Metallic Hydrogen is real and it would make a very powerful rocket fuel

Flyaway

Flyaway

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It was predicted that metallic hydrogen might be a metastable material so that it remains metallic when pressure is released. Experimental pressures achieved on hydrogen have been more than an order of magnitude higher than the predicted transition pressure and yet it remains an insulator. Tthe applications of metastable metallic hydrogen to rocketry. Metastable metallic hydrogen would be a very light-weight, low volume, powerful rocket propellant. One of the characteristics of a propellant is its specific impulse, Isp . Liquid (molecular) hydrogen-oxygen used in modern rockets has an Isp of ~460s; metallic hydrogen has a theoretical Isp of 1700 s! Detailed analysis shows that such a fuel would allow single-stage rockets to enter into orbit or carry economical payloads to the moon. If pure metallic hydrogen is used as a propellant, the reaction chamber temperature is calculated to be greater than 6000 K, too high for currently known rocket engine materials. By diluting metallic hydrogen with liquid hydrogen or water, the reaction temperature can be reduced, yet there is still a significant performance improvement for the diluted mixture.
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Nah! Monatomic hydrogen will get you to Saturn.
 
CNH said:
Nah! Monatomic hydrogen will get you to Saturn.
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yah, the USAF manage to store Monatomic hydrogen pebbles in liquid Helium
but no one manage to build a rocket engine on that concept.!

more interesting is that Metallic Hydrogen they created and Store it Lyman Laboratory of Physics at Harvard University.
If they manage to keep it Metastable, means it remind a Metal at room temperature at one atmosphere pressure
we got finally a Superconductor, Superexplosive and Super Rocket propellant with 216 Mega Joules/kg
some engineers believe Metallic Hydrogen could be used as construction material, 7 time stronger as Steel with density similar of water

back to Super Rocket propellant
Metallic Hydrogen would have specific impulse of 1700 sec (Lox/Hydrogen chemical 480 sec, Hydrogen nuclear heated 800 sec)
If Musk "Interplanetary Transport System" use Metallic Hydrogen instead Oxygen/Methane engines
he only need the second stage for reaching any destination in Solarsystem as Single Stage To Orbit !
 
Michel Van said:
some engineers believe Metallic Hydrogen could be used as construction material, 7 time stronger as Steel with density similar of water
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Wouldn't the mechanical energy required to form the material cause the material to spontaneously revert to it's gaseous state? What is the mechanism holding the atoms together into a solid at room temperature?
 
The claim is that metallic hydrogen is metastable -- meaning that the bond energy is strong enough to hold the material together after pressure is released. It's not exactly unprecedented -- the cited example of diamond is only one of many materials that can find a stable state that they remain in after being subjected to intense pressure and then released.

OTOH, utility as a construction material and as a rocket fuel seem mutually exclusive. Either it has a high energy density that can be easily liberated (in which case, it would be like making a bridge out of dynamite) or it can't easily liberate its energy (in which case, it's a very expensive and maybe somewhat lighter substitute for composite structures).

And of course, there's very conflicting research on whether it really is metastable at all. Whatever they've made so far exists in only very small samples -- extrapolating to macro-scale structural use seems very premature.
 
TomS said:
The claim is that metallic hydrogen is metastable -- meaning that the bond energy is strong enough to hold the material together after pressure is released. It's not exactly unprecedented -- the cited example of diamond is only one of many materials that can find a stable state that they remain in after being subjected to intense pressure and then released.

OTOH, utility as a construction material and as a rocket fuel seem mutually exclusive. Either it has a high energy density that can be easily liberated (in which case, it would be like making a bridge out of dynamite) or it can't easily liberate its energy (in which case, it's a very expensive and maybe somewhat lighter substitute for composite structures).

And of course, there's very conflicting research on whether it really is metastable at all. Whatever they've made so far exists in only very small samples -- extrapolating to macro-scale structural use seems very premature.
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Hopefully, it will be possible to create metallic hydrogen alloys, that are much less likely to go boom.
 
Must wonder if metallic Hydrogen formation needs to be 'seeded' per synthetic diamonds etc...

Like yet-elusive ambient superconductors, a really good trick if it works.
 
Another problem with metallic and monatomic hydrogen is that their exhaust temperatures exceed what any nozzle can handle. A 15% mix with regular hydrogen is about the best they can manage.
 
Jacketed thrust if you will…maybe that and an ablative nozzle?

I wonder if it could be used structurally somehow…strap-on attachments flash away as steam to cut debris down…
 
The issue isn't trying find the highest ISP or thrust but the best ISP or thrust for the dollar
 

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