Motivation of the military guy

So one of the people going on the trip to Lunar is a ex-military now working for oil company guy that claims not to believe in aliens and that stuff (he says it at the very beginning so no spoilers here).
So what was his motivation? why did he come there? and why bring his daughter that obviuosly didnt want to be there to begin with? What was the reason he did such a thing other than plot device?

---------------------------------------------
Applied Science? All science is applied. Eventually.