Is spaceship armor useless?

[Crakkerjakk]

Originally Posted by vicky_molokh

Lots of things make no sense in our setting, but they do in other settings. FTL and Reactionless drives are perhaps the first two that come to mind.

At spaceship velocities, conventional explosives don't make sense because the speed and mass of the projectile alone packs more energy than any detonation. An object traveling at 3 kps relative to it's target delivers equivalent kinetic energy to it's mass in TNT.