Can I display the image from a camera on a plane in the same scene? OK - I have a small spacecraft with limited vision inside. The spacecraft is racing against others. I want a holopanel to either side of the pilot, displaying what is to either side of the craft. It this possible in the scene? I want to try and avoid faking it in post if I can.

I will be rendering in Cycles as a short video.
I don't think  Blender is capable of render two cameras in the same process.

But you can make the light from the sides reaching the camera in the old way: make a hole in the ship and bend the rays by 90° (with a mirror).



In the picture above you can see Suzanne in a whaleish vehicle with some other smaller spaceships (red, yellow and green) on both sides.



Anyway I think it would be easier to put two cameras and composite the holograms in post. You'll surely have much more control on their final appereance.