Early modern sailors were uneducated manual labourers with few economic prospects in a world where simply living as a lower class individual was more dangerous than nearly any job that exists in the developed world today. Sailing often paid better than jobs on land which made up for the risk, and it offered the potential of massive reward to the high class leadership of the vessel.

There is no consummate economic incentive for being an astronaut. The incentive is the experience and making some impact on science, and while that motivates many people the probability of attracting the best and the brightest goes down as the probability of exploding goes up.

I'd say there's unlikely to be enough of an economic incentive to justify riskier manned space travel until the earth becomes a whole lot less habitable.