##Nope##

###Improper Usage### Remember that the purpose of a flamethrower is to set flammable targets on fire like wood structures and humans and to consume oxygen from enclosed spaces. It is safe to assume that spaceships will not be made out of flammable materials. Ships are sealed so that they do not lose oxygen to space, so unless the flamethrower can penetrate the hull it will not harm the air inside the ship. There are also far more effective methods to blind enemy sensors than generating a lot of heat and IR. Space ships already are going to be able to filter out far hotter things from their sensors like near by stars.

###Distance and Velocity### For a flame thrower to travel one kilometer it would need to ignite at the end of the stream on impact otherwise it will burn its fuel off before it got to the target.

Flamethrowers also run into an issue that the fluid is not going to be moving that fast compared to other weapons so enemies will easily see it coming and avoid it. You can switch it out for an incendiary missile, which will get the payload to its target faster, but it will cease to be a flamethrower at that point.

###Armor and Shields### Space ships are going to be designed to handle far worse than what a flamethrower can dish out. Flamethrowers are a chemical based weapon and so they generate energy through chemical reaction. However, there are a large number of weapons out there that can generate far more destructive forms of energy, and as such space ship defenses will be designed to handle those types of things. So when the flamethrower hits the shields or armor at the worst it will likely only damage the paint job.

Nope

Improper Usage

Remember that the purpose of a flamethrower is to set flammable targets on fire like wood structures and humans and to consume oxygen from enclosed spaces. It is safe to assume that spaceships will not be made out of flammable materials. Ships are sealed so that they do not lose oxygen to space, so unless the flamethrower can penetrate the hull it will not harm the air inside the ship. There are also far more effective methods to blind enemy sensors than generating a lot of heat and IR. Space ships already are going to be able to filter out far hotter things from their sensors like near by stars.

Distance and Velocity

For a flame thrower to travel one kilometer it would need to ignite at the end of the stream on impact otherwise it will burn its fuel off before it got to the target.

Flamethrowers also run into an issue that the fluid is not going to be moving that fast compared to other weapons so enemies will easily see it coming and avoid it. You can switch it out for an incendiary missile, which will get the payload to its target faster, but it will cease to be a flamethrower at that point.

Armor and Shields

Space ships are going to be designed to handle far worse than what a flamethrower can dish out. Flamethrowers are a chemical based weapon and so they generate energy through chemical reaction. However, there are a large number of weapons out there that can generate far more destructive forms of energy, and as such space ship defenses will be designed to handle those types of things. So when the flamethrower hits the shields or armor at the worst it will likely only damage the paint job.

##Nope##

###Improper Usage### Remember that the purpose of a flamethrower is to set flammable targets on fire like wood structures and humans. It is safe to assume that spaceships will not be made out of flammable materials. There are also far more effective methods to blind enemy sensors than generating a lot of heat and IR. Space ships already are going to be able to filter out far hotter things from their sensors like near by stars.

###Distance and Velocity### For a flame thrower to travel one kilometer it would need to ignite at the end of the stream on impact otherwise it will burn its fuel off before it got to the target.

Flamethrowers also run into an issue that the fluid is not going to be moving that fast compared to other weapons so enemies will easily see it coming and avoid it. You can switch it out for an incendiary missile, which will get the payload to its target faster, but it will cease to be a flamethrower at that point.

###Armor and Shields### Space ships are going to be designed to handle far worse than what a flamethrower can dish out. Flamethrowers are a chemical based weapon and so they generate energy through chemical reaction. However, there are a large number of weapons out there that can generate far more destructive forms of energy, and as such space ship defenses will be designed to handle those types of things. So when the flamethrower hits the shields or armor at the worst it will likely only damage the paint job.

##Nope##

###Improper Usage### Remember that the purpose of a flamethrower is to set flammable targets on fire like wood structures and humans and to consume oxygen from enclosed spaces. It is safe to assume that spaceships will not be made out of flammable materials. Ships are sealed so that they do not lose oxygen to space, so unless the flamethrower can penetrate the hull it will not harm the air inside the ship. There are also far more effective methods to blind enemy sensors than generating a lot of heat and IR. Space ships already are going to be able to filter out far hotter things from their sensors like near by stars.

###Distance and Velocity### For a flame thrower to travel one kilometer it would need to ignite at the end of the stream on impact otherwise it will burn its fuel off before it got to the target.

Flamethrowers also run into an issue that the fluid is not going to be moving that fast compared to other weapons so enemies will easily see it coming and avoid it. You can switch it out for an incendiary missile, which will get the payload to its target faster, but it will cease to be a flamethrower at that point.

###Armor and Shields### Space ships are going to be designed to handle far worse than what a flamethrower can dish out. Flamethrowers are a chemical based weapon and so they generate energy through chemical reaction. However, there are a large number of weapons out there that can generate far more destructive forms of energy, and as such space ship defenses will be designed to handle those types of things. So when the flamethrower hits the shields or armor at the worst it will likely only damage the paint job.