Hosted by EIC Mikael Angelo Francisco, Ask Theory shines the spotlight on Pinoy scientific brilliance, in a fun and entertaining “kwentuhan” format. Each episode of Ask Theory features a Pinoy scientist from one of the various scientific disciplines. In a very casual conversation, guests explain what they do in simple terms, as well as share their fascinating stories: how they got into science, the challenges they face, what motivates them to pursue their fields, what future scientists from the Philippines can look forward to, and so much more.
Episode 11: Ano Ba Ang Mapapala Natin Sa Pag-Explore Ng Mars?
Imagine spending seven-and-a-half years of your life working with the world’s top space agency to help it land a 2.4-billion-dollar rover the size of a car on a planet millions of kilometers away. This mission, of course, is a big step in humanity’s bid to someday walk on different worlds. How do you respond when someone sees the fire of your achievement and dumps a bucket of cold water on it with a harsh but understandable question: Why spend so much time and money trying to reach Mars, when there are so many problems to fix here on Earth?
Our guest on today’s show is Engr. Gregorio Villar III, an Entry, Descent, and Landing (EDL) Systems Engineer at the Jet Propulsion Laboratory of the National Aeronautics and Space Administration (NASA). He was part of the team that worked on ensuring the successful landing of NASA’s Perseverance rover on Mars.
We talked about what motivated him to pursue a career at NASA, his role in the Mars 2020 mission, the development of the Sky Crane system that helped Perseverance land safely on the Red Planet, why we spend time studying other planets instead of focusing on Earth, who would win in a fight between cavepeople and astronauts, and more.
Listen to Ask Theory Episode 011: Ano Ba Ang Mapapala Natin Sa Pag-Explore Ng Mars? here:
Engr. Gregorio Villar (GV): Hello, thank you for having me here today.
Mikael Francisco (MF): Thank you for accommodating our request. I know you’re very busy. And you’re in the headlines. Napag-uusapan ang Mars 2020 Mission. I want to know what motivated you to pursue your field. Specifically, when you were a new high school graduate, how did you imagine you’d be like by this time?
GV: Yeah, that’s a question I get a lot. And you know, I’m not like, I’m just like any other nerd. Growing up, I loved watching, you know, sci-fi movies like Star Trek and Star Wars. And in fact, one of my favorite scenes that I like to bring up is Independence Day, which stars Will Smith. And there’s this one scene that I remember where Will Smith and his partner takes the alien spaceship off of Earth. And once they break the Earth’s atmosphere, Will sees this blanket of stars. And he’s just dead silent. And his partner asks, “What’s wrong?” And Will says, “You don’t understand. I’ve been waiting for this my whole life.” And that scene was really impactful to me as a kid, mostly because I was a fan of The Fresh Prince. But also just ’cause it’s very meaningful to see stuff like that. And also movies like Contact, which I really loved. And watching astronaut movies like Apollo 13. All of those things really inspired me, growing up, to get into space. But it’s ironic because when I was in high school, you know, I usually represented my school at olympiads, like Physics and Math olympiads. But I also got really interested in the debate team. So I would watch our debate team practice, but never really participate myself. But at the time, I really thought that I would be a lawyer, because that intrigued me. So because of that, I went to study Accounting, pre-law, in college first. But after my first two years of college, my mom and my uncle sat me down. And they said, “Gregory, you don’t have to be what other people want you to be.” Because the stereotype is, you need to be a doctor or you need to be a lawyer. So that was a really good talk I had because then I thought to myself, yeah, I should be doing what I want to do. And so I started over again, I was two years into college, but I started with a new subject, I did Physics, and that eventually led me to a career at NASA. So, you know, when I was in high school, I never thought that. Maybe a part of me knew that I was meant to do this. But while I was in high school, my plan was to be a lawyer. And that ended up not happening.
MF: It’s interesting that you mentioned your plan to be a lawyer because in my discussions with other, you know, astrophysicists and space-loving folks, they keep mentioning that the frontier of space law is still like, largely unexplored. So there might be a potential career opportunity for that. I’m curious: What made you decide to pursue a career outside of the Philippines entirely? Well, I mean, working at NASA is great in itself, but what led you to that decision?
