NASA's drone-like quadcopter may explore Titan, say scientists

NASA is exploring a plan that could see a drone-like quadcopter buzz above the surface of Saturn's largest moon Titan, scientists say. The Dragonfly project would take advantage of Titan's dense, calm atmosphere to fly from site to site as it measures and analyses the massive moon's chemistry, geology, and potential for life. "There Is something very 'simple' about having a little drone flying around Titan," said Catherine Neish, professor at University of Western Ontario in Canada.

"It's clever in a way that people were not expecting and, I think, it is audacious and exciting - and realistic," said Neish, part of a team led by Elizabeth Turtle at Johns Hopkins Applied Physics Laboratory (APL) in the US. Turtle's proposal for a rotorcraft to investigate Titan was recently selected by NASA as one of two finalists for the US space agency's next New Frontiers mission, the researchers said.

The craft is modelled after drones on Earth, and would have four pairs of stacked rotors that would enable it to zip across Titan geography that has intrigued and mystified scientists for decades. Unlike conventional, slow-moving rovers on Mars, Dragonfly would be able to explore across hundreds of kilometres, researchers said. It will scout for geologic points of interest and take valuable measurements of surface, sub-surface and atmospheric conditions, they said.

The team said Dragonfly would be about two metres long, with multiple rotors that enable good control of the vehicle and built-in mechanical redundancies. For many years, people thought to explore Titan by balloon, rover or small airplane but each has limitations that include mobility, durability, range and effective control. The atmospheric conditions of Titan - with its orange-brown haze of methane and nitrogen - obscure high-resolution views and have made the moon largely inscrutable. 

The veil lifted only in part in 2005 when the Huygens probe (part of the Cassini mission) produced some images of the surface. Those were enough to tantalise researchers but not enough to show more than a glimpse of the whole. With solar power unavailable because of both Titan's distance from the sun and its dense atmosphere, Dragonfly would be plutonium-powered, using a Multi-Mission Radioisotope Thermoelectric Generator.

That is the same power source as used by the Mars Curiosity rover and the Cassini space probe. It could fly several kilometres on a single 'Titan overnight' charge and potentially cover hundreds of kilometres during a Titan day (equivalent to 16 Earth days). Dragonfly would spend less time flying than taking science measurements during its two-year mission.

Its main tasks would be sampling for organic chemistry and habitability; monitoring atmospheric and surface conditions; shooting and transmitting images of landforms; and conducting studies of the moon's seismology, researchers said.