Planetary Radio: Space Exploration, Astronomy and Science - Giving the University of Arizona Mirror Lab a spin

Episode Date: November 23, 2022

It has been on host Mat Kaplan’s bucket list for years. Join him for a tour of the cavernous Richard F. Caris Mirror Lab at the University of Arizona, where the mirrors for the Giant Magellan Telescope or GMT are being spun into reality. Want your own GMT? You might win a model kit when Bruce Betts delivers this week’s What’s Up space trivia quiz. Stumped by what to get that space nerd in your life? Check out The Planetary Society’s gift guide! Mat and Sarah Al-Ahmed share their favorite suggestions. Discover more at  https://www.planetary.org/planetary-radio/2022-buell-jannuzi-ua-mirror-labSee omnystudio.com/listener for privacy information.

Crossing another item off my bucket list, 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. Come with me deep below the University of Arizona's football stadium for a tour of the Keras Mirror Lab, where tons of molten glass are spun and polished to become the primary mirrors for several of our world's largest telescopes. Our guide will be astronomer Buell Genussi, head of UA's Department of Astronomy

and the Stewart Observatory. Sarah Alamed will stop by to help deliver a sampling of holiday gifts that any true space geek will go gaga over, and I'll have a gift for the winner of the new space trivia contest in this week's What's Up segment. We warned you, and it happened just as expected on or about November 17th. After three and a half years orbiting our planet, the Planetary Society's LightSail 2 ended its mission in a fireball somewhere over Earth.

We proved that a solar sail could be successfully deployed from a tiny CubeSat and that it could maintain its orbit by turning to face the sun and then turn away from it on every one of approximately 18,000 orbits. Hats off to the entire LightSail team and to the 50,000 society members and donors who made this triumph possible. LightSail program manager Bruce Betts will have more to say when we reach What's Up. And you can read more in the November 18 edition of the Downlink, our free weekly newsletter. You'll find it at planetary.org slash downlink. Check out the gorgeous image of the Gulf of Aden with our sail above it.

Let's see, what else? Oh, Artemis I launched successfully and spectacularly. It has already made its first pass by the moon. All's well on the uncrewed Orion spacecraft, but some of the CubeSats carried by the Space Launch System rocket have not been heard from as I speak. They include the Near-Earth Asteroid or NEA Scout solar sail. There's more, including the announcement of Canada's first lunar rover.

The mission will be a collaboration with NASA. It's expected to launch as early as 2026. You have till November 30 to help us select winners of the Planetary Society's Best of 2022 awards. Your ballot awaits at planetary.org slash best of 2022. Sarah Alamed is the Planetary Society's digital community manager. She's also barely a month away from becoming the host of this show. Happy holidays, Sarah. A little bit early, but not too early for the Planetary Society

gift guide, which you and I and a lot of our colleagues have contributed to. I want to hear about some of the things that you had in mind, and then I'll share some of mine. You go first. Yeah, well, anybody who knows me knows that I love to wear things that show off my love for space. It's a great conversation starter moment. So as soon as those new James Webb Space Telescope images came out, my first thought was, I need that Carina Nebula on a dress. And thankfully, the people at StarTorialist totally came up to bat for that and put out a wonderful Carina Nebula skater dress, which I bought and I wear all the time.

So I had to add that one to the list. That is great. And that is so in the tradition of our former colleague and my good friend, Emily Lakdawalla, who is just like you that way. Okay. My first one, no surprise to a lot of people out there. It's the Moon's Symphony. Amanda Lee Falkenberg, that terrific composer. I got, what, three shows now out of this symphony leading up to it with the recording that was done just on synth. But then my live show in London and that amazing recording session for the London Symphony Orchestra. And it's just great. I just love listening to it.

You would think that I got paid for this. I did not. I just love it, love it, love it. Seven movements, each inspired by a different moon from Signum Classics. It's out there and we have it in the guide. All right, Sarah, your turn. Well, another thing I really love giving to people, especially the younger people in my life or people that just need something to hug are the Celestial Buddy plushies. They're these beautiful little plushies.

You've got ones from all the different bodies in the solar system. So I personally want to collect all of them, but I can't, but you can get at least one for someone you love. So I threw that one up on the list. I like the Mars I have sitting behind me right now. Cosmos, not the Sagan Cosmos, a book that came out much more recently

by the amazing Jay Pasikoff, the man who we have talked to on the show many times because eclipses chase him. He's not an eclipse chaser. And Roberta J.M. Olson, art historian, Jay, terrific astronomer. This is a beautiful coffee table book. It is at that intersection of art and science that I love so much, and I know you do, Sarah. In fact, the subtitle of the book, it's Cosmos, the Art and Science of the Universe. And it's the kind of book you can and will, if you're a space geek, just spend hours paging

through. And the text is brilliant as well. Cosmos, the art and science of the universe. Your turn. Yeah, something that blew my mind. I went to go visit my brother recently, and he's trying to deck out his place at home with some more beautiful lights since he's been shut inside by himself during this COVID era. So to beautify his space, he got a Sega Homestar Planetarium. And now I am very jealous because this thing projects beautiful images up on the ceiling, just the quality of the stars. It's beautiful. And every time I go to his house, I have to turn it on and just kind of lay back and feel like I'm looking up at the sky. Just because, you know, living in Los Angeles, there's a lot of light pollution. I miss the

Milky Way. So, you know, that one's a little bit more on the pricier side. But if you want to fill your home with beautiful starlight, I highly recommend the Sega Homestar Planetarium. That may be one that I will go for because I have wanted a home planetarium ever since I was a little kid. There was one that they sold at the Museum of Science and Industry in L.A. And my parents would not loan me the money to buy it. I've never forgiven them. So now maybe I can make up for it. Okay, here's my big close. It's not new. It's our friend Andy Weir, Project Hail Mary. What an amazing book, as I've said many times, I think every page has

A, a good laugh, and B, a brilliant innovation from that amazing mind of Andy Weir. And Andy will be back on the show very soon with another amazing mind, Rob Manning, the chief engineer at JPL, the Jet Propulsion Lab. So have you read the book, Sarah? Yes, I had to after I heard the interview between you and Andy Ware on Planetary Radio. I know it did give away a lot of it, but just what a clever book. Loved it. Well, that's our list, but there are so many more items for you to check out.

