Planetary Radio: Space Exploration, Astronomy and Science - We’re Sending a Flying Machine to Titan

Episode Date: July 10, 2019

NASA has given the go-ahead for Dragonfly, a flying rotorcraft that will explore Saturn’s mysterious moon Titan. Mission Principal Investigator Elizabeth “Zibi” Turtle helps us celebrate. Troy Hudson tells us about the ongoing effort to rescue the Mole on Mars lander InSight. And Bruce Betts provides the latest on LightSail 2’s attempt to sail on the light of the sun. Learn more about all of this week’s topics at:  http://www.planetary.org/multimedia/planetary-radio/show/2019/0710-2019-troy-hudson-zibi-turtle-ls2.html Learn more about your ad choices. Visit megaphone.fm/adchoicesSee omnystudio.com/listener for privacy information.See omnystudio.com/listener for privacy information.

We're sending a flying machine to Titan, this week on Planetary Radio. Welcome. I'm Matt Kaplan of the Planetary Society. With more of the human adventure across our solar system and beyond, we're back from the light sail to launch with a packed show for your cosmic enjoyment. NASA announced on June 27th that the Dragonfly Rotorcraft will explore Saturn's marvelous moon. We'll welcome back Principal Investigator Zibi Turtle for an update on this thrilling mission. And when we get to this week's What's Up, Bruce Betts will tell us the latest news about LightSail 2. The little CubeSat is in great shape, but deployment of its big wings

has been delayed a bit further. First, though, we'll check in with Troy Hudson. You may remember that Troy was with us on Caltech's Beckman Auditorium stage when this happened. Touchdown confirmed! Whoa! Yeah!

Yes! Oh! Woo! Woo! Woo! Woo! Woo! Woo! Woo! Woo! Woo! Woo! Woo! Woo! Woo! Woo! Woo! Woo! Woo! Woo! Woo! Woo! Woo! Woo! Woo! Woo! Woo! Woo! Woo! Woo! Woo! That was the November 26, 2018 landing of InSight on Mars. InSight is interior exploration using seismic investigations, geodesy, and heat transport. The Heat Flow and Physical Properties Package, or HP3, is even better known simply as the MOL. Troy Hudson is a planetary geologist and an instrument engineer at the Jet Propulsion Laboratory.

He's worked very closely for years with the MOL's creator, the German space agency known as the DLR. The mole ran into trouble very soon after it began its attempt to hammer below the red planet's surface. Attempts to get it back on track have gone slowly and carefully, but there has been progress. And that's why I recently got a hold of Troy when he had a few minutes to spare at JPL. Troy, thanks so much for coming back to Planetary Radio. I wish that the circumstances were a little bit better, but you guys are working on this, right? Yes. Well, thank you very much for having me back. And yeah, it's an ongoing anomaly resolution action. I have just watched again one of the most remarkable videos I've ever seen

return from space. Really two videos since you had two cameras watching this. And it was using the arm and the grapple on inside to move forward with what you're hoping you'll be able to do. Could you talk about what these videos show us? Sure. Well, the mole didn't make very good progress after the first hammering attempt. And we've been trying over the past few months to understand this and to do what we can to help it make further progress. But at a certain point, we got all the information we could get. The support structure, which shepherded the mole on its way to Mars and to the surface of Mars, was in our way. It was covering up the mole, preventing us from getting a clear picture, and it also prevented us from interacting directly with the mole using the arm, for instance.

So the first step, or rather the next step at this stage, was to pick up the support structure and move it away. This is not something we ever planned to do. It was something that we had to test extensively before we would execute it. And there were a number of risks and challenges associated with it that made us do it in a few small steps. There was some nail biting going on. It's another example of this amazing ingenuity, folks at JPL and across all of space exploration have had to exercise on a regular basis, doing something completely unexpected with that arm and grapple. I mean, what might have gone

wrong? Is it possible that if you would drop the support structure on the mole, the mole might have been knocked over? Well, certainly if it had dropped, that would have been a problem, but that's very unlikely to happen given the design and construction of those claws and the way that they close around the grapple. However, there were other risks because we had to do the lift in three stages because we wanted to make sure when we were lifting the support structure, we weren't inadvertently extracting the mole from the ground. We weren't sure if there was a snag inside the support structure that might be acting to hold the mole from digging further. So we wanted to lift in small increments, but this meant that we had to stay suspended in a lifted configuration for several days.

And that's not something we ever did in the actual deployment. When we picked up an instrument from the deck and put it on the ground, it was in the air for at most 20 minutes. But in this case, we had the support structure suspended above the ground for, I think, a total of eight days. And Mars has winds, and those winds can interact with the support structure. It's very light. It's a carbon fiber device and can very easily be swung around by wind. And so we were concerned that that might yank on the mole or

change things in a way that was difficult to recover from. You're making this even more impressive and exciting, but you did it. I mean, it was successful. You got it away from the mole and what was revealed and how did it help you decide what the next step might be? One of the things about the mole is we have a very precise way of measuring its depth once it gets into the ground. But at this point, we didn't really have very fine depth knowledge. So we didn't know actually how much of the mole was sticking out of the ground. It could have been anywhere from three centimeters to 10 centimeters. So by lifting a support structure, we have a completely clear picture of how much of the mole is sticking out. It turns out it's about five centimeters. It's sort of pointing in the direction we expected from seismic measurements. But one of the big

surprises that we see is that there seems to be a large pit, or there is a large pit around the mole. It's about two mole diameters across, and the mole is about the size of a quarter. That's a big surprise. That was the clue, right, that told you that this might be a problem with friction? We had suspected that friction might be the problem before seeing the pit, clearly. But the friction problem could have come from the walls pulling away from the mole by a millimeter or something, a very small amount. That wouldn't really classify as a pit, more, I guess, a cavity. But in this case, it's big. Describe for us, what is it? Why does the mole need friction to be able to do its job? I mean, I would have thought that lack of friction might have even helped as it tried to hammer its way through Mars.

