Mospeada's HBT Canister Contents are...

[ShadowLogan]

Just what is in the fuel canisters the various human mecha use in Genesis Climber Mospeada contain?

From supporting source material the answer is hydrogen given the various mecha use Fuel Cells. But what state is that hydrogen stored in? Compressed Gas, Cyrogenic Liquid/Slush, Liquid Metallic Hydrogen (SLMH), compound (methane, amonia, etc)?

Using the following Data from Source Materials (as listed on Gears Online website):
-VR-052 has a 98HP engine for 30minutes in Armor Mode or 103.6minutes in Bike Mode (assuming maximum distance, 380km at maximum speed of 220kph) on 1 HBT Cell
-VR-038 has a 83HP engine for 20minutes in Armor Mode or 90minutes in Bike Mode (assuming maximum distance, 300km at maximum speed of 200kph) on 1 HBT Cell
-VR-041 has a 88HP engine for 22minutes in Armor Mode or 90minutes in Bike Mode (assuming maximum distance, 300km at maximum speed of 200kph) on 1 HBT Cell
-HBT Cell in Mospeada lineart can be measured to have a volume of 4.0225L (for simplicity lets call it 4L even, though not all of this is technically available), researching the MPC Cyclone/Mospeada product that has a removable HBT/PC canister shows it to go all the way through the cavity (which is what I assume here, I don't have the MPC with this feature). NOTE: 4 Liters is idealized volume, the canister itself might be physically smaller or hold less depending on material thickness.

And one link on real world fuel cell consumption rate for a given output (https://fuelcellstore.com/fuel-cell-facts#faq19, after doing some unit conversion it works out to 1.33x10^-5kg/L per shp). I am going to assume this applies to the GCM mecha along with Horsepower unit is taken to be Metric Horsepower not imperial horsepower (all other measurements are in metric which makes me think this is the case). I am also assuming the Oxygen Supply is stored independently of the HBT Cell (you need 8x the mass of each unit of hydrogen) due to the practical realities of storage (see Spoiler #1) and results later.

Spoiler:

Assuming 4L split with no loss in volume to account for canister thickness and separate tanks for each and storing oxygen in liquid state (LOX):
-Liquid Hydrogen 0.189kg w/1.512kg of LOX
-Slush Hydrogen 0.213kg w/1.704kg of LOX
-Liquid Metallic Hydrogen 0.488kg w/3.904kg of LOX

Based on extrapolated data from source material and the link on fuel cell consumption rate the canister holds the listed amount of hydrogen needed, density is also calculated assuming a 4L canister:
-VR-052: Bike (8.13kg, 2.033kg/L) Armor (2.35kg, 0.589kg/L)
-VR-038: Bike (5.98kg, 1.495kg/L) Armor (1.33kg, 0.332kg/L)
-VR-041: Bike (6.34kg, 1.586kg/L) Armor (1.55kg, 0.388kg/L)

The numbers are not consistent, but we can safely ignore the Bike Mode numbers as it would not be using full power to maintain maximum speed. The variance in Armor mode given the uniform tank size means the units are not as fuel efficient. This means we use the data from the VR-052 in Armor mode to establish a minimum amount of hydrogen in the canister that would apply to all mecha. It is possible the website is in error, the only confirmation I could find elsewhere is for the VR-38, so I will be listing that one as well.

Hydrogen Density and Phases:
-Cryogenic Liquid Hydrogen: 0.071kg/L
-Cryogenic Slush Hydrogen: 0.085kg/L
-Cryogenic Liquid Methane: 0.424kg/L (~42.62% of the mass is hydrogen)
-Liquid Ammonia: 0.6826kg/L (~48.48% of the mass is hydrogen)
-Liquid Metallic Hydrogen: 0.850kg/L (note the exact density is not known, the value might be slightly higher)

The only real viable candidate on the list is Liquid Metallic Hydrogen (the 4L canister could hold 3.4kg of the stuff). There is of course margin to account for the thickness of the container. Methane and Ammonia appear to be close contenders, but they require an extra step to extract the hydrogen AND not all of the mass is H2. Other hydrogen rich substances also exist, but will run into the same issues as the Methane and Ammonia.

Based on the VR-052 HBT Canister's implied mass and it does not waste any fuel (compared to the VR-052) then at maximum power the Legois-H/I's JG-97M engines have an operating time of 12.78minutes (Legois-Z is 11.47minutes), and assuming a Palladium RPG Cell Count for the Tlead's RT counterpart the Tlead would operate for 23.06minutes.

If the VR-038 is used in its place times the above changes to 7.22min (H/I), 6.48min (Z), 13.02min (Tlead).