They're all at planetary.org. You can get there right from that homepage. Have fun. And Sarah, like I said, happy holidays. Hope you get lots of great presents. You too, Matt. Many of you will remember that I was in Tucson, Arizona last September for the NASA Innovative Advanced Concepts Symposium. The visit also gave me the opportunity to meet the leaders of the Catalina Sky Survey and SpaceWatch. Both of these successful surveys are run out of the University of Arizona's Lunar and Planetary Lab.

Next door to LPL is the Department of Astronomy, that also runs the Stewart Observatory and the Richard T. Karras Mirror Lab. All three of these are directed by astronomer Buell Genussi. Buell and I met very early at the university's football stadium on the last day of my trip to fulfill a dream I've nurtured for a long time. Buell, as I was just telling you, this is a dream come true. I've been looking forward to visiting the Mirror Lab for at least 12 years now when we started to report on the giant Magellan telescope.

So it is an honor and a pleasure to be here. Thanks for hosting us. You're very welcome, and it's great to be able to share what we're doing with you and with your audience. So where are we headed? We're heading into the oldest part of the Richard F. Karas Mirror Lab. It's where we cast the mirrors. So you're going to get to see the spinning oven. It's not spinning at the moment, but it's the oven that's capable of spinning that is a unique aspect of how we make mirrors. And I encourage everyone who may be listening as we head down here to go to the Mirror Lab site.

You can check out a terrific video that shows you, thank you, as we go through a door, the entire process. Wow, you could probably tell now that we are through a door, the entire process. Wow, you could probably tell now that we are in a big room and what is this that we're standing in front of us? So what you're looking at right now is a giant turntable that's capable of rotating an 8.4 meter mirror and its mold. If you look up to your right you can see a large crane that is capable of lifting the lid of the oven and placing it in place after the mold has been constructed and the glass loaded and everything's ready to fire the next casting. I got to think that pretty much all of the hardware that we

see in front of us here and in the rest of this huge lab is custom. This is not stuff that's off the shelf. No, this is not off the shelf. Roger Angel envisioned how to make these mirrors over a period of 10 years. The Mirror Lab's been in existence for about 40. It's the product of the students and staff and faculty of Stewart Observatory and the College of Optical Sciences working together to do something that hasn't been done before which is make large optics that are 80% hollow that enable us to then use really giant telescopes to learn about the universe. So I'm a big fan well of telescopes first but I love

going to Palomar Mount Palomar to see the Hale telescope. It's kind of a shrine to me, and I even have a t-shirt that has the pattern, the honeycomb pattern, of that mirror on the back of the t-shirt. So a similar construction where a lot of the glass is gone, it makes it a lot lighter, but that was ridiculously difficult to put together. They did not have the advantages of the sorts of technology and this basic technique that you have here. That's right. That's a lighter weighted mirror compared to mirrors of its day, but ours are much more lightweight or hollow. That's largely because the casting method includes taking up space with mold material that later gets removed, washed out. So Roger and his colleagues could minimize

as much as possible how much glass goes into this mirror. Now this is not the only way that you can make a giant telescope. There are at least three different techniques or technologies or design fabrication paths you can go down for making really giant mirrors. And each of them have advantages and disadvantages. One of the advantages of our mirrors is that once you actually get the surface to the accuracy that you want and you put in a relatively straightforward support system, you don't have to worry about whether or not you're going to be able to maintain your image quality. And for the giant Magellan telescope, which requires seven of these 8.4-meter mirrors, all phased together, which we know how to do now,

it means that we only have to change out a mirror for recoding on a much more leisurely time scale than some of the telescopes that are using thousands of segments. But the thousands of segments have the advantage that if you break one, it's a very tiny fraction of your telescope. We have to make sure that that does not happen. I would also think, and I have read, that with telescopes like the TMT, the 30-meter telescope, one of those with thousands of segments, that each of those has to have a little mechanical actuator behind it, right, that has to react very quickly. They don't have to react that quickly. All of the primary mirrors, whether it's a thousand segments or seven, the time scale that we are adjusting the primaries is slow compared to what we do with other

optical elements farther down the chain. So for example, the University of Arizona pioneered what are called adaptive secondary mirrors. So the light comes from a distant star or galaxy, hits the primary or first reflective surface of the telescope, focuses the light light and you introduce a mirror that you can change its shape a thousand times a second it's only a few millimeters in thickness and that allows you to start correcting the wavefront right away with a minimum number of elements and the reason you want to

minimize the number of elements is especially when you're going into the thermal infrared the more elements you have that aren't pooled the greater the background is going to be in your measurement if you're going to look for exosolar planets near bright stars you want to have the diffraction limit we can reach that now from the ground thanks to adaptive optics because what we all want to do is go look for signs of life on exoplanets and And how? You can say that again. Adaptive optics have been a revolution. Maybe as big as using CCDs and getting away from old glass plates?

Oh, that's a hard question, which is more important, CCDs or adaptive mirrors. So adaptive optics, I guess compared to the average person, I'm an expert on adaptive optics, but I'm not the right person to talk to you about the history. But it goes way back. Certainly, Freeman Dyson had a lot of the early ideas, went into non-astronomy world, and then the government released what they developed, and a lot of pioneers, including people like Claire Max at UC, but also people here at the University of Arizona and other institutions, have developed it further. I think the unique contribution that we made here at the University of Arizona

was trying to start having the adaptive element be as early in the optical train as possible with the adaptive secondaries. So along with our colleagues at Ocetri in Italy, the MMT, the Multiple Mirror Telescope, which is misnamed at some level because it's now one big 6.5-meter mirror made from the Mirror Lab, had the first adaptive secondary. The CCD, I think I'm going to have to give the nod to, barely. I'm not surprised. But the diffraction limit, the ability to have these giant telescopes to the diffraction limit depends on the adaptive optics.

And if we didn't have it, we probably wouldn't be trying to build these giant telescopes. Because they still would do wonderful science, but there are other ways of collecting a lot of light. Roger Angel, for example, is working on an idea of using thousands of small telescopes, all fiber, feeding a spectrograph with a fiber, in order to do a lot of interesting spectroscopy that the giant telescopes are also going to do, but Roger's idea will cost a lot less. But his idea would not allow you to image an exoplanet next to a star because you're not creating an aperture that's phased that has the diameter of the giant telescopes.

