Planetary Radio: Space Exploration, Astronomy and Science - Ready to Sail! LightSail 2 Deploys its Silvery Wings

Episode Date: July 24, 2019

Join us as the little cubesat successfully unfurls its solar sail. You’ll hear from members of the LightSail 2 mission team on the morning of July 23, 2019, when the critical command was sent to the spacecraft.  Then we’ll congratulate Kris Zacny of Honeybee Robotics on the selection by NASA of the radically-simple PlanetVac sample collection system for a trip to the Moon. Learn more about both of this week’s topics at:  http://www.planetary.org/multimedia/planetary-radio/show/2019/0724-2019-lightsail2-deployment-kris-zacny-planetvac.htmlLearn more about your ad choices. Visit megaphone.fm/adchoicesSee omnystudio.com/listener for privacy information.See omnystudio.com/listener for privacy information.

135,786. Cell deployment complete. LightSail spreads its wings 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. And that was the moment we learned that LightSail 2 had successfully deployed its solar sail. I was there in the Mission Operations Center at Cal Poly San Luis Obispo as the team celebrated the moment. I rushed down the California coast soon after so that I could share it and more with you. Stay tuned later for a brief check-in with Honeybee Robotics' Chris Zachney. Chris will tell us about the selection by NASA of PlanetVac for a trip to the moon. But first, it's late

morning on July 23rd. We're in the Cal Poly School of Engineering, specifically the home of PolySat, the CubeSat research lab run by John Bilardo. John is one of the six mission controllers sitting at laptops displaying every intricate detail regarding LightSail 2. To John's left is project manager Dave Spencer, and next to Dave is the LightSail program manager, Bruce Betts. Good morning, Bruce. Good morning, Matt. Set the scene here. Tell us about what's going on.

We're in the PolySat lab at Cal Poly San Luis Obispo getting ready for sail deployment of LightSail 2. So we've got the core mission team here sitting at tables waiting for time to pass while we do some analysis of the last pass. And that just happened moments before we started to speak. What happened during that pass? We were able to upload a new orbital information file, so-called TLE, so the spacecraft more accurately knows where it is at any given time, and then make some slight tweaks to the attitude determination and control system in anticipation of being in solar sailing mode soon. And there was the answer to this week's trivia question, but we'll get back to that. It looks like maybe six people sitting in front of laptops that are running this mission.

That's exactly what's going on. We've got Dave Spencer, the project manager, and John Bilardo from Cal Poly, who is managing the uplink, downlink, and all the software on the spacecraft. Alex Diaz from Ecliptic Enterprises doing electrical, mechanical type things. And Barbara Plant from Boreal Space doing attitude determination control system work. And then Michael Fernandez, a student from Cal Poly, who's watching monitors and helping us track everything. And me.

And then we've got other people who are not actively involved in the operations but have been key to the history and success and development and testing. And one small child who's playing with her Disney princesses. Yeah, did we add her to the team? Talk about what's going on up here and the display that we saw, that waterfall so-called display. Yeah, waterfall display is pretty colors. And basically it plots the intensity versus the radio frequency map, radio frequency. And so we are looking for the appropriate frequency for light sail and then we see

increases in brightness when light sail transmits and we receive a beacon from light sail or its morse code continuous wave signal you saw this big kind of a bell curve jump up centered in the middle of the screen because that was the center of the frequency that you're transmitting on or light sails transmitting on yeah and that would have been showing the current time and then what it does is it rolls that down over time so you're kind of you're seeing the last few seconds last minute and it rolls that down over time. So you're seeing the last few seconds, last minute, and it transmits down, not transmits, moves down the waterfall plot. And you can also see the transmission from Cal Poly up to the spacecraft is, of course, a much stronger signal,

appearing red in the color coding they've done. How are we looking for less than an hour and a quarter from now for deployment of the sails? You look marvelous. How is the spacecraft looking? But thank you. Oh, okay. It's looking good. We accomplished what we wanted to on the last pass, and so nominally we'll deploy. But we'll go through a go-no-go check after people have looked at the data from the last pass to make sure that we really are ready and planning on doing it. And then we'll take in data very rapidly, a smaller set of data at the beginning of the pass, and then make the final decision to deploy. How soon after the deploy command is sent will we have some evidence, or do you hope we'll have some evidence, that it's actually happening?

