Parallel thinking is good, until, e.g., inches and centimeters are used in parallel and the whole thing blows, this time to the tune of 10 trillion dollars instead of 100 million like the last time - just a couple of years ago.
The more details there are, the more can go wrong. The Apollo program had a multitude of test runs, including many of the maneuvering experiments from the Gemini program. They even had an almost test landing on the moon (Apollo 10). Landing on Mars would have to be done with a minimum of, or even no testing at all.
Myriads of details mean myriads of possible screw-ups.
We got to the moon and back more or less because we *really, really* wanted to. Without that collective national/international impetuous, even a possible Mars landing just might not take place.
Do we *have* to go to Mars? No.
The dreams of a necessity of human expansion are nonsense. One often hears of a necessity to terraform Mars and go there when we've screwed up everything here. Even an Earth screwed up by humans would still offer us about 98% of what we need to survive. If we don't understand the Earth's eco-system enough to solve our problems here on Earth, how are we supposed to create a new one? Even if we could find water and create a new atmosphere on Mars, we'd still only have about 10% of all the things we would need for real, unassisted survival. Create an atmoshpere on Mars? If the were possible, then why not just use the same technology to fix ours?
Will humans ever leave the Earth (as a collective body) and permanently inhabit 'the stars,' or even Mars for that matter? I honestly do not believe so. The human race is a product of the Earth and is here to stay. Anywhere else, it's a fish out of water.
Every time I hear the likes of Puttkamer blabbing away about colonizing Mars, I just shake my head and think "he's *got* to know better, is he just trying to raise money?" In the sixties, during the Apollo program, I saw lots of short films about us having permanent settlements on the moon by about 1995, with tens of thousands of inhabitants. Ahh yes. The talk about Mars reminds me of those films - often word for word. So I think "ahh yes."
[/minirant]