You're just duplicating the collecting power of collecting a lot of light. I did not know that Freeman Dyson had a role in the development of adaptive optics. He was a guest of mine a couple of times, and I would have asked him about that. You also mentioned, though, this other pioneer, Roger Angel, who was behind the lab and I guess was the first to develop this idea of spinning molten glass and letting centrifugal force do a lot of the work for you. You know, I'm not going to stay with absolute certainty that nobody else ever tried spinning glass because people also have had ideas of spinning mercury to make a mirror.

Roger certainly and his colleagues were the first people to envision this complete fabrication method. It was inspired by the original MMT. So the original MMT used six mirrors that were originally intended for the Air Force's manned space lab. Are you familiar with that? I am. The one that was going to be, they didn't talk about it much at the time, but the one that was going to be basically a military space station. And then they realized, you know, we don't need people up there. We can do it with robots.

That's right. Or satellites. And so the... This is what I meant. I mean, just automated. This is where the connection to the University of Arizona gets strong, is that one of the fathers of space telescopes, Nancy Roman, Lyman Spicer, all those people deserve all the credit they get for the Hubble Space Telescope.

But a less well-known story is the role that Aidan Minnell played in the development of all of our space capabilities and our ground-based telescopes. Aidan Minnell was the first director of Kitt Peak National Observatory, and the first technical publication of Kitt Peak was concept for a space telescope, and this was in 1958. He worked out how you're going to have to do the remote control and lots of other challenges of doing a space telescope. He was also heavily involved in working with the government

on developing reconnaissance satellites. And so at some level he had a role in helping to make the Manned Space Lab not necessary because one of the things that that was going to do was use telescopes to look down and the astronauts, the Air Force astronauts were going to take photographs. Well when that got cancelled there had already been made mirrors, 72 inches in diameter, and Aden was able to convince the government to give them to the University of Arizona and the Smithsonian Astrophysical Observatory to build a ground-based telescope with an effective aperture of around four and a half meters in collecting area, six mirrors all

working together on a common mount. And when that telescope first came online, and the construction of that telescope was led by a bunch of people, I forget somebody, but Nick Wolfe, Nat Carlton, Bill Hoffman. When that telescope first came online, it was making sharper images than comparable telescopes of the day. And they quickly realized it was because the mirrors were coming into thermal equilibrium to the same temperature as the surrounding air more quickly than most mirrors, even the Palomar 5 meter. And that was because the mirrors had been lightweighted, because the dominant cost of going into space

is lifting things off the earth so these mirrors that Aidan had obtained were lightweighted because they were supposed to go into space and now they weren't and Roger quickly realized well okay, it would be wonderful to make mirrors that are bigger than this and he went to industry and industry listened to what he was suggesting,

and they said, no, this is not possible. So that's what set Roger off on trying to develop the techniques. And you asked or said earlier, is everything here custom? Almost everything in the lab is custom. The real genius of what Roger did was to think very deeply and carefully about every simple step that you're going through and extracting the important meaning of how to do it right. But there are other people like John Hill, Peter Stripman, or Buddy Martin who've played major roles in the early days of the lab, and almost everybody is still connected here in one way or another. Although I sometimes say that building a GMT is a little bit like modern

cathedral building because those of us that are working to build it aren't going to get to use it for very long. It sounds like sending missions to the outer solar system. Yeah, that would be another one except I think we'll at least know whether it's all working. So Roger is still active, obviously, as well, from what you said. Yeah, Roger's not retired yet. He's still working on new concepts for telescopes. He's working on a... I was talking to him yesterday.

He's working on a paper for conferences coming up on science from the moon. I heard just before we started to talk, you and I, that you've got someone here who started as a student and is now getting ready to retire, really has made a career of the mirror lab. Sure. I don't know who Stuart was thinking of. We actually have several people, but I suspect he's thinking about Karen Kanegi. Karen was a student here at the U of A, has had her whole career here.

A lot of the people that work at the Mirror Lab came here from very diverse backgrounds, our students or the military or engineering or you name it. But they have to be inquisitive, they have to be good at working as part of a team and they have to not be intimidated about trying to do something that that hasn't been done before and they also need to be very patient you know the we are not a short short order cook in a fast food restaurant the you know casting process takes a year to 14 months, whether it's a 6.5 meter or an 8.4 meter. And those are the two sizes we do right now. And then the polishing, it's going to take right now, although we're working to speed this up, it takes two to four years to complete the polishing.

And I'm going to recommend again that people watch the video on the Mirror Lab website because it will show you just how complex this process is. I mean, there may be people who think this is, you know, oh, what's the big deal? You melt some glass and spin it and then you grind it down for a little bit longer. It's far more than that. In fact, watching that video and then being in this huge facility reminded me of when I went to visit the JWST, the James Webb Space Telescope, and watching that and how it was being worked on. It's that level of complexity and detail. Yes. I mean, I think most of the mirrors that we're making here, we do have the luxury that we're not launching them into space.

Although we are now starting to work, well for about a decade we've been working on concepts for mirrors for large space telescopes. One of the things you saw for James Webb is that they had to fit inside a fairing or a housing for the whole spacecraft that was smaller in diameter than the diameter of their primary mirror. But there's a new generation of large rockets coming, you know some of them already, that have much larger fairings. So it is in much more ability to lift a lot of weight.

So we can now start making mirrors the way we make mirrors or meniscus mirrors, which is the third, the three types of making mirrors, meniscus, our way, and segments, small segments. Small segments worked for James Webb spectacularly, as we all know, but there is a different set of risks with that kind of telescope and a lot of testing required on the ground. And so we're exploring using our mirrors as a possible lower cost way of doing space telescopes. But here you can see the most recent mirror that we've cast. It's for a wide field spectroscopic survey telescope. So that hole in the mirror is the largest hole we've ever had in one of our mirrors. And you're looking at the backside that's in the mirror is the largest hole we've ever had in one of our mirrors. And you're looking at the backside that's in the turning ring.

So this mirror has had all the mold material washed out of it. And unfortunately, we have a queue. Fortunately for us, there's a lot of desire for these mirrors. But unfortunately for this mirror, it's going to have to wait probably about a year and a half before we can even get started on polishing it. I suppose that's a good problem to have. It's a good problem for us, but not a good problem for the people that want the mirror as fast as they can get it so they can make their telescope. Is this the 6.5 meter that you were talking about? This is a 6.5 meter telescope.