It could be very rapidly, within seconds or a minute. It depends on when it gets in and whether we continue to receive the beacon information. But the key thing we'll be looking for is the motor count. So the motor that rotates to unfurl the booms that pull the sails out, that count should go up, and it should go up fast and within a lot of it. All right, go light sail. Go light sail, too. Jennifer Vaughn is also in the Operations Center. She is the Chief Operating Officer of the Planetary Society. Jennifer, I was going to say big moment, but really this is the biggest moment. Well, it's close to the biggest moment. So it's the big moment that precedes the other big moments because it's a reminder what we're trying to do here is prove solar sailing in Earth orbit.

You can't do that without a sail. So the very first thing we have to do today is make sure the sail gets out correctly, that it's all the way out, and that we're ready to actually start solar sailing and watching the orbit raise. I don't know if you feel the same way I do, but I bet you do. Just being in this room and watching this team do what it does to control the spacecraft and everything going well. I've been so impressed. So I've been lucky enough to be lurking on the phone with this team since we first started hearing from the spacecraft. But today's my first day actually in the room with them. So on one hand, I feel like I've been along for the ride,

but it's nothing like being here in person, seeing them work, seeing them work out these issues in real time, watching the data come in, helping to analyze what they're seeing. It's very exciting. And this is something that I've covered with you and with others before. But just talk about what led to this day. Decades led to this day. And tremendous vision led to this day.

So it all started with our founders being very interested in this topic. So Carl, Bruce, and Lou all had deep interest and investment in seeing solar sailing become a reality. That led us to an opportunity to dip our own toes in the water with Cosmos One. That was our first project. That was 20 years ago. And we started working on that as a way for the Planetary Society to actively advance the concept of solar sailing. And then after failure of Cosmos 1, we went back to our members and said, what should we do now? Do you want us to try again? Members said, absolutely, get going, try it again. And that led to the concept of Light of light sail which is a very innovative design

of taking solar sailing which is robust propulsion and marrying it with a very small off-the-shelf spacecraft with the CubeSat and so with this demonstration we're not only testing solar sailing in earth orbit and controlling that sail in Earth orbit. But we're also looking at a combination of higher-tech propulsion tied with small CubeSats, and that might open up access for more players in space. And that really is the core of the dream, right? I mean, I know not only does solar sailing or light sailing present this opportunity to reach places around our solar system, but perhaps beyond. Yeah, well, there's the long-term dream.

Yeah, for those who really want to dream big, solar sailing is the only known method for one day reaching the stars. So obviously it wouldn't be with the sun anymore. It would be with other forms of light propelling a sail over these long distances. But this is the early, early stages of this technology design. The planetary study is on the front leading edge of this. And we hope that the successors will take this technology, develop it, and one day bring us to that point where we can explore beyond our own solar system. And why has the Planetary Society embraced this project, put so many resources into it, made it so central to what we do? Well, it's our members and supporters. So the members and the backers were the ones who really embraced it. So of course the organization

embraced it as well. We wouldn't have brought it to the public if we didn't see the promise. But it's really the public that jumped in and saw the promise and the ability to do something themselves. So it's our Planetary Society members and our Kickstarter backers who are realizing, I can do something myself to help this happen. And here it is. It's happening. It's because of them. They did it. I'm going to glance at my watch.

