If Hitlery gets in - it's gonna be a race for survival - we're gonna NEED other planets.
Elon Musk is a certified lunatic and shyster... Eventually, somebody is going to figure that out. When they do his house of cards will crumble into dust and a prison cell will be waiting for him.
As for traveling to Mars, that will happen eventually, without Musk being involved of course, and we do get there we will find the same thing on Mars that we found on the Moon... Nothing. We can do space exploration, so we do. The question is... Why bother?
Sorry Elon (and others). There are no aliens. This big blue marble is it. Other life forms in the universe? Absolutely. Other life forms that build rockets and travel about needlessly in space ships and Tesla Cars... Nope!
If the creator has found it fit to never make one snowflake like another, why would he bother to make one world like another world? We are completely unique and therefor alone in this universe. Nobody is ever coming to save us, so we’ll need to save ourselves.
Hold on now. You mean the rocket is powered by greenhouse gas!?
The engine is one of the smallest issues. I’d like to know more about how they plan to sustain human lives during a couple years of unshielded radiation and micro to macro particle bombardment, and zero gravity induced atrophy and bone depletion. Not to mention air and water recycling and food supply for a journey with no possibility of resupply. An inhabited transit to, landing, exploration, and return voyage through interplanetary space will require a lot more than a reliable engine.
I'm not saying the problems are unsolvable, but it's not really clear how they're going to be solved without a radical jump in technology to maybe, for example, supply the power necessary to create an electromagnetic field around the spacecraft that performs the same function as our planet's. Or develop a water and food recycling system that will sustain the crew. Drinking and eating what used to be urine and feces, without Earth's gradual recycling through soil and sun that allows us to not have to think about it, is something the astronauts might have to learn to stomach. Bottom line, getting the astronauts there is one thing. Getting them there and back alive is something else.