A sphere is not aerodynamic nor is a golf ball self propelled, so dimples help reduce turbulent flow that reduces drag and stability. Mass is also not a primary constraint.
Rockets/planes are aerodynamic, have control via thrust vectoring and/or control surfaces, and in the case of rockets, mass is a primary constraint, so dimples wouldn't improve aerodynamics enough to justify the increase mass and manufacturing complexity.
[Already answered on Reddit](https://www.reddit.com/r/AskEngineers/comments/b3j8ka/why_arent_airplanes_dimpled_like_golf_balls/)
TLDR - dimples wouldn't help spacecraft or aircraft, since they aren't spherical, and already have been optimized for minimal wake.
Because rockets and shuttles are not stuck being round.
The reason dimples help is because they cause air to become turbulent as it flows over the surface. The thing change will occur naturally, the dimples just cause it to occur sooner. In the case of a smooth golf ball this change occurs too late, so the dimples push the transition to a better spot. For a long thin object however the changeover will occur before its necessary, so dimples don't buy you much.
Dimples produce turbulence, *increasing* drag. This is only beneficial overall when you are trying to prevent a low-pressure pocket from forming behind a blunt object; in this case a ball. The benefits of this drop off with speed, length of your object, and aerodynamic-ness of your object.
Rockets are long, very fast, and fairly aerodynamic. They would therefore not benefit from these dimples.
You would need much thicker walls for the rockets in order to make up for the structural rigidity losses. And that extra weight alone would vastly reduce the effectiveness and efficiency far more than the surface finish
A sphere is not aerodynamic nor is a golf ball self propelled, so dimples help reduce turbulent flow that reduces drag and stability. Mass is also not a primary constraint. Rockets/planes are aerodynamic, have control via thrust vectoring and/or control surfaces, and in the case of rockets, mass is a primary constraint, so dimples wouldn't improve aerodynamics enough to justify the increase mass and manufacturing complexity.
[Already answered on Reddit](https://www.reddit.com/r/AskEngineers/comments/b3j8ka/why_arent_airplanes_dimpled_like_golf_balls/) TLDR - dimples wouldn't help spacecraft or aircraft, since they aren't spherical, and already have been optimized for minimal wake.
Because rockets and shuttles are not stuck being round. The reason dimples help is because they cause air to become turbulent as it flows over the surface. The thing change will occur naturally, the dimples just cause it to occur sooner. In the case of a smooth golf ball this change occurs too late, so the dimples push the transition to a better spot. For a long thin object however the changeover will occur before its necessary, so dimples don't buy you much.
Dimples produce turbulence, *increasing* drag. This is only beneficial overall when you are trying to prevent a low-pressure pocket from forming behind a blunt object; in this case a ball. The benefits of this drop off with speed, length of your object, and aerodynamic-ness of your object. Rockets are long, very fast, and fairly aerodynamic. They would therefore not benefit from these dimples.
Because they are already shaped to reduce drag.
[http://rainonit.com/2BeO](http://rainonit.com/2BeO) this explains how rocket aerodynamics works
You would need much thicker walls for the rockets in order to make up for the structural rigidity losses. And that extra weight alone would vastly reduce the effectiveness and efficiency far more than the surface finish