Let's see. Just over a half hour to go, no go. Only about 45 minutes until we find out if those sails are going to deploy and start sailing on the light of the sun. It's happening now. I'm so excited. Of course, there's always a little bit of nervousness with these moments, but it's also coupled with, hey, if it doesn't work the first time, there's ways to try again. So we'll have other passes that we

can work with. But here's hoping that everything works the first time out. I'm excited. We've got a great team here. So very excited for their work. Very proud of what they've done. Go LightSail 2. Go LightSail 2. What you're about to hear is what happened over the next few minutes. I've heavily compressed these events that actually stretched out over more than 40 minutes. It begins with a tradition that dates back to the earliest days of the space age, with Dave Spencer polling the mission team, making sure everything is go. Okay, this is our go-no-go for sail deployment, and we're making the

go-no-go determination based on the most recent tracking station pass. Start off with ground systems. Ground systems are go. Copy. Flight mechanics? We're go. Copy. Flight mechanics? We're go. Copy. ADCS? ADCS is go. Systems?

Systems is go. Copy. Camera? Camera is go. Okay. Program manager, we're go for sail deployment. Go. Now we wait for LightSail 2 to appear above the horizon so that we can communicate with it.

While we hope there will soon be images and possibly even video of the sail deployment, these will not be available live as it happens. In fact, as I record this, download of the images has been delayed. But the team will know that deployment has begun because telemetry from the spacecraft will tell us that a tiny motor has started spinning. It's this motor that will pull the big sections of sail from the bread loaf sized CubeSat. Each revolution of the motor is counted, and each revolution will bring us closer to full success.

Okay, just so you guys know, we're going to be rising over Cal Poly here in about three minutes. The Cal Poly tracking pass is about 13 minutes long. Then we'll be going over Purdue and Georgia Tech simultaneously. We'll switch over transmission from Cal Poly to the Purdue tracking station in terms of commanding at that point. The sun sector angle looks good, 66 degrees. Motor count increasing, sail deployment initiated.

Alright, 135,000 counts to go. Camera slots remaining or decreasing, so cameras are being taken, pictures are being taken. Excellent. Motor count 36,498. 41,500. Target value is 135,728. We're at 46K. 51K. 57K.

Sail deployment anomaly takes two and a half minutes. 68k motor position. 80,000. 86,000. 108,000. 135,786. Sail deployment complete. All right.

Yeah! Yeah! Yeah! Congratulations. We got the state packet up, setting to detainable. 1.23 p.m. Pacific time, and it's good. We got a sail out we got a spacecraft yeah I'm happy to light sail to sail deployment is complete we command a sail summary over the Skype call to on video here.

Yeah, I'm happy to. LightSail 2 sail deployment is complete. We commanded sail deployment a few minutes into the Cal Poly pass over the tracking station. We initially armed the sail. We waited a couple of minutes to make sure that everything looked good in telemetry and also to allow the sun geometry to improve

for our imaging during sail deployment. We commanded the sail deployment, saw the motor counts begin to increment, and over the next two and a half minutes they incremented out to the expected value, and that's our indication that the solar sail was fully extended. So we also took a sequence of images throughout the sail deployment event, and over the next tracking station pass we'll hopefully begin to downlink some of the image thumbnails from that.

Those are highly compressed images that will give us an idea of what we captured during the image sequence. Also next pass the goal is to transition into what we call mode two which is solar sailing mode where we orient the solar sail edge on to the sun when we're moving towards the sun, face on when we're moving away from the sun. And that allows us to increase the orbital energy over time, which is the objective of the mission. That's where we are. Great. Thank you very much.

Thank you. All right. Thank you, guys. Planetary Society CEO Bill Nye was unable to join us in person, but he was watching and listening with unable to join us in person, but he was watching and listening with the rest of us via Skype, and he knew when we'd achieve the goal of full deployment. Nicely done, you guys. Congratulations to everyone. That is fantastic. All right. Thank you all, LightSail supporters. This is just another, just an enormous kilometer marker, a.k.a. milestone in the LightSail program. And so the sails are out, and so expect any moment

the photons are pushing the sails higher and higher to a more distant apogee. We're advancing space science exploration, thanks to everybody there at Cal Poly, and thanks to our supporters around the world, who have just been great the last, depends how you reckon, the last four years, the last nine years, the last 42 years. Depends where you start counting. But this is a dream of our founders, Lou Friedman, Bruce Murray, and Carl Sagan. I've been a fan of solar sailing all

this time, and I'm so, I so honored to be representing the organization at this historic moment. So thank you all so much. We are sailing right now. Feel the photons. Sunbeam pushing us. As we waited for the next pass and an attempt to download images, I asked three of the longest-serving members of the LightSail team to join me. Justin Foley and Stephanie Wong started on the mission as Cal Poly students under lab director John Dilardo.