And where is this going? So the people that are building that are still trying to decide, so I can't tell you yet. But what I can tell you is that it's going to be a spectroscopic survey telescope. The dominant cost for ground-based telescopes, unfortunately, is the building, not the telescope. So the bigger the telescope gets, the building goes up, and it goes roughly as the 2.5 power of the diameter

of the primary mirror. So the 30 meter that they're trying to build or the 25 meter that we're building, those are billion plus projects. A 6.5 meter can be built for around 70 to 80 million, still a lot of money, but is much more reliable for a university or a small group of universities to raise on their own. Whereas the billion plus projects require involvement of governments and many institutions. Now, this is huge, six and a half meters. That much larger for the GMT mirrors. Right. Just amazing to see. This mirror is not that much smaller, although it is smaller than a single segment for the GMT, but the GMT will have seven of them. So as we continue to go through

the lab, the casting hall that we're in right now can barely fit three of these mirrors in a line, and you're going to see that in the integration hall too. And then imagine how big the building has to be to hold seven. Lead on, because I know your time is limited. There's so much more to see here. We're going down a little spiral staircase now. see here. We're going down a little spiral staircase now. Okay, deeper into the bowels of the mirror lab here, and here is a work area with lots of benches and equipment. Oh, and we're under the turntable now? That's right. We're under the turntable. What you're looking at,

it sort of looks like a merry-go-round. If they look at the mirror at the movie, I think there's a picture that shows the bottom. This is not the very first oven, but this oven has been used for the majority of the large 8.4 meter mirrors, all the 8.4 meter mirrors that we've cast. The information that all the sensors and computers on here get, all the temperatures, then gets sent to a control room that's over there on the left. And during the initial high-temp casting and then cooling for three months, everything's being monitored 24-7. We have backup power. It's all to make sure

that the glass anneals without having any stress left in the blank. Three degrees centigrade per day for cooling for how long? About three months. Wow. And an enormous amount of power. Oh, my God. All right, another huge room. And we haven't said yet where we are, the location on this campus. Yeah, so we're underneath the East Stands portion of the U of A football stadium. This football stadium has been here since the 1930s. has been here since the 1930s. Brian Schmidt, who was an undergraduate here and went on to win the Nobel Prize in 2011 for discovering that the expansion of the universe

is accelerating, along with his colleagues and a competing team, actually had his freshman dorm room was inside the stadium here. Wow. Because on the southern edge, they're dorms. People ask, why are you underneath the football stadium? Is it because Chicago did astronomy in their football stadium? No. Or

physics in their football stadium. First nuclear reaction, first fission reaction, right? That's right. So there is a positive relationship between football and innovative science. But the reason we're here is because it's close to the astronomy department and optical sciences, and there were big pillars of concrete that you could attach walls to and cranes. So it's that simple. And everything in here is incredibly heavy duty. I mean, we'll put some pictures on this week's episode page at planetary.org slash radio so that you can get a feel for it. But I suspect it's a little like the Grand Canyon. If you're not standing here, you're not really going to get the scale of it. Yeah, that's a nice analogy. I might use that sometime. Yeah, you're up close to something that's really big. And so

if you try to take a picture, your brain is doing a better job helping you have a sort of mental map of what you're looking at. What you're looking at right now is in the center here is what's called the test tower. We named it after Dan Neff, who's one of the founding engineers of a company in town called M3 Engineering. a company in town called M3 Engineering. They primarily work with mining companies around the world to build complex facilities out in remote areas. And they have worked with us in the past in building big telescopes, like the Large Binocular Telescope on Mount Graham. But Dan was one of the people that helped design the test tower. So what's the test tower? The test tower is what holds the mirror that you're testing isolated from vibration. So these three big pillars that you see here are the corners of a triangular part of the floor

here that's sitting on giant airbags so that we don't end up having vibrations from trucks or other people going by. And then above it is a tower that, in this case, you can look up and see. There's a four-meter fold sphere up at the top, that mirror. Yeah, and we're looking up through a very high tower. I don't know how distant that is. With different levels, it's almost as if we were at a launch pad at Kennedy Space Center. It's not quite that big, but I'm glad you're inspired by it. But it is not big enough to test

a segment of the giant Magellan telescope. You know, for your audience, the mirrors, the whole point of a mirror is to collect a lot of light, these primary mirrors, collect a lot of light, but then bring it to a focus to make an image. And if you want to test the surface, you can't just use your eye and look at the surface and say, oh, that's right, that's the surface we want. You have to have a way of measuring it. And we need to have the accuracy to be a fraction of the wavelengths that you're trying to actually focus. So you need to actually shine light on the mirror and measure where that light goes.

And when you can show that it's not exactly right, use math and computers to create an understanding of where the errors are in the surface. And then you go rub on any high points. And you have to be careful not to over correct or polish too much because there's no way to add glass back so if you take away too much you have to remove more glass from the rest of the surface to get the whole surface the way you want it it reminds me of when I was sanding an old wooden floor in my old house. And, of course, if you go too far in any one spot,

you're going to have a little divot there for the rest of the life of that floor. That's exactly right. And so the test tower was originally sized for testing where the light would come to focus for an 8.4-meter telescope. But now we're testing a segment of a 25 meter telescope. So we want to focus the light where the light of a 25 meter telescope would focus. That's going to be three times higher than where the 8.4 meter telescope was focusing it. And that would run into the football stadium. 0.4 meter telescope was focusing it and that would run into this football stadium.

So we had to put that fold sphere to bend the light back so that we have a total path length, total distance that the light from the primary travels that is long enough that we can test the image quality from the mirror. We have multiple different tests and then we need all of them to agree. They all have slightly different strengths in what they can test, so they are not a perfect substitute for each other, but you can require that they all be giving a consistent answer, and that's what we do. And the mirror you're looking at right now is the third segment for GMT. We've just completed it. We're going through the formal acceptance testing, And we have cast three others.

