On the Flying Castle, we'll have positions available for two hundred pilots. That's because each "motor" is a "lifeboat" as well.
Should the very worst scenario take place, and the Castle appear to be in danger of being lost, we will have two minutes or less in which to evacuate to the Gas-Cooled Nuclear Reactor/Rocket Motors which are our motors, our shuttles, and our lifeboats.
With a destroyed Castle habitat, those who survive would have to make their way in the shuttle lifeboats back to the orbiting Habitats A and B, and prepare for return to Earth.
That, of course, is the worst case. What we plan to do is land safely on Mars, do a bit of exploring, perhaps set up a subsidiary dome on a nearby crater, and eventually return to our sister habitats.
Where we go from there has not been decided yet.