3 ms·

If we ever get to heavy industrialization of lunar resources, how are we going to deal with the CO2 footprint of rockets?

by sho_hn 2y ago

p1mrx 2y ago
In theory it's possible to make a carbon-neutral methane rocket based on atmospheric CO2, though that depends on how completely the methane can be burned. https://en.wikipedia.org/wiki/Substitute_natural_gas https://en.wikipedia.org/wiki/Substitute_natural_gas
throwawaymaths 2y ago
A spacex falcon 9 contains ~as much fuel as a 747. Note: fuel, not fuel + oxidizer Edit: falcon 9, not starship
- MarkusQ 2y ago
  Source? I get Starship 34,000,000 kg + 12,000,000 kg vs 747 ~200,000 liters ≅ 150,000 kg, or about 1/300 th of what Starship holds.
  - throwawaymaths 2y ago
    Oh shit I'm sorry I am so wrong. I had calculated falcon 9. Thank you for the correction
SJC_Hacker 2y ago
Mass drivers.
deleted 2y ago
[deleted]
dotnet00 2y ago
You'd be moving other polluting industries off-Earth, thus offsetting the footprint of things that cannot be done without said footprint.
somenameforme 2y ago
There are a million viable (and often quite fun) answers here, but one is really kind of funny. What do you get when you mix oxygen and hydrogen? Water? No, of course not! You get rocket fuel! Seriously. Liquid oxygen + liquid hydrogen is a common, and highly effective, fuel that's been used for various engines such as on the Space Shuttle Main Engine. Rockets can also be carbon negative in another way. A rocket that uses less than 50% of its fuel getting to orbit would be carbon negative, because it's spending less than 'x/2' fuel to go burn at least 'x/2' fuel away from Earth. Factor in some of the fuel coming from carbon neutral sources, and it quickly becomes quite easy for a rocket to be carbon negative.
fnordpiglet 2y ago
The flow of mass would be the other way around. Lunar regolith has every element embedded in it and there’s little need to bring anything but bootstrapping -to- the moon. Return to earth from the moon wouldn’t be CO2 producing anywhere but the moon.
imtringued 2y ago
I don't remember exactly but a rocket launch has the carbon footprint of ten American citizens produce annually.

If we ever get to heavy industrialization of lunar resources, how are we going to deal with the CO2 footprint of rockets?

by sho_hn 2y ago

If we ever get to heavy industrialization of lunar resources, how are we going to deal with the CO2 footprint of rockets?

p1mrx 2y ago

In theory it's possible to make a carbon-neutral methane rocket based on atmospheric CO2, though that depends on how completely the methane can be burned. https://en.wikipedia.org/wiki/Substitute_natural_gas https://en.wikipedia.org/wiki/Substitute_natural_gas

throwawaymaths 2y ago

A spacex falcon 9 contains ~as much fuel as a 747. Note: fuel, not fuel + oxidizer Edit: falcon 9, not starship

MarkusQ 2y ago
Source? I get Starship 34,000,000 kg + 12,000,000 kg vs 747 ~200,000 liters ≅ 150,000 kg, or about 1/300 th of what Starship holds.
- throwawaymaths 2y ago
  Oh shit I'm sorry I am so wrong. I had calculated falcon 9. Thank you for the correction

SJC_Hacker 2y ago

Mass drivers.

deleted 2y ago

[deleted]

dotnet00 2y ago

You'd be moving other polluting industries off-Earth, thus offsetting the footprint of things that cannot be done without said footprint.

somenameforme 2y ago

There are a million viable (and often quite fun) answers here, but one is really kind of funny. What do you get when you mix oxygen and hydrogen? Water? No, of course not! You get rocket fuel! Seriously. Liquid oxygen + liquid hydrogen is a common, and highly effective, fuel that's been used for various engines such as on the Space Shuttle Main Engine. Rockets can also be carbon negative in another way. A rocket that uses less than 50% of its fuel getting to orbit would be carbon negative, because it's spending less than 'x/2' fuel to go burn at least 'x/2' fuel away from Earth. Factor in some of the fuel coming from carbon neutral sources, and it quickly becomes quite easy for a rocket to be carbon negative.

fnordpiglet 2y ago

The flow of mass would be the other way around. Lunar regolith has every element embedded in it and there’s little need to bring anything but bootstrapping -to- the moon. Return to earth from the moon wouldn’t be CO2 producing anywhere but the moon.

imtringued 2y ago

I don't remember exactly but a rocket launch has the carbon footprint of ten American citizens produce annually.