Planetary Radio: Space Exploration, Astronomy and Science - Cassini Update AND LightSail Spreads its Wings!

Episode Date: June 9, 2015

Cassini Project Scientist Linda Spilker, returns with another update on the magnificent mission at Saturn. You’ll also hear Bill Nye and the moment when LightSail began to deploy its solar sail.Learn more about your ad choices. Visit megaphone.fm/adchoicesSee omnystudio.com/listener for privacy information.See omnystudio.com/listener for privacy information.

Back to Saturn with Linda Spilker, this week on Planetary Radio. Welcome to the travel show that takes you to the final frontier. I'm Matt Kaplan of the Planetary Society. The Cassini Mission Project Scientist is back with another exciting update for us. But before we talk with Linda, there's this other project that has had a good week. On Sunday, June 7th, I was with several Planetary Society colleagues, waiting anxiously to hear if LightSail, the Society's solar sail test mission, would successfully unfurl its wings.

The attempt on an earlier orbit had failed. It was critical that the sail be deployed this time. We listened as the mission team did its work. We have beacon telemetry indicating that our motor current position is still zero. Recommend retransmitting sail deploy. Please proceed. We have beacon data that confirms motor count position at 18,000. Copy that.

Oh, my goodness. Oh, my goodness. Beacon data confirms position at 50,000. 50,000. 50,000 now. Avionics. This is system engineer. Were you referring to me, admission? Sure,000. 50,000 now. Avionics. This is System Engineer. Were you referring to the mission?

Sure, Alex. I just wanted to congratulate you on getting the sail out. Good job. Bill Nye, was that a great moment or what? Woo! Woo-hoo-hoo! Still celebrating. I didn't believe it.

When I heard the motor count was going and everybody, that was the real indication. When the motor count started going, that's when you really knew you had it. I didn't believe it. After a few moments or a beat, I figured it out. And now you believe it. Yes. Might as well get a little status report from you. And folks should recognize that we are speaking on the afternoon of Monday the 8th and results are coming

in quickly. Yeah. So today the focus, everybody's focus is to get that good image. Yes. In ideal circumstances, we would get the sequence of images showing the sail going out, except it's in outer space, you don't have any sound, it would just go. But the focus today is to get this image down. Now, everybody, the sail is quite big, and the orbit is elliptical enough, our spacecraft dips into the atmosphere, not like you and I breathe, but those very, very, very few molecules up there, very, very, very high altitude. The sky is black. You're looking at stars, but

there's still molecules up there. And the sail will drag things down very quickly. Some estimates are in just three days. Other estimates are a couple of weeks. But we're not counting on that. We're trying to get these images down. And that's what they call in the movie business, the money shot. Images or no images, and they will certainly be wonderful if we can get them. Has this mission, this test mission, served its purpose as we prepare for what's next? Now, that's a leading question. Yes. LightsSailA has done the job. So we found these subtle problems. The first one was the software deep in this circuit board called firmware programmed in software that you a long time, longer than we tested it on the ground. Well, why didn't you test it longer? Well, we thought we had tested it enough.

And if you remember the Spirit rover on the planet Mars back in 2004, after a few days they had to upload a whole new operating system because there was a glitch or a problem that developed many, many hours into the running of the software, some counters overfilled and so on. So we had a similar, really a similar problem with LightSail. And the other thing was this battery deal giving you a fault condition, as the engineers call it, probably a result of going into bright sunlight, dark space, bright sunlight, dark space. And it fooled some of our software into thinking that the batteries were full when they weren't. This is exactly the kind of problem we wanted to wring out on this

mission, which we call LightSail A, which we can, I believe the word easily may be an exaggeration, but we can carefully and diligently avoid on light sail B next year. Bill, with 30 seconds left, what would you want to say about the team behind light sail? Oh, man, another leading question. These people are amazing. People have worked all night. They've worked for days on end solving these subtle, subtle problems with a spacecraft you can't walk up to and just ask it questions. It's in orbit at 28,000 kilometers an hour, and you just can't get it. Oh, you just got to work really carefully to make these changes,

and these men and women did. I'm just so proud to know them, so proud to know them. Thank you, everybody, members and supporters who enabled this mission. That's Bill Nye, the CEO of the Planetary Society behind the LightSail project. Bill, we're going to hear just a little bit more now from yesterday's conversation. It was in the teleconference following the deployment after the satellite had gone around the horizon. We're going to hear Doug Stetson, the LightSail project manager, talking with Dave Spencer, the LightSail mission manager. He's from Georgia Tech. And as far as we know, then the sail will continue, you know, would have continued deployment until its conclusion. It had plenty