If you want to see how the space stats stack up...

Spoiler:

The Delta-V of the Legois and Tlead is a bit more difficult to pin down, assuming the fuel cell waste (ie water) is the reaction mass and it can use that for the full duration to generate thrust, the Legois-H/I has 21.11kps or 8.56kps and the Legois-Z has 20.71 or 8.16kps with the Tlead having 16.69/10.21kps or 0.91/0.56kps (Tlead lists solo first and then with Legois) depending on which engines can generate thrust in space (JG plus ATF or just ATF). Depending on Stig's destination in Ep25 the Cell count might need to be raised on the Tlead (in GCM). All Delta-Vs assume a Dry configuration.

Delta-V assuming the VR-38HBT mass would be 11.97kps or 4.85kps (H/I), 11.75kps or 4.63kps (Z), or 9.47/5.8kps or 0.52kps/0.32kps (Tlead).

[taalismn]

Just what is in the fuel canisters the various human mecha use in Genesis Climber Mospeada contain? ]

Extra Spicy Guacamole.
Greater energy density than Angelo Dante's mother's fruitcake(a substance belated classified by the GMP as a 'chemical explosive' and described by Louie Nichols as having 'more potential chemical energy than an equal weight of solid rocket fuel')

[Seto Kaiba]

Just what is in the fuel canisters the various human mecha use in Genesis Climber Mospeada contain?

So... in Artmic's 1987 artbook Artmic Design Works, there's a marginal note by mechanical designer Hideki Kakinuma that describes HBT as 複合水素燃料 ("compound hydrogen fuel") and relates an anecdote about a university research group that was working on a similar technology contacting the production. The term used, and the time period for the anecdote, strongly suggest that the HBT canisters actually contain an advanced saturated hydrocarbon compound used for high-density liquid state hydrogen storage at room temperature similar to methylcyclohexane.

Not coincidentally, the endurance of one Type-3 HBT canister in a VR-052 MOSPEADA is only a little bit better than the maximum driving range of the real-world motorbike the MOSPEADA was modeled on... the 1982 Suzuki GSX 1100 S Katana (which got about 350km per 22L tank of 87 octane). If the energy content of the Type-3 canister is similar to that tank of gasoline, that's about 704MJ or the energy of 20.4L of JP-8 jet fuel per canister. That would mean 16 canisters would contain the energy of approximately 326.4L of JP-8. The AFC-01 Legioss's turbines must be about 5x as efficient as a Ride Armor's turbine, since a smallish modern jet fighter normally carries around 1,700L of fuel internally (not counting drop tanks).

[ShadowLogan]

If the Legoiss is x5 more efficient than the Ride Armor, and JP-8 fuel is the standard... JP-8 is a kerosene fuel, RP-1 rocket fuel is a kerosene type and x5 the efficiency of that would put it in SLMH territory (based on Specific Impulse, which is a measure of efficiency). 1500s in vacuum (=5x the ~300sec in vacuum for RP-1), a bit less than the 1700sec SLMH can do. SLMH production is theorized to be easier if the SLMH is not pure and has some other material with it, which could explain the drop in ISP (I forget off hand if SLMH like this is considered a compound or a mixture).

[Seto Kaiba]

If the Legoiss is x5 more efficient than the Ride Armor, and JP-8 fuel is the standard...

That's just some back-of-the-envelope estimate math by me to approximate the amount of energy needed to equal the internally-carried fuel of the smallest modern fighter in service when the show was made. I wouldn't advise taking it entirely seriously, in no small part because the executive meddling by the original MOSPEADA's toy partner forced the Legioss Armo-Fighter into a more prominent role than it was ever intended to occupy. Having originally been intended to be a borderline background mecha used mainly in the first episode and series finale, it wasn't fleshed out at anything close to the level of detail the Ride Armors were. 326L of JP-8 - less than 1/5th of a tank - would only get 'em around 800-900km tops between refuelings.

I picked JP-8 partly because it's a multipurpose fuel used by aircraft, tactical ground vehicles, and even stationary generators... and because I happen to know its volumetric energy density offhand, as it was the grade of fuel used by the Stonewell/Bellcom/Northrop VF-0 Phoenix in Macross Zero.

[ShadowLogan]

I'm not taking it seriously. All I am saying is that JP-8 is a Kerosene fuel, and in rocket applications SLMH is x5 more efficient than Kerosene. What ever the Alpha and Beta have for propulsion it is far more efficient than SLMH (assuming Fuel Cell byproduct is used to provide maximum thrust for the full operating time, the specific value depends on just which engines can actually produce thrust in space).