's just a denser form of elemental hydrogen.

Really, it falls apart way, WAY before we could get to the point of injecting realism... the whole protoculture thing in Robotech was made up on the fly by its writers, so there are a lot of inconsistencies.

The way it's written up in RT now, it's "Magic space plant releases non-specific energy. Non-specific energy is converted into high-voltage electricity somehow. High voltage electricity is used to power fusion engines and electric motors. What exactly are those fusion engines fusing?"

1. Macross's thermonuclear reaction overtechnology is "like fusion but" in the sense that the reaction is still fusing elemental hydrogen, but the reaction is sustained, controlled, and catalyzed by the application of higher-dimension physics.

Basically agreed.

Thing is, science fiction attracts science nerds. So we start applying pop science to justify our love of our fiction. Magic space plant. Solves all problems. What's fusing? Magic space plant. How do we have metal that lets a machine stand like a man 40+ft tall and not collapse under it's own weight? Magic space plant! Why do we use anti-gravity systems for lift but not for flight? Magic space plant.

[eliakon]

I've said this before, but the amount of PC carried in the Alpha is unsustainable for thrust operations since it requires the mass to be expelled at velocities faster than the speed of light to maintain maximum thrust (4 main engines) for the entire heavy activity period listed in the 2E RPG (never mind the 1E RPG).

Quite frankly, it's doubtful that the fluid volume of sixteen cells would be sufficient to provide sustainable thrust for more than a few seconds at high output. The HBT cells in MOSPEADA are about the size of an old 1 quart oil can... four US gallons of fuel (15L) won't get you very far in space.

To lower the speed to a realistic value, would require that the 16 PC canisters to have much more mass (over x10 more massive), so the "propellant" has to come from somewhere else (air, storage tanks). Alternatively, the operational time has to come down from constant activity.

Yep... and based on the official cutaways from the original creators, we can take a pretty good guess as to where the "Alpha" has been keeping its propellant and how much it'd actually be carrying. Kind of a slam dunk, really, since the Alpha's internal spaces were packed full of equipment to the extent that the only free space is in the center of the wings. Rough order estimate, that's a space that'll get you about 300-400L of fuel slush, which is more respectable.

But we still have to have the propellant moving an c fractional speeds.
I mean if you have to be going 12.9c with 15L of fuel
with 400L of fuel you still need to be going .48c which is still seems unreasonably fast.

[glitterboy2098]

not really. having to move a hundred tons of lunar regolith to get a gram of helium 3 means its a non-starter. you expend more energy obtaining it than you obtain from fusing it.

Chinese don't think so.

the chinese were already talking about going to the moon and even building a base up there before the helium-3 thing. the helium-3 thing just gave them an excuse beyond "for the glory of the people's republic of china" to publicize.

notice that they've not actuall proposed how to extract it, or how we even use it..

GB, you're trying too hard. Magic space plant energy works. This is science fiction. It doesn't need to be anything more then that. Space plant makes Plasma, plasma makes reaction mass. We're good. Inject too much realism and this whole thing falls apart. I don't worry about how a light saber works, or how massive robots aren't crushed under their own weight or how black hole jump drives function. We have just enough science to drive our fiction. We're good my brother. Magic space plant.

in a thread about logistic issues your not really allowed to say "logistics don't matter"

and just because the magic space plant extract allows for immense power does not mean you can ignore the issue of not having enough magic space plant extract to use, or to violate fundamentals like mass/energy conservation. especially when the show (and RPG) is fairly clear that such stuff isn't being explicitly violated.



as for things like the alpha's remass tanks and stuff.. the main flaw i can see your arguments is your assuming those cutaway images made for GC:Mospeada are in any way valid in robotech. robotech has junked nearly all of the Mospeada OSm (scott isn't named 'stick', he's not from mars, they're invid not inbit, they sense protoculture not energy, they're called alphas not legioss, they run on protoculture not HBT, etc)

so why would artwork created for the japanese show (and not even for the show directly, but for a merchanisimg product!) actually apply?


ultimately the whole discussion is pointless.. no fictional setting ever holds up to minute scrutiny. but in a suspension of disbeleif realm of concern, saying the Alpha has tanks of remass elsewhere in the mecha is going to be less likely to break suspension of disbelief than telling people that it gets by 2 gallons of flower juice for everything.

[The Artist Formerly]

the chinese were already talking about going to the moon and even building a base up there before the helium-3 thing. the helium-3 thing just gave them an excuse beyond "for the glory of the people's republic of china" to publicize.

notice that they've not actuall proposed how to extract it, or how we even use it..

They're kind of secretive like that.

in a thread about logistic issues your not really allowed to say "logistics don't matter"

Don't need realism, just plausibility. And not even too much of that. I want to stomp around in a giant death robot with character I imagine having the most awesomely bad hair cut since Ace Ventura, pet detective. Something with a mullet, mutton chops, bangs and a bouffant. And maybe a soul patch...

and just because the magic space plant extract allows for immense power does not mean you can ignore the issue of not having enough magic space plant extract to use, or to violate fundamentals like mass/energy conservation. especially when the show (and RPG) is fairly clear that such stuff isn't being explicitly violated.

Does it matter?

as for things like the alpha's remass tanks and stuff.. the main flaw i can see your arguments is your assuming those cutaway images made for GC:Mospeada are in any way valid in robotech. robotech has junked nearly all of the Mospeada OSm (scott isn't named 'stick', he's not from mars, they're invid not inbit, they sense protoculture not energy, they're called alphas not legioss, they run on protoculture not HBT, etc)

so why would artwork created for the japanese show (and not even for the show directly, but for a merchanisimg product!) actually apply?


ultimately the whole discussion is pointless.. no fictional setting ever holds up to minute scrutiny. but in a suspension of disbeleif realm of concern, saying the Alpha has tanks of remass elsewhere in the mecha is going to be less likely to break suspension of disbelief than telling people that it gets by 2 gallons of flower juice for everything.

You're right. But we're mostly just kicking the ball around and talking about our third favorite sci-fi setting. Magic space flower.

[Seto Kaiba]

Thing is, science fiction attracts science nerds. So we start applying pop science to justify our love of our fiction. Magic space plant. Solves all problems. What's fusing? Magic space plant. How do we have metal that lets a machine stand like a man 40+ft tall and not collapse under it's own weight? Magic space plant! Why do we use anti-gravity systems for lift but not for flight? Magic space plant.

Normally those narrative handwaves come in more than one flavor... in this case, we simply have an oversight as to what they're using for a propellant in those fusion engines when the reactor isn't part of the engine.

But we still have to have the propellant moving an c fractional speeds.
I mean if you have to be going 12.9c with 15L of fuel
with 400L of fuel you still need to be going .48c which is still seems unreasonably fast.

That's only if you forget to discard the manifestly unrealistic assumption that the propellant supply is sufficient to provide the fighter with maximum instantaneous thrust for the entirety of its power plant's operational endurance while in space. With the exaggerated (non-canon) run times in the RPG, that's obviously not going to be possible, practical, or remotely plausible. ShadowLogan's original post on the subject alluded to that problem.

as for things like the alpha's remass tanks and stuff.. the main flaw i can see your arguments is your assuming those cutaway images made for GC:Mospeada are in any way valid in robotech. robotech has junked nearly all of the Mospeada OSm (scott isn't named 'stick', he's not from mars, they're invid not inbit, they sense protoculture not energy, they're called alphas not legioss, they run on protoculture not HBT, etc)

so why would artwork created for the japanese show (and not even for the show directly, but for a merchanisimg product!) actually apply?

... this weird notion that Robotech "junked" the OSM is as obviously false now as it has been for almost the entire existence of Robotech and the RPG. Practically every aspect of the technical data for the Alpha, and indeed most of the other mecha in the Robotech setting, is derived principally from the OSM. Even the 1st Edition RPG used the OSM, and Robotech's usage of the OSM has only increased with time. About all that changed are the changes you noted... which are proper nouns in terminology.

With practically every piece of canon technical information and a fair amount of the non-canon technical information in the RPG already coming from the OSM, why would those few specific pieces of official material NOT be valid for Robotech when there isn't anything in Robotech that contradicts them in any way?

These cutaways aren't unique to the model kits either, you can find them cited right alongside production art in official art books for MOSPEADA like the Genesis Climber MOSPEADA Graffiti book from January 1984 (pages 42-45).

Don't need realism, just plausibility. And not even too much of that. I want to stomp around in a giant death robot with character I imagine having the most awesomely bad hair cut since Ace Ventura, pet detective. Something with a mullet, mutton chops, bangs and a bouffant. And maybe a soul patch...

With hair like that, you're in the wrong genre... report to Super Robots for reassignment.

[The Artist Formerly]

With hair like that, you're in the wrong genre... report to Super Robots for reassignment.

Check out Zor's doo. He's almost there. I think I need knee high boots to o with that.

[ShadowLogan]

Quite frankly, it's doubtful that the fluid volume of sixteen cells would be sufficient to provide sustainable thrust for more than a few seconds at high output. The HBT cells in MOSPEADA are about the size of an old 1 quart oil can... four US gallons of fuel (15L) won't get you very far in space.