Well, the way the mole works, it's kind of like a pile driver. There's a mechanism inside that slams against the inside of the mole's tip and drives it forward. But because of the soil outside and the mechanism itself, there's always rebound. There's always something that bounces back. Newton's second law. Every action has an equal and opposite reaction. So we try to absorb as much of that rebound force in a spring inside the mole as we can. But some of it still makes it out.

The hull will tend to jump back. So a little bit of friction on the walls is necessary to prevent that and let the mole continue to make forward progress. It's a surprisingly small amount of friction which is needed. And so we expected that the soil on Mars, given what we've seen in other landing sites, would easily provide that friction. But the soil at this site seems to be a bit different. As a scientist, because you're a scientist and an engineer, you've studied the properties of the Martian surface for years. And if everybody is right

about this problem with the friction, is this also telling us that we still have a lot to learn about the red planet? And in a sense, we've kind of revealed something new. Oh, we absolutely have a lot to learn. Mars always surprises us. And that's one of the joys of doing science is that the unexpected comes up and you have to try to find a way to explain that given the same physics, the same principles operate on Mars and on Earth. But the specifics in a particular location can be very different. Mars is a big place. It's got as much land surface area as earth does and soil on earth is not homogeneous. It's not the same everywhere. And likewise, the soil on Mars seems to be different. And in this case, it seems to be slightly more cohesive

than we've seen in other places. Other landing sites like the Mars exploration rovers, they drove through some very loose sandy material, kind of like the Mars Exploration Rovers, they drove through some very loose, sandy material, kind of like granulated sugar. It just kind of flows back down and fills up any holes you try to make. But at this site, the soil seems to have properties similar to baker's flour in that if you put your finger in a bunch of flour and wiggle it around, you'll make a little well because the particles kind of hold itself up in a bunch of flour and wiggle it around, you'll make a little well, because the particles kind of hold itself up in a vertical wall. That could be an explanation for what we're seeing here. But we've got more information to get. We have some okay resolution pictures of the mole and the pit, but the grapple is still attached to the support structure. Over the coming days, we're

going to release the grapple, and then we'll be able to get closer pictures of the pit and the walls of the pit. And that might tell us, well, certainly tell us about the local geology, but it might also tell us about why the mole created this pit. So one step at a time, and great that you're taking it slowly. If all of this proves out, and you become relatively confident that this may be the problem, then what is the thinking about what you may be able to do to help the mole get a grip? Well, the best thing to do would be whatever we can to increase friction. And the simplest way to think about that, and one of the likely avenues we're investigating, is to collapse the pit, to use the robotic arm as a means to push

on the soil and fill in that pit. We could also potentially scoop soil up from somewhere else and fill in the pit, like filling up a hole, but that's even more complicated. So we're trying to come up with a solution which has a high probability of success, relatively low risk to the arm, and can be done quickly because the more complicated it is, the longer we have to test it. And we don't have an infinite amount of time. What is it that puts the time constraint on these efforts? Well, dust continues to collect on the solar panels. And so the amount of power that InSight has is going down over time. We're also in late winter, early spring era. So the amount of power that InSight has is going down over time. We're also in late winter, early spring era. So the amount of sunlight that we're getting is not very high right now.

The arm requires energy, even at night when it's not operating, it has heaters to keep it warm. That sucks power from the rest of the spacecraft. At a certain point, we haven't reached it yet, but at a certain point we'll have to make a choice. And obviously we're going to choose the spacecraft because the seismometer and all the other instruments are doing great. There's another constraint which is motivating us is that Mars is going to go behind the sun soon. We're approaching conjunction. And from about mid-August to mid-September, we won't be able to talk to InSight and tell it to do anything. So we're going to try to get as much of this anomaly

response in before conjunction. And then hopefully everything will still be working after conjunction, the arm included, and we'll be able to continue the process. Because we might reach a solution before conjunction, but I think it's more likely we're going to have to continue after. Are you hoping for one of those handy dust devils to pass by and sweep off the solar panels? Or could that be more trouble than it's worth? No, no. A cleaning event like that would be fantastic for everyone concerned. And we certainly see lots of vortices and dust devils or dustless devils also at this site. We can tell from our pressure sensors and wind sensors that they come

by, but we haven't seen yet any significant dust clearing events. I'm hoping for one, for sure, but we can't count on it. We'll join you in that hope. Thank you. I have to ask, what if it turns out that it is a big rock down there that's blocking your progress, or maybe Marvin the Martian's helmet, then what can you do? In the circumstance of a stone or some other sort of hard obstacle in front of us, there isn't a lot. We don't have many options. We can't pick the mole up out of the hole and put it somewhere else.

