[yarddog]

Human survival on Mars is limited to how much food and oxygen they can carry with them. They might some day figure a way to produce food but oxygen seems impossible to me.

[Mariner]

“They might some day figure a way to produce food but oxygen seems impossible to me.”

Nuclear submarines extract all their oxygen from sea water and expel the hydrogen.

[ClayinVA]

uh, water splits into 1 Hydrogen atom and 2 Oxygen atoms when hit with electricity. Water also can be made into Rocket fuel

https://en.wikipedia.org/wiki/Water_splitting

http://www.independent.co.uk/news/science/how-to-turn-water-into-rocket-fuel-ndash-scientists-unlock-power-of-the-sun-882613.html

[catnipman]

“They might some day figure a way to produce food but oxygen seems impossible to me.”

Uh, O2 is easy-peasy with all of that available water:

https://en.wikipedia.org/wiki/Electrolysis_of_water

And the H2 is extremely useful as well, particularly if a carbon source can be found.

[spokeshave]

They might some day figure a way to produce food but oxygen seems impossible to me.

Water is H2O

so you get Hydrogen (fuel for rockets and H2 powered vehicles), O for sustaining life...collect the CO2 from the humans for the plants....get food and more O.

[Vermont Lt]

The O2 is the easy part. Use nuclear generators to separate the O2 from the water.

[Secret Agent Man]

Theoretically they can split the water/ice jnto oxygen and hydrogen. A fuel, a catalyst, and breathable air to mix with nitrogen.