Justin is now a testbed engineer for the 2020 Mars rover coming together at the Jet Propulsion Lab. Stephanie is a mechanical integration engineer at Ecliptic Enterprises, which has played an essential role in bringing LightSail to its success. Stephanie was holding the youngest in-person witness to sail deployment. You guys have got to be feeling pretty good. John Bilardo? Absolutely. We've been working for many years as a team to get to this moment. And, you know, I'm personally very excited. As I know, the whole team is really excited as well.

I'm also really excited. I feel lucky to be here right now since I had to come up from Los Angeles. But this is really fun, especially having done LightSail 1, especially, you know, sitting next to John doing the deployment again was awesome, watching those motor counts go up. So excited right now. And you're the only person who brought a second generation for LightSail. Yeah, I remember LightSail 1.

She was in my belly during operations, and then we did test deployments, and she was just a tiny baby, and now she's grown up to see a different world we're going to come into. So it's kind of cool to see her grow up just as LightSail has kind of grown up to see a different world we're going to come into. So it's kind of cool to see her grow up just as light sail has kind of grown up to. John, where are we now? What's happening? Everything is exactly as it should be? Nominal? Yeah, absolutely. The spacecraft is nominal. The attitude control is where we want it.

It's de-tumble mode right now, so it's taking out some of the rates that could have potentially been induced when we deployed the sail. Right as to the next pass, we're going to work on transitioning into solar sailing mode. So that's sort of next up on the agenda. Does that mean that you'll start doing those 90-degree turns twice every orbit? Yep, that is what's going to happen starting next orbit, assuming things stay on schedule. So what is the orientation of the sail now? Do you know? Yes, we have data that will tell us where the sail is pointed. However, we're not trying to control it to be a particular

orientation. What we're trying to do is make the spacecraft spin down. So instead of spinning a few degrees a second, hopefully we'll get it, you know, maybe less than, you know, two or one degree per second on all the axes. That's what we're trying to do right now. I mean, it is only the light of the sun. Even if you're not oriented correctly now, it's not like light sail is going to be knocked out of its orbit. That's correct. The sun is not that strong. The solar sail effect is wonderful because you get propulsion continuously while you're in sunlight, and that's really what builds up a lot of momentum

and allows you to go sailing someplace. For an orbit or two, you're not going to really accumulate enough to make a large difference one way or the other. I just want to congratulate the three of you. The rest of the team is sort of spread all around us here. It is a great moment. It's something we've been building to for so many years. Congratulations. Thank you.

Yay. Can you say light sail? Yay sail. Our special LightSail 2 deployment coverage will continue with this week's special What's Up segment, but we first got another treat for you. PlanetVac is going to the moon. The brilliant little device that can replace a footpad on almost any lander going anywhere with a solid surface, has been given the go-ahead by NASA. Full disclosure that is well known to anyone who

has listened to Planetary Radio for very long, development of this small, simple sample collection system has been championed and supported by the Planetary Society for years. When news arrived on July 1st about its selection, I contacted old friend of the show, PlanetVac Principal Investigator Chris Zachney at Honeybee Robotics, where he also serves as Vice President and Director of Exploration Technologies. Chris Zachney, congratulations on PlanetVac being selected to be part of this great group of experiments and hardware and landers that are headed for the moon. Hi, Matt. Yes, this has been absolutely fantastic news. I've been very ecstatic for the past just over a week since this was announced. Since this was announced, it's been a very, very slow progress in terms of technology because of different funding levels. If you remember, we met at Honeybee Robotics back in 2013 or 2012 to discuss our very first vacuum chamber demonstration of PlanetVac.

