3 ms·

In the process that would likely be used the CO2 would be sourced from the atmosphere. https://en.wikipedia.org/wiki/Sabatier_reaction https://en.wikipedia.org

• sandworm101 6y ago
  Ya, but that isn't happening. Look at where liquid hydrogen for rockets is sourced. It could be made from water. In reality, it is made from hydrocarbons because that is cheaper. And even if CO2 is pulled from the air, a huge amount of energy is need to compress/store that rocket fuel, energy that could be put to far better uses. Instead of launching a passenger rocket to london, I'd rather divert that energy into shutting a coal-fired powerplant for a week or two. Once all those powerplants are shut, then we should look at passenger rocket services.
  • emilecantin 6y ago
    I don't doubt you're right for most existing rockets, but I think the main difference here is that SpaceX has every reason to test the hell out of their propellant-producing appliances here on Earth, even if it's not economical at the beginning. They depend on these appliances working perfectly on Mars for the return trip, so they need to be _very_ reliable.
  • ben_w 6y ago
    If these vehicles were from anyone besides a company whose explicit goal is to develop an interplanetary colony ship whose duty cycle will require the launch infrastructure on the other planet to convert atmospheric CO2 into methane using solar power, I’d agree — it hasn’t been done, it’s not economical to do it that way yet. But Musk needs this process to become economical so that Mars can become economical. (The same tech may, ironically given Tesla, compete with batteries for the energy storage PV calls for).