Is that how water is made in space?

@ArishMell oxygen is definitely flammable.

And i got the idea from watching science experiments where they mix the two gasses in a chamber and add a spark. The result was a violent explosion witha small amount of water plattered everywhere. So yeah it would result in water vapor that condenses to water droplets as it cools.

@GuyWithOpinions No - Oxygen is not flammable! Otherwise the atmosphere would catch fire.

(I think the idea that oxygen is flammable is fairly common, but it is totally wrong.)

What you saw was combustion: rapid oxidation of a flammable substance initiated with a small input of heat, and proceeding with a considerable release of heat.

Have you encountered the "Fire Triangle" - standard teaching in fire-safety courses?

Hard to replicate in a text-message but it's this:

........... FUEL

... HEAT...........OXYGEN.

Take away any one of those three and the fire will go out, or not start.

@ArishMell the atmosphere is 20% oxygen. Thats why we dont explode. But also why a match stays lit when you light it. If the atmosphere was 40% oxygen the flame would be bigger but we still wouldnt explode.

They add oxygen to rocket exhaust to help facilitate combustion.

@GuyWithOpinions True - but it still does not mean oxygen will burn. How can it? Combustion is exothermic oxidising of a fuel, and oxygen cannot oxidise itself.

Oxygen is not added to the rocket exhaust but to the fuel in the combustion-chamber, so the fuel can burn at all in the thin upper atmosphere, and air-less Space. It also burns more intensely than if fed ordinary air, releasing more energy.


Simple experiment for you, if you have access to an oxy-acetylene or oxy-propane set.

Turn on the fuel, light it then add oxygen and adjust to a steady flame.

Now turn off the oxygen.

Turn that back on, regain a stable flame, then turn off the fuel gas.

What happens at each stage?


Incidentally, in oxy-gas cutting steel, once the metal is white-hot extra oxygen is added so the iron itself actually burns, not just melts. The product is iron-oxide.