Topic: Room temperature superconductor?

[Nemesis]

Link to full article

Instead of super-cooling the material, as is necessary for conventional superconductors, the new material is instead super-compressed. The researchers claim that the new material could sidestep the cooling requirement, thereby enabling superconducting wires that work at room temperature.

"If you put hydrogen compounds under enough pressure, you can get superconductivity," said professor John Tse of the University of Saskatchewan. "These new superconductors can be operated at higher temperatures, perhaps without a refrigerant."

A little light on details unfortunately.

Some questions come to mind:

1/ Is this theory or has it actually done?
2/ is it created at high pressure or does it need to be maintained at those pressures?

A very different question:

3/ If you pressurize hydrogen to the point that it becomes a super conductor according to theory it would also boost its efficiency as a rocket fuel 5x.  How would this substance perform as a rocket fuel?

[Tus-XC]

answer to 3)  The performance will be the same in reality (if there is some theory on this point me to it... I would like to understand more), it just be more efficient to store i would imagine (if i'm not mistaken H2 takes up most of the room in that external fuel tank on the shuttle).

Some info on rocket efficiency (we measure this as ISP... sorta like miles per gallon),  it is determined by:

Nozzle efficiency
Nozzle exit pressure
Combustion chamber pressure
Ambient pressure (alt dependent, higher you go, the more effecient you get)
Isentropic properties (ratio of specific heats)
Nozzle expansion ratio
Flame temerature
Molecular mass
combustion efficiency

[marstone]

answer to 3)  The performance will be the same in reality (if there is some theory on this point me to it... I would like to understand more), it just be more efficient to store i would imagine (if i'm not mistaken H2 takes up most of the room in that external fuel tank on the shuttle).

Some info on rocket efficiency (we measure this as ISP... sorta like miles per gallon),  it is determined by:

Nozzle efficiency
Nozzle exit pressure
Combustion chamber pressure
Ambient pressure (alt dependent, higher you go, the more effecient you get)
Isentropic properties (ratio of specific heats)
Nozzle expansion ratio
Flame temerature
Molecular mass
combustion efficiency

Will have to agree here, high pressure should only increase storage area (as it will still burn with the same power), but you would still run into weight problems for take off.  Now if you could compress Hydrogen into a solid, it would make a great storage medium for long distance space flights if you load the fuel in space (you still have to deal with the mass, but that is easier in space also).  Long range flights could be done without a fuel tank the size of Cuba.

[Nemesis]

The theoretical increase in the performance of super conducting hydrogen is not due to being pressurized it is due to the different state the atoms would be in changing the reaction.  The theories have it that solid hydrogen would be stable at room temperature and pressure and perform as a super conductor at those temperatures and pressures. 

Whether a larger more complex molecule such as the one in the article achieves super conducting the same way and changes its chemical reaction in a similar manner resulting in increased specific impulse is something I don't know.  If the answer is yes and the pressure is low enough then it is possible that this could be a much more powerful rocket fuel.    If it does then there are likely other materials that are both super conducting and would be superiour rocket fuel. 

If this is a more powerful fuel it could still be undesirable.  I would imagine that part of the exhaust would be SiO₂ which is probably not something we want to put into the air.  In that case it might still be usable in space such as for changing orbits and lunar landing/launch.

[Tus-XC]

Hmm... well i suspect the ISP might actually decrease then... we aren't talking pure h2 and pure o2... part of the calculation takes into account molecular mass.  I would also have to see how this affected the reaction... my instinct tells me that the effiency comes from the fact that its solid and thus we can store more of it... but thats my guess really.

[Nemesis]

In the case of the Hydrogen super conductor as I recall it actually becomes (even while still fluid) a crystal of H₁ atoms not H₂. That might be what makes it more powerful as a fuel, you don't have to break the H₂ apart then form the H₂O as the H₁ is already in a monomolecular state.  (I've been thinking of this and remembered more of the details.)  In this state the Hydrogen becomes a metal.

It definitely has nothing to do with storing it in a more compact form.  The specific impulse (ISP) goes up and that would not increase just by burning more fuel.  An Ion drive has a ISP of 2000+ compared to the Shuttles main engine of ~460 and the shuttle uses far more reaction mass, just less efficiently.

[Tus-XC]

sorry, i when i was referin to storin i wasn't referin to ISP anymore, just refeirn to the fact we are decreasing the amount of inert mass on the rocket by increasing the amount of fuel... which is a good thing.  If in fact its h1 then that means we could have some 0H- as some of the products... so that would be good. , not sure how much though.  Granted ISP is not the end all be all (ion engines have really freakin high ISPs but no thrust) but when we are talkin makin a rocket 5x more effecient that is the first area i think of.

[Nemesis]

sorry, i when i was referin to storin i wasn't referin to ISP anymore, just refeirn to the fact we are decreasing the amount of inert mass on the rocket by increasing the amount of fuel... which is a good thing.  If in fact its h1 then that means we could have some 0H- as some of the products... so that would be good. , not sure how much though.  Granted ISP is not the end all be all (ion engines have really freakin high ISPs but no thrust) but when we are talkin makin a rocket 5x more effecient that is the first area i think of.

Ion drives have an ISP of 2000+.  If metallic hydrogen could replace the Liquid H₂ on the shuttle engine and multilply its ISP of 460  by 5 times that would be an ISP of 2300 which is in the Ion drive range.  It would combine the ISP of an Ion drive with the acceleration of a rocket, the best of both worlds.  If the LOX was replaced with liquid cyclic ozone the ISP would be increased by a further 1.3x (2990).  Assuming those 2 fuels were cheap enough that would give single stage to orbit and make a trip to Mars a matter of weeks if not days.