Reactionless drive ships orbital flight in 3rd ed physics?

[Anthony]

Originally Posted by Ulzgoroth

I'm not sure thrust to weight is actually relevant to the calculation at all, which (going from the wiki here) was about lift vs. heating.

You need enough thrust to exceed your drag, or you slow down (thus failing to accomplish your purpose), and drag is equal to the weight of the vehicle divided by its lift to drag ratio.