We can't grab onto it with the grapple. It's not designed for that. We could try to angle the mole in a different direction, push it with the arm, kind of tilt it over and see if we can get it to go around an obstacle if it's not too big. But there's a lot of assumptions in any such path because you can't really see what's going on at the tip. Anything else you want to say about your colleagues who are working with that seismometer size on InSight, which was, of course, the other major instrument that was carried by InSight to the red planet? Well, I've been mostly focused on the HP cubed anomalies, but I do know that the seismometer

has been working flawlessly and has been reporting Mars quakes. I think the biggest one was a little bit bigger than a magnitude three, three and a half. Um, that's been seen so far. Uh, Mars seems to be a bit more seismically quiet than we expected, but it still does have quakes. And the seismometer was very helpful for us in determining the location and orientation of the mole. Even though it's so close, we could actually determine what direction the mole was pointing, what compass direction it was pointing in from the seismometer data. So it's certainly been a help in resolving this anomaly, but they're doing all their own excellent science and the whole science team is very happy with the way SAIS is going.

Absolutely fascinating that this other instrument was able to help you guys in this way that you've now described a couple of times. I'll close with this. You remember that moment of total joy and celebration that we shared with over a thousand people at Caltech when we watched the landing back on November 26th. Until the end of my days, I will remember it. It was me too. I'm right there with you. I was right there with you. I have to think that it's been an emotional roller coaster since then.

Am I right? And what's the mood now? I mean, you sound pretty upbeat. I am now. I wasn't then. what's the mood now? I mean, you sound pretty upbeat. I am now. I wasn't then. When this first happened, it did send me into a bit of a, I would say, depression for a month or so. I mean, I continued to come to work and tried to do my best to solve the problems. But when I got home at the end of the day, I didn't want to talk to anybody. I didn't want to go outside. I just wanted to sleep. And just my, Matt was, was a wonderful support during that time and my friends as well. Um, but you know, as all humans do, you know, crisis happens and if it continues to happen, we adjust. And now it's at a point where I feel, uh, I feel

good that, that we can do things and that we are doing things and they're going well. We still may not succeed. And if that ends up being the case, I'll have to deal with that. But right now, it's uncertain. And so I'm looking at it with the most reasonable optimism I can. I tend to be a pretty optimistic person. So I'm just hoping that we'll continue to have opportunities to try. Troy, kudos to Matt and to your friends. And please know that there are lots more of us out here

who are pulling for you and the rest of the HP cubed or mole team and hope that you're still going to be able to get down there meters below the surface of Mars and tell us a lot more about the red planet. Well, thank you so much for the well wishes. And I also wish you all the best of luck with LightSail 2's deployment. That's very exciting for me as well. And I'm thrilled to be able to watch that and see that literally unfold. Thank you so much. You're absolutely right. It may actually do that unfolding by the time people

hear this show, but maybe not. And your good wishes are much appreciated. Thank you, Troy. And my pleasure, Matt. Best of success to you and the entire team as this effort continues. Oh, thanks so much. JPL planetary geologist and instrument engineer Troy Hudson. Next up is Zibi Turtle and Dragonfly. There are so many worthy missions of exploration and discovery that never get the opportunity to explore our solar system and beyond. It's a long, hard road just to get the green light from NASA or another space agency, and then the work has just begun. But

it's reason to celebrate, and that's why I've invited Elizabeth Zibby Turtle back to Planetary Radio. Zibby became one of our first guests back in March of 2003. We talked back then about icy worlds like Mars and Europa. Now she will lead a mission to yet another frigid globe, but one that is in some ways more like our own warm Earth than any other body in our solar neighborhood. Dragonfly will be a nuclear powered eight rotor science powerhouse able to fly high above Titan's surface and then set down for extended stays at the most intriguing spots on Saturn's big moon. I caught Zibi as she was in the United Kingdom wrapping up attendance at a conference. She was kind enough to spend a few minutes bringing us up to date on this exciting mission. Zibi, welcome back to Planetary Radio and congratulations from all of us at the Planetary Society.

Planetary Society. I cannot tell you how thrilled we all were to hear that we're going to be sending a flying machine to this moon of Saturn. Again, congratulations. Thank you very much. It's so exciting to be looking ahead to going to explore Titan in situ. How did you learn that Dragonfly had been selected as part of the NASA's New Frontiers program? I mean, where were you? I was in my office and I got a call from Thomas Zurbuchen. Oh, that's great. Right from almost the top from Thomas Zurbuchen himself, who has, among others, said a lot of great things about this mission,

including the NASA administrator, Jim Bridenstine, who said that this mission, which was unthinkable not many years ago, it's just terrific that basically we're able to take this on now. I mean, he's right, right? I mean, this is just not something that could have been considered not long ago. The timing has really come together well in a number of different areas for this mission. We have the scientific information from Cassini and Huygens about Titan's surface and about its atmosphere. And we have the technology in the payload. A lot of the technology that we're using is based on technology that's on the surface of Mars or is operated on other spacecraft missions.

