Sending a few people to Mars with current tech is like cavemen trying to get to the moon by finding bigger and bigger trees to climb, and thinking they're making progress.
The first ancestor to actually hold a flaming branch in hand after a lightning strike, after all the others had sensibly run away... was a total loon doing something terrifying and incomprehensible. Once it became clear that one end was on fire and the other was not, it was easy to gather the courage to pick it up and examine the fire closely. Carrying it and touching flame to dried leaves, fire-daughters are born and take on a life of their own. This is amazing stuff. Blowing on orange embers, the flame is reborn. Keep a glowing ember in a pouch with you always, and devoting your own life to ensuring that it does not go out... you become the one who carries fire, the first scientific shaman. There is a direct lineage of awe and wonder from that proto-human to that Zippo in your pocket.
The space corollary to your finding bigger trees to climb metaphor -- we can do this! -- is an tether/elevator dangling from geosynchronous orbit. Such a thing *is* achievable in our lifetime, but while fire was a great idea, not all ideas are good ideas. You have to apply technology in ways that do not create single points of failure that malicious persons can exploit with a few explosives or the push of a single button..
Solar power is a good idea. Orbital solar power is a bad idea: the entity that owns it controls the world, those who destroy it bring civilization down. Energy -- the modern ability to make fire -- should be autonomously generated in many places, in many ways. If you want it down you must campaign, invade and fight on countless fronts.
Unfortunately, most of our modern information technology infrastructure has been designed by engineers with casual disregard for autonomous operation, who even glorify single points of failure. Without a network connection to that distant city that is a prime nuclear target, that cell phone tower in your backyard is too stupid to connect local calls. On the edge of town is an empty building that used to house a telephone switch that could connect local wired phones indefinitely.
An orbital tether would be good for making space accessible, transporting loads and people. But Kim Stanley Robinson in Red Mars has shown us that a sabotaged, fallen tether could be an equatorial whiplash of terrifying proportions. And once all other transport vehicles are rendered 'obsolete' and head for the scrapyard (economics=no one's fault), this single point of failure becomes an absurd tragedy.
Even manned space exploration described in this Bill, which makes me jubilant, has a nagging anxiety with it. I fear that IF we spend too many resources for mere exploration (and even colonization) and do not place an urgent enough priority on impactor NEO/comet detection with several tested techniques for interception and vector adjustment, with a triple backup of hardware in orbit and in the asteroid belt ready to deploy quickly, our pioneers in space may one day become witnesses to our (and their own) funeral.
We are the choices we make.
Effective planetary defense means the weaponization of space, as soon as possible.
There is no such thing as a single-use technology.
We just need to deal with it. The threat of Mutual Assured Destruction is a great equalizer.
Failure to move in this direction is an evolutionary dead end.
Any ancestor who failed to wield a club fell to those who did.
Everyone now has a club. In civilized society this is also known as a "talking stick".
Welcome to the club.