of power. It had sunlight left if it was required to operate on sunlight. So no reason to suspect that it didn't get all the way out. Yeah, that's right. Now we've got a 10 and a half, 11 hour wait until we get more information. Okay, well listen, Dave and everybody, that's fantastic. You guys have done an outstanding job. Everybody's been working, you know, especially John and Justin up at Cal Poly,

you know, staying up all night getting these commands in. So that's really, really good news. So fantastic job. You guys did really great, and we really appreciate it. All right. Let's get to the next round. We'll take our break and then check in with Cassini Project scientist Linda Spilker.

First, though, an apology to our British listeners. I proved once again last week that I'm another American who can't speak the Queen's English. Our Friday, June 19 get-together with London-area listeners will be at the Harryford Arms Pub in South Kensington. There, did I get it right that time? If you plan to join us, please write to me by June 16th at planetaryradio at planetary.org. That's planetaryradio at planetary.org. Back in a minute. Greetings, PlanetaryRadio at Planetary.org. That's PlanetaryRadio at Planetary.org. Back in a minute. Greetings, Planetary Radio listeners.

Bill Nye here, inviting you to become part of our citizen-funded LightSail project. LightSail is at the center of our very first Kickstarter campaign. Help us realize the fantastic potential of this innovative spacecraft for as little as $1. We've got terrific rewards for those who can afford even a little bit more. How about a square centimeter of the sale? Or lunch with me? Learn more at planetary.org slash kickstarter. Together we will change the world.

Random Space Fact! Nothing new about that for you, Planetary Radio fans, right? Wrong! Random Space Fact is now a video series, too. And it's brilliant, isn't it, Matt? I hate to say it, folks, but it really is. And hilarious. See?

Matt would never lie to you, would he? I really wouldn't. A new Random Space Fact video is released each Friday at youtube.com slash planetary society. You can subscribe to join our growing community and you'll never miss a fact. Can I go back to my radio now? Welcome back to Planetary Society. You can subscribe to join our growing community and you'll never miss a fact. Can I go back to my radio now? Welcome back to Planetary Radio. I'm Matt Kaplan. Linda Spilker became the Cassini mission's deputy project scientist in 1997, the same year the Great Probe was launched. She has been checking in with us since 2009, and it was in the following year that she moved up to Project Scientist, basically

serving as the chief science officer for this mission that has revealed so much about Saturn, its moons, and its rings. She joined me on the Skype line a few days ago. Linda, always a pleasure to get you back on Planetary Radio, our most frequent guest. You're back among the moons now out there at Saturn. Right. That's right, Matt. It's a pleasure to be here, and it turns out that we've moved the Cassini spacecraft back into Saturn's equatorial plane, and that gives us a really good chance to get close-up looks at some of the moons. We have a flyby of Dione coming up, and in October, two close flybys of Enceladus,

one of which will fly through the plume again. Okay, so that's some of what's ahead of us. Let's talk about what's happened in just the most recent months, or maybe the present for now. How is the health of the spacecraft? The Cassini spacecraft is doing very well. No problems at all. Wow. It truly is amazing.

And I'm knocking on wood because we need, what, a couple more years, right? That's right. That's right. Is that fuel tank, the gauge on the fuel tank is close to empty. Yes, we need some luck. So far, so good. Let's go to Enceladus, first of all. It is a really pretty, stupendous story. Tell us why there is more reason to believe that we found the source of heat that may be keeping

an ocean liquid on that moon. Yeah, it's just amazing. We have some new results back that show us that there are present-day hydrothermal vents. You can think of that as hot water activity, hot water chemistry going on on the seafloor of Enceladus. It's very exciting. And the way we figured this out is that there are tiny nanosilica grains that come out with the jets into the plume and were sampled by our cosmic dust analyzer instrument. And the only way you can get such grains is if you have hot water in contact with the rocky core of Enceladus, it becomes mineral laden, picking up these nanosilica grains. When that hot water comes in contact with the cold water, these minerals crystallize out and form these tiny

