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LOX/RP1 is pretty awful for the environment - space-flight is by no-means eco-friendly (I suppose apart from the Space-shuttle main-engines)

by iab 5y ago

garmaine 5y ago
Notably SoaceX doesn’t use RP1 for Starship, and is aiming for a carbon neutral fuel source.
- PaulHoule 5y ago
  New Shepard uses hydrogen + oxygen which could be produced without CO2 emissions. It's relatively straightforward to synthesize methane (Starship fuel) from a stream of carbon monoxide and hydrogen. In the past people got the carbon monoxide from pyrolysis of coal https://netl.doe.gov/research/Coal/energy-systems/gasification/gasifipedia/great-plains https://netl.doe.gov/research/Coal/energy-systems/gasificati... but today people are doing it with carbon dioxide extracted from the air or from another combustion process. You could make RP1, Jet Fuels, and other hydrocarbons this way too https://www.netl.doe.gov/research/coal/energy-systems/gasification/gasifipedia/ftsynthesis https://www.netl.doe.gov/research/coal/energy-systems/gasifi... but the chemistry is tricky because the reactions that break chains down to methane or build them up to polyethylene will run quickly except when conditions are balanced on a knife edge... One where the reaction rates aren't too high and amount of product you get for the size of the machine is not good.
  - winternett 5y ago
    The emissions aren't the only issue in question though, the vast amounts of heat generated during each launch contributes to mounting environmental problems as well, right?
    - garmaine 5y ago
      No. It doesn’t release any more heat than burning that fuel in cars or airplanes would. Chemistry is chemistry. And a Falcon 9 consumes about as much fuel as 3 fully loaded 737s. While not trivial, it’s also negligible in the grand scheme of things. We could be launching hundreds of these every day before it has a noticeable impact on the global environment.
      - winternett 5y ago
        >3 fully loaded 737s 3 fully loaded 747s carry a lot more passengers than Falcon 9 does on one launch, and for a much more effective and better reason than just outer-atmosphere space tourism... The primary ideal of space tourism is simply entertainment. It's a roller coaster ride of sorts. Especially if the launches grow in popularity, the impact will be far worse. It's is not sound logic to say it's harmless.
        PaulHoule 5y ago
        The 737 can take 150 people across the United States, let’s attribute that to one Dragon passenger; that is 150 flights, which is a lot, but some ‘frequent fliers’ do two or more flights a week. Such a person could easily burn an orbital flight full of fuel in less than two years.

LOX/RP1 is pretty awful for the environment - space-flight is by no-means eco-friendly (I suppose apart from the Space-shuttle main-engines)

by iab 5y ago

LOX/RP1 is pretty awful for the environment - space-flight is by no-means eco-friendly (I suppose apart from the Space-shuttle main-engines)

garmaine 5y ago

Notably SoaceX doesn’t use RP1 for Starship, and is aiming for a carbon neutral fuel source.

PaulHoule 5y ago
New Shepard uses hydrogen + oxygen which could be produced without CO2 emissions. It's relatively straightforward to synthesize methane (Starship fuel) from a stream of carbon monoxide and hydrogen. In the past people got the carbon monoxide from pyrolysis of coal https://netl.doe.gov/research/Coal/energy-systems/gasification/gasifipedia/great-plains https://netl.doe.gov/research/Coal/energy-systems/gasificati... but today people are doing it with carbon dioxide extracted from the air or from another combustion process. You could make RP1, Jet Fuels, and other hydrocarbons this way too https://www.netl.doe.gov/research/coal/energy-systems/gasification/gasifipedia/ftsynthesis https://www.netl.doe.gov/research/coal/energy-systems/gasifi... but the chemistry is tricky because the reactions that break chains down to methane or build them up to polyethylene will run quickly except when conditions are balanced on a knife edge... One where the reaction rates aren't too high and amount of product you get for the size of the machine is not good.
- winternett 5y ago
  The emissions aren't the only issue in question though, the vast amounts of heat generated during each launch contributes to mounting environmental problems as well, right?
  - garmaine 5y ago
    No. It doesn’t release any more heat than burning that fuel in cars or airplanes would. Chemistry is chemistry. And a Falcon 9 consumes about as much fuel as 3 fully loaded 737s. While not trivial, it’s also negligible in the grand scheme of things. We could be launching hundreds of these every day before it has a noticeable impact on the global environment.
    - winternett 5y ago
      >3 fully loaded 737s 3 fully loaded 747s carry a lot more passengers than Falcon 9 does on one launch, and for a much more effective and better reason than just outer-atmosphere space tourism... The primary ideal of space tourism is simply entertainment. It's a roller coaster ride of sorts. Especially if the launches grow in popularity, the impact will be far worse. It's is not sound logic to say it's harmless.
      - PaulHoule 5y ago
        The 737 can take 150 people across the United States, let’s attribute that to one Dragon passenger; that is 150 flights, which is a lot, but some ‘frequent fliers’ do two or more flights a week. Such a person could easily burn an orbital flight full of fuel in less than two years.