And then this revolution in rotorcraft technology and autonomous navigation. in rotorcraft technology and autonomous navigation. The timing couldn't be better in terms of the opportunity to do this mission because we're really not having to invent anything at this point. The innovation is taking these existing technologies and applying them to exploring Titan. That is great to hear. And I'm so glad that you mentioned Cassini-Huygens. Could you have considered a mission like Dragonfly without Cassini-Huygens. Could you have considered a mission like Dragonfly without Cassini-Huygens having delivered all of the data and the success that it did? We could have considered a similar mission, but the information, the details about the surface, Cassini has really shown us where we need to go to take the next steps in answering questions about habitability and prebiotic

chemistry on Titan. And so it certainly informs the questions and the mission design to be able to answer those questions. But people have been talking about flying on Titan since before the Cassini mission. We've known that flight would be a good way to explore Titan for a couple of decades at this point. I didn't know that. Let's talk a little bit about the spacecraft before we talk more about where you're going to go on this big moon and what you hope to find, where you'll be visiting. I've watched a lot of your videos on the APL website, and we'll put a link up, of course, to the Dragonfly site there, along with some links to some of our past conversations on the show page at planetary.org

slash radio. It includes an animation of Dragonfly's entry, descent, and landing. And watching it, I could almost fool myself that I was watching Curiosity come down to Mars, that I was watching Curiosity come down to Mars, at least until Dragonfly was released and actually flies down to the surface. So it is a flying machine right from the point of its arrival. Yes, absolutely. There are a couple of differences for Dragonfly. One is that the Titan atmosphere is actually very extended because the gravity is very low on Titan comparatively. And so the entry sequence is two hours long as opposed to the very short sequences we're used to on Mars. And that means we have a lot of time to phase all the different activities during the entry, descent, and landing sequence. And then yes, at the end, we don't need a separate landing system to take us down to the surface because Dragonfly can fly away from the back shell and descend to

the surface on its own power. So many reasons for those Mars folks to be jealous or envious of you. It's easier to fly on Titan. That's true. Yeah, by far. Although, of course, we wish that little helicopter on the 2020 rover the best of luck as well. Exactly. Absolutely. I mean, it's great to be developing the technology for two different destinations in parallel. That's a lot of fun. You've already had a rotorcraft designed for testing on Earth. There is video of it flying around in a field somewhere, I bet, not far from APL, I'm guessing. But how do you test a flying machine that's going to have to work in this kind of terrible cold and in this atmosphere that is four times as dense as Earth's? I mean, how do you simulate that down here? Earths? I mean, how do you simulate that down here? There are a number of ways we can do testing. And one of the great things actually is that we can do a lot of direct testing as we will fly on Titan. Testing components, testing the actual flight hardware, testing the navigation algorithms

as well. And so there are a number of different things. And in each test, we can design it to emphasize the particular aspects that we want to address. And there are a number of test chambers. We'll be building a chamber at APL as well to do direct testing and to be able to test at pressure. Titan's atmosphere at the surface is about one and a half times the surface pressure here on Earth. We're used to doing pressure testing at very low pressures or in vacuums for flight hardware. But here, we actually need to do the opposite and have a slightly higher pressure. But that's absolutely something that test chambers have the capability to do. And we've done some testing already of the motors at cryogenic temperatures. Wow. That's reassuring. And pretty far ahead of

time. I mean, since you're not expecting to launch until 2026, what's going to be keeping you most busy between now and then as this spacecraft comes together? Oh, well, there's a lot of work to go. Seven years sounds like a long time, but it's going to fly by. We're through the preliminary design phase at this point and moving into the more detailed design. And so there'll be a lot of work refining the design, continuing to make sure everything fits together. We will do testing, lots of testing throughout the development to make sure things are functioning as we expect to make sure they function in the appropriate environment for Titan. And it'll be a few years before we're really getting into building the hardware itself. So 2026 launch and then eight years to get to Titan arriving in 2034.

I don't even want to talk about how old I will be at that point. It's more proof that exploring the solar system takes a lot of patience. Yes, the outer solar system definitely takes a lot of patience in terms of the cruise times that can be involved. Titan's a pretty dark place. You've mentioned, I think we talked about in January, how Dragonfly will be nuclear powered. You're going to have an RTG to get you around this world. Yes. Yeah. We use the same power source, the multi-mission radioisotope thermal electric generator, the MMRTG, the same power source that the Curiosity rover is using on Mars. So well proven.

Yes, exactly. Exactly. For Dragonfly, we use that to charge a battery. So we're not doing the operations directly off of the power that comes out of the MMRTG, but we can charge a battery, which allows us to do high power activities like flight and some of the science activities from the battery. You also confirmed for us in January, the Dragonfly is going to have to communicate with Earth via the deep space network, I assume, directly from the surface of Titan. Is that going to be much of a challenge? Direct-to-Earth communication is the most straightforward way to design a mission within some of these cost cap mission categories. So the time mission, the Titan

Mare Explorer that was proposed under Discovery several years ago, did the same thing. The proposal was to do direct Earth communication from the surface. For Dragonfly, we'll be at lower latitude than that mission was proposed to, and we'll be stable, stationary on the surface. If there were a relay satellite, we'd of course have more bandwidth to communicate, but the communication is absolutely sufficient from the surface. Again, because we spend so much time on the surface, most of Dragonfly's time is spent on the surface making science measurements and communicating data to Earth. And because we have the luxury of time at Titan, bandwidth is certainly sufficient to get the science data that we need down. One can always ask for more data, of course, though.

