A couple posts ago, I reviewed a book about an expedition to Titan—arguably the most interesting celestial body in the Solar System—and I’d like to continue in that theme this week, turning my attention to a real, official Titan exploration project under development at NASA: the Dragonfly mission.
Dragonfly will be a quadcopter aircraft sent on a nine-year voyage to Saturn, with launch in 2027 and arrival in 2036. The lengthy transit time is due to the unavailability of SLS for this mission; instead, Dragonfly will fly by Venus once and by Earth three times, using successive gravity assists to boost its apoapsis into the outer Solar System. Once there, it will land using an aeroshell quite like Curiosity‘s.
The whole spacecraft architecture is, in fact, somewhat reminiscent of Curiosity. Its plutonium RTG power source is essentially the same, and many instruments will be copied over, too. Why reinvent the wheel? Of course, Dragonfly will be a mere 450 kilograms against Curiosity‘s 899, which makes sense, since it a) has to travel much deeper into the Solar System, and b) has to be light enough to take off.
The RTG will provide just enough juice to sustain half an hour of flight across ten kilometers, after which Dragonfly will have to find a safe landing zone and recharge for the night. During this time, though, it will not be idle—nighttime scientific activities will include sample analysis, seismological and meteorological observations, and microscopic imaging. Since Titan is tidally locked to Saturn, its local day is equivalent to its orbital period of about sixteen Earth days; nights are going to be long and frigid. When dawn arrives, then, the probe will take off again and resume its explorations, hopping from site to site in an effort to unravel Titan’s numerous mysteries.
Besides taking cool pictures, Dragonfly’s primary scientific objective is to study the development of prebiotic organic compounds in Titan’s various nooks and crannies, and assess how far the moon has made it towards producing life. We currently know very little about its biochemistry, our only sources thus far being the orbital scans made by Cassini and the data from Huygens, which only lasted ninety minutes on the surface before its batteries ran out.
Amino acids and pyrimidines are of particular interest, according to Wikipedia. The whole biological aspect is well beyond my understanding—I spent high school biology sketching spaceships in my planner and playing Call of Duty on my friend’s laptop—but Titan represents a tremendous opportunity for those who specialize in the field, sure to revolutionize our understanding of how organic processes occur beyond Earth. In terms of scientific instruments, the exobiology goals will be realized by DraMS (Dragonfly Mass Spectrometer) and DraGNS (Dragonfly Gamma-Ray and Neutron Spectrometer). These will, respectively, analyze surface samples and analyze the ground beneath the probe.
Might Dragonfly find life? Well, nothing can be ruled out, but at the present stage NASA is not counting on the discovery of extraterrestrial microbes—chemical building blocks will be enough. Unless the probe’s instruments happen upon irrefutable biosignatures, the question of life on Titan will have to be settled by a follow-on mission with more capable instruments.
Note that if we find life on Titan, human settlement will probably go out the window (curse you, planetary protection lobby!), so I’m not really rooting for that possibility. Hopefully they’ll discover life on Europa or Enceladus instead—those worlds are worthless from a colonization perspective.
Interestingly, Dragonfly will not be the first aircraft to take to the skies of another world—that honor will (barring a mishap) belong to Ingenuity, a very small testbed helicopter that launched with the Perseverance rover last July, and is expected to land on Mars in February 2021. Of course, Mars’ atmosphere is one percent as dense as Earth’s and Titan’s is four times denser, so you tell me which body is easier to fly on.
Some notes on Dragonfly’s travel itinerary: upon the completion of its long voyage through space, it will land in Titan’s Shangri-La region, an area that was formerly an ocean but now is a plain coated with some type of dark compound. Since it is not limited by having to crawl slowly over uneven terrain like Curiosity, Dragonfly will be able to traverse Shangri-La with relative ease and reach its next stop, Selk Crater. Selk Crater has the distinction of being quite young, as well as the site of cryovolcanic activity. It is expected that water ice and organic compounds will mix in interesting ways here.
The Dragonfly mission will be a grand adventure through one of the most fascinating sites in our Solar System, and it is shaping up to be one of the most hotly anticipated space events of the early 21st century (though Artemis and SpaceX’s Mars colony will doubtless get much more attention). I’ll be in my late thirties when it finally arrives at Titan. That’s the nature of these sorts of space missions, unfortunately—they are long shots, with extremely delayed returns. Space is huge and it takes a ridiculously long time to get anywhere. But, at the end, when the first dun-colored images stream back from the surface of Titan, I am sure the wait will have been worth it.