So we've cast a total of six, and we're casting the seventh this coming year in 2023. And that'll be it. So we're hoping to make one more, the eighth, that would be swapped in to help just with logistics when we're recoding mirrors. But one reason I'm excited about getting the seventh cast and then finished

is that is the minimum number, and then we'd be ready to go. Cannot wait, of course, to see that telescope reach first light. And it says right here, Giant Magellan Telescope, Segment 3. Here there's also a sign that says Interface, and that's the company that Richard F. Karras founded. It makes load cells for lots of applications, predominantly the oil industry. The woman that we were talking about earlier, Karen Carnegie, who is about to retire after having a long career here in many roles, including helping us maintain and develop a culture of safety.

She is responsible for our connection to Richard F. Karras. She was our procurement officer and when Richard F. Karras, who was the head of the company he founded Interface, called us up to say, why are you guys at the University of Arizona buying load cells at weird times of the year in small numbers compared to what he was used to. And Karen was smart enough to tell my predecessor, Peter Stripmatter, that the head of Interface had called up wanting to know what we were doing with his load cells. And that started a connection with Richard. Richard had no prior connection to the University of Arizona, but he was very interested in doing things that were exciting and new and fell in love with what we're doing here at the Mirror Lab.

And over a 15-year relationship, he helped support the start of the Large Synoptic Survey Telescope, now the Vera Rubin Observatory. He was the second philanthropist to help contribute to that project, allowed us to buy the glass that made the primary mirror for that observatory. And then he made a very generous contribution to our involvement in the giant Magellan telescope. And that's why we renamed Mirror Lab in his honor. You can see, I can show you a picture of him and Roger Angel touring the lab on one of his visits. But that's why we honor Interface with their sign-up.

Right next to the University of Arizona, the big A there. And the giant Magellan telescope logo. Yeah. I guess we better move along if we're going to get back upstairs. This is what's called the large optical generator. It's basically a turntable with a beam and a tool, a generating tool, where you can actually do the polishing of the back of the surface. Then we attach the load spreaders.

They can see this in the video you're referencing. Then the mirror gets flipped over so that the front side is up. And then the initial stages of generating the surface are done on this machine. Then it gets moved over to the large polishing machine, which is on the other end of the hall. And it then spends, you know, a year or two moving back and forth from being polished and then being tested, polished and tested. And each time that move, I mean, you're moving many tons of glass and support structure. Yeah, about 17 tons and plus a few more tons. And we're squeezing through a little spot here to go over to the other end of this long

room and here's that big laser for your interferometer. Yeah, this is actually monitoring the fold sphere because every element that's helping to test the mirror surface needs to also be monitored. All right, we've just stepped through a doorway into yet another room and yet another amazing assembly here. What's happening here? So this is what we call the integration hall. So the Mirror Lab now has three big rooms, casting, polishing, and integration. Integration is where we put load cells on the back of the mirror, ways of supporting the mirror when it's in a polishing cell. It's also where we store mirrors

while they're waiting for the next step. And what you're looking at here is a relatively new thing that Jeff Kingsley and I came up with when we were realizing that we were running out of space. And I said, can we have a CD rack? And that's what our engineers were able to come up with. I mean, you got three mirrors here stacked on this, again, very heavy duty monster girders. And it is kind of like a little CD storage system. Old enough to still use CDs and it's it's like a CD rack

storage and so you can see here that the fourth segment which is the one that has the central hole in it the central hole of that mirror is 2.4 meters which is the size of the Hubble Space Telescope and then the fifth segment and the sixth segment. And behind us a huge gantry that's going to slide those gigantic cds in and out that's right that crane uh which can lift 55 tons and these mirrors are around 17 to 20 is the way we get them in and out and then that doorway is how the mirrors leave the lab i know it doesn't look like a door because it's the whole wall. The whole wall slides open. Absolutely magnificent. Sign on the wall, crane lift in progress. Do not enter.

Not at the moment, but it's there. Safety is important. Incredibly important for our people and also for all the equipment and the mirrors. People sometimes say, why aren't you wearing hard hats all the time? Well, we are wearing hard hats when we're like doing crane lifts or moving and things like that, but we don't want hard hats falling on top of our mirrors. Oh, yes. Right. So if we were polishing a mirror right now and we're not, we're testing it, it would be on this turntable. And over on the upper right there is the stress lap, which is one of the laps that we have. That's the largest one. And its shape can actually be changed by applying forces on the back of it. And then over on the left...

Almost like a mirror that's being deformed. A little bit like a deformed mirror, except that the technology is very different. But I'm sure that in Roger and other people's thinking, it's not a coincidence. That polishing lab is on the other end of this beam. You can see that everything in the lab was designed for making mirrors that are symmetric around their own center. And if you think of a circle, your brain says, well, of course, a circle is the points equidistant from the center. And you say, is a circle symmetric? Of course it is.

Then you look at a circular mirror. If you ask, is that symmetric around its center? For most telescopes, the answer would be yes. But for the Giant Magellan Telescope, it is not. Because the mirrors out on the petals, the six outer mirrors, are symmetric around the center of a 25-meter mirror. That means that each of these mirrors depart by like 11 millimeters from being symmetric around their own center.

They look more like a potato chip. And you can't see that with your eye, but that makes them much harder to polish. And to me, what Buddy Martin and Steve West and their groups do to accurately measure where the surface is and then compute where they need to polish and then polish it is one of those really amazing things that's done here at the lab. Almost miraculous. Do you remember the analogy that's used where if you like took a GMT mirror and it was as wide as the United States? Yeah, so Buddy likes to, when he's describing this, Buddy says that if you were trying to make a mirror that is as accurate in terms of its surface as the GMT mirrors or the ones we made for the LBT, and you thought of the mirror as being as big as North America,

the biggest mountain range or valley that you could have would be about one to two inches. So the surface isn't flat, but it has to match what we want it to be to an accuracy of 20 nanometers. And Buddy's analogy just gives you a more intuitive sense. We can't internalize what 20 nanometers means, but we understand what one inch is compared to North America. Yeah, absolutely. When we return, I'll sit down with Buell to learn more about the University of Arizona's very accomplished Department of Astronomy and the equally distinguished Steward Observatory.

There's so much going on in the world of space science and exploration, and we're here to share it with you. Hi, I'm Sarah, Digital Community Manager for the Planetary Society. Are you looking for a place to get more space? Catch the latest space exploration news, pretty planetary pictures, and Planetary Society publications on our social media channels. You can find the Planetary Society on Instagram, Twitter, YouTube, and Facebook. Make sure you like and subscribe so you never miss the next exciting update from the world of planetary science.

