11 thoughts on “Rocket Propellant From Water”

  1. “water is an energy carrier”

    The columnist’s ignorance is amazing. No, it’s not an “energy carrier”. It’s a cheap (in terms of tankage) way to carry propellant at low cost IF there’s an energy source.

    1. So the idea is to split the H2 from the O then recombine them? Yeah, that would work, but wouldn’t that be very inefficient?

      How is this better than sending up LH & LOX and combining them?

      2. Cryogenic liquids are subject to boiloff. Also, liquid water is more than twice as dense as the same ratio of elements in their separate cryogenic liquid states.

  2. You are so right about it being over hyped Rand. Even Bush stupidly called for a hydrogen economy.

    Water is easy to store, but converting it to fuel costs energy.

    Perhaps they hope to make the loss up in volume (sounds like Pelosi logic.)

    1. We’re actually surprisingly close to the point where the cheapest way to make hydrogen in some markets, like the Persian Gulf, will be via electrolysis with PV electricity. A recent utility-scale solar bid there came in at $.242/kWh. Natural gas would have to be below $3/million BTU to be competitive with that as a feedstock for making hydrogen. Some gulf states have been importing LNG from the US recently (!), so it’s no longer the case NG is overabundant there. This is why there’s been a lot of solar being installed in that area to displace (or instead of adding) NG-fired generating capacity.

  3. The question is why not use solar-electric with an ion drive instead of this. It’s not like xenon is the only thing you can use in an ion drive. as reaction mass…

    I think solar-thermal with H2 has better chances than this.

    1. The advantage of chemical propellants is they are also energy stores. Their energy content can be released in a short period. If you are maneuvering near massive objects this is a significant advantage, as the energy change is maximized if impulse is delivered deep in a gravity well.

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