GV: It was kind of a, you know, it’s kind of where life took me. So I was born and raised in Long Beach, California. And so I was fortunate. I’m fortunate enough to be an American citizen. But I did go to high school in the Philippines in Baguio City, Saint Louis University Laboratory High School. And at the time, my dad was living in Baguio. So, after I graduated high school, it was time to come back to the US. And that’s why I made it back here. But again, you know, I was going through my career, and I never really knew that I was going to work at NASA. When I got my Physics degree, my plan was to go to Physics graduate school. But I did really poorly on the GRE, I believe it’s called the Graduate Record Exam, for Physics. I did really poorly. And so instead, I, you know, tried to do a career in Engineering. And that worked out well, because when I was a junior in college, I applied for a NASA scholarship. And I got that scholarship. And that scholarship came with an internship at a NASA center of my choice. And that’s where I started at the Jet Propulsion Laboratory, where we build Mars rovers.
MF: Pretty cool. Basically, life brought you to where you are right now. And you know, this wasn’t something that you planned, right? It wasn’t something that you, you were- you love space, you’re interested in space science, but the dream wasn’t really to work at NASA.
GV: I would say, as a kid, my dream was to be an astronaut. And I still want to be an astronaut. But along the way, I changed it to becoming a lawyer or becoming a physicist, I never planned to be an engineer until I found engineering. And I think that’s a very important lesson. Because, you know, at the beginning of college or my career, I was not doing what I ended up doing now. So I think it takes time for people to just find the right thing that they end up loving for the rest of their lives.
MF: Yeah. Tell us a bit about your role as the Entry, Descent, and Landing Systems engineer of the Mars 2020 mission.
GV: Right. So systems engineer, that’s kind of a function that’s not common, but it’s becoming more common in larger engineering companies. And so the idea of a systems engineer is, these are functions that are required for very complex projects or missions, because they’re just so large and span so much breadth. And the idea behind a systems engineer is, you would learn a little about a lot of things. So the way I kind of share this with people is, when you work on a spacecraft, there’s a whole team of mechanical engineers who build a rover, right? The hardware. There’s a whole team of electrical and power engineers who run the batteries and all the power supplies. There are engineers who work on the software, the software engineers. But there are a team of systems engineers that have to learn a little about all those pieces, because eventually, all those expertise is has to come together to form a spacecraft, right? Another way to think about it is maybe like a contractor for a house. So usually, you hire a contractor. And the contractor will hire plumbers and electricians and carpenters, right? We’re kind of like the contractors for spacecraft. Now getting a little more specific, I’m an Entry, Descent, and Landing Systems engineer. So my role really focuses on anything that has to do with the landing system itself. There’s a team that launches the rover, there’s a team that flies the rover to Mars, there’s a team that operates the rover on Mars, and I’m part of the team that is responsible for landing the rover at Mars. And so I’ve learned a little about a lot of those things in a lot of different areas, whether it’s this thing that we call a thermal protection system, which is just material that we use to protect us as we’re going through the atmosphere. Or if I have to learn about parachutes, or actually learn about this jetpack that we use to get the rover to the ground. So I just have to learn a little about a lot of different things in the world of landing technologies on Mars.
MF: I like how you mentioned landing, because that’s going to be my next question. I want to ask about the Sky Crane landing system. Well, how long how long it took to develop? And you know, interestingly enough, I was reading and I saw that in other missions like Pathfinder, they use the cluster airbag system. So why was the Sky Crane landing system used during this mission?
GV: The Sky Crane. The really, really, really crazy new technology here. Actually, the Sky Crane, we started using that on the Curiosity rover back in 2012. And so I was not around for the development of that. But as the story goes, I think it’s years in the making, when they were trying to figure out how to land something more massive. At the time, Curiosity was the largest, most massive rover ever. So missions like Pathfinder, and the Mars Exploration Rovers, Spirit and Opportunity? You’re right, the way we landed them with these giant airbags that wrapped around the rovers. And we dropped these, you know, capsules of airbags, and it just bounced on the Martian surface until it stopped. But when Curiosity came about, we knew how big Curiosity was going to be, and quickly realized that the airbag system would not scale accordingly. Because Curiosity was too massive. The airbags would not be able to support something as big as Curiosity. So throughout the development, they were thinking of several things. Before the Sky Crane, there was even the idea of using what’s called like a pallet lander. So the idea is that you put the rover on a platform, and this platform has engines, and you try to land this platform with engines on Mars. But that ended up not being a good solution for several reasons. And eventually, one day, the team thought of the Sky Crane. And so when they first proposed that, people were looking at it and thinking, “It’s pretty crazy.” And so over years, they had to prove to them that this concept would actually work. And they would have to go to all the bosses at JPL, and even report to the head of NASA at the time at NASA headquarters. So a lot happened to make that technology work. And coincidentally, it did work on Mars in 2012, when Curiosity safely touched down on the surface of Mars. And after that happened, NASA said, “Do that again.” And that’s why we have the Sky Crane, again, for Perseverance. We used the same system to land Perseverance. Because Perseverance is slightly heavier than Curiosity, but not too much that the Sky Crane could not be used.
