What if a portion of the space craft that carries the crew to Mars were inflatable? It could be infalted after the ship is on its way to Mars to make more living space and deflated once the ship arrives. A burrowing device could then burrow into the side of a mountain or into the ground and the inflatable could be inserted into the burrow to create an airtight and radiation resistant living space.
This would be reasonable, yes. Notably, the inflatable fabric would be used as a pressure seal / liner, to prevent loss of atmosphere through porous rock.
However, keep in mind that such structures have virtually no structural support. This means that the tunnels would have to be independently reinforced before inserting the inflatable module. Unfortunately, it also means that the shell would most likely no longer be able to support the mass of internal subdivions (decks and bulheads) and/or furnishings, once under the influence of gravity (not so much a problem for low mass asteroid sites, however). Usually, the shell is also inflated (often with water, which makes a good radiation shield); but this probably won't work under these consitions. The shell does not have to be independently pressurised, though. If left unpressurised, the only precaution necessary would be to take care not to rip the fabric
liner when inserting the modules. Alternatively, you could have reinforced
hardpoints that would distibute the mass of the internal structure and furnishings, while resting on an external support structure. In this way, it would be possible to inflate the shell, without any of the mass applying pressure to it that might result in a rupture.
If you are interested, I could probably draw up a CAD model showing how different configurations might work.
Thanks Mikkel! I would love to see some CAD designs.
Maybe someday we could convince Elon Musk to make a special boring machine for Mars. That would be a nice combination of work from SpaceX and The Boring Company.
Mikkel, it is my understanding that pressurized inflatable habitats are quite rigid, not requiring support structures (unless of course it's something really huge). Is this not your understanding?