chamber demonstration of PlanetVac. This has been a tipping point where we took the idea that was in a CAD file and we turned it into reality and everyone else got super excited about it. And since then, we received additional funding and also Planetary Society was part of this. We actually flew PlanetVac on a mast and lander. And these two demonstrations, one in the vacuum chamber and one on the mast and essentially the scale, folks realized that this technology actually can work and has a potential to change paradigm

of space exploration. Most of the landers to the moon or other planetary bodies require a sample. Most of this time, the sample has to be acquired using these power-hungry, large robotic arms, large and slow robotic arms. And complicated. And very complicated. That's right. Very complex, require very sophisticated software. At the end, you have a scoop. So you're grabbing the sample with a scoop. But to deliver a sample, you rely on gravity. There is no other force that will move the sample to the instrument. You're essentially relying on the gravity of planetary bodies. And

Moon has only one sixth, Mars has one third. If you go to other planetary bodies that has less, the forces are significantly reduced. So if your sample is sticky, it's not going to flow. This has been on the mind of mission planners for a long time until the PlanetVac came in. And PlanetVac does not rely on gravity. It relies on a force provided by gas. And that's a very, very powerful force. And only one moving part. I remember that 2013 vacuum chamber test.

Vacuum chamber test. And I will always remember that test in the Mojave on the foot of that Masten rocket as we stood behind big concrete blocks to protect us just in case. That was so exciting. Wasn't there a NASA representative or two at that test? three NASA representatives watching over this particular technology and reporting up the ranks to other NASA officials. So it did receive a lot of press outside of NASA and a lot of press within NASA. So it has been very, very exciting. So I hope you guys won't mind that we Planetary Society folks, our members included, of course, we also take some pride in this because of that support, the encouragement that we were able to provide. Absolutely. We wouldn't be here without the Planetary Society. And as I mentioned, initially, you know, we did a lot of technology development with NASA SBIR program.

And where the technology ended was with some testing and some demonstrations in a reduced gravity flight. The final CAD design that showed how this technology could be implemented on a future Mars or lunar landers. And if you remember, initially it was called MarsVac. It was designed for Martian sample return mission. But we did say that it could work on a planetary body. And the Planetary Society brought additional funding

to essentially turn this initial design into a prototype, into a prototype, a lander prototype that could be, that was tested in a vacuum chamber, in a Mars vacuum chamber. And to us and to many other folks developing technology, this was a Yahoo moment when you realize how simple this stuff is. It's one thing, you know, looking at the slides, at the animations and things like that. But it's another thing when you actually see the end-to-end functional hardware in a vacuum

chamber showing all the elements of the lander and the sample delivery. So that was huge. You know what Bill Nye says, one test is worth a thousand opinions. What's next?

Do you know who's going to give PlanetVac a ride to the moon? I've been getting a lot of emails. I've been getting a lot of emails because PlanetVac essentially is an enabling technology for any instrument that requires a sample. As you know, the easy stuff has been done. You can only do so much by looking at the surface with non-contact instruments and taking pictures and so on. You really, really need a sample.

And there is an array of instruments that will not work unless they actually get a sample. If you do not have PlanetVac, you will have to figure out some other means of delivering a sample, which we know is very complex and very difficult. Folks, I've been getting a lot of emails asking about the details of the PlanetVac, but a lot of folks want to fly it. Well, I'm not surprised that you're getting this attention now.

Best of luck to all of you folks at Honeybee Robotics, the entire PlanetVac team, great group of people that you've pulled together there. And again, congratulations on this. Can't wait to see PlanetVac do its stuff on the surface of Earth's moon. Thank you, Matt. And thanks again to the Planetary Society. Without you, we wouldn't be here. It's going to be exciting to go together to the moon. That's Chris Sackney, Vice President and the Director of Exploration Technology for Honeybee Robotics. You can take a look at their site. You can see our coverage at planetary.org of PlanetVac as well. We'll put a whole bunch of links on this week's episode page, episode of Planetary Radio, the one you're listening to right now at planetary.org slash radio, including a link to the show in which we covered that test in the

Mojave Desert of PlanetVac on that Mastin rocket. Chris, just one more question. It says here in your bio, you got your PhD from UC Berkeley in Mars drilling. Is that right? Yes, that's right. This was my last ditch trying to get to space. I really wanted to work on aerospace or space missions, but my mining and drilling background took me in different directions. And the last ditch at turning my career into space was essentially doing something related to extraterrestrial drilling and mining.

