We took a hiatus this summer, but SpaceX sure didn’t, with the tests of the Starhopper prototype. Today we’re going to talk about the revolution in reusable rocketry and quest to build a fully reusable two-stage rocket.
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This episode is sponsored by: Barkbox
- SpaceX Starhopper
- SpaceX Starhopper Rocket Prototype Aces Highest (and Final) Test Flight
- SpaceX’s Starhopper completes test flight
- Reusable Launch Systems
- Rocketlabs Electron Rockets
- SpaceX Falcon 9
- SpaceX Starship
Transcriptions provided by GMR Transcription Services
Female 1 Announcer: Today’s episode of Astronomy Cast is sponsored by Magellan TV. Claim your two-month free trial only available at MagellanTV.com/astronomycast.
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Fraser Cain: Astronomy Cast Episode 534, Modern South African Astronomy.
Welcome to Astronomy Cast, our weekly fact-based journey through the cosmos where we help you understand not only what we know, but how we know what we know.
I’m Fraser Cain, Publisher of Universe Today. With me, as always, Dr. Pamela Gay, a Senior Scientist from the Planetary Science Institute and the Director of Cosmo Quest.
Hey, Pamela, how are you doing?
Dr. Pamela Gay: I’m doing well, how are you doing?
Fraser Cain: Great! Here we are, our penultimate episode, our penultimate live studio episode that we are recording from our home studios during Season 11. So, there’s this episode and the next week, I don’t even know if we have a topic for next week yet, and then we will wrap up for the summer.
However, we are going to be at the All Stars Party. We’re gonna be with our friends, and we’re gonna be with a bunch of our other space podcast creators, and so we will be creating all kinds of content with them and we will be dropping a ton of this into the feed.
So, stay tuned, you’re gonna get a lot. If you can’t join us, you will at least get, as if you were there, with some of the conversations that we had while we were there.
Dr. Pamela Gay: Educational astronomy on the go, silliness, will be coming your way.
Fraser Cain: Yeah, exactly. All right. You know the drill now. Last week, we talked about some ancient South African astronomy. So, this week we’ll talk about the modern state astronomy in the southern part of Africa, which happens to be a great place with nice dark skies and a perfect view into the heart of the galaxy.
Now, I haven’t been to South African, have you?
Dr. Pamela Gay: Yes!
Fraser Cain: You have!
Dr. Pamela Gay: It’s fabulous.
Fraser Cain: Yeah.
Dr. Pamela Gay: And I, I really recommend it as the kind of place that brings some hope. Because there are a lot of nations right now that you visit, my own included, where you get the sense of a nation on decline. You get a sense of a whole bunch of people who have lost hope and are just forlornly watching the world burn.
Well, when I was in South Africa in 2010, this was the first generation of adults that had grown up with apartheid ending with opportunity on the rise, with people of different colors all able to mix in the cities. And the amount of poverty was great, but the amount of hope was great as well.
And one of the things that they’ve been working to do is, this has been a technologically advanced nation and they’re now looking to advance all the people of their nation through science. And astronomy is one of the places they’re putting a great deal of effort because it gives them an excuse to get amazing infrastructure into remote parts of their countryside.
Fraser Cain: Yeah. And, I mean, I, again, I haven’t been to Southern Africa, I have been into the southern hemisphere now. And so, I’ve got to assume that the view of the skies from South Africa is as amazing as the view from Australia; dark skies, away from light pollution, staring into the core of the galaxy.
Dr. Pamela Gay: But the difference is the wildlife. So, in Australia you have to worry that something deadly –
Fraser Cain: Yes, something –
Dr. Pamela Gay: – is gonna be on the ground when you sit down, so maybe you don’t sit on the grass.
In South Africa, out at Sutherland Observatory, a whole group of us decided we were gonna walk up from the visitor center to the main observatory at the peak of the mountain. And I, we did this after dark because we’re astronomers and morons, and just settled on the side of the observatory road so that none of the astronomers leaving the mountain to go to sleep would run us over. And we didn’t have flashlights, we didn’t wanna ruin anyone’s observing.
