4 ms·

Question, while these Moxie things seem like they would be obviously good assets for a long term self sufficient base, is there any reason we can't just burn ca

Question, while these Moxie things seem like they would be obviously good assets for a long term self sufficient base, is there any reason we can't just burn candles like on nuclear subs? I would assume that any effort to start colonizing mars would have to get the transport so cheap that shipping an absurd quantity of these candles is probably much more economical than a MOXIE unit?

arcastroe 4y ago
Wouldn't burning candles consume oxygen rather than produce it?
- spywaregorilla 4y ago
  Not normal candles https://en.wikipedia.org/wiki/Chemical_oxygen_generator https://en.wikipedia.org/wiki/Chemical_oxygen_generator
  - ceejayoz 4y ago
    "On the International Space Station, chemical oxygen generators are used as a backup supply. Each canister can produce enough oxygen for one crewmember for one day." That's a lot of candles if you intend to use it as the primary supply for a multi-year multi-human mission like Mars will entail. "An explosion caused by one of these candles killed two Royal Navy sailors on HMS Tireless" probably gives NASA engineers the shivers, too.
    - extrapickles 4y ago
      They have also been the cause of fire[0] on the Mir space station. They make for a reasonable emergency oxygen supply (no working infrastructure required), but you don't want to use them regularly due to the fire risk they represent. [0]: https://www.nasa.gov/feature/25-years-ago-fire-aboard-space-station-mir https://www.nasa.gov/feature/25-years-ago-fire-aboard-space-...
outworlder 4y ago
So, keep shipping a finite resource versus producing in situ? What if there's disruption in the logistics chain? Even submarines, here on Earth, don't use the candles all the time. Why?
- spywaregorilla 4y ago
  > So, keep shipping a finite resource versus producing in situ? What if there's disruption in the logistics chain? This point isn't obvious though. E.g. we'll likely be shipping them finite supplies of food. Supply chain disruption sucks but so is your MOXIE breaking down. MOXIE and 10 weeks of backup candles or 10,000 weeks of backup candles. It's not obvious to me which is the cheaper / safer option. We don't use them on subs all the time because subs don't have a lot of storage, and electrolysis is pretty easy to do.

arcastroe 4y ago

Wouldn't burning candles consume oxygen rather than produce it?

spywaregorilla 4y ago
Not normal candles https://en.wikipedia.org/wiki/Chemical_oxygen_generator https://en.wikipedia.org/wiki/Chemical_oxygen_generator
- ceejayoz 4y ago
  "On the International Space Station, chemical oxygen generators are used as a backup supply. Each canister can produce enough oxygen for one crewmember for one day." That's a lot of candles if you intend to use it as the primary supply for a multi-year multi-human mission like Mars will entail. "An explosion caused by one of these candles killed two Royal Navy sailors on HMS Tireless" probably gives NASA engineers the shivers, too.
  - extrapickles 4y ago
    They have also been the cause of fire[0] on the Mir space station. They make for a reasonable emergency oxygen supply (no working infrastructure required), but you don't want to use them regularly due to the fire risk they represent. [0]: https://www.nasa.gov/feature/25-years-ago-fire-aboard-space-station-mir https://www.nasa.gov/feature/25-years-ago-fire-aboard-space-...

outworlder 4y ago

So, keep shipping a finite resource versus producing in situ? What if there's disruption in the logistics chain? Even submarines, here on Earth, don't use the candles all the time. Why?

spywaregorilla 4y ago
> So, keep shipping a finite resource versus producing in situ? What if there's disruption in the logistics chain? This point isn't obvious though. E.g. we'll likely be shipping them finite supplies of food. Supply chain disruption sucks but so is your MOXIE breaking down. MOXIE and 10 weeks of backup candles or 10,000 weeks of backup candles. It's not obvious to me which is the cheaper / safer option. We don't use them on subs all the time because subs don't have a lot of storage, and electrolysis is pretty easy to do.