Hydrogen ISP is still king by a significant margin, but ISP isn’t the whole story – hydrogen comes with additional tank weight (due to lower density) and storage issues (pesky molecular size…). So that trade-off for ISP only really makes sense for an upper stage like Centaur. I’m not sure it makes sense for New Shepherd even…
Production, consumption, electrolyzer efficiency limits and capital cost, storage problems, fueling problems, transportation problems, pretty much every aspect of this stuff makes it terrible for use as a vehicle fuel. All green hydrogen efforts should be focused on fertilizer production before anything else.
It would’ve been a great transition from fossil fuel, had we embraced it before EV tech was consumer ready. Now it’s just a step backward.
Hydrogen was never and will never be a viable and efficient transportation fuel
Special exception maybe for aviation and rocketry. But even then, methane (if made using green energy and the Sebatier process).
You can get comparable isp with methalox engines without any of the weight required to keep the hydrogen inside the rocket, right?
Hydrogen ISP is still king by a significant margin, but ISP isn’t the whole story – hydrogen comes with additional tank weight (due to lower density) and storage issues (pesky molecular size…). So that trade-off for ISP only really makes sense for an upper stage like Centaur. I’m not sure it makes sense for New Shepherd even…
Why do you think that? The fuel production side or the fuel consumption side?
Production, consumption, electrolyzer efficiency limits and capital cost, storage problems, fueling problems, transportation problems, pretty much every aspect of this stuff makes it terrible for use as a vehicle fuel. All green hydrogen efforts should be focused on fertilizer production before anything else.