Those entrants may need all the extra cash they can get, though, since they're about to enter the home stretch. At least one of the teams has until the end of 2015 to prove that there's a scheduled launch before the December 31st, 2016 deadline. If no one makes the cut, the group won't move ahead and have a shot at some of that $30 million in grand prize money. In other words, the time for experimentation is over -- the competitors have to finish their lunar landers and rovers relatively soon.

[Image credit: Getty Images]