Of course. One can always ask for more data, of course, though. Of course. I suppose you must take some encouragement from the fact that this has been done before. I mean, we heard from Huygens right down to the surface of Titan. Yes. Yes, absolutely. And Huygens landed at the same time of year as Dragonfly will. And so that's kind of another one of these timely aspects of this mission is that based on the schedule laid out for the New Frontiers program, the dragonfly like at that time of year at a similar latitude. And so we can use the information from Huygens directly in terms of the design for Dragonfly.

That is great. How autonomous do you expect Dragonfly will be? I mean, like compared to Curiosity on Mars or other spacecraft? In most cases at this point, there's enough of a delay in communication that a degree of autonomy is needed. And Dragonfly will fly autonomously because there's a 70 minute plus or minus light time. So Dragonfly will be designed to be able to do flights autonomously. We will, of course, have ground in the loop to do checkouts and things like that before and after the flights. But the actual flight will be done autonomously and will navigate autonomously. And that's one of the things that we've been testing in these early design phases is the navigation software and hazard avoidance algorithms and things like that. So you've been able to do that with this test rotorcraft that's been flying around Earth? Yes. And with software algorithms as well. There are a couple of different ways we've done testing. One is testing with a scale model. And we've used both the onboard navigation and compared that to the GPS results. Because of course, on Titan, we don't have GPS, but here on Earth, we have GPS. And so we can use that as a comparison. So we've been able to do that kind of flight testing directly.

We also have really good analogs on Earth for the initial landing site on Titan. Because the dunes on Titan, these great sand seas, are actually longitudinal dunes. And we have very similar landforms in some of the deserts here on Earth. So like the longitudinal dunes in the Namib Desert are a very good analog in terms of the scale of the dunes and the spacing of the dunes. And so we actually can use stereo model, a digital elevation model of the Namib Desert as a test input for our navigation algorithms to make sure that the terrain we expect to find on Titan will have sufficient markers to be able to navigate from location to location on the surface.

Well, let's talk more about the mission and what you hope to accomplish. I saw that you're going to be starting out in this dune field called Shangri-La. Is this one of these longitudinal dunes that you were just talking about? Yes. So the Shangri-La Sand Sea, Dragonfly will target the northwestern reaches of the Shangri-La Sand Sea. And this is one of these areas with longitudinal dunes that Cassini has characterized quite well. We have data from the Cassini Imaging Science Subsystem, Cassini ISS, from the Visual and Infrared Mapping Spectrometer, or VIMS, and from the Cassini radar, all have covered this area. And so we have data from multiple types of instruments to assess the nature of the surface here. The sand seas, the longitudinal dunes, are particularly good in a

number of ways as an initial landing site. And that's because although we tend to think about deserts or sand seas as being entirely sand, these longitudinal dune fields, actually a substantial fraction of the material is these exposed interdune areas. And so one of the reasons we want to target this area is that on Titan, the dunes are made of organic material, not like the silicate sand we have on Earth. And the interdunes often have a water ice component. And that means that in our initial landing site in very close proximity, there are two different types of material that we'd be able to sample and characterize. So it's a very scientifically

appealing landing site. It's also from the perspective of designing a system to land on Titan, having wide flat areas is another attractive aspect of the longitudinal dunes or the interdunes. You've provided more evidence of just the wonder of this world, Titan, and how very different it is from our own planet, and yet how very similar. I mean, you can see this in the animations that I was talking about earlier, where you could almost believe in those animations that Dragonfly was flying over dunes here on Earth that were made of silicate sand, but this is a very different place. Yeah, it's amazing how familiar Titan is. It's out at Saturn's orbit. It's much colder. And the materials are very different. The bedrock is made of water ice. The atmosphere is mostly nitrogen, but has a methane component. And so the rain and clouds and lakes and rivers and seas are liquid methane instead of liquid water. And yet the features that we see are very familiar. And so it's fascinating that such similar processes

occur, similar geologic processes, similar interactions between the atmosphere and the surface that we're very familiar with here on earth in this environment that is so fundamentally, or seems so fundamentally different. You've got a two and a half year baseline mission. How much ground do you hope to cover in that period, beginning at this Shangri-La dune field or sand sea? What we want to be able to do with Dragonfly is measure the composition of Titan's solid surface materials in different environments, different geological settings, where the materials have had different histories. sourced from across Titan. And so that allows us even in a single location, perhaps to sample materials that have come from a broad region or perhaps even globally distributed on Titan. And then in the course of the mission, we traverse toward an impact crater through its ejecta field and then into the impact crater itself, where in the past there will have been liquid water

on the surface of Titan, and it may have had the opportunity to mix with these organic materials. And so that's one of the other reasons we've chosen this landing site is that there's proximity to these other geologic settings associated with the Selk impact crater. So how far we need to travel depends to some extent on where we land in the landing ellipse. But really for Dragonfly, the journey is the goal because it's along the journey that we will be finding different materials that will be able to sample the diversity of the materials on Titan, and to get progressively into these impact crater deposits where the organics will have been able to mix with liquid water.

