On the space shuttle, I understand that the quick roll and pitch maneuver wins because it increases payload, aligns antennae, etc.

But if one looks at the Apollo missions on a Saturn V, why is this necessary?

According to Wikipedia - and recordings from the time - the Saturn V rocket (1) first did a movement of some 1.5 degrees or more to clear the launch tower, and then, quickly (2) did a roll and pitch maneuver to "align" it with its intended orbit.

But why should a symmetric spacecraft require this sequence? which way the heads of the astronauts faced seems irrelevant. One should, it would seem, be able to capture the earth's rotation as a benefit without requiring 2 moves.

Put another way, rotation about the axis of symmetry of the rocket seems unnecessary. So, why was it done?


To inject a rocket into its intended orbit, it has to be steered along a course which begins vertically and ends horizontally. This requires the thrust line of the motors to be actively angled relative to the ground so the rocket's path over the ground matches its intended trajectory. This requires that the rocket, which is cylindrically symmetric, be fixed in roll attitude relative to the ground, or else the angle of the thrust line will not match the trajectory and the rocket's path will wander off track.

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