The holy grail of cheap acesses to space & single-stage may have been found

[nec207]

Atomic metallic hydrogen, if metastable at ambient pressure and temperature could be used as the most powerful chemical rocket fuel, as the atoms recombine to form molecular hydrogen. This light-weight high-energy density material would revolutionize rocketry, allowing single-stage rockets to enter orbit and chemically fueled rockets to explore our solar system. To transform solid molecular hydrogen to metallic hydrogen requires extreme high pressures, but has not yet been accomplished in the laboratory. In the proposed new approach electrons will be injected into solid hydrogen with the objective of lowering the critical pressure for transformation. If successful the metastability properties of hydrogen will be studied. This new approach may scale down the pressures needed to produce this potentially revolutionary rocket propellant.

- Wigner and Huntington first predicted that pressures of order 25 GPa were required for the transition of solid molecular hydrogen to the atomic metallic phase. Later 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. We discuss the 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.


Read more here http://www.planettechnews.com/science/item945

[Eric Hedman]

Interesting, but I'll bet there are plenty of things to work out before this proves to be viable.  Definitely worth following.

[kkattula]

I think the title of this thread should end in 'has been wildly speculated about' instead of may have been found.

The only people to have actually made metallic hydrogen, found at room temperature it started transforming at 200 GPA but became fully metallic at 260-270 GPA. It then remained metallic back down to 200 GPA. That's your metastatic region.  http://www.nature.com/nmat/journal/v10/n12/full/nmat3175.html


Cooling doesn't help, it actually prevents metallization through at least 300 GPA.

So who want's to build a rocket with tanks pressurized to at least 2 million atmospheres (30 million PSI)? That may detonte like a small atomic bomb if a stray cosmic ray passes through?

[Moe Grills]

Atomic metallic hydrogen, if metastable at ambient pressure and temperature could be used as the most powerful chemical rocket fuel, as the atoms recombine to form molecular hydrogen. This light-weight high-energy density material would revolutionize rocketry, allowing single-stage rockets to enter orbit and chemically fueled rockets to explore our solar system. To transform solid molecular hydrogen to metallic hydrogen requires extreme high pressures, but has not yet been accomplished in the laboratory. In the proposed new approach electrons will be injected into solid hydrogen with the objective of lowering the critical pressure for transformation. If successful the metastability properties of hydrogen will be studied. This new approach may scale down the pressures needed to produce this potentially revolutionary rocket propellant.

- Wigner and Huntington first predicted that pressures of order 25 GPa were required for the transition of solid molecular hydrogen to the atomic metallic phase. Later 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. We discuss the 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.


Read more here http://www.planettechnews.com/science/item945

  It's probably easier to fuse hydrogen protons together with a device built in your garage to generate fusion energy than it is to compress
large numbers of hydrogen atoms to form a (questionably) stable solid form for hardware purposes.

[JohnFornaro]

NIAC just awarded a contract to a group studying this.

[Tass]

I think the title of this thread should end in 'has been wildly speculated about' instead of may have been found.

Yes.

And where is the news? It has been wildly speculated about for a long time, and it is no closer to being a reality.

[go4mars]

Polymeric nitrogen is just as close.  Not holding my breath.

[nec207]

From what I understand they found new type of hydrogen that is most powerful chemical rocket fuel ever found that will lower allow cheap acesses to space & single-stage .

Not sure what the mix up is over it here.

[go4mars]

From what I understand they found new type of hydrogen that is most powerful chemical rocket fuel ever found that will lower allow cheap acesses to space & single-stage .

Not sure what the mix up is over it here.

  Google how much pressure a GigaPascal is. 

It isn't like you can build a diamond anvil big enough.  And even if you could, dragging it to orbit through the controlled release of that pressure would more than offset its potency. 

Needs a light-weight method of containing the immense pressure.  That's the (main) problem.

[93143]

No, the main problem is that we're not sure if it can be metastable at pressures low enough for use in a rocket.  And if so, how much of a disturbance would be required to kick it out of the stability region.

200 GPa is a non-starter.

[go4mars]

No, the main problem is that we're not sure if it can be metastable at pressures low enough for use in a rocket.

No, we're pretty sure that it can't.  Hence the biggest problem is:

It isn't like you can build a diamond anvil big enough.

Though I would be happy to be educated to your point of view if you think I'm wrong.  I did a lot of reading related to the potential for metastability of polymeric nitrogen (nitrogen diamond) and a little reading about this hydrogen option a few years ago.  My impression then, which hasn't yet changed, is that we are pretty sure it can't be stable at low pressures (like carbon diamond).

And if so, how much of a disturbance would be required to kick it out of the stability region.

And even if you could, dragging it to orbit through the controlled release of that pressure would more than offset its potency. 

I think we are agreeing there (though I'll admit that your description is much more technically accurate). 

[93143]

No, the main problem is that we're not sure if it can be metastable at pressures low enough for use in a rocket.

No, we're pretty sure that it can't.

We're a lot more sure that we can't build a flight-weight pressure vessel to take 200 GPa.  Even hyperdiamond or multi-wall carbon nanotubes won't do it.

Just because one study found reversion at 200 GPa and 295 K doesn't mean there isn't a way to keep it metallic at ambient conditions.  Other studies have found different behaviour at different temperatures, and any path dependence is very poorly quantified at this time due to lack of observations.

[nec207]

From what I understand they found new type of hydrogen that is most powerful chemical rocket fuel ever found that will lower allow cheap acesses to space & single-stage .

Not sure what the mix up is over it here.

  Google how much pressure a GigaPascal is. 

It isn't like you can build a diamond anvil big enough.  And even if you could, dragging it to orbit through the controlled release of that pressure would more than offset its potency. 

Needs a light-weight method of containing the immense pressure.  That's the (main) problem.

What is problem with pressure ? Is this type of hydrogen under too much  pressure that it is a safety problem?

Have they done this in science lab ?


And how much cheaper with  this be than what they are using now ?

[e of pi]

The problem with pressure is the stresses it places on materials. Say you want to build the pressure vessel to contain this 200 GPa pressure out of carbon fiber that has a maximum stress of 6.3 GPa (just going off of a wikipedia table for the fiber only, the actual laid up material would be weaker). In order to keep material stresses below yield in a tank with a diameter of 5 m, you'd need a tank 6.25 cm thick. For a metal like steel or aluminum, the maximum stress is going to be an order of magnitude or so lower, and thus the walls another order of magnitude thicker.

And yeah, if that pressure vessel failed...it'd be a bad day all around.

[go4mars]

What is problem with pressure ? Is this type of hydrogen under too much  pressure that it is a safety problem?

200 GigaPascal's is 29 million pounds per square inch. 

Have they done this in science lab ?

Yes.  But the equipment is relatively heavy (and small scale), and controlled extraction of energy at those pressures (in this context) hasn't been done (to my knowledge).