My Comments on "Inhabiting The Moon & Other Planets".
Recently, I was emailed by someone, who asked me whether or not, it is possible to build a submarine; which can also be used as an aircraft? My reply was, “Yes, if you use carbon nanotubes for the construction of the pressure hull & the associated structures”. Carbon nanotubes have about 600: 1 of the strength to weight ratio of high-tensile steel. For example, if you design a spherical pressure hull of (say) 50 miles diameter, to house humans, in a 1 atmosphere internal steel pressure vessel, on the Moon, then its wall thickness will be about 100 ft (See my book on, "Pressure Vessels-Table 1.5 & Section 11.11.8"! If, however, you design the same specification spherical shell, of 50 miles diameter, using carbon nanotubes for the structure, its wall thickness will only be about 1 ft! Moreover, its mass will be about 1/600th that of the comparable high-tensile steel vessel. If the spherical pressure vessel, made from carbon nanotubes is of (say) 20 miles diameter, its wall thickness need only be about 5 ins!!! Thus humankind can inhabit the Moon & other planets! We will have lift-off; albeit; when it happens, I will be "off the planet"!
Carl Ross. University of Portsmouth, UK.