MF: So in summary, if it’s a bigger rover or a bigger exploration vehicle, you’ll most likely be using the Sky Crane landing system in future missions.
GV: That’s tricky. So if it’s on the scale of Curiosity or Perseverance, yes, that’s true. We could be using Sky Crane. But also, you know, there could be… It really depends on the mission, on how big something is. We could use, you know, things like the the platform lender that I mentioned earlier. Or just, you know, part of the landing of- Curiosity and Perseverance included a parachute before the Sky Crane, right? And there are some architectures where you could just go straight to using rockets. So you don’t have to use a parachute, you could just, from the atmosphere, after you enter the atmosphere, you can go straight to just using really powerful rockets, and landing straight with those instead of a parachute and the Sky Crane. But it really depends on what you’re sending. And you know what the objective is, because there will be heavier missions in the future. And those missions will be human missions. Those are going to be much, much heavier than the rovers that we’ve sent to Mars.
MF: Oh, man. Yeah, that’s, that’s really exciting. And that makes me want to skip to one of the questions that I was supposed to ask you later, as you mentioned human missions. If given the chance, would you join a manned mission to Mars?
GV: That answer for me has changed throughout my life. Well, okay. I am currently- I’m almost 34. And let’s say when I was, I don’t know, you know, a kid from five years old to 20 years old, the answer would have been absolutely yes. That’s always been my dream: to go into space and be an astronaut. When I was in my mid-20s, I took a class in graduate school, it was called Human Spaceflight. And in that class, I learned how scary and how much work it is to be an astronaut. And it is scary, right? And also uncomfortable. You’re basically in a room, a small room for months or years, maybe by yourself, or maybe with one or two other people. There are really no plants around, right? You take for granted just being able to see green things. You probably don’t have the food that you want every day. You have to recycle your pee, your urine, and you have to be writing, you know, you have to be worried about getting hit by space rocks or anything like that. And on top of that, you’ll be leaving all of your loved ones on Earth. So nowadays, I’m a little less enthusiastic, but I would still love to go to space. And I think that answer will change if I have a family one day. Or if I’m getting getting really old, and I’m about to die anyway. (laughs) So I think as I progress through life, that answer will change. But I would say, as of now, I would still love to go to space, of course. It would be such an honor. And that’s always been a dream of mine.
MF: So some of these questions came from our listeners. We actually crowdsourced some of these questions. And one of them is related to this question. If you were to go to Mars, what would be the last Terran thing that you’d do, and the first Martian thing you’d do?
GV: Okay, that that’s kind of easy for me because I think about what I love to do on Earth. And there are two things I love to do. One is eat; I love food. And two is hanging out with family and friends and people that I love. So people who know me know my favorite sushi place here, because I love sushi. It’s my number one cuisine. It’s a place called Sugarfish in LA. So what I would do, as my last thing is, order a whole bunch of Sugarfish to go, and eat it somewhere with all my close friends and family before I leave. That’s the way I would want to leave Earth. When I get to Mars… Oh man, that’s tough, because I never really thought about what I would do. But you know, I would step out of the spaceship, maybe like walk or hike somewhere far away. And I would probably just lay down on the floor and look up in the sky, and just take a really deep breath and appreciate the fact that I’m on the planet Mars. And that would be like a huge honor. I’m assuming, in this hypothetical scenario, I’m going to assume I’m one of the first humans on Mars. So I would be very proud to be there as a human and also as a Filipino.
MF: Yeah, and you know, you’ll get the chance to see a blue sunset.
GV: When you said that, it made me think about the Star Wars scene where Luke’s on Tatooine, and he sees, like, the sunset.
MF: The stuff of science fiction, definitely. So yeah, going back to your responsibilities as systems engineer, I’m interested to know: Are there things about the development of Mars exploration vehicles that we can actually apply when we are making vehicles here for Earth?