We're back now up above the lab to talk a little bit more about how this fits in to the Department of Astronomy, the Stewart Observatory. You head all of this. You're basically the chair, right, of the Department of Astronomy, but also the director of the Stewart Observatory. Yes, I'm the seventh director of Stuart Observatory and head of the department. Peter Stritt Matter, my predecessor, served for 37 years. I am not going to be doing that, but I am in my 11th year. And most department heads or chairs will serve three to five years, and that I think is an adequate sentence for misbehavior. The role of a chair or department head is working on helping to run the academic affairs,

the graduate program, the undergraduate program, hiring, review of faculty. Directors of observatories, and I was director of Kitt Peak National Observatory before I came to Steward, director of Kitt Peak National Observatory before I came to Steward. We're working on projects like telescope building or new instruments that last on a longer time scale. That's why we need both jobs. And the reason one person has it here and not two, and someday it might be two, is more historical accident. I know when I was being hired, I asked my dean, Dean Joaquin Ruiz, why don't you split these jobs? The University of Texas has the director of McDonald Observatory, Taft Armandroff, and someone else is the department head. And he said, well, the budgets for the two units here are so intertwined that the director and the department head would be arguing with each other and would need to come to me to resolve the dispute.

That's your job. need to come to me to resolve the dispute. That's your job. But I really enjoy the mix for me personally because I was at the National Observatory. I spent a lot of my career helping to develop capabilities for the whole country. So I love doing the kinds of work that you do as a director of an observatory, but I also love working with students and sharing what we're learning with the world through our outreach programs. So for me, it works out pretty well. We are an unusually large department. We have currently 341 undergraduate majors. We have 80 graduate students.

Of those 80 graduate students, 55 are getting their PhDs in astronomy and astrophysics, and the others are students in the College of Optical Science or physics or electrical engineering who are working with our faculty. And then we have 70 faculty, 35 of them are tenure track, and we have a large number of research faculty. We are involved in a lot of exciting missions like the James Webb Space Telescope, the near-infrared camera was led by Marcia Ricci, former associate head in our department and regents professor here. She also, we're celebrating the 100th anniversary of our public lecture series on September 28th with Marcia as the speaker.

And she's also our very first holder of an endowed chair in honor of Elizabeth Romer. Elizabeth was an expert on comets and on our faculty here in the 60s, 70s, and 80s. She also played a major role in helping to get the Department of Planetary Science, our sister department, created. There are a lot of busy astronomy departments, but I don't know that there are any that have their hands in more diverse areas of development and observation than Steward. And what you've just said is more evidence of that. Talk about some of the ground-based telescopes that are part of the observatory. Sure. No, you're right. I mean, along with our sister department, LPL, take us together.

The University of Arizona has ranked number one in the NSF herd rankings. Sounds like cattle, but what it actually is is a tracking of research dollars expended in an area or activity. And so we have been spending more money, and that gets us a number one ranking. The fact that we keep winning grants from NASA, DOE, NSF, and other groups to do the work is a sign that we have a lot of talent and talented staff and experience doing really big missions. And you're right, that includes telescopes like the Large Monocular Telescope, the Giant Magellan Telescope, but we also help others build telescopes.

The University of Tokyo is building a telescope called the Tokyo Atacama Observatory. It is going to be at an altitude of over 5,000 meters, 18,000 feet, on Chetnantur in Chile. It will be the highest observatory on the planet, and it'll be able to observe at mid-infrared wavelengths that no other observatory can reach without going to space. We just shipped their mirror this past Monday on the 19th. It's making its way to California right now and then down to Chile, and so in the next two years it'll be integrated into their telescope. The Large Synoptic Survey Telescope, Vera Rubin Observatory, which was delayed, the construction

was delayed by the pandemic. But that should be coming online very soon. It's going to be operated by NORLAB, the National Observatory, in partnership with DOE. And by the way, that is one a lot of us at the Planetary Society are very excited to see finally coming online. Yeah, no, it's going to be an amazing facility. It's got four major science themes. U of A was one of the four institutions that got that going. We're still part of the LSST Corporation, which has transitioned from trying to get the project

started, which they did successfully, to raising funding to help do the science that will be done. And then we're also very involved in smaller space missions, things that are still exciting, but not as well known as James Webb. We have a new faculty member, Carlos Vargas, who as a postdoc here won a $20 million award from NASA for a project called Aspera. It's going to map the warm gas around nearby galaxies, learn more about feedback and star formation. That, by the way, came up here

because it was also supported, I believe, by a NIAC award, SPHERA. And, yeah, it was good. Very interesting. I didn't know there was a relationship there. So he is, I haven't finished researching this, we think he's the youngest person ever to be selected as a PI for an NASA mission. And one of the reasons I think he's able to do that is because we provide an environment.

One, we don't say no to a postdoc when they come to us and say, I want to do a space mission. We do say, are you sure? And then we try to help them out. Chris Walker, a member of our faculty, has a high-altitude balloon mission that will be going up in December of 2023 called Gusto. altitude balloon mission that will be going up in December of 2023 called GUSTO. So this is NASA's program to use high altitude balloons to get as close to space as you can get without actually going to space. And that enables things like UV astronomy and terahertz or far infrared astronomy at a much lower cost than space.

And you just couldn't do it, you know, at sea level or on a mountaintop. So we were involved, and then we have one of the largest groups of theoretical astrophysicists of any university. We're known more for things like the mirror lab, but in the modern era, our students are working not only to understand how to make innovative new measurements, but also how to model the problems they're trying to understand using the most sophisticated techniques, high-performance computing, as well as simulations. So we need to have the world's experts in those kinds of techniques to train our students as well. Training the astronomers of tomorrow, the ones who will be taking on these instruments.

Absolutely. And you'll often hear people say, oh, I got to live in the golden age of astronomy. And I think it turns out that the reason that's true is it's a very human endeavor. And so the more people who are doing it, the more people you have to share what you're doing with. And it stimulates each other to do more. And you can collectively do more. When Andrew Ellicott Douglas, the first director of Steward, about 100 years ago, was dedicating our first research telescope, which was a 36-inch telescope.

