4 ms·

So this will run on Methane and Liquid Oxygen, right? Is it possible to source this CO2 neutral? Maybe it's not economical right now, but I wonder whether it's

So this will run on Methane and Liquid Oxygen, right? Is it possible to source this CO2 neutral? Maybe it's not economical right now, but I wonder whether it's realistic to use renewables to produce the fuel in the near future. The massive cost reduction will probably result in far more flights, so I wonder about the environmental impact. Edit: And would this even be the solution? Methane is a greenhouse-gas after all...

adrianN 5y ago
Yes, it's not terribly difficult to make Methane from CO2 and water using some electrolysis and the Sabatier reaction. You can also do that on Mars.
- LeanderK 5y ago
  Do you know what happens when the engine burns the fuel? What gets released into the atmosphere? I know methane is a greenhouse gas but when it's getting burned it doesn't get released raw.
  - adrianN 5y ago
    Methane burns with oxygen to carbon dioxide and water. CH4+2O2->CO2 + H2O
  - yazaddaruvala 5y ago
    Very basically this is the bi-directional formula: Methane + O2 <=> CO2 + H2O + energy
  - lizknope 5y ago
    methane + oxygen = carbon dioxide + water https://www.middleschoolchemistry.com/multimedia/chapter6/lesson1 https://www.middleschoolchemistry.com/multimedia/chapter6/le...
  - nickik 5y ago
    This video is very informative: https://www.youtube.com/watch?v=C4VHfmiwuv4 https://www.youtube.com/watch?v=C4VHfmiwuv4
yazaddaruvala 5y ago
They need to build these refineries[0] for fuel creation on Mars, so it's very likely they will build and use them at Starbase on Earth to test and gain long-term maintenance experience. The happy consequence is relatively low net-carbon emissions. [0] https://cleantechnica.com/2019/10/30/no-you-dont-have-to-worry-about-emissions-from-spacexs-mars-rocket/ https://cleantechnica.com/2019/10/30/no-you-dont-have-to-wor...
mabbo 5y ago
Methane is a greenhouse gas, until you burn it. Then it's water and CO2. The wikipedia article on methane says something like "There is little incentive to produce methane industrially". Basically, we have too much of it already, from fracking, from livestock, from all sorts of places. Giving it to SpaceX to burn as rocket fuel makes it a less potent greenhouse gas.
Me1000 5y ago
Musk has stated it's SpaceX intention to create methane from the CO2 in the air, powered by solar panels. (Basically the same technology they want to use on Mars to produce the return trip propellant) Burning the methane will of course release CO2 back into the atmosphere, but if they indeed make the methane by pulling CO2 from the air, it would effectively make Starship (the fuel anyway) carbon neutral. (I guess actually it's a bit carbon negative because some of the engine burn will happen in space).

adrianN 5y ago

Yes, it's not terribly difficult to make Methane from CO2 and water using some electrolysis and the Sabatier reaction. You can also do that on Mars.

LeanderK 5y ago
Do you know what happens when the engine burns the fuel? What gets released into the atmosphere? I know methane is a greenhouse gas but when it's getting burned it doesn't get released raw.
- adrianN 5y ago
  Methane burns with oxygen to carbon dioxide and water. CH4+2O2->CO2 + H2O
- yazaddaruvala 5y ago
  Very basically this is the bi-directional formula: Methane + O2 <=> CO2 + H2O + energy
- lizknope 5y ago
  methane + oxygen = carbon dioxide + water https://www.middleschoolchemistry.com/multimedia/chapter6/lesson1 https://www.middleschoolchemistry.com/multimedia/chapter6/le...
- nickik 5y ago
  This video is very informative: https://www.youtube.com/watch?v=C4VHfmiwuv4 https://www.youtube.com/watch?v=C4VHfmiwuv4

yazaddaruvala 5y ago

They need to build these refineries[0] for fuel creation on Mars, so it's very likely they will build and use them at Starbase on Earth to test and gain long-term maintenance experience. The happy consequence is relatively low net-carbon emissions. [0] https://cleantechnica.com/2019/10/30/no-you-dont-have-to-worry-about-emissions-from-spacexs-mars-rocket/ https://cleantechnica.com/2019/10/30/no-you-dont-have-to-wor...

mabbo 5y ago

Methane is a greenhouse gas, until you burn it. Then it's water and CO2. The wikipedia article on methane says something like "There is little incentive to produce methane industrially". Basically, we have too much of it already, from fracking, from livestock, from all sorts of places. Giving it to SpaceX to burn as rocket fuel makes it a less potent greenhouse gas.

Me1000 5y ago

Musk has stated it's SpaceX intention to create methane from the CO2 in the air, powered by solar panels. (Basically the same technology they want to use on Mars to produce the return trip propellant) Burning the methane will of course release CO2 back into the atmosphere, but if they indeed make the methane by pulling CO2 from the air, it would effectively make Starship (the fuel anyway) carbon neutral. (I guess actually it's a bit carbon negative because some of the engine burn will happen in space).