wrote:
I wonder if the size of the vehicle was chosen because of limits on how
small the beam can be? It seems they chose up to 19g acceleration
because of the need to do all the accelerating while the ship is in
sight of the microwave array. Would it be that big a deal to build a
series of smaller microwave arrays, spaced out over 1000 km, and
passing the vehicle from one array to the next? Obviously the cost is
higher but then acceleration can be kept lower, allowing human flight.

Human testing has proved that taking 19G for 1 minute is quite possible.
Which takes you to most of orbital velocity.
Bloody unpleasant, but possible, at least for selected humans.

The arrays would have to end up nearly the same size - otherwise they
wouldn't have the focus I suspect.