Given we know what the max thrust value is, we can work backward. If we assume each PC canister holds 2.1kg of PC (see below), and an exhaust velocity of 0.99c (highest possible w/o breaking speed of light), the Alpha could max thrust for ~14.8hrs straight. At 0.01c it would last ~538seconds (or nearly 9minutes). This though might take it to low based on what we are told about PC's energy density (it should be on par w/nuclear at minimum I would think). To get a few seconds of full thrust (~5), the Alpha would have to exhaust the matter at 0.0001c (which is still very good compared to modern systems, but the Delta-V wouldn't even allow launch into orbit around the Moon from the Moon's surface).

If we assume Rand/Rook are at their carry limit based on the RPG's PS score in "Curtain Call" entirely from PC stolen, and Rand carried 28 canisters (animation, 7 four packs), each then has a mass of ~2.1kg (canister/PC/-part of carrier). If we treat that as all mass for expulsion (which is not the case in the animation), the matter would leave the Alpha's engines at ~22.5c. Now if each PC "canister" is allowed 46kg of additional remass, we drop the exhaust velocity down to ~.99c

Using those numbers, the Alpha would have a Delta-V of over 13,000kps (either ev). What ever this additional mass is, it can't be water if 300-400l TOTAL is all that the Alpha has to work with, as 1l = 1kg of water. So we are dealing with a substance more dense than water (around x2 at minimum I would say).

At which point, we have broken the Alpha for the setting(s) from a variety of angles. Given 8kps is all that is needed to launch into LEO from the Earth's surface...

I will also add that I am not factoring in relativistic effects on mass expelled at any point, which for the higher speeds would likely lengthen burn time.

But we still have to have the propellant moving an c fractional speeds.
I mean if you have to be going 12.9c with 15L of fuel
with 400L of fuel you still need to be going .48c which is still seems unreasonably fast.

Velocities less than 1.0c are not the issue as far as I'm concerned. It is when those velocities are greater than or equal to 1.0c where you get into the impossible.

Fusion engines are projected to be capable of expelling matter at fractional (less than 1.0) c velocities. I've seen fusion engine proposals occasionally rated at 1million Isp, which means it has an exhaust velocity of ~3% of c in a D-He3 system (and seen statements it might go higher still). Given Protoculture's involvement, we are dealing with a substance with more energy density than conventional nuclear so velocities higher than fusion seem reasonable, but not velocities that break the laws of physics.

[Riftmaker]

Alpha's have enough protoculture fuel (16 canisters) for 1 month (30 days) of operation.
Beta's use 32 canisters for the same duration.
Bioroid Interceptors, Condors, and conbats use a reactor. we don't know how long those last yet. (it wasn't listed in the shadow chronicles RPG main book)
Cyclones use 1 canister to get 1 month of operation (30 days), 2 weeks (14 days) if doing a lot of flying and heavy fighting.

invid mecha aren't specified.

Southern Cross era human Mecha use SLMH, stabilized liquid metallic hydrogen. this is basically hydrogen compressed so densely it's taken on some of the properties of a metal. they use fusion reactors for power. they carry a lot more fuel but also use it a lot faster so their durations are less.
the Logan, Ajax, and Spartas hovertank carry enough SLMH to power it for 7 days
the Myrmidon hover tank has 10 days.
ASC battloids carry enough fuel for 14 days (2 weeks)
the ASC powered armors use a SLMH fuelcell system that gives them 1 week (7 days) of power.

Robotech master's bioroids use "compressed protoculture fuel slugs", basically regular protoculture that has been compressed into something more liek a solid. we don't know how many canisters one slug equals.the hoversled, and pretty much all the bioroid mecha can run for 1 month (30 days) on a single slug.
the Terminator powered armor can operate for 2 years between refueling, but we do not know if it uses the slugs or not (probably)

Macross era human mecha also use SLMH.
the destroids are not listed how long they last.
the VF-1 Valkyrie has enough SLMH for 48 hours of operation.


Zentreadi mecha are powered by a micronized reflex furnace (basically a tiny copy of what powers the big starships), fueled by protoculture. sadly we are not given how long they last between refueling or how much fuel they require.

for the ones with no details you can pretty much decide for yourself at the moment.

Thanks for this.

Man robotech mecha are just screwed on rifts earth if stuck for the duration arent they?

[Seto Kaiba]

Given we know what the max thrust value is, we can work backward. If we assume each PC canister holds 2.1kg of PC (see below), and an exhaust velocity of 0.99c (highest possible w/o breaking speed of light), the Alpha could max thrust for ~14.8hrs straight. At 0.01c it would last ~538seconds (or nearly 9minutes). This though might take it to low based on what we are told about PC's energy density (it should be on par w/nuclear at minimum I would think). To get a few seconds of full thrust (~5), the Alpha would have to exhaust the matter at 0.0001c (which is still very good compared to modern systems, but the Delta-V wouldn't even allow launch into orbit around the Moon from the Moon's surface).

A pretty sound argument, on the whole, that the Alpha is no different from any other craft in the setting in that it needs a supply of propellant separate from its protoculture power system.

Man robotech mecha are just screwed on rifts earth if stuck for the duration arent they?

Yeah... though, to be frank, it's actually a major plot point that protoculture-powered ships and mecha are thoroughly screwed even within the Robotech universe. The series starts and ends with only one viable source of protoculture in the entire universe... initially, the protoculture factory Zor hid aboard the SDF-1, and at the end it's the protoculture matrix aboard the SDF-3. The raw materials are so fiddly they only grow on one planet in the entire universe, and the technology to refine the stuff into fuel is often depicted as bordering on a lost technology itself.

The RPG actually makes it worse by insisting upon an exotic form of hydrogen for fusion reactors, which is much, MUCH harder to produce than real-world fusion reactor fuels... and also by citing greatly exaggerated run times for various mecha that aren't borne out by the series.

On the other hand, the Macross and MOSPEADA OSM versions of those mecha wouldn't have any problems. The mecha from MOSPEADA run on high-output hydrogen fuel cells, and the ships of that series run on hydrogen fusion. Macross's mecha would have an even easier time, since their thermonuclear reaction overtechnology is multifuel capable and the "preferred" fuel is also elemental hydrogen (usually stored in slush form). You could top up your giant robot's fuel tank using 1960's tech.

[eliakon]

Given we know what the max thrust value is, we can work backward. If we assume each PC canister holds 2.1kg of PC (see below), and an exhaust velocity of 0.99c (highest possible w/o breaking speed of light), the Alpha could max thrust for ~14.8hrs straight. At 0.01c it would last ~538seconds (or nearly 9minutes). This though might take it to low based on what we are told about PC's energy density (it should be on par w/nuclear at minimum I would think). To get a few seconds of full thrust (~5), the Alpha would have to exhaust the matter at 0.0001c (which is still very good compared to modern systems, but the Delta-V wouldn't even allow launch into orbit around the Moon from the Moon's surface).

A pretty sound argument, on the whole, that the Alpha is no different from any other craft in the setting in that it needs a supply of propellant separate from its protoculture power system.

Of course this has the unstated premise "there is propellant involved"

Man robotech mecha are just screwed on rifts earth if stuck for the duration arent they?

Yeah... though, to be frank, it's actually a major plot point that protoculture-powered ships and mecha are thoroughly screwed even within the Robotech universe. The series starts and ends with only one viable source of protoculture in the entire universe... initially, the protoculture factory Zor hid aboard the SDF-1, and at the end it's the protoculture matrix aboard the SDF-3. The raw materials are so fiddly they only grow on one planet in the entire universe, and the technology to refine the stuff into fuel is often depicted as bordering on a lost technology itself.

The RPG actually makes it worse by insisting upon an exotic form of hydrogen for fusion reactors, which is much, MUCH harder to produce than real-world fusion reactor fuels... and also by citing greatly exaggerated run times for various mecha that aren't borne out by the series.

On the other hand, the Macross and MOSPEADA OSM versions of those mecha wouldn't have any problems. The mecha from MOSPEADA run on high-output hydrogen fuel cells, and the ships of that series run on hydrogen fusion. Macross's mecha would have an even easier time, since their thermonuclear reaction overtechnology is multifuel capable and the "preferred" fuel is also elemental hydrogen (usually stored in slush form). You could top up your giant robot's fuel tank using 1960's tech.

So https://en.wikipedia.org/wiki/Slush_hydrogen which is cooled at -214c is easier and more effective than SLMH, which has no temperature restriction, and is ALSO made out of hydrogen (just pressurized).
How is it that Hydrogen A is better than Hydrogen B since both of them are Hydrogen that has been processed by advanced technology?

[Seto Kaiba]

A pretty sound argument, on the whole, that the Alpha is no different from any other craft in the setting in that it needs a supply of propellant separate from its protoculture power system.

Of course this has the unstated premise "there is propellant involved"

's kind of an easy premise to prove, as we're clearly shown exhaust coming from the engine nozzles of the Alpha, Beta, and other ships and mecha when operating in space.

(To date, the only faction mentioned or described as possessing reactionless drive technology is the Robotech Masters... and their implementation was only on their starships.)

So https://en.wikipedia.org/wiki/Slush_hydrogen which is cooled at -214c is easier and more effective than SLMH, which has no temperature restriction, and is ALSO made out of hydrogen (just pressurized).
How is it that Hydrogen A is better than Hydrogen B since both of them are Hydrogen that has been processed by advanced technology?

Put simply, the amount of energy involved in producing them differs by orders of magnitude.