It was called the All-American Telescope because it was the first telescope made of entirely American-made parts in North America. And it was dedicated on April 23, 1923. He was the whole department. And now we have 450-some-odd people. The staff are incredibly important. It's not just the astronomers and the students. And then you've got another few hundred people over in planetary science. So we went from one person doing astronomical research to over 600.

You run a medium-sized corporation or the equivalent of that, but you're an astronomer and a cosmologist. Do you get to do much anymore? I actually survived maintaining what I was doing for the first seven years that I was here. I basically am mostly doing administration now, but I'm still the PI of the GMT mirror contracts. That's not necessarily what I would have called research 10 years ago, but there are elements of that.

I'm also part of the Event Horizon Telescope Collaboration, which uses a bunch of radio telescopes to make images of the Event Horizon, which I didn't even get to mention. That project is something that about 20 faculty and 20 of our faculty and students, graduate students, are involved in here. I didn't know the UA had such involvement in the EHT. That's great. We have two millimeter wave telescopes. One of them, the submillimeter telescope on Mount Graham,

has been involved in the EHT from the very beginning. It was one of the first telescopes that was used to help make, to demonstrate that these kinds of observations might be possible. That got started under Lucy Zuris, a member of our faculty, and Peter Stripmatter. And then Demetrius Saltis and Ferriel Ozel and Dan Maroney and others here. Demetrius and Faryal have recently moved to Georgia Tech, but Dan Maroney is still here, C.K. Chan and others. We have been involved since 2012 when the Event Horizon Telescope Collaboration was being formed. we were part of that. And we now support two telescopes, one instrument, also a lot of the simulations.

So we have a lot of faculty and students that play a major role in that project. Just one more question. I will mention in passing, you talked about your sister department, the LPL, Lunar and Planetary Lab, which I'm also talking to folks, some of the folks from there. We like to say that they get the solar system, we get everything outside the solar system, and we fight over the exoplanets. And with any luck, pretty soon we may be identifying some of those exoplanets as being Earth-like, thanks to a lot of the work that's being done here. The outreach side of what you do, we're very close to a planetarium, which is one of the most popular attractions in Tucson, Arizona. Is that also under your department or no? It's a fantastic planetarium. I'm very grateful I'm not in charge of running it.

They do a great job. It was originally part of the astronomy department back in when it was first built but it became a it's become a standalone broader than just astronomy and it's part of the College of Science and College Science Outreach. The outreach that we run and that astronomy runs includes the Mount Lemmon Sky Center which is a nighttime observing program for the public. Its director Alan Strauss also does a great job of working. There are multiple educational and outreach programs that they support, some of high school students, some elementary school kids. There's a wide variety. And it's part of our mission because if you're not sharing what we're learning with the public, then you're failing.

Sharing what our boss, Bill Nye, likes to call the PB&J, the passion, beauty, and joy of space and science. And thank you for sharing all of this with us today, Buell. It has been a realization of one of my dreams as host of this show. Thanks for sharing it with our audience as well. And I will just say one more thing. On a cabinet near us is the cardboard model of the GMT that I built with my grandson. And so it's great to see that. I cannot wait to see the actual GMT. I agree. Our colleagues in Korea, so one of the partners in GMT is the Korean Astronomy and Space Institute. And, yeah, I'm ready. I love this model, but I'm ready to move on to the real thing. Maybe we'll come up with one or two more that we can give away as part of this week's What's Up Space Trivia Contest.

Yeah, we'd be happy to give you some. Thank you. Thanks very much for all of this. You're very welcome. Time for What's Up on Planetary Radio. Here is the chief scientist of the Planetary Society, Dr. Bruce Betts. He is also the program manager for the LightSail program. And Bruce, just as you predicted last week, LightSail 2 is no more except in our very fond memories.

Yes. Yes, LightSail 2, as you probably mentioned, deorbited, burned up after three and a half years on November 17th-ish. The spacecraft is done, but the mission is not over as we continue to analyze data over the coming months and years. I think it will be a legacy for many, many, many years to come. Cool. That's just my opinion. Don't go by me. I mean, frankly, that's all that matters, Matt.

Well, we'll have more. In fact, we will hear from the CEO, Bill Nye, about this topic next week when we also celebrate the 20th anniversary of Planetary Radio. There's still stuff up there, right? It didn't all fall and burn up. No, but it's surprising how much stuff is falling down and burning up on a regular basis. No, there are planets that are nowhere near us, so they don't have much of a chance. Although Mars is coming closer and closer. It'll still be a really, really, really, really long ways away. But it will have its closest approach, so to speak, to Earth for the next 26 months on December 8th.

What does that mean? It means it is really bright. I'm sorry, December 8th is when it's on the opposite side of the Earth from the sun. It is really bright. I'm sorry, December 8th is when it's on the opposite side of the Earth from the Sun. Opposition, technically usually shifted by a few days due to elliptical. Later in the evening, higher up, it's really bright. It's almost as bright as Jupiter now. It's reddish because, you know, it's Mars. And it's cool. So Jupiter also up higher in the sky over in like the south.

Or just high up in the north if you're in the southern hemisphere. And Saturn farther towards the west looking yellowish and not as bright. And one more thing. We're getting to the winter hexagon, which I've mentioned before, but I mentioned it again later in the evening. If you look over in the east, and it is one, not winter in either hemisphere, but it will be soon, and it's named for the northern hemisphere winter. Sorry. Surprisingly enough, six stars form the hexagon. Really bright stars over a big part of the sky, including Rigel in Orion, and the brightest star in the sky, Sirius, and that will be up in the east, and Mars is inside

the hexagon right at the moment. Sort of in between, but not quite. Aldebaran and Capella. You can find more information, including a graphic of that at planetary.org slash night hyphen sky. You look like you have a question. Is it true that it used to be an octagon, but two of the stars were kicked out for unbecoming conduct? I'm just asking. I can neither confirm nor deny that. I'll have to check with the appropriate sources. Moving on, how about this week in space history? Sure. It was four years ago that NASA's InSight mission landed on Mars, giving us

Marsquake information and other information about the surface and the interior of Mars, and is about to be decommissioned due to dust on solar panels. On to Random Space Fact! That was the deliverance version of Random Space Fact, I think. I'm waiting for the drooling banjos. Random, random, random space fact. Random, random, random space fact. Okay.

