Reactionless drive ships orbital flight in 3rd ed physics?

[Ulzgoroth]

The appeal, of course, would be to be able to use something much more efficient than normal rockets.

But most concept deep-space rockets likely wouldn't work in atmosphere anyway, or have enough thrust to sustain flight.

Originally Posted by Fred Brackin

Yes, but the 1956 Karman line was calculated based on the capabilities of the Bell X-2. That had a thrust-to weight ratio of 3 to 5 fully loaded but better than 1 to 1 just before the fuel ran out.

We can do a little better than that today but not with a payload-carrying craft. The numbers are already far higher than the theoretical winged orbiters from Space 1e.

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.