To produce liquid or slush hydrogen, you need a regenerative chiller and about 13 atmospheres of pressure to get hydrogen down to below the critical point of -259.14°C in a vacuum flask. This can take time, but liquid hydrogen production can be easily carried out with simple commercial-grade compressor and chiller technology, and can easily be scaled up to produce industrial quantities of fuel swiftly. Slush hydrogen is only marginally more difficult to produce, requiring a somewhat more robust chiller and vacuum pump in place of compression. Production and storage of liquid or slush state hydrogen is well within the capabilities of modern technology.

To produce metallic hydrogen, elemental hydrogen needs to be subjected to pressures of over 3.25 million atmospheres (comparable to being in the Earth's core or the interior of a gas giant) and around 2,700°C (4,900°F). Stabilizing metallic hydrogen is impossible with our modern technology, but would doubtless require a significant input of energy in and of itself to restructure the metallic hydrogen in such a way that it will retain its metallic state after the temperature and pressure are restored to STP. The extent of the infrastructure necessary to produce metallic hydrogen in the industrial quantities necessary to sustain a military would be immense, due to the mechanical and energy requirements necessary to sustain those temperatures and pressures in amounts on hydrogen in quantities larger than a few grams. It does have the advantage of not needing to be stored in a pressure vessel, but that advantage is diminished somewhat by the need for even more rigorous ignition prevention measures... because its ignition energy is every bit as low as liquid or slush hydrogen's, and because it will not sublimate/evaporate (and because it releases seven to ten times as much energy when burning) it poses a much greater fire/explosion risk in the event of a leak.

Metallic hydrogen has a lot of potential uses, but using it as fuel in a fusion reactor is a spectacular waste of energy. Stabilized, it's an almost-ideal room temperature superconductor, and burned in the presence of liquid oxygen it's an enormously powerful rocket fuel. Being a denser form of liquid hydrogen, it doesn't actually offer any advantage in terms of energy vs. fuel mass in a fusion reaction... it just makes it easier to initiate fusion in a laser-catalyzed inertial confinement fusion reactor, which is possibly what's used for space propulsion on Zentradi mecha but would not be particularly effective in supplying continuous power generation.

[guardiandashi]

realistically (from a science standpoint) the main advantage of "stabilized metallic hydrogen" would be if you could store large amounts of the "stabilized" form then upon demand, cause a very small amount to return to a "normal" state, preferably without the MASSIVE thermal draw that would likely occur. being able to suddenly turn 1cubic millimeter of metallic hydrogen into cubic meters (at a guess) of liquid or gas hydrogen when you wanted would actually be really cool.

[glitterboy2098]

actually in stabilized form the stuff basically has the traits of jet fuel as far as storage and handling. just much more flammable, but that's mostly a minor engineering and safety proceedures issue (minimizing static and sparks basically)

a crygenic slush that has to be kept at -14 kelvin exactly is a much trickier concern.. the systems needed to store it and pump it are going to be massive power hogs, fairly bulky thanks to the needed insulation and powerful cooling systems, not to mention that any tanks of the stuff need a mechanical "stirrer" system to keep the solid ices from settling out or congealing at the top, and that system has to be built to operate at only 14 degrees above absolute zero and generate virtually no heat. pipes to move the stuff run into the same issues.

and all that for something that is only 20% denser than liquid hydrogen (which just needs to be below 30 kelvin..still an issue but one humanity has a fair degree of experiance with already)

by comparison mettalic hydrogen, even in the theoretical liquid form, would have a density 8-10x that of regular liquid hydrogen. which mean you've basically got that many times more fuel available to you in the same volume of tankage. and while the mass difference is going to be similar, liquid hydrogen is so light mass wise it doesn't really make much difference.

[Seto Kaiba]

realistically (from a science standpoint) the main advantage of "stabilized metallic hydrogen" would be if you could store large amounts of the "stabilized" form then upon demand, cause a very small amount to return to a "normal" state, preferably without the MASSIVE thermal draw that would likely occur.

That'd render the whole process little more than a massive and unnecessary waste of energy... on an apocalyptic scale, when you consider the amount of energy necessary to produce the temperatures and pressures necessary for the creation of industrial-scale fuel production.

a crygenic slush that has to be kept at -14 kelvin exactly is a much trickier concern.. the systems needed to store it and pump it are going to be massive power hogs, fairly bulky thanks to the needed insulation and powerful cooling systems, not to mention that any tanks of the stuff need a mechanical "stirrer" system to keep the solid ices from settling out or congealing at the top, and that system has to be built to operate at only 14 degrees above absolute zero and generate virtually no heat. pipes to move the stuff run into the same issues.

But all of these are issues addressable with 1960s technology... we've been using cryofuels for space flight on an industrial scale for decades. The maintenance of large quantities of stored cryofuel takes energy, yes, but nowhere near the amount necessary for the creation of the conditions under which metallic hydrogen can form. You could reasonably store and operate the equipment to make liquid or slush hydrogen fuel in a spacecraft without having to take any significant additional safety measures. Worst case scenario for an accident is a fire or small explosion... compared to SLMH, where the production facilities would have to be MASSIVELY heavy to withstand the enormous pressures involved, and the potential for an accident is more on the order of a nuclear blast.[sup]1[/sup]

by comparison mettalic hydrogen, even in the theoretical liquid form, would have a density 8-10x that of regular liquid hydrogen. which mean you've basically got that many times more fuel available to you in the same volume of tankage. and while the mass difference is going to be similar, liquid hydrogen is so light mass wise it doesn't really make much difference.

Almost exactly 10x, for the projected density of liquid metallic hydrogen without Lithium doping.

The real question is why is that extra fuel mass necessary?

If you look to NASA's projection for fuel efficiency of a thermonuclear turbine engine from their 2005 position paper[sup]2[/sup], a pound of fuel could get you over 12,300 miles of flight range. Without account for alien technology cheats, that's potentially 3.26 MILLION MILES on a tank for the VF-1.[sup]3[/sup]

That sounds real impressive on its own, but let's frame that in a usable context. If we assume the VF-1 was cruising at maximum speed (Mach 3.87) at its rated altitude (30,000m), that's enough fuel to fly for 51 days, 23 hours, and 26 minutes.[sup]4[/sup]

Now naturally they're not going to be putting the entire amount of energy from the reaction into flight... running a robot takes lots and lots of juice... but even if we cut that value in half, that's still an operation time of almost four weeks on a tank... and that's WITHOUT the VF-1's optional drop tanks that boost the capacity by almost 4x.


1. Seriously, that's 22 times the pressure necessary to create synthetic diamond... and only about 1/1000th the pressure necessary to induce fusion. About 1.159 million times the overpressure within 50m of an airbursting 1KT nuclear bomb.

2. NASA/CR-2005-213749

3. The VF-1's fuel tanks are 1,410L capacity, holding 119.85kg of slush hydrogen. This is without any optional bolt-on, internal, or space-use supplemental tanks, which can boost the VF-1's tank capacity by as much as 5,000L.

4. At NASA's low-end estimate of 2955mi/lb, you still have 12 days, 10 hours, 41 minutes of flight time.

[eliakon]

realistically (from a science standpoint) the main advantage of "stabilized metallic hydrogen" would be if you could store large amounts of the "stabilized" form then upon demand, cause a very small amount to return to a "normal" state, preferably without the MASSIVE thermal draw that would likely occur.

That'd render the whole process little more than a massive and unnecessary waste of energy... on an apocalyptic scale, when you consider the amount of energy necessary to produce the temperatures and pressures necessary for the creation of industrial-scale fuel production.

The problem is you need a major industrial infrastructure to make ANY hydrogen fuel, so the claim of massive infrastructure fall flat on its face.
Especially since the point of metallic hydrogen is its high energy density. Your 'storing' energy from your ground station in the fuel for later extraction.....

a crygenic slush that has to be kept at -14 kelvin exactly is a much trickier concern.. the systems needed to store it and pump it are going to be massive power hogs, fairly bulky thanks to the needed insulation and powerful cooling systems, not to mention that any tanks of the stuff need a mechanical "stirrer" system to keep the solid ices from settling out or congealing at the top, and that system has to be built to operate at only 14 degrees above absolute zero and generate virtually no heat. pipes to move the stuff run into the same issues.

But all of these are issues addressable with 1960s technology... we've been using cryofuels for space flight on an industrial scale for decades. The maintenance of large quantities of stored cryofuel takes energy, yes, but nowhere near the amount necessary for the creation of the conditions under which metallic hydrogen can form. You could reasonably store and operate the equipment to make liquid or slush hydrogen fuel in a spacecraft without having to take any significant additional safety measures. Worst case scenario for an accident is a fire or small explosion... compared to SLMH, where the production facilities would have to be MASSIVELY heavy to withstand the enormous pressures involved, and the potential for an accident is more on the order of a nuclear blast.[sup]1[/sup]

Except that no, the technology for properly mixing and maintain Hydrogen Slush has not been 'in use' Some cyrofuels are, yes. But they are not ones that require the advanced special technology of Slush (there is likely that the technology was abandoned for other easier forms of cyrogas technology, part of which is that it is very hard to make/maintain/move Slush but not regular liquid hydrogen.....)
And its only speculation on your part what the results of an industrial accident at a SLMH plant, and a Hydrogen Slush plant would be as there is nothing known about how it is produced in universe. You cant just say "well it has this drawback that I say it has so its worse". Now if you have a citation please, by all means share it. Because as it is your simply fiating that one is worse than the other.
Especially ones on the size of the production facilities for both Slush and SLMH, I am interested in the source of your claim that Slush (and only slush) can be made shipside.

by comparison mettalic hydrogen, even in the theoretical liquid form, would have a density 8-10x that of regular liquid hydrogen. which mean you've basically got that many times more fuel available to you in the same volume of tankage. and while the mass difference is going to be similar, liquid hydrogen is so light mass wise it doesn't really make much difference.