grains. So it's a very interesting result. You have to have temperatures very close to the boiling point of water to have these interactions occur. Did it occur to anybody almost 25 years ago when the instruments were being chosen for Cassini that this grain analyzer, this would be able to tell us something about stuff going on in an ocean on a moon? When we built the instruments, we had no idea that Enceladus was active in this way. We knew that Enceladus somehow was the source of the E-ring, and maybe it was active, but Enceladus was so small, we didn't think it really could be active. And so this is using an instrument that was designed to measure the dust around the system, and also in the solar system being used in a new way to measure these particles from Enceladus. In fact, we saw these tiny grains when we were first coming into Saturn in 2004, and then it was like a detective story to try and figure out what the source of these grains might be. Pretty amazing science. And of course, most of us know what happens around hydrothermal vents down at the bottom of Earth's oceans. There's a lot of stuff living down there. That's right, and that's so exciting because the potential now is that perhaps the ocean of Enceladus might be habitable. Very exciting. Another piece of evidence

we had is that there was an excess of methane coming out of the jets, and that was measured by our ion and neutral mass spectrometer. And this excess of gas can also be explained via hydrothermal vents. Exciting stuff. Before we leave Enceladus, talk to us about what's happening up at the surface where the shape of those jets, those eruptions, it's being reconsidered. Yes, and looking carefully at the images, it turns out that we noticed a glow

coming from around the tiger stripes. One thought was that perhaps rather than being a lot of individual jets, perhaps most of the material coming out was actually coming from curtains of material. And so some researchers got together, led by Joe Spitali, and looked at this hypothesis and actually did a lot of modeling and showed that perhaps some of the jets we were seeing on Enceladus were actually phantom jets, that there were maybe folds along the tiger stripe, folds or kinks, and that sometimes we'd be looking through more material that would look like a bright jet, and then as you turned the spacecraft, you'd see that jet disappear and another one appear instead.

So many of the individual jets are probably just parts of curtains, these phantom jets, although we know that there still are individual jets, very strong ones coming out, creating the tendrils that we see in the E-ring. And there's a beautiful image, maybe we'll be able to post that as part of the radio show this week at planetary.org slash radio, of those tendrils. They're really quite beautiful, and I guess they've been modeled on computers? Yes, yes, modeling the tendrils, basically mapping them back to the strong individual jets on the surface of Enceladus. And what's interesting is we see these tendrils change with time. And we think that's the result of the fact that the tidal

forces squeeze the tiger stripes together sometimes and lower the flow and then pull them apart at other times and the flow increases. And of course, then this influences the appearance of the tendrils. And also I've been able to get another measurement of the size of the particles. And they're very, very tiny, consistent with what other instruments have detected for a particle size. Back to those curtains. Does that indicate possibly that we're seeing this stuff emerge,

erupt from over a substantial part of the length of what amounts to a crack, which we see as the tiger stripes? That's right. It looks like, much like if you have a fracture on earth, you can get volcanic lava curtains coming up in the same way. There's probably a curtain of activity along the entire length of these fractures on Enceladus. All right, we want to give fair coverage to Enceladus's big, big sister, and that's Titan. Why was this first observation of Titan recently, when it was outside of an important part of Saturn's influence, this apparently was pretty important and pretty surprising? Right, we've made many flybys of Titan, and it just so happens that Titan was out in front of Saturn. We had a very strong blast of solar wind that pushed Saturn's magnetosphere inward,

and we had a chance to see Titan for the first time basically naked in the solar wind and see how its atmosphere would interact with the solar wind. And that was quite exciting. So what was surprising about it? Well, we weren't sure what we would see. And it turns out that the way that Titan interacts with the solar wind is very much like Mars interacts. And so we can use some of the same models and the same ideas. When you study the effects of the solar wind on planets, it helps us understand how the sun's activity can affect atmospheres, how it can modify chemistry, how it can perhaps strip away the atmosphere. And so it was just surprising to see if you put Mars at the distance that Titan

is at from the sun, it would look very similar in its interaction with the solar wind. We know, don't we, that Mars doesn't have a magnetic field, at least not one to speak of. So that applies now to Titan as well? That's correct. Now that we actually saw Titan outside the magnetic field of Saturn, we know that it doesn't have a field, or at most a very, very weak field, too weak for us to even detect. As we speak, you have some recent results from a moon that I guess Cassini has just visited for the last time.

I call it the creepy moon. It's Hyperion. Yes, we had our last flyby of Hyperion. At closest approach, we're about 34,000 kilometers away. And we got a chance to see a little bit of the new terrain and once again to see the dark material in the bottoms of these little craters or what we call sun cups on Hyperion, probably Phoebe dust that it's collected.

