Fire will be caused on your ship randomly either by enemy fire, or by too steep an angle of re-entry. A Fire Extinguisher can be picked up to extinguish these fires whilst free-roaming inside of the ship. Fire will not spread on tiles that have recently been sprayed with a fire extinguisher.
To put out a fire, aim directly at the base of the flames with the Fire Extinguisher equipped. Alternatively, if the ship is currently in an area with little or no atmosphere present, the player can use the Operations Computer to open all doors on the ship. The vacuum of space will suck all the air out and deprive the fire of oxygen. However, if the player is not careful, they can easily be sucked out into space. Therefore, this method should only be used in extreme emergencies.
Fire Extinguishers can be dropped by pressing tab. They will automatically vanish after being used up otherwise.
Bear in mind that one cannot edit the layout of the ship while it is on fire, therefore there must always be a fire extinguisher in the ship. If there is not, there is no way to put out a fire outside of using the Operations Computer method described above.