Almost exactly 10x, for the projected density of liquid metallic hydrogen without Lithium doping.

The real question is why is that extra fuel mass necessary?

Um lets see....we were just discussing the need for high quantities of Remass? You know where the question was "is there enough tankage for the needed remass? Yeah, I think that if the quantity of fuel is an issue getting 10x the mass in the same volume might be a wee bit important
And of course there is the fact that the SLMH has a higher energy density meaning you get more bang for your buck (which extends range, increases available power.....all stuff that is valuable)

If you look to NASA's projection for fuel efficiency of a thermonuclear turbine engine from their 2005 position paper[sup]2[/sup], a pound of fuel could get you over 12,300 miles of flight range. Without account for alien technology cheats, that's potentially 3.26 MILLION MILES on a tank for the VF-1.[sup]3[/sup]

That sounds real impressive on its own, but let's frame that in a usable context. If we assume the VF-1 was cruising at maximum speed (Mach 3.87) at its rated altitude (30,000m), that's enough fuel to fly for 51 days, 23 hours, and 26 minutes.[sup]4[/sup]

Now naturally they're not going to be putting the entire amount of energy from the reaction into flight... running a robot takes lots and lots of juice... but even if we cut that value in half, that's still an operation time of almost four weeks on a tank... and that's WITHOUT the VF-1's optional drop tanks that boost the capacity by almost 4x.

Except of course for the minor problem that those designs are for spaceships in space AND don't have the specific impulse we want.....
But hey lets try to shoehorn a different technology into this and pretend that it works right?

1. Seriously, that's 22 times the pressure necessary to create synthetic diamond... and only about 1/1000th the pressure necessary to induce fusion. About 1.159 million times the overpressure within 50m of an airbursting 1KT nuclear bomb.

Yes a pressure btw that is routinely created on earth with modern equipment....your point is?

3. The VF-1's fuel tanks are 1,410L capacity, holding 119.85kg of slush hydrogen. This is without any optional bolt-on, internal, or space-use supplemental tanks, which can boost the VF-1's tank capacity by as much as 5,000L.

or 1,410L of SLMH.....(remember what we said about remass and stuff?)

4. At NASA's low-end estimate of 2955mi/lb, you still have 12 days, 10 hours, 41 minutes of flight time.

I missed the NASA files on Veratech fighters, can you provide the link to where they studied this?

[Seto Kaiba]

The problem is you need a major industrial infrastructure to make ANY hydrogen fuel, so the claim of massive infrastructure fall flat on its face.

No, it's perfectly possible to make usable quantities of hydrogen fuel on a relatively low budget... that's one reason it's been toyed with as an alternative fuel for cars and aircraft.

There is a significant difference between the LEVEL of infrastructure necessary to produce the fuel types in question. It takes a LOT more energy and a lot more equipment to heat hydrogen to thousands of degrees and impose several million atmospheres worth of pressure than it does to build a vacuum flask and regenerative chiller. We're talking multiple orders of magnitude difference here.

Especially since the point of metallic hydrogen is its high energy density. Your 'storing' energy from your ground station in the fuel for later extraction.....

The point is that the energy input necessary to produce industrial quantities of metallic hydrogen is not even remotely likely to meet or exceed the energy requirements necessary to make it, considering the forces necessary. It's like antimatter, very sci-fi, but the logistical hurdles to implementation make it ridiculously impractical.

Except that no, the technology for properly mixing and maintain Hydrogen Slush has not been 'in use' Some cyrofuels are, yes. But they are not ones that require the advanced special technology of Slush (there is likely that the technology was abandoned for other easier forms of cyrogas technology, part of which is that it is very hard to make/maintain/move Slush but not regular liquid hydrogen.....)

Apparently NASA's jet propulsion laboratory and research partners didn't get the memo that they're not working with liquid and slush hydrogen...

(Seriously though, they've been working with slush hydrogen storage and production technology as a potential replacement for the liquid hydrogen in their rockets since the 90's.)

And its only speculation on your part what the results of an industrial accident at a SLMH plant, and a Hydrogen Slush plant would be as there is nothing known about how it is produced in universe. You cant just say "well it has this drawback that I say it has so its worse". Now if you have a citation please, by all means share it. Because as it is your simply fiating that one is worse than the other.

Did you miss my discussion of the temperatures and pressures necessary to produce metallic hydrogen? This is not something that requires intimate in-universe knowledge to point out... the most likely point of failure during production is the pressure vessel that the fuel is produced in. You need to bring over three million atmospheres of pressure to bear to create metallic hydrogen, and for most approaches you also need temperatures of thousands of degrees kelvin. If the pressure vessel fails, you're going to see that pressure released. The ~13 atmospheres of pressure used in liquid hydrogen production is going to make a bang and probably it'll hurt your ears. The vacuum used to create slush hydrogen'll make a pop and hurt your ears. The 3.2-3.4 million atmospheres of pressure used in metallic hydrogen production will pulp you instantly with force greater than an airbursting nuke.

The other obvious safety concern is leakage from a storage vessel. We know, from basic chemistry, that liquid hydrogen and slush hydrogen will evaporate at STP and thus a fire or explosion can be mitigated or prevented entirely with good ventilation and/or the usage of inert gas additives in the storage room. (Much like the fuel handling protocols used in pretty much any automotive or jet propulsion laboratory). Because stabilized liquid metallic hydrogen will remain liquid at STP by definition, that means that a leaky vessel can much more easily build up an explosive amount of leakage because it won't evaporate and has the same extremely low ignition threshold.

I'd like to dismissively say this isn't rocket science... but to be honest, it kind of is. It's not complicated chemistry though.

Especially ones on the size of the production facilities for both Slush and SLMH, I am interested in the source of your claim that Slush (and only slush) can be made shipside.

I didn't say it's not possible, just that it's not safe or practical to produce metallic hydrogen aboard a ship based on the physics that are involved in its production. To make liquid or slush hydrogen you need a pressure vessel that can withstand drawing a vacuum and/or being subjected to a dozen or so atmospheres of pressure. That's no biggie... we've gotten so surpassingly good at making vacuum flasks that people use cheap ones to keep their coffee hot. That can be done on a small form factor, and storage vessels aren't terribly difficult to build or maintain.

The temperatures and pressures involved in producing metallic hydrogen mean that you're going to need a MUCH more robust and heavy-duty system than you would if you were producing liquid or slush hydrogen. Your storage needs will be lower, but you will inevitably expend a LOT more energy imposing pressures that are normally only found in the interiors of gas giants or the core of Earth on the interior of a pressure vessel. A lot more material is going to go into making a pressure vessel that can withstand all that pressure. 3.2 million atmospheres of pressure is nothing to sneeze at.

If a pressure vessel used to produce slush or liquid hydrogen blows, the worst you're looking at if nobody's drenched in cryofluid would be a fire and maybe some hearing loss among the workers. The change in pressure isn't going to be severe enough to do anyone any lasting harm on its own. You blow up a pressure vessel that's holding the 3.2 million atmospheres, and you're hitting everyone (and the inside of the ship) with 3,600 times the pressure you'd experience at the bottom of the Mariana trench. That's emphatically not survivable... and could potentially severely damage the airtight ship on top of the fleshy meats inside it. If that plant were hit by a beam weapon or missile... that's basically a huge bomb inside the ship.

Um lets see....we were just discussing the need for high quantities of Remass? You know where the question was "is there enough tankage for the needed remass? Yeah, I think that if the quantity of fuel is an issue getting 10x the mass in the same volume might be a wee bit important

Now THAT'S fair... but you don't really get much benefit from the additional density of metallic hydrogen in most fusion reactions, because those are temperature-dependent rather than pressure-dependent. You'd be better served to use normal liquid or slush hydrogen for your power plant and SLMH for your rocket motors and pulse-detonation fusion drives where its density can be used to its best advantage.

And of course there is the fact that the SLMH has a higher energy density meaning you get more bang for your buck (which extends range, increases available power.....all stuff that is valuable)

The problem is that your net cost in energy to produce SLMH is going to be much higher and the tradeoff in production cost vs actual tangible benefit is much less favorable vs. more conventional alternatives unless they've found some physics-violating way to make metallic hydrogen without having to artificially create the temperature and pressure conditions (like mining a gas giant).

Except of course for the minor problem that those designs are for spaceships in space AND don't have the specific impulse we want.....
But hey lets try to shoehorn a different technology into this and pretend that it works right?

Ah, I take it you didn't bother to read the paper then? You've fallen prey to the common misconception that NASA only experiments on space flight.

NASA/CR-2005-213749 is not a paper on designs for engines for space flight... it's a paper on the practical aspects, benefits, and implementation issues of fusion-driven jet engines intended for atmospheric use on commercial and military aircraft.

(... and it is WICKED cool.)

Yes a pressure btw that is routinely created on earth with modern equipment....your point is?

As noted in the section this was a footnote for, this is substantially worse than the overpressure from an airbusting nuclear bomb. While a breach in a 1,300kPa-class storage tank for liquid hydrogen would hurt your ears and maybe cause nosebleeds and trauma from flying shrapnel if the breach were severe enough, a blowout in a metallic hydrogen pressure vessel could severely damage or even destroy a ship with the massive release of pressure.

