New Frontiers missions are mid-range missions intended to explore our solar system. They each have a budget that is capped at roughly one billion dollars. For comparison, the cost of the Curiosity Rover and the upcoming Mars 2020 rover each cost over two billion dollars. Previous New Frontiers missions have taken us out to Pluto (New Horizons), Jupiter (Juno), and one of them (OSIRIS-REx) is careening towards an asteroid. Now it's almost time to add another mission to the list. NASA asked for contenders that fit one of six themes, including returning a sample from either a comet or the Moon's south pole, probing Saturn, exploring Venus, rendezvousing with a Trojan Astroid, or heading out to the ocean worlds Titan and/or Enceladus.