So do you expect that some of where you will send some of the destinations you may send Dragonfly to, we're not even aware of right now that you may actually say, my goodness, those hills just over that way, maybe a kilometer away, look like they're worth taking a look at? Yes. I mean, that's been one of the fun things with the rovers on Mars, right? Adding mobility to exploration gives you so many different options. And we'll be able to take aerial data to scout future landing sites with Dragonfly as we fly out to scout landing sites, come back to the landing site and send the data back to Earth. I'm sure there'll be all sorts of fascinating discussions about where we should go next.

It's going to be a lot of fun to figure out, to decide all of the different things that we'll be able to explore. I'm sure like we found on Mars, there will be more places we want to go than we can get to at one time. Fascinating discussions. I would expect some heated ones as well, but that's your job as PI, I guess, to resolve that stuff. Are you going to let Dragonfly, are you going to send Dragonfly anywhere near liquid on the surface of Titan? The seas, the flowing liquid, the liquid methane sounds a little bit hazardous, but wouldn't that be interesting? It'd be fascinating. We are landing at low latitude. That's for a couple of reasons, as we talked about. But one of those reasons is that the low latitudes are going to be the

most efficient place to communicate with Earth. Another is that the solid surface materials are one of the big outstanding mysteries after Cassini, the compositions of those materials. And those are going to carry the keys to a lot of the questions we have about prebiotic chemistry. But of course, the lakes and seas on Titan are tantalizing destinations. On Titan, the lakes and seas are mostly seen at high latitudes. There's some hints that maybe there are some lakes at lower latitude, but the really definitive evidence is at higher latitudes. And when Dragonfly arrives, it will be northern winter. And so the high northern latitudes will not be illuminated. And if the sun isn't up, the Earth isn't going to be up in the sky either. And so direct Earth communication becomes a actually constrained the composition of the liquids fairly well, because the Cassini radar was able to penetrate to the bottom of some of the lakes and seas.

And so we actually could do bathymetry, which is fascinating. But that puts a constraint on the composition of the lakes and seas as well. And so they're actually better known. But there would be absolutely fascinating processes at the shorelines of these features. One can dream of extended missions wherein dragonfly can go further and further afield and perhaps dip the skids in the shores of an alien sea. A little tide pool on the shores of Titan. Well, I'll join you in that dream. a little tide pool on the shores of Titan. Well, I'll join you in that dream. Or perhaps we'll find evidence of liquids at lower latitude that we haven't seen at the scales that Cassini has been able to observe. There are almost certainly mysteries that await at the scales that we'll be able to explore with Dragonfly compared to the data from orbit that Cassini took. explore with Dragonfly compared to the data from orbit that Cassini took.

I am literally shaking my head in additional wonder over this mission. You've got a great team. A lot of them are listed on the website, the APL website for Dragonfly, including Ralph Lorenz is your project scientist. Good catch there. You want to say anything about this group? It's been an absolute privilege being part of this team. It's an incredibly dedicated group of people. The proposal process is intense, and there's a lot of work in a lot of very short turnaround

times. In fact, one of the things we commented upon this spring as we were going through one of these intense periods with very short turnaround times was that Dragonfly's operations cycle will have this fairly relaxed schedule by comparison because the Titan day is two weeks long. And so it's kind of a contrast to think about how much more relaxed it would be when we were actually operating on Titan. But the team is incredibly dedicated and brings together experience from Cassini-Huygens, from Mars exploration, from a number of different spacecraft missions, instrument development, as well, of course, as the aeronautical side of things, which we don't usually get to do with spacecraft exploration. This multidisciplinary team, not only in terms of the science, but in terms of the engineering breadth, has just been an incredible amount of fun. We're just so looking forward to spending the next 20 years working

together on this mission. Yeah, in for the long haul. I want to let you say a couple of words as well about some of your partners, partly because I was talking just yesterday with Chris Zachney of Honeybee Robotics, because next week he'll be on the show talking about their PlanetFact system, which we learned at about the same time you got the go-ahead with Dragonfly, is going to be headed to Earth's moon in the coming years. I told him that I'd be talking with you today, and he surprised me. He said Honeybee is part of your mission. with the lander and the instrumentation, been able to take advantage of a lot of the development work that's been done and instrumentation that's active exploring other planets as we speak. The mass spectrometer, which is one of the key instruments, of course,

for measuring the composition of Titan's surface, has heritage from SAM, the SAM instrument on MSL Curiosity that's on Mars right now. And so we're working with the Goddard Space Flight Center on that instrument and working very closely with Goddard and with Honeybee for the sampling system, because Honeybee is building the drills and the pneumatic system that, like a vacuum, will just suck material up from the surface because we have an atmosphere on Titan and we can use pneumatic transfer to bring the material into the mass spectrometer. That's great. Anything else that you want to say about these partners or other instruments on the spacecraft? How we're going to learn what Dragonfly will be able to tell us about Titan. The primary science we want to accomplish is understanding the prebiotic chemistry on Titan that may be so similar to the chemistry that occurred here on

