On 04-Sep-20 3:12 pm, Sylvia Else wrote:
How does this actually help?

The aerodynamic forces on the craft are a function of its speed and air
density. There's not much one can do about the speed, given that the
craft is accelerating.

If the craft accelerates more slowly overall, for each speed it will be
traversing less dense air than it would do otherwise. But in that case,
is there a benefit from high initial acceleration and then reducing
acceleration on the approach to max-q?

Is it really about reducing vibration loads during max-q?

Sylvia.

The thing is, it's not as if the rocket thrust and aerodynamic forces
are adding together to squeeze the vehicle from both ends. The
longitudinal component of the aerodynamic force is transferred from the
exterior to the internals of the vehicle, and acts to reduce the
acceleration imparted by the rocket. This transferred force is not a
function of rocket thrust. For some parts of the internals of the
vehicle, it reduces, not increases, the loads.

I'm not suggesting that the throttle down is not required, but the
rationale for it doesn't appear as straight forward as it might seem at
first sight.

Sylvia.