GV: Yeah, I think it’s a very complicated question to answer. But I think it’s “yes.” And a lot of people think, you know, “Why are we spending so much money going to space?”, whether it’s Mars or somewhere else. But something that people should appreciate is, whenever we build these technologies, we learn a lot that we can apply here on Earth. It’s not just, you know, ships, planes or spacecraft on Earth, but things like telecommunications, right? A lot of our technologies here on Earth are kind of derived from space projects as well. If you’re talking about, like, applying directly to spacecraft here on Earth, I’m not an expert in that domain. But I’d imagine things like thermal protection systems, which are things that we use to protect our spacecraft from intense heating. Whenever we have things like, you know, the Apollo, the Apollo space capsules, or the space shuttles coming back to Earth, we apply similar materials onto those spaceships to come back to Earth. Or just also simulations, right? Sometimes we can run full tests or analyses. So we have to build simulations, computer simulations for space exploration, and our understanding of spacesuit simulations can be applied to similar simulators here on Earth. So there are a lot of applications that go hand in hand with space exploration and development here on Earth.
MF: The interesting thing about this debate is that the the the primary argument is, “Why are we, or why are space explorers, space scientists, spending so much time looking to the stars when we have so many problems here on Earth?” And to me, that raises the question, and maybe you you might have some insight on this: “Do you think that space research, or you know, the desire to go to other planets, are we taking away time and resources from looking at the problems here on Earth? Does that necessarily happen?”
GV: Yeah, that… from a practical sense, it does. But I think one has to step back and look at the bigger picture. Although it takes away attention from Earth, it’s probably a small amount compared to what else we’re doing, right? At least in the US, NASA’s budget is less than 1% of the overall US budget. That’s a very small amount of money. And it’s a very high return, right? And As I mentioned earlier, even though we are exploring space, these technology developments can help us back here on Earth, with our technologies here on Earth. And so, I do agree, I think our primary focus should be our own planet. But that doesn’t mean we can’t explore other places that will help us along the way. Eventually, if we can’t save our own planet with, you know, climate control, or whatever, we need to be able to leave our planet, right, that’s the whole idea about eventually going to Mars or elsewhere. So we need to make progress in that direction. Otherwise, one day, if we destroy our own planet, we have nowhere else to go. So we need to make progress moving forward here. And, you know, I don’t think it’s a waste of time, because ultimately, we’re all humans. And we have this sense of exploration and curiosity. And that is just part of being human. And we should be able to fulfill those kind of desires and… natural inclinations to fulfill that. I mean, and I mean, you know, we need to progress ourselves as a human race on to other planets, because, you know, we don’t, it’s better than just staying in our own planet.
MF: I agree. And it reminds me of how the situation was- I don’t know if you’ve heard of or read about this, but the Philippines approved, or enacted into law, the Philippine Space Act, which in turn, established the Philippine Space Agency. So the Philippines has its own space agency now, and the process of going through, like the legislation, developing that… man, the amount of resistance that I would read online, in the comments, like, “Why would you send, why are you trying to send people to space? Andaming problema ng Pilipinas.” So I definitely agree with you that we have to, like, broaden how we appreciate and look at these things, because it’s really not just all about, you know, looking at looking at the stars and abandoning Earth. It’s really like… the science, it goes into a lot of things in life. And it’s not just always about abandoning Earth, or not solving its problems.
GV: I mean, I can only imagine how tough that is, in terms of policymaking. I’m not a politician at all. But, you know, I guess all of our leaders have the challenge of allocating funds to certain places. And somewhere especially like the Philippines where, you know, we have a limited number of resources, I think it would be a struggle to do that. But like with anything, it would be an investment, right? And sometimes you just got to invest in yourselves. Imagine one day if the Philippine Space Agency creates technology that no other country has, because of the Philippines trying to get into space. That would put the Philippines on the map, right? It would be a highly marketable country, the Philippines would have technology that no one else has. And that will just help the Philippines with more funds, right? To be able to tackle the other problems that everyone wants to tackle as well. So I would encourage people to think of space exploration, whether it’s in the Philippines or in the US, or everywhere, as an investment for yourselves. Because it’s just something that can help. It can only help further our advancement in life.