And that was it. I love it. Worked out. Well, Dr. Zachny, doctor of Mars drilling, it has been a pleasure to talk to you again. And we'll be talking to you yet again, I have no doubt. Thank you, Matt. Looking forward to it. Chris Zachney of Honeybee Robotics, the principal investigator for PlanetVac.

Time for a very special What's Up on Planetary Radio. for a very special What's Up on Planetary Radio. So we are joined by the chief scientist of the Planetary Society who is sitting in the exact same chair that he was in as the program manager for LightSail 2 when LightSail deployed its sails. Congratulations. Thank you. We're excited. And I just want to point out I did not steal the chair.

We're still in the same room. This is operations. This is where the whole team was. Your neighbor here, our special guest on this What's Up, introduce him. This is Dave Spencer, a professor at Purdue University and project manager for LightSail2. Good to see you again, Dave. Congratulations. Thank you. It's an honor to be here. It's a huge day for us. You know, everything's gone great, and we're really excited to have the sail deployed at this point and looking forward to solar sailing. And so what we're waiting for now, right, are pictures, because we want our pictures.

Well, I always want the pictures, but we also want to get down telemetry data that tells us other engineering information, so we'll be working on both those things. More news about LightSail 2, no doubt, next week. Tell us what's up in the night sky. Well, now LightSail 2, it's been up there, but now it should be potentially brighter. You can go to the Planetary Society website at sail.planetary.org to the update page and see when the next pass is for you. But it's going to be highly variable depending on whether you're edge on when you won't see it

or whether you face on and then it may appear bright in the sky. So check it out. But if you want a sure thing, go for Jupiter. Jupiter is dominating in the evening sky in the south and looking like a super bright star. And over to its left is yellowish Saturn, also looking bright, but not nearly as bright. What if Jupiter's edge on? Hmm. I think you'll still see the red spot. Is that how that works? We move on to this week in space history.

It was 50 years ago that Apollo 11 returned from the moon and splashed down with the astronauts who were first to walk on the moon. Dave, we're ready for a little bit more of your special guest spot. Bruce, how about a random space fact? Sure, Dave. This is one that you and four other people know the answer to. The ending motor position of the light sail deployment motor that deployed the sail, 135,786. Nearly exactly what we were shooting for. That's a number that will be etched in history. Exactly. Don't forget it. 1-3-5-7-8-6. What are those call letters again? 1-3-5-7-8-6. Oh, sorry. W9XP. It doesn't matter.

Nobody's listening to that station, except for you guys and some shortwave guys. All right. Let's keep going. Let's go to the contest. All right. Last time we asked you something, and I have no idea what it was. Let me help. You asked people, what does ADCS stand for?

Oh, it's so light sail themed. And we even have Barbara Plant right over there, ADCS expert. Yeah, she's waving us off. That's showing attitude, Barbara. Speaking of determined attitude, ADCS, yes, we asked what it stands for, Attitude Determination and Control System, or they could have said software or sheep, but that would have been, sheep would have been wrong. Here's how Dave Fairchild, our poet laureate, put it.

If you are a satellite, there's things you need to know to help you decide on where you are and where you need to go. Your attitude determination may be found, I hope, with systems of control that might include a gyroscope. And indeed it does. But here's our winner for this week. It's Brian McCarville in South Beloit, Illinois, who says, Go Light Sail! Congratulations, Brian. We have gone and we're still going.

You have won yourself a 200-point itelescope.net astronomy account, a Planetary Society kick asteroid, you want to say it with me? Rubber asteroid. And Bruce Bett's book, Astronomy for Kids. Yay!