the early Earth. And so the mass spectrometer allows us to get the chemical details. And we have a complement of instruments that allow us to get context for those compositional measurements. Gamma ray and neutron spectrometer, this allows us to get the bulk elemental composition and even information about very near surface layering beneath the lander. So that's very complementary to the very detailed chemistry we'll do at the drill sites. We can get the larger scale, the lander scale composition with the gamma ray and neutron spectrometer. And again, this is based on technology that has flown on Messenger and is being developed for the Psyche mission. And then we also have a meteorology and geophysics package. Of course, we want to be able to understand the weather on Titan and follow

it from day to day. We can do atmospheric profiles because we can fly up to different altitudes to measure how the atmosphere changes with altitude. And then we have, as part of the geophysics package, we have a seismometer so that we'll be able to measure the seismic activity on Titan the same way InSight is doing on Mars right now. Of course, we have a suite of cameras developed by the Male in Space Science System. MS Cube, of course, has experience developing cameras for Mars and many other spacecraft as well. And again, we've learned from Mars. Great place to go for your cameras. Exactly. And we've learned from Mars, you know, the kind of nesting you want of the different resolutions. And so we'll have a suite of cameras with different imaging scales and different views.

Again, we can do observations both from the surface, but also aerial imaging, which will be a lot of fun. And because the high gain antenna is articulated to be able to track earth, we've mounted two cameras on the high gain antenna, and those will allow us to do panoramas, to do stereo imaging by moving the high gain antenna to target the cameras as well. So we'll be able to get understanding of the geology, the atmosphere, and the subsurface to provide the context to understand how materials have interacted on Titan with the detailed chemistry measurements to inform the detailed chemistry measurements we'll get with the mass spectrometer. I can hardly wait, but I will have to wait.

wait, but I will have to wait. I sure hope, Zibi, that we can continue to check in with you as you proceed toward that 2026 launch of Dragonfly toward Titan. And I sure hope, I can't say that I'll still be doing planetary radio, but if I'm here anywhere in 2034, I look forward to sharing that tremendous excitement with you as Dragonfly flies down to the surface of this really amazing and mysterious world. Absolutely. We're looking forward to it, too. Thanks again, and congratulations once again, and best of luck as it all comes together. Thank you. That's Zibby Turtle, Principal Investigator for the Dragonfly mission to Saturn's cloud-shrouded moon, Titan. Time for What's Up on Planetary Radio with a special light sail report built into it. It's a two-for-one.

So we're going to talk to the chief scientist for the Planetary Society, who is also the light sail program manager. Bruce Betts is still up there in San Luis Obispo. Hey, give us the status. It's a little different from what we thought we might be able to say today. Well, yes, if you want to look at it that way. The important thing is we've got a healthy spacecraft in a stable orbit, and we're communicating with it on a daily basis quite frequently. As happens with complex spacecraft, we have been finding various issues and then fixing them.

And particularly right now, we're working issues with the Attitude Determination and Control software, ADCS, and how it's speaking and getting information from some of the sensors. And so we're spending the next few days working those issues because we have to do software and other fixes and then upload them to the spacecraft. We have limited communications. So we're not going to deploy the sail until at least July 21st. So we can really have the ADCS in a good situation, which we'll need when we have that sail out. So we're getting pretty pictures back too, kind of slowly, but we're just releasing some. So check out planetary.org or sail.planetary.org. You can also check out the dashboard that's there and see what the status of the spacecraft is and where it is in any given time. And we'll have links to all of that,

including this brand new, gorgeous image of Earth taken by LightSail 2. Yeah, I'm pretty happy about that. You should be. It's amazing. And you know who else is happy? A lot of our listeners, Amazing. And you know who else is happy? A lot of our listeners, many of whom are members. This from Jose Costa in Brazil, who says he's feeling very proud to be part of the Planetary Society since 2001. We are happy to have you on board, Jose. And this from Chris Beck, Christopher Beck, who was there with us. I got to say hi to him at the launch, the Falcon Heavy launch that put LightSail to where it is now. Cheers from Williamsburg, Virginia. It took me two hours to get the two miles back to my car from the Saturn V center after the launch, and only 11 and a half hours to drive home the 813

miles to Williamsburg the next day. Christopher, we take no responsibility for the traffic leaving the Kennedy Space Center, but I know he had a great time like the rest of us while he was there. But we've got more What's Up stuff to do before we get back to LightSail. What is up? Well, on July 16th, there's a partial lunar eclipse visible from throughout most of Europe, Africa, Central Asia, and the Indian Ocean. So that'll be cool. And we've got planets in the evening sky. We've got Jupiter still dominating the evening sky, looking super bright in the evening in the south. And then Saturn is at opposition, opposite side of the earth from the

sun. And so that means it's rising around sunset, setting around sunrise, looking yellowish in the east in the early evening. She mentioned Jupiter is also still hanging out near the reddish star Antares in Scorpius, which is bright, but much dimmer than Jupiter. And the moon is feeling left out, so it will visit Jupiter on the 13th and Saturn on the 15th. Was this a big week in space? This was a very big week in space, Matt. And we had the first ever Mars flyby, Mariner 4, in 1965. The Apollo 11 launch, you may have heard of that, 50 years ago this week. 40 years ago this week, Skylab reentered the atmosphere and did not hit us. And then just four years ago, New Horizons did its flyby of the Pluto system. Big, big week.