Safety is naturally going to be a factor in equipment produced for operation in a military environment.

or 1,410L of SLMH.....(remember what we said about remass and stuff?)

Cited the way it was because the factoid comes from a Macross source... and in that setting, SLMH does not exist.

(Technically it doesn't exist in Robotech proper either, but that's neither here nor there.)

I missed the NASA files on Veratech fighters, can you provide the link to where they studied this?

NASA technical brief NASA/CR-2005-213749, Section 1.1.3 "Calculated Emissionless Aircraft Ranges"... not on VFs, but the engine designs they discuss are not far off from what the VF-1 uses.

[eliakon]

The problem is you need a major industrial infrastructure to make ANY hydrogen fuel, so the claim of massive infrastructure fall flat on its face.

No, it's perfectly possible to make usable quantities of hydrogen fuel on a relatively low budget... that's one reason it's been toyed with as an alternative fuel for cars and aircraft.

There are many kinds of hydrogen fuel though. No one is woring with SLUSH....

There is a significant difference between the LEVEL of infrastructure necessary to produce the fuel types in question. It takes a LOT more energy and a lot more equipment to heat hydrogen to thousands of degrees and impose several million atmospheres worth of pressure than it does to build a vacuum flask and regenerative chiller. We're talking multiple orders of magnitude difference here.

You do realize that Slush requires more than that too right?

Especially since the point of metallic hydrogen is its high energy density. Your 'storing' energy from your ground station in the fuel for later extraction.....

The point is that the energy input necessary to produce industrial quantities of metallic hydrogen is not even remotely likely to meet or exceed the energy requirements necessary to make it, considering the forces necessary. It's like antimatter, very sci-fi, but the logistical hurdles to implementation make it ridiculously impractical.

Uh you don't understand the 'store energy' thing do you?

Except that no, the technology for properly mixing and maintain Hydrogen Slush has not been 'in use' Some cyrofuels are, yes. But they are not ones that require the advanced special technology of Slush (there is likely that the technology was abandoned for other easier forms of cyrogas technology, part of which is that it is very hard to make/maintain/move Slush but not regular liquid hydrogen.....)

Apparently NASA's jet propulsion laboratory and research partners didn't get the memo that they're not working with liquid and slush hydrogen...

You have any support for that claim? Because I can't find any public documents on any research in Hydrogen Slush.....Hydrogen yes, but not Slush (a specific form of hydrogen fuel)

(Seriously though, they've been working with slush hydrogen storage and production technology as a potential replacement for the liquid hydrogen in their rockets since the 90's.)

Again, source?

And its only speculation on your part what the results of an industrial accident at a SLMH plant, and a Hydrogen Slush plant would be as there is nothing known about how it is produced in universe. You cant just say "well it has this drawback that I say it has so its worse". Now if you have a citation please, by all means share it. Because as it is your simply fiating that one is worse than the other.

Did you miss my discussion of the temperatures and pressures necessary to produce metallic hydrogen? This is not something that requires intimate in-universe knowledge to point out... the most likely point of failure during production is the pressure vessel that the fuel is produced in. You need to bring over three million atmospheres of pressure to bear to create metallic hydrogen, and for most approaches you also need temperatures of thousands of degrees kelvin. If the pressure vessel fails, you're going to see that pressure released. The ~13 atmospheres of pressure used in liquid hydrogen production is going to make a bang and probably it'll hurt your ears. The vacuum used to create slush hydrogen'll make a pop and hurt your ears. The 3.2-3.4 million atmospheres of pressure used in metallic hydrogen production will pulp you instantly with force greater than an airbursting nuke.

Well assuming of course that no one uses gravity tech (which is explicitly in universe...)

The other obvious safety concern is leakage from a storage vessel. We know, from basic chemistry, that liquid hydrogen and slush hydrogen will evaporate at STP and thus a fire or explosion can be mitigated or prevented entirely with good ventilation and/or the usage of inert gas additives in the storage room. (Much like the fuel handling protocols used in pretty much any automotive or jet propulsion laboratory). Because stabilized liquid metallic hydrogen will remain liquid at STP by definition, that means that a leaky vessel can much more easily build up an explosive amount of leakage because it won't evaporate and has the same extremely low ignition threshold.

Again interesting claims....but I can't find support for it....and explosions and fires of fuel is still explosions and fire of fuel....

I'd like to dismissively say this isn't rocket science... but to be honest, it kind of is. It's not complicated chemistry though.

Well since there is nothing in the public domain about the full properties of hydrogen slush it is a bit complicated.....

Especially ones on the size of the production facilities for both Slush and SLMH, I am interested in the source of your claim that Slush (and only slush) can be made shipside.

I didn't say it's not possible, just that it's not safe or practical to produce metallic hydrogen aboard a ship based on the physics that are involved in its production. To make liquid or slush hydrogen you need a pressure vessel that can withstand drawing a vacuum and/or being subjected to a dozen or so atmospheres of pressure. That's no biggie... we've gotten so surpassingly good at making vacuum flasks that people use cheap ones to keep their coffee hot. That can be done on a small form factor, and storage vessels aren't terribly difficult to build or maintain.

You do realize that a coffee thermos is not going to provide the controls needed to make slush right? You need exacting pressures and temperatures....

The temperatures and pressures involved in producing metallic hydrogen mean that you're going to need a MUCH more robust and heavy-duty system than you would if you were producing liquid or slush hydrogen. Your storage needs will be lower, but you will inevitably expend a LOT more energy imposing pressures that are normally only found in the interiors of gas giants or the core of Earth on the interior of a pressure vessel. A lot more material is going to go into making a pressure vessel that can withstand all that pressure. 3.2 million atmospheres of pressure is nothing to sneeze at.

Or maybe it just uses gravity control.....again I ask for your evidence on what is required to make SLMH in universe.

If a pressure vessel used to produce slush or liquid hydrogen blows, the worst you're looking at if nobody's drenched in cryofluid would be a fire and maybe some hearing loss among the workers. The change in pressure isn't going to be severe enough to do anyone any lasting harm on its own. You blow up a pressure vessel that's holding the 3.2 million atmospheres, and you're hitting everyone (and the inside of the ship) with 3,600 times the pressure you'd experience at the bottom of the Mariana trench. That's emphatically not survivable... and could potentially severely damage the airtight ship on top of the fleshy meats inside it. If that plant were hit by a beam weapon or missile... that's basically a huge bomb inside the ship.

Again a lot of speculation based on nothing from the actual published material, or more bluntly "well I want it to work this way so it does"
Or to reiterate, your source for this claim?

Um lets see....we were just discussing the need for high quantities of Remass? You know where the question was "is there enough tankage for the needed remass? Yeah, I think that if the quantity of fuel is an issue getting 10x the mass in the same volume might be a wee bit important

Now THAT'S fair... but you don't really get much benefit from the additional density of metallic hydrogen in most fusion reactions, because those are temperature-dependent rather than pressure-dependent. You'd be better served to use normal liquid or slush hydrogen for your power plant and SLMH for your rocket motors and pulse-detonation fusion drives where its density can be used to its best advantage.

Source? Specifically information on the energy density and released energy values of fusing SLMH vis-à-vis fusing HS?

And of course there is the fact that the SLMH has a higher energy density meaning you get more bang for your buck (which extends range, increases available power.....all stuff that is valuable)

The problem is that your net cost in energy to produce SLMH is going to be much higher and the tradeoff in production cost vs actual tangible benefit is much less favorable vs. more conventional alternatives unless they've found some physics-violating way to make metallic hydrogen without having to artificially create the temperature and pressure conditions (like mining a gas giant).

To bad that we have gravity systems in RT.....and once again your assuming that the trade off is not valid. Source for these claims?

Except of course for the minor problem that those designs are for spaceships in space AND don't have the specific impulse we want.....
But hey lets try to shoehorn a different technology into this and pretend that it works right?

Ah, I take it you didn't bother to read the paper then? You've fallen prey to the common misconception that NASA only experiments on space flight.

Care to provide the link to this paper?

NASA/CR-2005-213749 is not a paper on designs for engines for space flight... it's a paper on the practical aspects, benefits, and implementation issues of fusion-driven jet engines intended for atmospheric use on commercial and military aircraft.

(... and it is WICKED cool.)

Interesting because I cant find such a paper, care to provide an actual citation for it?
The one I found with that number ( http://ntrs.nasa.gov/search.jsp?R=20050170447 ) has this abstract

" NASA has identified water vapor emission into the upper atmosphere from commercial transport aircraft, particularly as it relates to the formation of persistent contrails, as a potential environmental problem. Since 1999, MSE has been working with NASA-LaRC to investigate the concept of a transport-size emissionless aircraft fueled with liquid hydrogen combined with other possible breakthrough technologies. The goal of the project is to significantly advance air transportation in the next decade and beyond. The power and propulsion (P/P) system currently being studied would be based on hydrogen fuel cells (HFCs) powering electric motors, which drive fans for propulsion. The liquid water reaction product is retained onboard the aircraft until a flight mission is completed. As of now, NASA-LaRC and MSE have identified P/P system components that, according to the high-level analysis conducted to date, are light enough to make the emissionless aircraft concept feasible. Calculated maximum aircraft ranges (within a maximum weight constraint) and other performance predictions are included in this report. This report also includes current information on advanced energy-related technologies, which are still being researched, as well as breakthrough physics concepts that may be applicable for advanced energetics and aerospace propulsion in the future. "

I see hydrogen fuel cells (and other stuff from batteries, to beamed power to zero point energy and beyond) powering electric motor driven fans.....I don't see anything about fusion turbines though.....(edit, I see an idea to use a Beam Collimated fusion reactor to power the fan....)

