Three ambitious space missions have made NASA’s short list for a planned robotic planetary expedition to launch in 2016. The candidates include a mission to glimpse Mars’ interior, a voyage to the extraterrestrial sea of Saturn’s moon Titan, and a probe to take an unprecedented look at the surface of a comet’s core.

NASA plans to spend the next year studying the three concepts before selecting one to proceed toward launch under the agency’s Discovery Program of cost-capped space science missions. The investigation team for each mission proposal will receive $3 million for a preliminary design stage, NASA officials said.

The chosen mission will be given a fixed budget of $425 million, not including the cost of its launch vehicle.

“This is high science return at a price that’s right,” Jim Green, director of NASA’s Planetary Science Division, said in a statement. “The selected studies clearly demonstrate a new era with missions that all touch their targets to perform unique and exciting science.”

The three Discovery finalists are:

  • The Geophysical Monitoring Station (GEMS), a Mars lander designed to study the structure and composition of the planet’s interior, potentially improving scientific understanding of the formation and evolution of terrestrial planets. NASA’s Jet Propulsion Laboratory in Pasadena, Calif., would manage the project.
  • The Titan Mare Explorer (TiME), which would land in and float on a large methane-ethane sea on Saturn’s moon Titan, providing the first direct exploration of an ocean beyond Earth. The Johns Hopkins University Applied Physics Laboratory in Laurel, Md., would manage the project.
  • Comet Hopper, a probe designed to land on a comet multiple times and observe its changes as it interacts with the sun. NASA’s Goddard Spaceflight Center in Greenbelt, Md., would manage the project.

In addition, the Discovery Program also chose three space technology development efforts for potential future planetary missions:

  • NEOCam: A telescope to analyze near-Earth objects, study their origin and evolution, and monitor their risk of impacting Earth.
  • Primitive Material Explorer (PriME): A mass spectrometer that would yield highly precise measurements of a comet’s chemical composition and explore comets’ role in delivering the potential ingredients of life to Earth.
  • Whipple: An effort to develop and test a technique called blind occultation to discover and investigate celestial objects in the outer solar system.

In upcoming years, research teams will bring their respective technologies to a higher level of readiness, receiving funding determined through contract negotiations, NASA said. They must demonstrate progress in a future mission proposal competition to be considered for flight.