why are the noses of rocket, shuttles, planes, missile(…) half spheres instead of spikes?

Question

why are the noses of rocket, shuttles, planes, missile(…) half spheres instead of spikes?

In: 5557

Answer 1

Blunt noses are fine if not preferable at low speeds because the airflow can start to move out of the way before it hits the aircraft. The air in front of the craft pushes on the air further ahead to allow for a smooth transition.

Supersonic travel does not have this. The air is ‘notified’ of the oncoming plane right as the plane comes up on it because pressure waves cannot travel out ahead of the plane. This makes pointier designs better in this region.

At very *very* high speed, a blunted nose forces the shockwave to form farther in front of the vehicle, protecting it from the heating of the air that forms at the shock.