So, as the sun came up, we realized we had sat down in the middle of a herd of spring buck!
Fraser Cain: Right.
Dr. Pamela Gay: And so, all of these giant antlered, giant jumping critters, wake up, and they’re like, what is this strange thing? And one of them came over and was like flaring its nostrils at one of the cameras that we had on an automatic timer. And it was just this amazing experience to see this diocle light get bright and the sun come up, and then to realize you’re in a herd of wild animals.
Fraser Cain: Yeah. Some of my favorite, my favorite astronomy power couple comes from South Africa, Cory and Tanja Schmitz, from Photographing Space. And the pictures that they are just sending back are stunning. So, I, you know, I cannot wait to get a chance to head down to South Africa.
We’ll talk about observatories, then. Do you know, not just we who have suspected it’s a great place for astronomy, the astronomical community is pretty certain as well. So, what are some of the observatories and facilities that are there in Africa?
Dr. Pamela Gay: So, well, here we’re focusing on South Africa with a touch of nations around it. So, we’re gonna start in the City of Cape Town, where you have the Royal Observatory of the Cape of Good Hope that is built up on a hill in a part of Cape Town that’s called Observatory.
And one of the really amazing things about this part of the city is it was one of the areas that, even during apartheid, allowed the mixing of races. This was what was called a gray area of the city; it’s student housing, it’s kind of think about that super-weird and trendy neighborhood near your favorite large university campus. And you kind of have this area, but maybe with like a touch of Haight Ashbury thrown into the mix.
Now, the observatory itself was built in 1820. This is one of the great historic observatories that was put there so that they could figure out when they were. So, just like with the Sydney Observatory, this is a facility that once upon a time had a large telescope, and was responsible for figuring out latitude and longitude so they could literally accurately put Cape Town on the map.
Now Cape Town has kind of grown since 1820. The light pollution has more than kind of grown since 1820. And so, with all of those changes, and with the desire to have one of the best observing facilities in the southern hemisphere, starting in the 1970s they began moving the nation’s telescopes that were at universities and other random places out to Sutherland.
Fraser Cain: And so, where, and so how far away is Sutherland?
Dr. Pamela Gay: It’s a several-hour drive to the north and east from Cape Town. It takes you through some of the oldest landscape in the world. You can actually see chaotic terrain where the land is flipped up and you can see the [inaudible] [00:09:27] line through the sedimentary layers that marks “here be dead dinosaurs”. And there are baboons along the say, beware of the baboons, they’re freaky. And then, once you get out to Sutherland, this is not just a great place for professional astronomy, but they also do astro-tourism and it’s a dark sky preserve.
So, once you get out there, there’s all of the normal small-town countryside things that you’ll find anywhere that is yearning to be a tourist trap. But once you get up to the top the mountain, there are 15 different domes up on that plateau.
Fraser Cain: And so, I mean, we’ve seen how this plays out; some small ones, some big ones, and some very big ones.
Dr. Pamela Gay: Yeah. And like so many other places, what we also see is the history of the development of astronomy. One of my favorite telescopes that they have up there, because the data from it is near and dear to me, is the Alan Cousins Telescope. This is just a 30-inch telescope, doesn’t sound all that tremendous, 75 cm. But this particular telescope, if you’re ever heard of like the Cousins filters, the precision photometry, that photometric system was defined for the southern hemisphere using this telescope. So, if you ever needed to use standard stars to figure out how bright something was in the southern hemisphere, you owe a thank you to this little 30-inch telescope.
Fraser Cain: That’s really cool. I mean, there are planet hunting telescopes, there are sky surveys, and there’s one very, very big telescope, the SALT Telescope. So, let’s talk about some of the other instruments that you can find at this one place?
I mean, there is a level of concentration of astronomical equipment in this one location greater than, I think, you know, in any of the places that we’ve talked about. They’re more spread out in other areas, but in Southern Africa they are, they are –
Dr. Pamela Gay: This peak.
