this post was submitted on 08 Sep 2023
108 points (100.0% liked)
Space
7921 readers
11 users here now
News and findings about our cosmos.
Subcommunity of Science
This community's icon was made by Aaron Schneider, under the CC-BY-NC-SA 4.0 license.
founded 3 years ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
The good news about SLS is that it’s not burning fracked natural gas like Elon’s rockets… it’s burning Hydrogen that was produced from fracked natural gas. It’s not green now, but it has the potential to be in the future. Cryogenic H2 requires some expense compared to cheap-and-dirty methylox.
The other advantage of SLS is that these rockets are owned by the people, not private companies. If we want an equitable future in space, we need NASA rockets. Right now the SLS is that rocket.
Natural gas can be green too. You can extract it from landfills or from bioreactors of organic waste.
But still... you're burning hydrocarbons so you end up producing a lot of CO2 which is going straight into the atmosphere. That's not what I'd call super green.
It’s carbon that’s already part of the carbon cycle. Like burning wood or consuming food.
The carbon to worry about is the stuff we’re extracting from underground.
And where are the bioreactors located? What would happen to that carbon if it weren't collected by the reactors?
I agree its better than mined gas, it falls under the 3Rs, but it's still taking carbon from the ground and releasing it into the atmosphere.
In the grand scheme of things the deus ex machina of fusion is the only long term solution.
If it’s capture from a landfill, it’d likely be released as methane directly into the atmosphere.
If it’s made from things like chaff, it often gets simply burnt and released immediately back as CO2 into the atmosphere. No difference but significant usable energy.
I was absolutely arguing the wrong side of that, sorry. I didn't realize landfill emissions don't stay in the ground.
https://www.epa.gov/lmop/basic-information-about-landfill-gas
The methane just breaks down into an equivalent amount of CO2 when vented anyways and until then is a much more potent greenhouse gas. That's why it's usually flared off apart from safety.