Yes a pressure btw that is routinely created on earth with modern equipment....your point is?

As noted in the section this was a footnote for, this is substantially worse than the overpressure from an airbusting nuclear bomb. While a breach in a 1,300kPa-class storage tank for liquid hydrogen would hurt your ears and maybe cause nosebleeds and trauma from flying shrapnel if the breach were severe enough, a blowout in a metallic hydrogen pressure vessel could severely damage or even destroy a ship with the massive release of pressure.

Safety is naturally going to be a factor in equipment produced for operation in a military environment.

And yet again your proposing that your view of how the technology must work is the only way it can work.
And yet again I must point out that since the RT universe has access to both MDC materials and Gravity technology that it does not have to be done this way.

or 1,410L of SLMH.....(remember what we said about remass and stuff?)

Cited the way it was because the factoid comes from a Macross source... and in that setting, SLMH does not exist.

(Technically it doesn't exist in Robotech proper either, but that's neither here nor there.)

My point is that if there is a 1,410L fuel tank it can hold 1,410L of fuel. Unless this tank is magical and can only hold HS and not SLMH.

I missed the NASA files on Veratech fighters, can you provide the link to where they studied this?

NASA technical brief NASA/CR-2005-213749, Section 1.1.3 "Calculated Emissionless Aircraft Ranges"... not on VFs, but the engine designs they discuss are not far off from what the VF-1 uses.

You mean the electric turbine driven fans that are powered by a conventional hydrogen fuel cell? Or the "Colliding Beam Fusion"?
Because I still don't see thing on HS fusion turbines in here. (though I am still reading it, but 114pages is pretty long. if you could just kindly provide the page/paragraph/section where it talks about HS we can skip straight there and get down to analyzing it)
Because as written this paper is talking about ways to make subsonic fans that fly atmospheric craft. As such it has no relevance to supersonic fusion thrusters in space.

And the ranges in 1.1.3 are "Finally, it is noted that prior work indicated that the calculated range of the emissionless aircraft described by this concept would be 2,658 nautical miles (nmi) for conservative near-term assumptions and as far as 10,715 nmi using long-term assumptions (i.e. technology that is plausible but not yet developed)"
Which is not 12,300 miles per pound of fuel and certainly not 3.26 million miles.

[Seto Kaiba]

There are many kinds of hydrogen fuel though. No one is woring with SLUSH....

Really? Because in less than fifteen seconds of searching I found two papers by the National Bureau of Standards and one by NASA itself. NASA also specifically identifies hydrogen slush as the fuel of choice for the developmental Rockwell X-30 spaceplane program.

You do realize that Slush requires more than that too right?

Not by much, unless you're working with a significantly different set of physics from the rest of us...

You have any support for that claim? Because I can't find any public documents on any research in Hydrogen Slush.....Hydrogen yes, but not Slush (a specific form of hydrogen fuel)

NASA technical memorandums 106863 and 107324, for starters.

(Seriously though, they've been working with slush hydrogen storage and production technology as a potential replacement for the liquid hydrogen in their rockets since the 90's.)

Again, source?

The aforementioned technical memorandum (report no. NASA TM-106863) is from April 1995.

Well assuming of course that no one uses gravity tech (which is explicitly in universe...)

That's a fair point. We haven't, however, seen a gravity control system localized enough or strong enough to produce that kind of intense gravitational force. That's not to say it's not possible, but we just don't have any evidence for it at present. It would likely end up the safest and most elegant solution to SLMH production.

Again interesting claims....but I can't find support for it....and explosions and fires of fuel is still explosions and fire of fuel....

That's simple reasoning based on the known and published properties of metallic hydrogen and the theoretical stability thereof. It's pretty straightforward stuff. Also sourced (for conventional hydrogen alternatives) from AIAA G-095-2004, which is the AIAA set of standards for safe handling of hydrogen fuels.

Well since there is nothing in the public domain about the full properties of hydrogen slush it is a bit complicated.....

No, there's plenty out there... it won't cease to exist simply because you don't want to take a moment and look.

You do realize that a coffee thermos is not going to provide the controls needed to make slush right? You need exacting pressures and temperatures....

*Sigh* The coffee thermos is a derivative of vacuum flask technology. It's an example of how that technology really isn't all that complex in implementation. Yes, one designed to hold temperatures of just a few kelvin is going to be necessarily more advanced and of higher quality, but the basic principles are all there.

Or maybe it just uses gravity control.....again I ask for your evidence on what is required to make SLMH in universe.

There is no evidence of SLMH production practices in universe because SLMH does not exist in canon Robotech, as far as we know. All we can do is extrapolate from the known, physical properties of the substance as published.

Again a lot of speculation based on nothing from the actual published material, or more bluntly "well I want it to work this way so it does"
Or to reiterate, your source for this claim?

There's a good twenty-three articles on the properties and experimental pursuit of metallic hydrogen on Wikipedia alone... do you honestly need to be spoon-fed this data?

To bad that we have gravity systems in RT.....and once again your assuming that the trade off is not valid.

Source for your claim that a gravity control system capable of the deed exists in Robotech?

Interesting because I cant find such a paper, care to provide an actual citation for it?
The one I found with that number has this abstract

From the abstract, it sounds like you found either the paper in question or an earlier report in the series (NASA/CR-2003-212169).

I see hydrogen fuel cells powering electric motor driven fans.....I don't see anything about fusion turbines though.....

It's possible you found NASA/CR-2003-212169 instead, which talked about non-nuclear options for emissionless aircraft. The sequel paper, NASA/CR-2005-213749, talks about two different versions of flight-weight fusion reactor technology.

And yet again your proposing that your view of how the technology must work is the only way it can work.
And yet again I must point out that since the RT universe has access to both MDC materials and Gravity technology that it does not have to be done this way.

At the risk of pointing out a problem, the only difference between using a pressure vessel and using gravitational force is how the pressure is being exerted... it doesn't change the fact that you're exerting 3.2 million atmospheres worth of pressure on the gas or liquid hydrogen starting sample. To quote Scotty... "Ye cannae change the laws of physics!"

My point is that if there is a 1,410L fuel tank it can hold 1,410L of fuel. Unless this tank is magical and can only hold HS and not SLMH.

I know, I'm just being accurate to my cited source. No worries.

You mean the electric turbine driven fans that are powered by a conventional hydrogen fuel cell? Or the "Colliding Beam Fusion"?
Because I still don't see thing on HS fusion turbines in here. (though I am still reading it, if you could just kindly provide the page/paragraph where it talks about HS we can get down to analyzing it)

The two reactor concepts discussed therein are the colliding beam type and inertial electrostatic confinement type... the fuel type they mostly discuss is H[sup]1[/sup]-B[sup]11[/sup], but the same principles can be applied to any aneutronic fusion reaction.

[glitterboy2098]

Seto i find it funny you claim that SLMH would suffer a pressure explosion.

SLMH is STABILIZED liquid metallic hydrogen. meaning it has been stabilized against the molecular phase change resulting in the removal of pressure. that is, that after the initial pressure is applied to make it metallic hydrogen, the pressure can be removed at it remains metallic even at normal pressures.
(as explained in "pathways to metallic hydrogen", by Issac Silvera, Harvard university, 1996)

thus SLMH, once produced, can be handled as just a highly flammable room temp and pressure liquid. or like i said earlier, effectively like a more flammable version of jet fuel.

[Seto Kaiba]

Seto i find it funny you claim that SLMH would suffer a pressure explosion.

SLMH is STABILIZED liquid metallic hydrogen. meaning it has been stabilized against the molecular phase change resulting in the removal of pressure. that is, that after the initial pressure is applied to make it metallic hydrogen, the pressure can be removed at it remains metallic even at normal pressures.

Superficially true, but you're missing my point.

Once the fuel is complete, it no longer needs to be held under pressure... but the point about the pressure explosion is talking about the production facilities where the massive pressures necessary to induce a metallic state in hydrogen are applied. Production is where the bulk of the danger and the enormous energy requirement lies in SLMH.

thus SLMH, once produced, can be handled as just a highly flammable room temp and pressure liquid. or like i said earlier, effectively like a more flammable version of jet fuel.

Very true, though my point is still valid that its stable nature makes it more dangerous in the event of a leak because the leaking fuel's ignition risk can't be mitigated by ventilation due to it being stable in the liquid state. (Inert gas and other safety measures would still work fine, of course.)

[eliakon]

Seto I provided a link to the paper I can find. if you have a different paper that specifically discusses a hydrogen fusion rocket the paper I provided a link to IS CR-2005-231749.
http://ntrs.nasa.gov/search.jsp?R=20050 ... allpartial

That 144 page paper IS the one you are referring to. And it is about an electrically powered zero emission airplane. There are two theoretical fusion turbines that provide the electricity for the fans yes. But there is no direct fusion turbine that provides the actual thrust.
I would also point out that the listed paper does not use HS as a fuel, and has as I previously cited a much lower range than your claims. If its not about fusion turbines, its not about supersonic engines, and its only in atmosphere then its not really applicable to a supersonic fusion turbine for use in space.


