Artist’s concept of Dragonfly soaring over the dunes of Saturn’s moon Titan.
What if there was a spacecraft that could land on an Earth-like world in our solar system and then fly around, picking a new spot every day? It would send back images of lakes, oceans, shorelines, valleys, mountains and mesas.
That’s precisely what NASA is planning for Titan, Saturn’s largest moon and the only world in the solar system other than Earth with liquids on its surface. The Dragonfly mission, just confirmed by NASA, looks set to inspire a generation with planetary views the likes of which none of us have ever seen before.
Bigger than Mercury and with the most complex atmosphere in the solar system, Titan is about to be revealed by a drone. “Dragonfly is such a daring endeavor, like nothing that has ever been done before,” said Zibi Turtle, Dragonfly's Principal Investigator.
This is how it’s going to be done.
Meet The ‘Dragonfly’
Welcome to Dragonfly, an autonomously operated rotorcraft or octocopter with eight blades that will, from 2034, spend a minimum of two Earth-years exploring the Earth-like world in a series of flights that see it change location every Titan day (16 Earth days). It will travel tens of miles or kilometers in under an hour.
The vehicle itself is much like a helicopter. It’s about the same size as a Mars rover—so, about the size of a small SUV—and has been tested over California deserts that resemble Titan’s dunes, in wind tunnels at NASA’s Langley Research Center, and in NASA Applied Physics Laboratory’s Titan Chamber. It’s not fitted with solar panels. It’s not practical to be so far from the sun beneath a hazy sky, so Dragonfly will be nuclear-powered.
Onboard Dragonfly will be a suite of science instruments designed to explore the prebiotic organic chemistry of Titan:
- Neutron spectrometer.
- A drill system.
- Mass spectrometer.
Together, these will allow Dragonfly to investigate Titan’s surface and literally scratch it looking for organic molecules and potential biosignatures.
Dragonfly will pick up where Huygens left off. Much of what scientists know about Titan comes from Huygens, which, on Jan. 14, 2005, descended to Titan’s surface over 2 hours 27 minutes, shooting this iconic time-lapse video. It’s the farthest spacecraft from Earth on the surface of another world.
The Pull Of Titan
Titan resembles early Earth, but there are many interesting differences between it and present-day Earth. Its atmosphere is 98% nitrogen and 2% methane. Its surface temperature is around -290ºF/-179ºC. Titan gravity is 14% of the Earth’s—a fact that will permit a spacecraft like Dragonfly to fly around almost effortlessly.
The largest of Saturn’s 82 known moons—and the only one you can see in a small telescope—Titan is considered an ocean world. Like on Ganymede and Europa at Jupiter and Enceladus at Saturn, Titan’s ocean is thought to exist below the surface. It also has a sea, “Kraken Mare,” almost as big as all five Great Lakes combined, which, in theory, a robotic submarine could explore. But its seas and lakes contain not water but liquid ethane and methane.
Although it’s known to have many Earth-like features—such as lakes, rivers, mountains, and canyons—it’s proved a complex world to study from afar because of its dense, hazy atmosphere. During its 2004-2017 mission, NASA’s flagship Cassini probe flew 600 miles above Titan, sending back data on its Mississippi-like liquid rivers and lakes, valleys, mountain ridges, mesas and dunes.
Images from NASA's Cassini mission show river networks draining into lakes in Titan's north polar ... [+]
Exploration Of Titan
“Because of Titan’s thick, hazy atmosphere, its surface had barely been seen before Cassini and Huygens arrived,” said Turtle. “The first infrared and radar images revealed the surface, but in many cases, the features were still quite hard to interpret because Titan’s so different from other places we’ve explored ... Titan was still a very unfamiliar place when the Huygens probe descended through the atmosphere making measurements of the atmosphere and taking images of the surface.”
When planetary scientists first saw Huygens’ images of river channels and Earth-like landscapes, they were astounded. “I can’t wait to go back with Dragonfly,” said Turtle.
Titan’s atmospheric chemistry is more complex than any other known atmosphere in the solar system. Scientists know that it contains many organic molecules, including hydrocarbons and minerals that don’t exist on Earth. Titan's chemistry is thought to change with the seasons. However, because Saturn orbits the sun once every 29 Earth years, each season lasts about seven Earth years.
Increasing Costs
The Dragonfly mission will launch in July 2028 atop a superheavy rocket—possibly a SpaceX Falcon Heavy—to give it enough thrust to land on schedule in 2034. That’s despite a COVID delay that has delayed its planned launch in 2026.
The use of a much bigger rocket and an increase in other costs associated with the delay means NASA has committed to spending $3.35 billion on Dragonfly. Back in 2019, when it was selected for NASA’s New Frontiers program, it was meant to cost $1 billion—the cost-cap of that mission category.
Other New Frontiers missions include the New Horizons mission to Pluto and the Kuiper Belt, the Juno mission orbiting Jupiter and OSIRIS-REx, which returned samples from the asteroid Bennu in September.
At $3.35 billion, Dragonfly is approaching the budget of a full-scale NASA flagship mission—and that’s delayed the following New Horizons mission, which could include:
- A Ceres sample return mission.
- Flyby mission of Saturn’s moon Enceladus.
- An orbiter of Titan.
- A comet surface sample return.
- A Saturn probe.
- An orbiter and lander mission to a Centaur.
- A Venus in-situ explorer.
Wishing you clear skies and wide eyes.