This thing, which looks like Swiss cheese and does, you know, it's a psychological fact. Apparently, there is a certain percentage of the human population that sees this kind of shape of texture or topology as creepy, and I seem to fall into that minority. Do we have an idea of why this little object looks so different from most of the other objects in the solar system? Well, we know for one thing that it's very porous, lots of space in between the particles on its surface.

It's small. It's also rotating chaotically. The other moons tend to keep one side always, one face always facing Saturn. And in the case of Hyperion, it tumbles chaotically. And we're not exactly sure what has created the unique texture of its surface. And you're right, it is unique in the solar system. Let's go down to Saturn itself. And there has been some new theoretical work, I guess, based on data from your spacecraft, about the storms we see on Saturn, on that big planet. And they seem to come in a regular cycle. Right, right.

We saw the one, you know, giant storm erupt, and those giant storms seem to come in about a 30-year cycle. And so it's very interesting to study the storms on Saturn. In fact, we're watching a small storm right now as it's developing. This has got to be hard stuff to model. Is somebody attempting to build computer models of the atmosphere of this planet? Yes, they're trying to see if we can better understand the storms and the activity that's happening on Saturn. Well, whether we understand them or not, they sure are beautiful. Oh, absolutely. Absolutely. And some of the biggest storms actually have lightning that go along with it. And we have instruments on board Cassini that can detect the lightning.

The last component, of course, that we generally talk about, those rings. Is there anything new to talk about there? No, not recently. Since we're in the equatorial plane, we really don't get a good view of Saturn's rings. So this is really sort of, you can think of this as the time of the icy satellites. And if you're a Saturn scientist, a really great time to look at the planet without having those pesky rings in the way. Yes, and I suppose the yin to that yang is the ring scientists who are biding their time, like yourself, I think. Well, you're the project scientist. I guess you have to give them

their fair share. Tell us once again, as we near the end of our time, what is ahead? I know you already mentioned a couple of things at the beginning of our conversation. Right. In this time period that's coming up, we're going to have three flybys of Enceladus, our last three very close flybys. Two of those are in October, and one is in December. And one of those flybys in October will be our last flyby through the plume and a chance to sample once again what the composition of the plume is using our cosmic dust analyzer and our ion and neutral mass spectrometer. And of course, we'll be making some detailed maps of the planet as well. As I said, with the rings out of the way, you can now get really good equatorial coverage on the planet itself. And with some mixed emotions, I'm, in a sense anyway, looking forward to 2017 when I hope to be part of a celebration of this mission when it ends its life in the big planet.

Right, right. Cassini and will go into Saturn's atmosphere, much in the same way that Galileo entered Jupiter's atmosphere. And at that point, the spacecraft will burn up and will have kept both Enceladus and Titan safe from any collisions with Cassini once it runs out of fuel. All right. But still two more years of great science, great data coming back from that spacecraft. I'll knock on wood once again. And Linda, you've done it once again. Thank you for this terrific look back at just the last few months of great science from Cassini. And I certainly hope that we can do this again soon. Oh, it's been a pleasure, Matt. I hope so too. Linda Spilker, she has been with the Cassini mission, well, essentially for most of recorded history, but and for a good piece of the life of that mission, has served as the project scientist there

at the Jet Propulsion Lab, where the mission originated and where it is still controlled. Just one more soundbite from Linda. When we had completed our conversation about Cassini, she asked me about the status of light sail. Here's what she had to say. I've been a huge fan of solar sails. I think it's just a wonderful concept. I do too. Really rooting for you guys to get it to get everything to work out. Bruce Betts is on the Skype line. He's ready to bring us this week's helping of What's Up in the Night Sky. Welcome back.

Listen, before we go on, I want to do a shout-out to John Lomberg, friend of the Planetary Society, who worked with Carl Sagan and Andrew Yen to put together the Golden Record on Voyager. His project now is the one that wants to put a whole bunch of stuff on New Horizons. They're going to send it out there by radio

once it's done doing its other work. It's the One Earth Message, and he's trying to raise some money to back this. It's the Fiat Physica site. We'll put a link up on the show page that you can reach from planetary.org slash radio. So thank you for allowing me to squeeze that in, and John, good luck with this. All right. Let's talk about sky for the next few weeks.