Fraser Cain: This is the place.
Dr. Pamela Gay: They are all there!
Fraser Cain: Yeah.
Dr. Pamela Gay: So, like most big observatories, there is, of course, the Las Cumbres Observatory Global Telescope Network. Telescope, it’s a 39-inch telescope, part of the network, been there since 2013. So, your standard player is, of course, there.
Fraser Cain: So, what’s, what, I mean, I don’t think we talked too much about the Las Cumbres, what do they, what are they doing?
Dr. Pamela Gay: So, Las Cumbres is a network of telescopes scattered across pretty much the entire planet. So, there is no part of the sky that can go unseen at any time of day, it’s ultimate goal. And they’re everything from telescopes that teachers can get time on for their classrooms, to regular everyday people can rent them, to they’re also used for a variety of photometric need science projects. So, things like follow up on super novae, monitoring of asteroids, follow up on things where your needs are; is this thing’s orbit still what we thought before we snuggle up our spacecraft. So, they do follow up on Rosetta, on the Asteroid Rosetta, went to [Inaudible] [00:13:12].
So, it’s just a really cool network that is pretty much, if you have a good mountain top, you’re gonna have one of their telescopes.
Fraser Cain: Yeah. There’s one in McDonald Observatory, one at Haleakala in Hawaii, in the Canary Islands. So, they are really across the world. It’s such a great idea, that they’ve got a series of telescopes that can literally track an object from hemisphere to hemisphere, wherever and whenever you need to, which is such a wonderful concept.
Dr. Pamela Gay: Yeah. And –
Fraser Cain: And I know you can, they do give, I think they’re the ones that give time to interesting outreach educational projects, and things like that.
Dr. Pamela Gay: And the Las Cumbres, this particular network of telescopes has gone through many different phases. It started as the Faulkes Telescopes funded out of Great Britain by a man named Faulkes. He couldn’t fund it to get as large as the goal, it evolved into the Las Cumbres system, Google got in for a while funding a lot of it. And so, this has really been a long-term effort with a whole lot of people seeing the need, and helping us scatter telescopes hither and yon, essentially.
Now, other things that you might’ve heard of. We have talked about KELT objects on a fairly study basis across all of the years. These are the Kilodegree Extremely Little Telescopes. The first one was built by the Ohio State University to monitor the northern hemisphere; now, we also have a southern hemisphere version. And these are survey telescopes that are out plugging away looking for exoplanets. So, you have things like KELT-9b, which is an extremely hot exoplanet that I’m particularly fond of, that was found with this system.
Fraser Cain: Let’s talk about the big one.
Dr. Pamela Gay: [Laughs] And you’re like, we’re just gonna skip WASP and everything else!
Fraser Cain: [Chuckling] No-no-no! No. You know what, no, I appreciate the way you’re setting this up. Yeah, let’s talk about WASP.
Dr. Pamela Gay: Okay. So, WASP is another one of these robotic telescopes that’s just out there looking for exoplanets. And one of the things that I appreciate about this, which is why I wanted to bring it up, is this is a telescope that has multiple incarnations around the world, and in this case it’s a joint venture between the Canaries and South Africa. And they are also pulling up little planet after little planet orbiting distance stars.
We also have a variety of monitoring systems to do things like monitor for incoming near-earth objects. We have systems that are designed to monitor the sun, helping to detect the oscillations that we see in its atmosphere. And now, we can go to SALT.
Fraser Cain: Okay. Because this is a very big telescope.
Dr. Pamela Gay: And this one, I have to admit, is a bittersweet telescope to me. Because I went to the University of Texas where they built the Hobby-Eberly Telescope, which I was supposed to use to do amazing science for my dissertation. The goal, when I wrote my dissertation, was we were gonna get 30 spectra per galaxy cluster of galaxy cluster after galaxy cluster, and we’re going to do detailed studies of how these systems were evolving as a function of mass and redshift!
And about 10 years later, another astronomer got an amazing award for doing a dissertation on this! Because mine was blighted by the Hobby-Eberly Telescope not functioning the way [sighing] it was supposed to function.