The abstract of 106863
Slush hydrogen, a mixture of solid and liquid hydrogen, offers advantages of higher density (16 percent) and higher heat capacity (18 percent) than normal boiling point hydrogen. The combination of increased density and heat capacity of slush hydrogen provided a potential to decrease the gross takeoff weight of the National Aero-Space Plane (NASP) and therefore slush hydrogen was selected as the propellant. However, no large-scale data was available on the production, transfer and tank pressure control characteristics required to use slush hydrogen as a fuel. Extensive testing has been performed at the NASA Lewis Research Center K-Site and Small Scale Hydrogen Test Facility between 1990 and the present to provide a database for the use of slush hydrogen. This paper summarizes the results of this testing.
I will correct my statement. There is nothing in the literature to suggest that HS can be feasibly manufactured or use. Interestingly though one of the purposes of using HS was its increased density. Which would sort of suggest that SLMH would be even MORE preferable. It also had questions of if sloshing, loss of ambient pressure and excessive tank weight could be solve.

But I will agree, there is some research into HS creation. Although they seem to still have a problem actually moving the HS once made...

And 107324
Energy optimized Gaussian basis sets of triple-zeta quality for the atoms Rb-Xe have been derived. Two series of basis sets are developed: (24s 16p 10d) and (26s 16p 10d) sets which were expanded to 13d and 19p functions as the 4d and 5p shells become occupied. For the atoms lighter than Cd, the (24s 16p 10d) sets with triple-zeta valence distributions are higher in energy than the corresponding double-zeta distribution. To ensure a triple-zeta distribution and a global energy minimum, the (26s 16p 10d) sets were derived. Total atomic energies from the largest basis sets are between 198 and 284 (mu)E(sub H) above the numerical Hartree-Fock energies.
THAT doesn't sound like any sort of HS research, do I have the wrong number?

[Seto Kaiba]

That 144 page paper IS the one you are referring to. And it is about an electrically powered zero emission airplane. There are two theoretical fusion turbines that provide the electricity for the fans yes. But there is no direct fusion turbine that provides the actual thrust.

The point was that the CBFR-type engine as outlined in Section 2.2 is functionally very similar to a VF-1's thermonuclear reaction turbine's air-breathing mode. The thrust is not provided directly by the fusion reaction, but rather by an electrically-driven set of superconducting compressor stages and the waste heat from the generation process. (I'll see about posting some of the reaction engine diagrams from Macross's creators tomorrow morning for your perusal.)

The fuel cell implementations aren't too far off how the Legioss/Alpha's engines should work too.

I will correct my statement. There is nothing in the literature to suggest that HS can be feasibly manufactured or use.

See NASA and Rockwell's work on the X-30, which was a planned implementation of a slush hydrogen engine for space flight. I'd stress a point of distinction between your statement and the current state of research though... just because it isn't being done at commercial levels right now doesn't mean the production process isn't feasible for large-scale use if demand emerges.

Interestingly though one of the purposes of using HS was its increased density. Which would sort of suggest that SLMH would be even MORE preferable. It also had questions of if sloshing, loss of ambient pressure and excessive tank weight could be solve.

The goal given in NASA's memorandum was to reduce tankage and, thus, airframe mass... but the biggest obstacle to SLMH ought to be, as I mentioned before, the incredible amount of effort that needs to be brought to bear to create the conditions under which it can form.

In terms of the ratio of energy input to create the fuel to energy output from the fuel's consumption, SLMH should be at a substantial disadvantage compared to more conventional cryogenic fusion fuels because of the colossal pressure requirements involved.

THAT doesn't sound like any sort of HS research, do I have the wrong number?

TM-107324 should be "Comparison of continuous-freeze slush hydrogen production"... what you found definitely doesn't sound like the correct document.

[eliakon]

That 144 page paper IS the one you are referring to. And it is about an electrically powered zero emission airplane. There are two theoretical fusion turbines that provide the electricity for the fans yes. But there is no direct fusion turbine that provides the actual thrust.

The point was that the CBFR-type engine as outlined in Section 2.2 is functionally very similar to a VF-1's thermonuclear reaction turbine's air-breathing mode. The thrust is not provided directly by the fusion reaction, but rather by an electrically-driven set of superconducting compressor stages and the waste heat from the generation process. (I'll see about posting some of the reaction engine diagrams from Macross's creators tomorrow morning for your perusal.)

The fuel cell implementations aren't too far off how the Legioss/Alpha's engines should work too.

similar. Other than the fact that the CBFR 'engine' is a closed power plant that generates electricity through a different process than the one your mentioning, to drive an air fan (I guess that is sort of like an air-compressor.....maybe), doesn't use HS, is not a turbine, and STILL doesn't work in space

I will correct my statement. There is nothing in the literature to suggest that HS can be feasibly manufactured or use.

See NASA and Rockwell's work on the X-30, which was a planned implementation of a slush hydrogen engine for space flight. I'd stress a point of distinction between your statement and the current state of research though... just because it isn't being done at commercial levels right now doesn't mean the production process isn't feasible for large-scale use if demand emerges.

It doesn't mean that it is feasible either. And since the whole POINT of HS is its increased density then anything that can use HS would seem to also be able to use SLMH (and would preferentially wish to if the choice is available)
But hey, if you have actual links to literature that supports your claim by all means post it.

Interestingly though one of the purposes of using HS was its increased density. Which would sort of suggest that SLMH would be even MORE preferable. It also had questions of if sloshing, loss of ambient pressure and excessive tank weight could be solve.

The goal given in NASA's memorandum was to reduce tankage and, thus, airframe mass... but the biggest obstacle to SLMH ought to be, as I mentioned before, the incredible amount of effort that needs to be brought to bear to create the conditions under which it can form.

A effort that is not supported though. One that I might note that right NOW applies to HS. So we are to assume that some how we can solve the effort problem with HS, but not SLMH?

In terms of the ratio of energy input to create the fuel to energy output from the fuel's consumption, SLMH should be at a substantial disadvantage compared to more conventional cryogenic fusion fuels because of the colossal pressure requirements involved.

Do you have any sort of information on the energy needs of the two production methods? Or are we just assuming that SLMH will be harder and more intensive and that all problems with HS will be solved but not ones with SLMH? Because a premise that entails the conclusion isn't a valid premise.....

THAT doesn't sound like any sort of HS research, do I have the wrong number?

TM-107324 should be "Comparison of continuous-freeze slush hydrogen production"... what you found definitely doesn't sound like the correct document.

nts.NASA.gov has no paper by that name that I can find.

[Seto Kaiba]

similar. Other than the fact that the CBFR 'engine' is a closed power plant that generates electricity through a different process than the one your mentioning, to drive an air fan (I guess that is sort of like an air-compressor.....maybe), doesn't use HS, is not a turbine, and STILL doesn't work in space

Two issues with this statement:

• Kindly refer to Section 2.4 "Hybrid Colliding Beam Fusion Reactor Aircraft Propulsion—The "Turbojet" Concept" on page 31 of NASA/CR-2005-213749, which describes the CBFR application to which I refer. A relevant quotation follows:
  

  In this concept, the CBFR is to be thought of as a (nearly) fueless burner. Ambient air is
  compressed, heated by the CBFR, expanded, and exhausted through a turbine and nozzle,
  thereby providing thrust. There are no combustion-related chemical compounds to change the
  composition of the air as it passes through the engine (the amount of nitrogen oxides that may be
  produced by heat-induced reactions of atmospheric nitrogen and oxygen may be estimated in a
  more detailed analysis).
  By using unavoidable CBFR heat to produce propulsive thrust, it is potentially possible to
  downsize the primary P/P system, which uses electric power extracted from the ends of the
  CBFR to drive motors coupled to fans that provide propulsive force.

  
  
  In principle, this implementation is very much in line with the description Macross's creators present for the functionality of the thermonuclear reaction turbine engines in Macross Journal Extra: VF-1 Valkyrie Special Edition[sup]1[/sup], Variable Fighter Master File: VF-1 Valkyrie[sup]2[/sup], Variable Fighter Master File: VF-19 Excalibur[sup]3[/sup], Variable Fighter Master File: VF-25 Messiah[sup]4[/sup], Macross Chronicle[sup]5[/sup], and so on[sup]6[/sup].
  
  
  
  
• Space propulsion-use propellant is a separate concern, as indicated in the post which began this line of inquiry, this document was cited to indicate that SLMH is not, in point of fact, necessary to produce a fusion engine with the described endurance in the RPG.

It doesn't mean that it is feasible either. And since the whole POINT of HS is its increased density then anything that can use HS would seem to also be able to use SLMH (and would preferentially wish to if the choice is available)

If it were not feasible, then it is highly doubtful that NASA and DARPA would have been considering its practical implementation in commercial aviation concepts. NASA's report can be found here.

Your assumption, of course, assumes that SLMH could be produced with equal ease and efficiency to slush or liquid hydrogen.

A effort that is not supported though. One that I might note that right NOW applies to HS. So we are to assume that some how we can solve the effort problem with HS, but not SLMH?

If the effort problem was not solvable, why was slush hydrogen the fuel of choice for single-stage-to-orbit NASA concepts and the subject of extensive testing at NASA's Lewis Research Center and Small-Scale Hydrogen Test Facility?

Do you have any sort of information on the energy needs of the two production methods? Or are we just assuming that SLMH will be harder and more intensive and that all problems with HS will be solved but not ones with SLMH? Because a premise that entails the conclusion isn't a valid premise.....