Random, random, random space fact. I get the idea. All right. I'll stop. Artemis I, SLS, launched, launching Orion towards the moon. Orion will fly farther than any spacecraft built for humans although it doesn't actually have humans in it yet

any farther than any spacecraft built for humans has ever flown away from Earth over the course of the mission it'll travel about a half million kilometers from Earth or about 64,000 kilometers beyond the far side of the moon, which puts it farther away than any other human-designed spacecraft. There will be

humans in there eventually. Someday soon. Also, it'll stay in space longer than any human spacecraft without being a space station, docking to a space station, but it will also, it's going to be hotter. It's going to return faster and hotter than ever before when it hits that atmosphere. And I hope to be there when it is brought ashore at the San Diego Naval Station, which is like five minutes from where I live. So I hope to make another trip down there and this time watch them pull in a real one. Is it true that they picked San Diego because you were down there? I hate to say that I use my influence, so I won't.

Let us go on to the trivia contest where I still manage to confuse people accidentally, apparently. Sometimes I do it on purpose. Usually it's not. I'm confused by this one, but I suppose it was. I asked you, for whom are the two Viking lander sites named? Tell us how we did, Matt. It was quite clear to me. There were a number of people who sent in entries with the names of the regions on Mars that the two spacecraft landed in back in 1976. You know, thank you to those of you who went to the trouble of looking that up. I have the answer, I believe. Please share.

It's from Dave Fairchild in Kansas, our poet laureate. If you want some images from Mars of rocks and stuff, then look to find the landing spot that's named for Thomas Mutch. And then your project scientist at Gerald Soffen Station, it's no surprise we emphasize their Martian exploration. That stuff and much is a little bit of a stretch for a rhyme, but I get it, I get it.

It was a tough one. And such? For rocks and such, You're absolutely right. Bruce, you are the new poet laureate for a planetary. I'm the poet editor. A strange little known. From Mars of rocks and such. You're right. You're absolutely right. Dave is slapping his forehead as he hears this. I have no doubt. This person has not won in 15 years, almost exactly

15 years. One, that is amazing and way to go persistence. And two, it is amazing that you have those records. Well played, sir. I don't this time. I'm not sure I would if I didn't have to check because Mike told me himself, Mike Tate in in Texas he said his last win was November 26 2007 when we gave him a little piece of a Martian meteorite remember when we did that I do I do that was a very fine prize well anyway then never mind on the compliment to you just to compliment to him. Congratulations, Mike, you're back. He also says, thank you for the many years of delivering the universe each week.

Planetary Radio is and has been my favorite podcast since they were invented. You're a trailblazer. You have my eternal gratitude for teaching and forming and bringing the PB&J of this in every world to myself and the many fans of Plan Rad. I wish you the best for what comes next. Thank you, Mike. That's very nice.

And thank you to all of you. I continue to get so many of these wonderful messages from those of you who have enjoyed the show. I love every one of them. Thank you so much. The poem mentioned Gerald Soffin was indeed the project scientist of Viking. Thomas Mutch was the head of the Lander imaging team, who unfortunately Mutch passed away while the mission was still going along. Mike, before I forget, we should remind everybody that we're going to send you a signed CD copy of the Moon Symphony, composed by Amanda Lee Falkenberg and available from

Signum Classics. Seven movements, each inspired by a different moon in the solar system. Highly recommended. It's on my Christmas gift list that people heard me mention. Sarah and I talked about our choices on the Planetary Society holiday gift list, not just Christmas, of course. I do have a couple of others. I'll just do this really fast. Mel Powell, if we ever find the landing site for the Mars Polar Lander, I assume it'll be named for Wiley E. Coyote,

splat, poor thing, too soon. And Robert Klain in Arizona, gonna miss you muchly, Matt, but you have softened the blow by hiring such a great replacement. Bruce is holding his head in his hands. Shall we move on? Yeah, it's time.

The Artemis program has launched. First SLS rocket. They named it Artemis partly because Artemis was the twin sister of Apollo, the whole Apollo program. You may have heard of it, Matt. It went to the moon with humans. So here's something for you mythology fans out there. We all know, okay, maybe we all don't know, but a lot of people know Zeus was the father of Artemis and Apollo. Who is the mother in greek mythology who is the mother of artemis and apollo go to planetary.org radio contest love these mythological questions uh you have until

the 30th that'll be november 30th at 8 a.m pacific time and some of you may have heard me mention that model of the giant mage telescope that I built with my grandson. I told Dr. Januzzi about that during our tour of the Mirror Lab. I've got several of these to give away. It's from Skolas, a Korean company. Buell mentioned that it came out of their Korean partners on the giant Magellan telescope. It's really fun. Came out of their Korean partners on the giant Magellan telescope.

It's really fun. It's a neat thing to build. Four out of seven stars in terms of difficulty. It's a little bit of a challenge, but it's fun. I can tell, but I wanted you to be clear. You're not giving away the one you and your grandson made together. Oh, gosh. I guess I should clarify. No, these are in the package,package, brand-new, unbuilt GMT model kits.

Ooh, new and unopened. Nice. All right, everybody, go out there, look up at the night sky, and if a moon symphony is too much for you to create, to write, as it would be for me, what would your moon jingles sound like? Thank you. Good night. And the dish ran away with the spoon.

I guess there's no music to go with that, but you can come up with a jingle for us. Music. We're looking for the music. All right, never mind. Okay. I got the lyrics. He's Bruce Betts,

the chief scientist of the Planetary Society, who joins us every week here on What's Up. Congratulations on the completion of a three-and-a-half-year solar sail journey around the Earth. Thank you, and thanks to all who made it possible, including the 50,000 individuals who gave to it, and all of the staff, all the people. I'm going to name every one of them, if that's okay, Matt.

We're going to go now, Bruce. Okay, there was Bruce. Matt was there for some stuff. Oh, yeah, the project manager for operations, Dave Spencer, and John Villardo from Cal Poly San Luis Obispo, handling ground communication and software, Barbara Plant. Planetary Radio is produced by the Planetary Society in Pasadena, California, and is made possible by its farsighted members.

Catch your reflection at planetary.org. Mark Hilverda and Ray Paletta are our associate producers. Josh Doyle composed our theme, which is arranged and performed by Peter Schlosser. Ad Astra.