Billionaires have entered the space race, and now they're funding a different kind of race—one against time itself.

Currently, a $101 million prize is on the table for the entrepreneur who can create an elixir of youth.

So, as billionaires line up at the fountain of youth. How are those without a billion dollars in the bank trying to cash in on this new medical frontier?

When is trying to stop the clock on aging taking it too far?  And why are humans so obsessed with living forever?