Fraser Cain: [Chuckles] Right. So, you didn’t wanna use that telescope. It was broken.
Dr. Pamela Gay: No. No. So, I ended up with like nine spectra total on two clusters for my dissertation [chuckling].
So, the Hobby-Eberly Telescope had issues when it was first constructed. It was built, it was designed to be the largest, cheapest, telescope of its kind. The original budget was $15 million to build what would be, at the time, the largest light gathering telescope in optical wavelengths in the world. And, and it was! It just could only stay in focus [chuckling] for like 10 to 20 minutes.
Fraser Cain: Right.
Dr. Pamela Gay: And it was thought that they’d be able to do monitoring of how the mirrors flexed and changed as temperature and humidity changed. But it was actually a chaotic problem. So, their original plan to use computer models to keep the telescope in focus by measuring humidity and temperature variations, and flexing the system accordingly, and it didn’t work.
And so, the last couple of years that I was finishing up my Ph.D., the observatory was invaded by South African engineers. Because they came in an exchange for the plans for the Hobby-Eberly Telescope and more complexity things. They came in and put in tremendous effort to help get that telescope working, and now the Hobby-Eberly is a workhorse. And from what they learned helping to get the Hobby-Eberly to live up to its full potential, they took everything they learned, returned to South Africa, and built what it is still the largest collecting area telescope in the southern hemisphere, and they’ve been using it to do tremendous science.
So, this is a case of really clever engineer saying, we don’t have a whole lot of budget but we’ve got a whole lot of skill, so let us fix that for you.
Fraser Cain: Yeah, yeah. Right. And so, I mean, this telescope, again, you know, it is, it’s a 10-meter telescope. So, when we think about the Keck Observatory –
Dr. Pamela Gay: But the mirror is 11 –
Fraser Cain: Yeah, the mirror, right.
Dr. Pamela Gay: – it’s a fixed azimuth telescope.
Fraser Cain: And it’s this weird collection of hexagonal elements all collected together. And so, you don’t, so it’s not this one single ground mirror, it’s these hexagonal alone, it’s the work together to form the mirror. And so, it was done exactly right, it was done on the cheap and, yet, it is an 11-meter telescope. And so, again, compare that; you’ve got the Keck Observatory at 10 meters, you’ve got the very large telescope, the individual telescopes, they’re only 8-1/2 meters, the Gemini’s. Like, the only thing that really gets close size-wise is you’ve got the one in the Canary Islands, which is 11 meters, and then you’ve got the ones, the binocular telescope which we talked –
Dr. Pamela Gay: Yeah.
Fraser Cain: – about a few weeks back.
Dr. Pamela Gay: But those are both in the northern hemisphere.
Fraser Cain: But they’re both in the northern hemisphere. And so, there is a telescope that is easily one of the largest telescopes in the earth, you know, on the earth located in this prime location that has the skies all to itself.
So, it’s like, if you wanna do astronomy from the southern hemisphere, there is just a phenomenal tool at your disposal. And it’s pretty exciting.
Dr. Pamela Gay: Yeah. And this is –
Fraser Cain: And they get it –
Dr. Pamela Gay: – a super clever design.
Fraser Cain: Yeah, yeah.
Dr. Pamela Gay: So, the way they keep the costs down on the design is the telescope is, is at a fixed tilt. And there is a smooth cement donut that the telescope has these airlifts, so think Luke Skywalker’s craft [Inaudible] [00:31:25], they lift the telescope and they can rotate it, but they can’t change its tilt, but they can move the secondary mirror.
Fraser Cain: Right.
Dr. Pamela Gay: So, they’re able to track objects for brief periods of time. You’re not gonna track all night, you’re gonna track for like 20 minutes. But they’re able to track, and as they track, they’re using a different 10-meter-ish section of that 11-meter mirror that has a spherical surface. And so, they’re able to greatly reduce the costs by not having to engineer, and the ability to change the tilt of the telescope. So, they can just rotate and then they can move around the secondary. And that’s enough.
