Weird Harold wrote:kzt wrote:Honorverse missiles spin. It's just how they do it. Remember the gunnery exercise in one of the short stories? I'd assume it's to allow vector changes. Without spin is still going to be pretty darn destructive to the surface.
That was a drone, simulating a hostile ship making evasive maneuvers. There is no textev indicating Honorverse missiles spin.
Missiles (and drones) in the Honorverse "spin" only to interpose their wedges against potential enemy fire. That is, it constitutes a form of evasive action without making major changes in base vector and heading. They have absolutely no other need to spin and more than a fin-stabilized rocket would need to spin in atmosphere.
The reason projectiles spin is for stabilization purposes, not to increase the distance to which they can be fired. Any projectile's density/weight will be less than uniformly distributed, no matter how careful your manufacturing processes, and that weight distribution will tend to pull it off course. By spinning it, the weight differential is moved rapidly around its axis, effectively negating the differential and stabilizing its flight path and attitude. Because its flight is more stable, it can be fired to a greater effective range because (1) it's more accurate at any range (including long ones), (2) it can be counted upon to maintain its orientation in flight, optimizing any aerodynamic efficiency designed into its shape, and (3) it can be cylindrical in shape which both reduces drag and increases mass (because it's as much as five or six times as long as it is across), and for a given initial velocity, a heavier projectile will travel farther and hit with more kinetic energy than a lighter one.
None of those factors apply to an impeller wedge or an impeller drive missile, however.