Although the advisory didn’t include any specific details, it did reveal the inclusion of the lead program scientist for NASA’s New Frontiers program, Curt Niebur. In December 2017, the agency selected two finalists for the New Frontiers mission. As such, the mission set to be announced will likely be one of those two missions.
The first of the two finalists is the Comet Astrobiology Exploration SAmple Return (CAESAR) mission, which would visit comet 67P/Churyumov-Gerasimenko and return samples from its nucleus. Comet 67P/Churyumov-Gerasimenko has previously been studied by the European Space Agency’s Rosetta mission. CAESAR would, as a result, look to build on the data gathered during that mission.
The second of the two New Frontiers missions is the ambitious Dragonfly mission, which would visit Saturn’s largest moon, Titan to study its microbial habitability at various locations. To visit multiple locations, the multi-rotor Dragonfly vehicle would perform controlled flights and vertical takeoffs and landings between locations. Unsurprisingly, the Dragonfly mission is considered incredibly ambitious, which may hurt its chances of being selected.
The New Frontiers program was developed by NASA and granted by Congress in 2002 and 2003 respectively. Since then, a total of three New Frontiers missions have been launched (New Horizons, Juno and Osiris-Rex), all of which are currently still operational. The last New Frontiers mission, Osiris-Rex was an asteroid sample return mission launched in September 2016.