Fraser Cain: And you know, if you wanna think of an analogy, we’ve talked about the Arecibo Observatory, which is a radio telescope in Puerto Rico. And it is a, you know, it’s a segment of a sphere carved out of a, like, a collapsed crater, you know, on Puerto Rico.
And so, they move the instrumentation on cables, that hangs up above the telescope, and that how they get data on different parts. So, as long as this thing is kind of in the field of view, then they can move the instrumentation and capture imagery. And it’s the same thing on what they do with this telescope. So, it doesn’t work the way a regular telescope does, but for what it does, it does it better than almost any other instrument on earth. And I just, I’ve always been a gigantic fan of this specific telescope because they did it on a shoestring, and they run it on a shoestring.
Dr. Pamela Gay: Yeah.
Fraser Cain: And you know, for tens of millions of dollars in ongoing budget to run this world class observatory. So, congrats to everyone in South Africa, you should be really proud of this telescope that’s operating there.
Dr. Pamela Gay: And they need to be really proud of what is coming.
Fraser Cain: Yes! Yeah! I mean, we’re talking big telescopes.
Dr. Pamela Gay: So, Sutherland is where all of the optical is done. But if you go out to Karoo, which is a different desert-y part that is truly stunning with magnificent animals. If you go out to Karoo, which is a bit further to the east and a little bit further to the north, you are going to run into an array of 64 13.5-meter dishes that are currently out there in this vast swath of plains. They have an inner cluster that is spread over a not very large area, it’s about 1 kilometer across, but then for another 4 kilometers in all directions they have another 30% of their dishes scattered. This particular pattern is fairly unique to the other telescopes, this is the MeerKAT Array.
Fraser Cain: Yes!
Dr. Pamela Gay: This is a precursor to the SKA that is testing the science, proving the technology, and already doing some really phenomenal science. And when they start building SKA, it’s not gonna be limited to this 8-meter diameter area of desert-y landscape. No! SKA is going to span across multiple nations as they build what will be half of the greatest radio facility in the world across Southern Africa.
And this is why they talk about the next International Astronomically Union Meeting after Korea, is going to be in Southern Africa because they’re holding it in Cape Town. But it’s going to be hosted by all these different nations. They’re working together, collaborating together, to do radio astronomy that will have from one telescope amazing resolution, thanks to one giant continent.
Fraser Cain: Yeah. And we talked about this two weeks ago from the Australian perspective. And the great thing about the MeerKAT Observatory is that these are what, these are some of the technologies that they tested out and demonstrated both that Southern Africa would be a good spot to house the square kilometer array. But also, that they have the technological chops to do this kind of astronomy that the engineers and the designers and the astronomers –
Dr. Pamela Gay: The engineering and the materials all came.
Fraser Cain: Yeah, it’s all world class. And –
Dr. Pamela Gay: And it’s locally built. This is locally built, it’s not half of it came from Germany, no, it’s them rocking it out. And now, astronomers from around the world are doing astronomy with the best sets of acronyms I have ever seen.
Fraser Cain: [Chuckles] Such as?
Dr. Pamela Gay: So, I just had to bring this up. MeerKAT is, of course, an acronym itself and it has led to MHONGOOSE, spelled weirdly, MHONGOOSE, which is the MeerKAT H1 Observations of Nearby Galactic Objects: Observing Southern Emitters. It’s a little bit forced, but awesome!
There is MeerGAL, which is the MeerKAT High Frequency Galactic Plane Survey.
There’s MIGHTEE, which is the MeerKAT International GigaHertz Tiered Extragalactic Exploration Survey.
There is ThunderKAT, The Hunt for Dynamic and Explosive Radio Transients with MeerKAT.
It’s just amazing thing after amazing thing, with amazing acronyms. So, go team go.
Fraser Cain: Yeah, yeah. Were there any other interesting instruments from other wavelengths? Isn’t there a Cherenkov Radiation Observatory in Southern Africa? I’m trying to remember.
