We see that the atmosphere is clear but actually it is cluttered with debris, enough for a collision to occur. A piece of a former satellite comes into contact with a spaceship and you are a goner. Just look at the speed those pieces float around at that altitude. I should say race around waiting to hit an obstacle.

Now it seems that targets are being created so that the Earth can be evacuated without any inconvenience. The pathway to Mars and beyond as humanity wants to escape itself. It started when places to exploit became fewer and the desire to live as equals goes out the window. At one time equality was successful and those battling for liberty gave their lives. Now its a race out through that singular opening and only when the time is right.

But the time has never been right, it has never been. What was around appeared to be there and that was why the great escape began. We used to think the the room we were just in existed when we had left it. We will not race to leave some antiquated prison stuck in the middle of the desert or on a spot surrounded by shark infested waters, we would be leaving in some kind of order, where only those physically fit are to go up into space after rigorous testing. Now you say that leaves the weak behind but so has the selective process, it has left millions of the weak behind while the stronger have succeeded. I am not saying that is lovely, but the rat race has been  fueled by economic needs amounting to more greed and corruption this world can handle.

There is one thing which could change all that; a collision between worlds here and now, as had happened hundreds of thousands of years ago or a  drying up of our water resources, such that millions will perish whether they be weak or strong. So once you see that your place here is temporary, you will risk going through that small opening even though the atmosphere on Mars has not been proven to support our kind of life.