Aerial probes can cover more ground than rovers. At top speed, Mars rovers like Curiosity and Opportunity can only reach about 0.1 miles an hour. Rovers aren’t built to traverse over difficult terrain, and their wheels are prone to damage from sharp rocks. Autonomous, drone-like spacecraft could hop from one spot to another, providing humans with an unprecedented degree of mobility on another planet.
It would also provide them with a better view. The cameras on rovers can produce some very high-resolution photos, but they can only see so far. Aerial spacecraft can scout exploration targets and then gently swoop down to get a closer look.
The concept of a Mars copter is not new; NASA has been thinking about the possibility of autonomous aircraft on Mars since the beginnings of space exploration. NASA and others have worked on such technology on Earth just as long. But only in the last decade or so has the technology of autonomous aircraft seemed to mature, such that now drones seem like they’re everywhere—they deliver packages, film movies, crash into the White House lawn.
Now that the technology appears ready, it seems like a natural next step for NASA to take one to Mars—and beyond. NASA is currently considering sending a drone to Titan, a moon of Saturn and one of the most exciting candidates for life in the solar system.
As part of a robotic-mission competition, NASA gave $4 million to the team of Elizabeth Turtle, a planetary scientist at Johns Hopkins University’s Applied Physics Laboratory, to develop her design for an autonomous dual-quadcopter that would roam Titan, Saturn’s largest moon.
Dragonfly would spend its mission flitting from location to location, touching down on the surface to study the moon’s chemical composition and search for signs of life. NASA will decide next year whether to pursue this mission or the competition’s other finalist, the Comet Astrobiology Exploration Sample Return (CAESAR), which would study a comet that approaches the sun about every six-and-a-half years. “In just a few flights, Dragonfly will be able to go farther than the Opportunity rover on Mars has in the last 12 years,” Peter Bedini, the program manager for Dragonfly, said at a talk last year.
Titan, like Earth, is an ocean world. Through a process similar to that of our water cycle, methane clouds release methane rains that feed methane seas, lakes, and streams that scientists hope contain some kind of life-forms. Titan is also a great place to fly.
Titan has a thick atmosphere and low gravity, which together provide the perfect conditions for easy flight. If you strapped some makeshift wings on your arms and started flapping on Titan, you’d soar. You’d be unfathomably cold—maximum surface temperatures hover around -292 degrees Fahrenheit—but you’d be flying.