Dr. Pamela Gay: Checking?
Fraser Cain: Yeah. Maybe I’m wrong. Maybe not.
Dr. Pamela Gay: So, there are members of the Cherenkov Telescope Array, but I’m not seeing it as being built there. If the big one is south of Paranal. There is a Namibia South African Cherenkov Telescope Task Force.
Fraser Cain: Okay. Yeah. No, I –
Dr. Pamela Gay: Or Namibia.
Fraser Cain: I recall, yeah –
Dr. Pamela Gay: Sorry, Namibia.
Fraser Cain: – I recall there being one there, but, no.
Cool! Well, I think we’ve reached the end of our time, anyway. But I think, again, if you want an interesting vacation, if you wanna go to a place that’s up and coming on the astronomy scene, it sounds like South Africa is the place to go. Just avoid the [chuckling] dangerous wildlife while you, while you’re looking up at the big sky.
Dr. Pamela Gay: And one more, I, so go to Cape Town and do two things for me in addition to the astronomy.
One, go on a wine tour. There’s actually a winery called Goats do Roam, that is the result of not being able to be coaxed to roam anymore because of EU regulations. And you can do a wine and goat cheese tasting, it is fabulous.
In addition to this, go to the beach that has both penguins and baboons, and break your brain. Because no children’s coloring book prepared any of us for penguins and baboons to be collocated in the wild as natural things to laugh at on a beach. But be aware the baboons will try and break into your camera gear.
Fraser Cain: [Chuckling] Sounds awesome.
Do you have some names for us for this week Pamela?
Dr. Pamela Gay: You know, I just might do that. So, today’s names. We have:
Bill Hamilton, Greg Thorwald, Fredrik Sjoge, Kavan Jensen, Helge Bjorkhaug, Kjatan Saevre –
Fraser Cain: This is awesome, I love this, keep going, keep going!
Dr. Pamela Gay: Joseph Hoy, Dana Nourie, Emily Patterson, Paul Jarmen, Jos Cunningham, Cory DeVoli, Les Howard, Laura Kittleson, Robert Palsma, TheGiantNothing, Brian Cagle, David Truog, Andrew Poelstra, Ramji Enamuthu, Burry Gowen, and Jordan Young.
Thank you for being our patrons, and all the rest of you. If you really wanna help us out and you wanna help us keep this show going and expanding, join us on Patreon. I will be releasing content throughout the summer, or at least letters letting you know what all we’re up to that have pictures included.
Thank you, we’re here because of you.
Fraser Cain: The great thing about Patreon is that only a small group of people need to support what we do so that we can make this information available to everyone around the world. But we don’t have to put it behind a paywall, that we can just make it freely available, which is the goal of science!
Dr. Pamela Gay: Yeah.
Fraser Cain: Of education and information. And so, thank you, thank you, thank you to all the Patreons. And if you’re sitting on the fence and wondering will I make a difference, you will totally make a difference! You will allow us to create more content. And whether it’s even through Astronomy Cast or through our personal Patreons, through my Universe Today, and Pamela through Star Stryder, you make a difference on allowing us to create content, to pay our teams to be able to come up with new ideas and to dedicate our lives to educating the world about space and astronomy.
So, thank you!
Dr. Pamela Gay: Yeah. And you’d really be surprised at just how far things go. Since we’ve not had the massive funding that we’ve had in the past, my Patreon is what pays for all of my software and servers every month, and that just makes me functional.
Fraser Cain: Yeah.
Dr. Pamela Gay: So, that one thing allows me to do everything else that I do. It’s everything when you support us. Thank you.
Fraser Cain: Yeah. Same for me. Right, every penny we’re getting from Patreon I just spend on writers, and editors, and etc. So, that’s how we are able to make more content.
All right! Thanks, everybody! We will see you all next week.
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Female 1 Announcer: Thank you for listening to Astronomy Cast, a nonprofit resource provided by The Planetary Science Institute, Fraser Cain, and Dr. Pamela Gay.
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[End of Audio]
Duration: 34 minutes