re: No, not Mass, how about innovative design???
Let's put the astros INSIDE the fuel tanks for shielding. Duh!
Or let's use fast transit systems like VASIMR powered by (Gasp!!!) nukes to make the transit times quick with Mars 'dirt' piled over the Mars habs at the destination - just like would be done for Luna shelters.
Geting more exotic, how about strong mag fields around any bio habs in space or on surface? Just takes power, those non-PC nukes again.
Unreasoning fear of radiation is SO twentieth century. Try thinking.