MF: I agree. And just thinking about the possibilities, it’s really exciting. Like, we often talk about Philippine ingenuity, creativity, brilliance, and I think this is one of those many areas where we can show just, you know, what the Philippines is capable of.
GV: Exactly. One of the things that we’re all kind of trying to solve is space travel is expensive, right? And Filipinos are very creative and innovative, right? So if the Philippine Space Agency can, can provide space travel or space devices or spaceships in a more cost-effective way, then that’s going to be a step forward for the space industry as a whole. And so there’s something to be said for people who have a limited number of resources, but much more creativity.
MF: Yeah. Speaking of creativity, a lot of our ideas about Mars, space, other planets, are shaped by pop culture. So from what you’ve seen, which fictional movies that feature Mars can be described as, you know, close to accurate based on what we know about the red planet?
GV: Great. Basically, all the movies with aliens are the most accurate, you can bet on that. (laughs) I’m just kidding. I’m really biased towards The Martian. I love that movie.I saw that movie, like maybe 10 times. I even saw it before it came out in theaters. There was a special screening. So I was watching it when there were still strings on the actors to pretend that they’re flying through space. And then I saw it in theaters twice. I bought the movie on, you know, online, and I bought the audio book and I listened to that. So to answer your question, I think that’s a pretty realistic future of Mars. And for those of you who have not read it, you should go read or listen to it. And the author as my, as I understand, he did a lot of research with every little thing, maybe even just like, botany, right? Whether or not we can actually grow potatoes on Mars, or technologies like the oxygenator, where, you know, Mark Watney was trying to produce oxygen on Mars. There’s so many levels of detail in that movie, that I’m thinking, that’s how either that’s how we do it at NASA, or that’s how we’re going to do it in the future. And so I really like pointing to The Martian, because what it took to set up a human colony or a human establishment on Mars, is in that movie. But we’re not there yet. Right? We don’t have all those problems solved like, something like the Mars ascent vehicle, which is what’s in the movie. It’s the ginormous rocket that the humans would have used to launch off of Mars to get back to Earth. That’s something that we have not done successfully yet, or haven’t gotten to yet. There are things like, you know, like, the spacesuits that we need at Mars to protect us from different radiation, the problem of solving food, right? Like, can we bring or generate that much food that would last a year or two? I don’t know if we’ve done that yet. But there are things that we have done, right, right. Perseverance is carrying an instrument called Moxie. And that’s kind of an oxygenator. Right now, that instrument, hopefully, we will be able to ingest or breathe in the Martian atmosphere. The Martian atmosphere is mostly carbon dioxide. And that instrument on Perseverance will breathe out oxygen. So that’s a really cool piece of technology that we’re going to try to demonstrate with Perseverance: to be able to produce oxygen from Mars, and hopefully, in the future, astronauts can use that to breathe and/or use it as rocket fuel.
MF: That’s really exciting. To be able to get to that point where we can, you know, live or survive on Mars, it feels like we’re gonna have to be building things from the ground up.
GV: Yeah. We have some of that technology, but we’re not there yet. And, you know, it’s the same problem, I believe, whether it’s the Philippines or the US or anywhere, it’s a priority of maybe funding and time or effort, right? There’s just too many things that we need to worry about. But, you know, one day I’m sure, I’m hopeful that we’ll get there. Maybe it’ll take another space race. Back when we did Apollo and got to the moon. It’s because Russia and the US are trying to out compete each other. Right? So that’s another reason I think it’s cool that the Philippines has a space agency to is you need competition, because without competition, there’s no progress.
MF: That’s true. Speaking of competition, here’s a fun question from one of our listeners. Okay, so which group would win in a fight would be cavemen or astronauts?
GV: (laughs) Oh. I think that I need more parameters to answer that, but let’s pretend it’s just like, maybe let’s pretend it’s like a fist fight. Yes, I would probably go with the caveman because they’re just more ruggedized and they’re just eating raw meat and berries, and they just do manual labor all day. (laughs) But if it was a you know, if it was like a, an overall mental and physical competition, no doubt the astronauts. I like to think of astronauts as superhumans. You know, most astronauts have multiple degrees, usually multiple doctorate degrees, maybe even some are doctors. They’re just super impressive individuals. And someone in the last astronaut class is probably my favorite. His name is Johnny Kim. But this guy, he- let’s see, he was a Navy SEAL, right? One of the top soldiers in the American military, right? A Navy SEAL over 100 combat missions. After that, he went to Harvard Law School, or sorry, Harvard Medical School, and became a doctor, a Harvard doctor. And now he’s going to be a NASA astronaut. So this guy was a Navy SEAL, a Harvard doctor, and now a NASA astronaut. That’s three careers all in one. And so these are the type of people that become astronauts. So overall, I think the astronauts would beat cavemen but in a straight up physical fight, they would probably lose to cavemen. Or cavepeople, actually, more appropriately.