We got some other stuff, of course. This from Setapong in Glen Oaks, New York. He wishes that ADCS stood for Aliens Detection and Capture System. Just hate to have to clarify everything in this political climate. He says, do I need to clarify climate? I think they have one of those in Area 51 and ADCS. Here's somebody who says, speaking of attitude determination and control system, Ian O'Neill in Tokyo says, wants to know if he can get one to help with his teenager.

They cost extra. From Aaron Mindigo in New Smyrna Beach, Florida, who listens to us on WMFE, sounds like a great start to a new relationship. Think about it. Attitude determination and control system, that'd be a useful thing in relationships. It would. I'm sure my wife wished I had one. Finally, this from Joe Murray in Hoboken, New Jersey.

All of us have the same attitude. Go LightSail. Go LightSail. It's going with a sail and everything. We're ready for a new contest. Following the LightSail 2 theme in the logo for LightSail 2. What is the lowermost element in the logo that's not just a line? Lowermost element in the logo.

Go to planetary.org slash radio contest to get us your answer. You have until Wednesday, July 31st at 8 a.m. Pacific time to get us this answer. No cheating, Dave. I saw you looking at that sticker right there. I couldn't resist. I took a quick look. I know the answer, but I won't tell anyone. Thank you. Thank you very much. You have a chance to win and bring anything special with us. So we'll just leave it at a 200-point itelescope.net account this week. That, of course, iTelescope is the worldwide network of remote-operated telescopes that you can use to, oh, I don't know, if you're really, really quick, you might catch light sail, although binoculars are probably a better idea.

And a planetary society, KICK Asteroid, rubber asteroid. And that'll be it for this week. All right, everybody, go out there, look up at the sky, and think about, Dave, what should they think about? Go light sail. Go light sail. Thank you, and good night. That's Bruce Betts, the chief scientist for the Planetary Society, also the program manager for LightSail2, with Dave Spencer, the project manager for LightSail2.

And that's what's up. Many thanks to those of you who've given us a rating or review in iTunes or Apple Podcasts. Planetary Radio is produced by the Planetary Society in Pasadena, California, and it's made possible by our spacefaring members. Mary Liz Bender is our associate producer. Josh Doyle composed our theme, which was arranged and performed by Peter Schlosser. I'm Matt Kaplan with a little gift for all of you who celebrated a certain 50th anniversary on July 20th. Here's a tribute from the amoeba people called One Giant Leap.

Ad Astra. July 16th, 1969, a Saturn V rocket took off from the skies. It orbited Earth, then left for the moon. Armstrong altered Collins II. Apollo 11, out to the moon. They took Apollo 11, out to the moon. They took Apollo 11, out to the moon. Basil Capado, 11, out to the moon. 20 July 1969.

That's one small step for man, one giant leap for mankind. 20 July 1969. That's one small step for man, one giant leap for mankind Woo-hoo! Woo-hoo! Woo-hoo! In lunar orbit, Collins in control The Columby awaited for the land to unfold Armstrong and Aldrin and the Eagle descended Down to the surface as intended The Eagle has landed, that's what I said, I said The Eagle has landed, that's what I said, I said The Eagle has landed, that's what I said, I said, the eagle has landed. That's what I said, I said, the eagle has landed.

That's what I said. 20 July 1969. That's one small step for man, one giant leap for mankind. 20 July 1969. That's one small step for man, one giant leap. One giant leap. For mankind. Woo-hoo.

Woo-hoo. Woo-hoo. Receiving transmission from the moon. Go ahead, Neil. Neil, come in. That's one small step for man, one giant leap for mankind. I didn't quite get that. I couldn't make it out. What did he say?

I believe he said that's one small speck of ham and one giant grease stain on my thigh. No, he says that's one mall cop and Stan and one giant Jeep that Stan drives? Yeah, that doesn't make any sense either. I don't quite know

what he's saying. No, no, no, no, no. I said that's one small step for man, one giant leap for mankind. Oh. Well, that makes a lot more sense. That's actually quite profound. I'd say poetic even. Maybe he has a career in radio. Well, he certainly has the face for it.

No. Why, why, why? Well, he certainly has the face for it.