Definitely. And next week will be at least as big. I bet you have a random space fact for us. This time I do. Random space vac! Which, of course, I should have gotten from Zippy Turtle, but you know how it is. That's okay. I enjoy it. I'm sorry, everyone. I'm just absorbed in LightSail 2, so you're going to get all LightSail all the time for a little while. LightSail 2 transmits a beacon with spacecraft engineering

data every seven seconds and a so-called continuous wave or CW Morse code signal every 45 seconds. The CW is LightSail 2's FCC call sign, which of course is WM9XPA, and that's transmitted Morse code. The signals are centered on 437.025 megahertz for those who want to listen in. Most of you can't, but those with amateur radio setups actually can. Yeah, and I've heard from a couple of fans who did pick up the signal. What are those call letters again? Those call letters are WM9XPA. There really ought to be a little radio jingle to go with that, you know, like an old 60s, 70s radio jingle.

This is WM9XPA in orbit. That's magnificent. Don't hurt yourself. Thank you. You're proud of yourself on that one. I know. I really am. You should be.

That was beautiful. I have to go copyright that. Okay, on to the contest. All right, on to the contest. I asked you in my LightSail 2 fit of fitness, what does the label on LightSail 2 on its mini DVD, which contains the names of all members and backers of Whitesail and contributed names and selfies. What does the label on the mini-DVD say that's flying in space right now? How do we do, Matt? First, from Joseph Poutre in Fanwood, New Jersey. He says, I'm certain you've heard this one an

excessive number of times, so I'm trying a variation. Because it is in space in near vacuum, it cannot say anything. You must read it. Oh. Guess what, Joseph? We heard that from absolutely no one else. Here is the person I think who is our winner, chosenbyrandom.org. It's Daniel Huckabee in North Las Vegas, Nevada, who says that printed on the DVD, the mini-DVD, is LightSail, citizen-funded, flight by light. That is correct.

Congratulations to you, Daniel. You are going to be getting a Planetary Society kick asteroid, rubber asteroid, a 200-point itelescope.net account, and a beautiful graphic novel, Apollo, by Fitch, Baker, and Collins. The Collins is Michael Collins, as we mentioned before, but not that Michael Collins. It's all about the mission of Apollo 11 and the three astronauts who became the heroes of that mission. It really is a great graphic novel. We will put that stuff in the mail. He also says, as a new member of the Planetary Society, as of only April this year, I probably missed the deadline to be put on the CD. Beautiful launch, though. What an amazing group to be part of for my passion for space. Nicely put, Daniel.

Yes. That's lovely. Mel Powell in Sherman Oaks, California. I heard that among the rejected label messages were objects reflected in mylar may be closer than they appear. And Dr. Betts is the man. Yes, they were considered not seriously enough, in my opinion. Yes, but in your dreams. Finally, a poem from, not from our poet laureate this time, but from David Douthat in Charlestown, West Virginia. How can you change the world we know and help scientific knowledge grow

with people distracted by phones and TV or arguing politics viciously? Look to the stars and the cosmos fair, inviting us forward if we dare. Build you a spacecraft small and wide. Write people's names on a disc on the side. Let their imag imagination soar. The rocket now rises.

Hear it roar. Now flies the light sail launched at night. Citizen funded flight by light. Beautiful. Pretty darn good. Thank you very much, David. All right. We're ready to move on.

So I mentioned I'm thinking a lot about light sail too. This is a little bit broader question. However, I may have discussed this already. I'm throwing you a bone here. With regards to spacecraft, what does ADCS stand for? I can't get that out of my thoughts right now. Go to planetary.org slash radio contest. You have until the 17th that'll be july 17 wednesday at 8 a.m pacific time to get us this answer uh regarding that abbreviation which is haunting the dreams of dr bruce bett and and you know you might win yourself a 200 point itelescope.net account that account for doing astronomy remotely from anywhere on, they have telescopes all over our planet. We'll throw in a Planetary Society kick

asteroid, rubber asteroid. And can you spare another copy of Astronomy for Kids? I can do that. Well, that's it. It's Astronomy for Kids, except that it's not just for kids. It's Bruce's great book, if I do say so myself, A Guide to the Night Sky, whether you're doing naked eyes, binoculars, or a telescope. It's pretty cool. We'll put that in the

prize package as well. And that means we're done. All right, everybody. Go out there, look up the night sky, and think about what you'd put on your DVD label in space. Thank you. Good night. I hope you're enjoying life in San Luis Obispo because you're going to be there for a while longer. You know, it's beautiful. And every day when I walk outside to head over to Cal Poly, I think, gosh, this is lovely. I'm going to go spend the next many hours inside. It is a great town and a great campus.

That's Bruce Betts. He is the program manager for LightSail and the chief scientist of the Planetary Society, who joins us every week here for What's Up. I'm way behind on responding to the wonderful notes so many of you send. Be assured I read and appreciate all of them. And while you've got your virtual pens out, please give us a review on Apple Podcasts, still also known as iTunes for a while longer. These reviews make a big difference.

Planetary Radio is produced by the Planetary Society in Pasadena, California, and is made possible by our members who take flight almost every day. Mary Liz Benders, our associate producer, Josh Doyle composed our theme, which was arranged and performed by Peter Schlosser. I'm Matt Kaplan, Ad Astra.