All we can do for SLMH (being that it's a purely fictional substance) is approximate based on the known conditions needed to induce metallic properties in elemental hydrogen. The details of slush hydrogen production are well-documented in NASA reports, though I can't seem to get copy-paste to work on them because they were digitized as images rather than run through OCR.

Hopefully, this link will take you right to the document. The relevant production information can be found starting at page 3-7.

The pressures necessary to induce metallic behaviors in hydrogen are, as cited here are on the order of 300-400GPa (or about 58,015,100psi, if you convert it). Assuming a perfect-world scenario of a 100% impermeable tank and a 100% efficient compressor, you're looking at about 11 billion joules per second per square inch (about 11,000MW) to compress hydrogen to a metallic state. I think it goes without saying that you don't need to bring the full output of an industrial-scale nuclear reactor to bear to create slush hydrogen, but with the energy requirements to produce the pressures involved without working in gram-level volumes with diamond anvil compression, you absolutely would need a nuclear power plant to sustain SLMH production.

(If we accept, without evidence, the notion that gravity control is used to achieve metallic hydrogen compression, that raises its own problems as those are only employed on starships powered by reflex furances, which implies a monstrous output far beyond what a nuclear reactor could produce.)

THAT doesn't sound like any sort of HS research, do I have the wrong number?

TM-107324 should be "Comparison of continuous-freeze slush hydrogen production"... what you found definitely doesn't sound like the correct document.

nts.NASA.gov has no paper by that name that I can find.

Very strange. I will check ntrs.nasa.gov and see if I can find it there.


1. Macross Journal Extra: VF-1 Valkyrie Special Edition is the original VF-1 Valkyrie tech manual produced during the original Macross series' televised run by Macross mechanical setting coordinator Masahiro Chiba. The relevant description and diagrams may be found on pages 39-44.

2. Pages 079-080 of Vol.1.

3. Pages 037-039.

4. Pages 037-039, 58-61.

5. Technology Sheet 01H "Variable Fighter: Engines and Cockpits" in both 1st and 2nd Edition.

6. See also, Great Mechanics.DX 9 pg38, This is Animation Special: Macross Plus "Variable Fighter's Aero Report" pg66-67.

[eliakon]

similar. Other than the fact that the CBFR 'engine' is a closed power plant that generates electricity through a different process than the one your mentioning, to drive an air fan (I guess that is sort of like an air-compressor.....maybe), doesn't use HS, is not a turbine, and STILL doesn't work in space

Two issues with this statement:

• Kindly refer to Section 2.4 "Hybrid Colliding Beam Fusion Reactor Aircraft Propulsion—The "Turbojet" Concept" on page 31 of NASA/CR-2005-213749, which describes the CBFR application to which I refer. A relevant quotation follows:
  

  In this concept, the CBFR is to be thought of as a (nearly) fueless burner. Ambient air is
  compressed, heated by the CBFR, expanded, and exhausted through a turbine and nozzle,
  thereby providing thrust. There are no combustion-related chemical compounds to change the
  composition of the air as it passes through the engine (the amount of nitrogen oxides that may be
  produced by heat-induced reactions of atmospheric nitrogen and oxygen may be estimated in a
  more detailed analysis).
  By using unavoidable CBFR heat to produce propulsive thrust, it is potentially possible to
  downsize the primary P/P system, which uses electric power extracted from the ends of the
  CBFR to drive motors coupled to fans that provide propulsive force.

  
  
  In principle, this implementation is very much in line with the description Macross's creators present for the functionality of the thermonuclear reaction turbine engines in Macross Journal Extra: VF-1 Valkyrie Special Edition[sup]1[/sup], Variable Fighter Master File: VF-1 Valkyrie[sup]2[/sup], Variable Fighter Master File: VF-19 Excalibur[sup]3[/sup], Variable Fighter Master File: VF-25 Messiah[sup]4[/sup], Macross Chronicle[sup]5[/sup], and so on[sup]6[/sup].

Like I said, its not a turbine, and is only vaguely like the described engine. And far FAR more importantly its fuel ratings, and thrust ratings are massively smaller. To get to the levels described in the show and OSM you are required to invoke handwave level improvements. Improvements that then take it off of "based on a theoretical device" to "technobabble that uses existing science for the buzzwords". At that point its sort of a stretch to claim that it is 'more realistic' than any other technobabble based non-realistic system.

Space propulsion-use propellant is a separate concern, as indicated in the post which began this line of inquiry, this document was cited to indicate that SLMH is not, in point of fact, necessary to produce a fusion engine with the described endurance in the RPG.

Nothing is necessary to produce the described engine, and the described engine can not realistically exist. It comes down to a choice of which non-realistic system to use. SLHM was selected AFAIK because it provides the highest energy density of fusion fuels as well as the greatest amount of remass. It is for these reasons that it is the preferential fuel.

It doesn't mean that it is feasible either. And since the whole POINT of HS is its increased density then anything that can use HS would seem to also be able to use SLMH (and would preferentially wish to if the choice is available)

If it were not feasible, then it is highly doubtful that NASA and DARPA would have been considering its practical implementation in commercial aviation concepts. NASA's report can be found here.

Your assumption, of course, assumes that SLMH could be produced with equal ease and efficiency to slush or liquid hydrogen.

My assumption is that we have literally NOTHING to go on for the ease or efficiency of EITHER fuel. meaning that speculation on the relative merits of their production is quite literally simply dueling opinions as there are zero facts to support either stance.

A effort that is not supported though. One that I might note that right NOW applies to HS. So we are to assume that some how we can solve the effort problem with HS, but not SLMH?

If the effort problem was not solvable, why was slush hydrogen the fuel of choice for single-stage-to-orbit NASA concepts and the subject of extensive testing at NASA's Lewis Research Center and Small-Scale Hydrogen Test Facility?

Easy the abstracts themselves answer this question. HS>LH(Liquid Hydrogen)>HG (Hydrogen Gas) for energy density. However since SLMH>HS if it were possible to make SLMH in our world it would also be being looked at as a fuel. This is infact why MH is the subject of research, because it would make a great fuel, if we could just get it. Since the RT material establishes that they can make SLMH (unless we are going to claim that the canon RT material is wrong, in which case there is no way to have a fruitful rational discussion about RT) then it would follow that they would use the highest energy density fuel as that is the reason that HS is being investigated in the first place. HS is not being investigated because it is HS, it is investigated since it has a higher energy density than LH, or HG

Do you have any sort of information on the energy needs of the two production methods? Or are we just assuming that SLMH will be harder and more intensive and that all problems with HS will be solved but not ones with SLMH? Because a premise that entails the conclusion isn't a valid premise.....

All we can do for SLMH (being that it's a purely fictional substance) is approximate based on the known conditions needed to induce metallic properties in elemental hydrogen. The details of slush hydrogen production are well-documented in NASA reports, though I can't seem to get copy-paste to work on them because they were digitized as images rather than run through OCR.

Hopefully, this link will take you right to the document. The relevant production information can be found starting at page 3-7.

The pressures necessary to induce metallic behaviors in hydrogen are, as cited here are on the order of 300-400GPa (or about 58,015,100psi, if you convert it). Assuming a perfect-world scenario of a 100% impermeable tank and a 100% efficient compressor, you're looking at about 11 billion joules per second per square inch (about 11,000MW) to compress hydrogen to a metallic state. I think it goes without saying that you don't need to bring the full output of an industrial-scale nuclear reactor to bear to create slush hydrogen, but with the energy requirements to produce the pressures involved without working in gram-level volumes with diamond anvil compression, you absolutely would need a nuclear power plant to sustain SLMH production.

(If we accept, without evidence, the notion that gravity control is used to achieve metallic hydrogen compression, that raises its own problems as those are only employed on starships powered by reflex furances, which implies a monstrous output far beyond what a nuclear reactor could produce.)

So short answer is "no there is nothing whatsoever to allow us to make any judgment on the relative merits of the production, or the required infrastructure."
I would also add that if the gravity systems that are used are found on spaceships.....then that would be a plausible reason for ship based SLMH production. I mean if you already have the gravity controls....
I would also point out that we don't know the power needs of the gravity system, simply that they are found on spaceships with Reflex Furneces. There are light bulbs on those ships too, that does not mean that the light bulbs on the SDF-1 are special super power draining ones that can only be run off of Reflex Furnaces....

THAT doesn't sound like any sort of HS research, do I have the wrong number?

TM-107324 should be "Comparison of continuous-freeze slush hydrogen production"... what you found definitely doesn't sound like the correct document.

nts.NASA.gov has no paper by that name that I can find.

Very strange. I will check ntrs.nasa.gov and see if I can find it there.

No problem, you find it and I will be happy to read it

1. Macross Journal Extra: VF-1 Valkyrie Special Edition is the original VF-1 Valkyrie tech manual produced during the original Macross series' televised run by Macross mechanical setting coordinator Masahiro Chiba. The relevant description and diagrams may be found on pages 39-44.

2. Pages 079-080 of Vol.1.

3. Pages 037-039.

4. Pages 037-039, 58-61.

5. Technology Sheet 01H "Variable Fighter: Engines and Cockpits" in both 1st and 2nd Edition.

6. See also, Great Mechanics.DX 9 pg38, This is Animation Special: Macross Plus "Variable Fighter's Aero Report" pg66-67.

I will check this out as well.