I'm reluctant to support the expenditure of trillions of dollars because of "unknown reasons". If we want to find something out we can do so far more easily an

I'm reluctant to support the expenditure of trillions of dollars because of "unknown reasons". If we want to find something out we can do so far more easily and cheaply using unmanned probes. And what "humanity sustaining environment"? That's a pipe dream - if you had the technology to colonize mars you could do better by building a bunker complex on the earth.