It's all about Jupiter and Venus because they're really bright in the early evening. Have you checked them out there? I have, over and over. And they're going to just keep closing over the next few weeks, getting closer. So right now, Venus is near the Gemini stars, Castor and Pollux, but will appear in the sky over the next few weeks to be moving closer and closer to its not as bright, but also really bright friend, Jupiter. And by July 1st, they will be less than half a degree apart from each other. Wow. Very impressive.

And June 20th, you can get a lovely view of the moon hanging out with Jupiter and Venus in a cosmic party. And then you can check out Saturn over in the east, south, and the early evening looking kind of yellowish. That's our planet sky. All right, on to this week in space history. It was five years ago that the Japanese Hayabusa spacecraft returned samples, a little bit of sample from Itokawa, an asteroid, so the first asteroid sample return. And it was 30 years ago in 1985 that the Soviet Vega balloons entered the Venus atmosphere and also dropped landers. We've got to send some more balloons there and have them hang out in the atmosphere for a while.

That just would be – I love that mission concept. Maybe we can send you with them, Matt. I'd be happy to. Up there, you know, before you hit the sulfuric acid rain, that'd be fine. Float around for a while, catch some rays. Sounds fun. On to... From the Golden Age of Radio, it's the dulcet tones of Bruce Betts.

Hubble Space Telescope, its pointing accuracy, how well it can point in the sky, which is obviously critical for looking at distant objects, is.007 arc seconds. That's like being able to shine a laser on a dime, an American dime, so a small coin 320 kilometers or 200 miles away. That's very, very good. Hit a dime with your pointing from 200 miles. It's not polite to point, but we'll make an exception in Hubble's case. That coming from NASA's Hubble Twitter feed.

All right, we go on to the contest. And we asked you, how many launches did the Atlas V have in 2014? How did we do, Matt? Before we get to our winner, I want to get to somebody who just watched an Atlas V launch with us. It's Dana DeFilippo. Chase, the little five-year-old, was along for the ride. And I got a note from Dana along with the entry for the contest this week saying we just

discovered Planetary Radio after meeting Matt at the LightSail Atlas V launch last week and that I did ask Chase a few questions. A fine little guy. But now let me go on to the person who I think is our winner. It's Dane Sablehouse of Greenwood, Indiana who said

that in 2014 there were nine launches of the Atlas V. That is correct. Excellent. Well, Dane, you have just won yourself a 200-point itelescope.net account and a stylish Planetary Radio t-shirt. So congratulations to you. Everybody, almost everybody, who entered the contest this time was talking about LightSail and how inspiring it is. We did get a few other nice messages. A lot of people pointing out the 100% success rate of the Atlas V.

Jeffrey Perry was among them. He said, with that kind of record, I wish my beloved Boston Red Sox would get an Atlas V in the starting rotation. Now batting cleanup. That's a lot of power. It's a high rocket straight out of center field. This from Craig Journet, friend of the show from Los Alamitos, California. The first human-carrying Atlas V will have the Boeing CST-100 crew space transport capsule on its tip, taking it up to the International Space Station. At least that's the plan.

I got one more here. Dan Campbell from Cumming, Georgia. He said, I was disappointed to discover the link to the United Launch Alliance Atlas V product page doesn't have an add to shopping cart button. Oh, wait. I think I get it. I don't get it. Oh, to add the whole rocket to the... He wants to buy one.

He wants to buy one. You know, Dan, don't be silly, Dan. You got to go over to Amazon. Yes, in the propulsion store. So the bad news for the audience this week is that, and for Bruce apparently, no contest. In fact, no contest this week or next week. We have not skipped the contest in years. I don't know how many, but years. Why have you forsaken us?

You know why? It's purely convenience on my part because I'm going to be out of town for two weeks. It would just be really difficult to handle all of this. So please don't blame Bruce. Blame yours truly. No contest for the next two weeks. And then we will rocket back into shape with some more great space trivia questions for you. No doubt. Okay.

That means, I guess, what a strange feeling. We're done. All right, everybody. Go out there, look up at the night sky, and think about what galaxies must taste like. Thank you. Good night. Okay.

We can only hope that somewhere out there in the limitless cosmos, there is a chocolate Milky Way. Mmm, tasty. He's Bruce Betts, the Director of Science and Technology for the Planetary Society. He joins us every week here for What's Up. Once again, our very informal gathering at the Hereford Arms in South Kensington, London, is on the evening of Friday, June 19th. Let me know if you're joining us by writing to planetaryradio at planetary.org. Thank you. is our associate producer. Josh Doyle created the theme. I'm Matt Kaplan. Clear skies.