Nasa details its Dragonfly mission to Saturn’s Moon Titan

It will be the first mission to explore the surface of Titan, which is the only moon in our solar system with a substantial atmosphere and liquid on the surface that could potentially harbour life.

It even has a weather system like Earth’s, although its rains methane instead of water.

Dragonfly’s goals include searching for chemical biosignatures, investigating the moon’s active methane cycle, and exploring the prebiotic chemistry currently taking place in Titan’s atmosphere and on its surface.

“Titan represents an explorer’s utopia,” said Alex Hayes, a Dragonfly co-investigator. “The science questions we have for Titan are very broad because we don’t know much about what is actually going on at the surface yet. For every question we answered during the Cassini mission’s exploration of Titan from Saturn orbit, we gained 10 new ones.”

The Cassini probe, which was launched in 1997, orbited Saturn for 13 years, but Titan’s thick methane atmosphere made it impossible to reliably identify the materials on its surface. 

However, the probe did have a radar that enabled scientists to penetrate the atmosphere and identify Earth-like morphologic structures, including dunes, lakes and mountains, although their composition could not be determined.

“In fact, at the time Cassini was launched we didn’t even know if the surface of Titan was a global liquid ocean of methane and ethane, or a solid surface of water ice and solid organics,” said Hayes.

Cassini came equipped with a module known as the Huygens probe, which actually landed on Titan in 2005. However, it only managed to return data to Earth for around 90 minutes, using the orbiter as a relay.

At the landing site, it encountered of pebbles of water ice scattered over an orange surface, the majority of which is covered by a thin haze of methane.

Huygens found the brightness of the surface of Titan (at time of landing) to be about one thousand times dimmer than full solar illumination on Earth.

“My primary science interests are in understanding Titan as a complex Earth-like world and trying to understand the processes that are driving its evolution,” Hayes said. “That involves everything from the methane cycle’s interactions with the surface and the atmosphere to the routing of material throughout the surface and potential exchange with the interior.”

Dragonfly will spend a full Titan day (equivalent to 16 Earth days) in one location conducting science experiments and observations, and then fly to a new location.

The science team will need to make decisions about what the spacecraft will do next based on lessons from the previous location in a similar fashion to the Mars rovers.

Titan’s low gravity (around one-seventh of Earth’s) and thick atmosphere (four times denser than Earth’s) make it an ideal place for an aerial vehicle.

Dragonfly’s search for chemical biosignatures will also be wide-ranging. In addition to examining Titan’s habitability in general, the team will be investigating potential chemical biosignatures, past or present, from both water-based life to that which might use liquid hydrocarbons as a solvent, such as within its lakes, seas or aquifers.