NASA’s next billion-dollar mission will either visit Saturn’s moon Titan or bring back samples of a distant comet

Saturn's fourth-largest moon, Dione, passes behind the ringed planet's largest moon, Titan, in a view from NASA's Cassini spacecraft.

Saturn’s fourth-largest moon, Dione, passes behind the ringed planet’s largest moon, Titan, in a view from NASA’s Cassini spacecraft.
NASA/JPL-Caltech/Space Science Institute

  • NASA just announced two finalists for its next New Frontiers mission.
  • One project, called Dragonfly, would head to Saturn’s largest moon, Titan.
  • The other, nicknamed CAESAR, would fetch samples from the Churyumov-Gerasimenko comet.
  • One of the two options will be selected for full funding in 2019, and will be launch-ready by 2025, NASA said.

NASA just announced two finalists for its next robotic mission to explore mysterious corners of our solar system.

The picks for the mission, called New Frontiers-4, were chosen from a class of 12 proposals. The final winner will be chosen in 2019, NASA said, and will be granted $850 million and a free rocket ride into the solar system, at a combined value of about $1 billion.

One of the finalists, named Dragonfly, is a lander that would head to Saturn’s moon, Titan. The other, nicknamed CAESAR (which stands for Comet Astrobiology Exploration SAmple Return), would go to the Churyumov-Gerasimenko comet and collect samples.

Each team now has roughly one year and somewhere around $4 million to finalize their concept before NASA makes its ultimate decision.

Here’s a first glimpse at what theDragonfly mission to Titan might look like. The project would attempt to follow up on and advance the Cassini probe’s groundbreaking 13-year exploration of Saturn.

dragonfly new frontiers 4


Dragonfly is a dual-quadcopter lander, being built and tested at the Johns Hopkins University Applied Physics Laboratory. It would take advantage of the thick atmosphere of Saturn’s largest moon to fly to a variety of locations, some hundreds of miles apart.

“Titan is a unique ocean world,” planetary scientist Elizabeth Turtle, who’s leading the Dragonfly mission, said during a NASA teleconference on Wednesday. “It has lakes and seas of liquid and methane and rivers that flow across the surface.”

A false-color image of Titan's Ligeia Mare lake of methane.

A false-color image of Titan’s Ligeia Mare lake of methane.

The radioisotope-powered lander would sample materials and determine surface composition to investigate Titan’s organic chemistry and habitability, monitor atmospheric and surface conditions, capture images of landforms to investigate geological processes, and perform seismic studies. Turtle said the probe would arrive on Titan in 2034 and radio back data to Earth as it hops from location to location.

The other option, CAESAR, a rendering of which is shown below, would fly back to a comet that the European Space Agency explored in 2004 with its Rosetta mission. The mission would grab a sample from the nucleus of Churyumov-Gerasimenko, with the hope of learning about how those materials contributed to the early Earth, including the origins of our oceans and life.

“They’re the most primitive building blocks of planets,” CAESAR mission leader Steve Squyres said, adding that comets carry volatile ices that can’t be found anywhere else in the solar system. “They obtain materials that date from the very earliest moments of solar system formation and even before.”

If picked, Squires said, his spacecraft would collect at least a 100-gram sample of the comet, which will come back to Earth in capsules.

“The sample will arrive back on Earth on the 20th of November, 2038, so mark your calendars,” he said.

caesar concept


The CAESAR spacecraft would be built by space manufacturing company Orbital ATK, and would use solar-electric propulsion.

Whichever option NASA ultimately chooses, both missions would allow deeper exploration of fascinating corners of the solar system that we already have a bit of knowledge about.

This will be the fourth New Fronteirs mission (hence the number in its name). The three previous missions were the New Horizons nuclear-powered probe that flew by Pluto in 2015 and is now going deeper into the Kuiper Belt; OSIRIS-REx, a robot that’s flying out to meet asteroid Bennu and bring a sample of it back to Earth in 2018; and the Juno mission, which is looping around Jupiter, recording unprecedented data and breathtaking images of the planet.