MF: Yeah, I would. I actually was thinking the same thing. In a battle of fists, yeah, absolutely, hunting, you know, brutality and all. So for Filipinos out there who are listening now, who say, “Oh, yeah, working at NASA’s cool. I kind of want to work there someday. I want to work there someday.” What’s your advice for them?
GV: I have a few pieces of advice. Just to be practical, you know, I am fortunate enough that I’m a US citizen. And it’s so much harder to get a job at NASA if you’re not a US citizen. It’s not impossible, but it’s just so much harder. And so, but that being said, with anything, this is a cliche, but you need to work hard, no matter what you do. Nothing in life comes easy. So you need to work really hard, and really do something that you love. Because, you know, like I said, I tried to go into law when I started college, but I knew deep down that that’s not what I wanted to do. So if you want to work at NASA, make sure you actually want to work at NASA, or in space. Don’t just rush into it. That being said, along the theme of the Philippines starting its own space agency, I would try to also encourage you to work try to get there, right, the Philippine Space Agency, because then you’d be kind of helping your own country or our country progress, right? You can contribute to our own country and not necessarily work at NASA to do so. You can bring, you know, further our own space industry and our own country.
MF: I’m not sure how you can answer this, but one last question. Are there any projects, any interesting stuff, that you’re working on that you can share with our listeners?
GV: That I’m working on? (laughs) Yeah. So as of this recording, I think we are a little under two weeks since we landed on Mars. My main project right now is getting sleep and relaxation. (laughs) But after that, for the first few months or so, the landing team and I, we’re doing something called reconstruction, which is basically looking at all of the data that we had from landing and making an understanding it. Like writing a report, you know, when you do your experiments in science class, you have to look at the data and write a report. And also compare it to what we thought was going to happen to see how close we got to our predictions. After that, I’m not quite sure what I want to do yet. There’s a lot of work at JPL. I will probably end up on the next mission, which is the Sample Retrieval Lander. So one of the goals of Perseverance is to collect samples so that a future mission can grab them and bring them back to Earth. And that project, the Sample Retrieval Lander is already started. And a lot of my colleagues have moved on over to that project. And maybe when I’m ready, I’ll join them there. And our job is going to be to work with other space agencies to send another rover there a smaller rover to pick up the samples that Perseverance collected, and then put them on a small rocket called the Mars Ascent Vehicle. And we’ve never launched anything from Mars before, so that’ll be a huge challenge. So I think that’s likely to happen in my future. But again, I’m not sure because right now, I’m just trying to relax and enjoy life.
MF: As we’re all trying to do, under these strange times under these strange circumstances. I can only imagine how challenging it probably was to work on this project, while under a pandemic.
GV: Exactly. That’s why the name Perseverance was so fitting.
MF: Yeah, you guys really persevered. A lot of Perseverance went into this. Thank you so much for sharing your time with us. And, you know, I look forward to hearing more from, you know, about your projects. And, you know, just watching how the retrieval project will go, and all of the other exciting new things that we can see from you know, space agencies, not just NASA, but hopefully you know, the Philippine Space Agency – space science all over the world in the coming years.
GV: Yeah, Mikael, thank you so much for having me. I really enjoyed these interviews with more, more technical questions, and I really appreciate those fun questions you threw out with the caveman and the astronauts. So thank you so much for all of that.
MF: Thanks, and stay safe. Take care.
GV: Thank you. Salamat, ingat!
The Ask Theory Podcast is available via these platforms — make sure to subscribe, as we’ll be releasing a new episode every week:
Apple Podcasts: https://podcasts.apple.com/ph/podcast/ask-theory/id1550251048
Google Podcasts: https://www.google.com/podcasts?feed=aHR0cHM6Ly9hbmNob3IuZm0vcy80OTAyMWNjMC9wb2RjYXN0L3Jzcw==
Pocket Casts: https://pca.st/gv6jxkki