A thought that occured to me recently is that one of the big challenges with moving bulk cargo to Mars is that we don't really have a proven system of landing large weights on the Martian surface safely. The best we've done so far is that Skycrane system for Curiosity, which doesn't sound like it would scale all that well to heavier weights.<p>Meanwhile, SpaceX is working on making their F9 first stage land on Earth under its own power. Very cool, and a nice cost saver if they get it working, but maybe not super-revolutionary.<p>Put those thoughts together, though, and it looks like the system used for landing the F9 would be very useful for landing a heavy shipment on Mars, and it would have already been proven on Earth.
If you haven't already, read KSR's Red Mars (the first of the Mars Trilogy):<p><a href="http://en.wikipedia.org/wiki/Mars_trilogy#Red_Mars_.E2.80.94_Colonization" rel="nofollow">http://en.wikipedia.org/wiki/Mars_trilogy#Red_Mars_.E2.80.94...</a>
>> "By late-2012, additional information made public included that Musk envisions a Mars colony of multiple tens of thousands[4][5] with the first colonists arriving no earlier than the middle of the 2020s."<p>>> "In June 2013, Musk stated that he intends to hold off any potential IPO of SpaceX shares on the stock market until after the "Mars Colonial Transporter is flying regularly."<p>I've been hoping to get in on a SpaceX IPO for some time now. Looks like I'll be waiting a few more years... =/