OT
A moon base would be a useful springboard from which to launch Mars missions. In addition to testing space-faring craft, launching shuttles from the moon requires a lot less energy than launching from Earth.
However, I feel that Mars should not be the next objective. The planet we should look to colonize should be Venus.
Do you know that the temperature on the Venus surface is just below 500 deg. Celsius? And then there is an air pressure of near 100 times our own and all those clouds ( sulfuric acid ) .....
Mars has enough water, oxygen and food come from your crops, energy from the Sun.
On Mars you have an atmosphere ( carbon dioxide with a large amount of Argon ) with a pressure similar to that on Earth at an altitude of 30 km, a temperature of between minus 180 and plus 25 Celsius and few clouds. The occasional dust storm of course. You can use solar power to melt some eutectic at say 800 Kelvin and freeze another at 200 Kelvin using radiation into the night. A gas engine between the two would have a Carnot efficiency of 75%. After losses you might be left with 60%, two or three time the efficiency to be derived from a photo-voltaic system and working day and night. You would live comfortably below ground, safe from meteorites and cosmic rays and grow crops in tunnels with light piped to those tunnels from mirrors above ground. You might need a few thousand people to keep this running and growing with little input from Earth. Of course the initial input will be very considerable.