This Week in Space 234 Transcript

Please be advised that this transcript is AI-generated and may not be word-for-word. Time codes refer to the approximate times in the ad-free version of the show.

Tariq Malik [00:00:00]:
Coming up on This Week in Space, we finally have our first clear look at China's secretive Shenzhou space plane in orbit. You're not going to want to miss that. Virgin Galactic has a new space plane of their own. When will it carry tourists? And couldn't astronauts really live in lunar caves? And are there actually lunar caves and lava pits in the first place? We're going to get down to that with Dr. Than Putzig of the Planetary Science Institute and a new mission to explore a pit on the Moon. Tune in and be there.

Tariq Malik [00:00:40]:
This is This Week in Space, episode number 234, recorded on October 30th, 2026: Living in Lunar Caves. Well, hello everybody and welcome to another episode of This Week in Space. This week we're calling it the Living in Lunar Caves edition. Woo! A little spooky. 'Cause it's almost Halloween. And I'm Tarek Malik, editor-in-chief of Space.com. Rod Pyle is on a spacewalk again.

Tariq Malik [00:01:05]:
I hope he's not lost in space, but he has been checking in. So he will, I guess, come back to Earth sometime soon. But with us this week to fill in his shoes is Mike Wall, editor, spaceflight and tech editor at Space.com, and longtime friend of mine. Mike, welcome, welcome to the show. How you doing today?

Mike Wall  [00:01:22]:
Good, good, good. It's like good to be here. I don't know that I can fill Rod's shoes, but I will do my best.

Tariq Malik [00:01:27]:
Well, we'll see how that goes, but by the way, you know, no one can fill Rod's shoes, but you know that you have your own shoes, right? But today, we're going to talk all about some exciting new research, a new mission to go to the Moon and explore lunar caves with Dr. Than Putzig of the Planetary Science Institute is going to be there. So it's gonna be really exciting. They're gonna look at the Marius Pit, which also sounds like a spooky place for Halloween. But first, we do have a space joke. It is from Scott Farnsworth. And this is the part, Mike, where you say Scott, right? So you can say it.

Mike Wall  [00:02:00]:
Scott.

Tariq Malik [00:02:01]:
Yeah, there you go. There you go. Okay, here he goes. In the aerospace communications class, how did the assignment go where each student had to marry together 2 satellite dishes?

Mike Wall  [00:02:12]:
I don't know. How did it go?

Tariq Malik [00:02:15]:
It says the wedding was just so-so, but the reception was amazing. Yeah.

Mike Wall  [00:02:20]:
I should have seen that one coming. That

Tariq Malik [00:02:22]:
was a good one. That was a good one. A bit of a long lead-up. Thank you, Scott. Thank you. And, and of course, Rod and I have heard that folks would like to send us into geosynchronous orbit when it's joke time on the show. Rod wrote that, right? That's a really clever one. But you can help like Scott.

Tariq Malik [00:02:42]:
He emailed us the best or worst or indifferent space jokes at twist@twit.tv. We'll be happy to blame it on you on the air or credit you, right? Because it's better than my astronomy is looking up joke, which I was gonna default to if we didn't have Scott here. So Please send those in, TWiS@twit.tv. TWiS@twit.tv. And now it's time for headline news. Oh, there it is. All right.

Speaker C [00:03:11]:
Headline news. Headline news.

Tariq Malik [00:03:16]:
All right. Well, we got a few stories. We've got 2 good ones and, and I guess one big sad one, but we'll try not to let us bring down. The big story, this is a big one for you, Mike, and Brett over at space.com. We have our first clear, super clear picture of China's Shenzhou space plane. So what do you think about that? We've got, this is from Vantor, is that the name of that

Mike Wall  [00:03:42]:
company? Yeah, yeah, it's from a couple years ago. Maxar, yeah, yeah, it's changed names since the photo was taken. Maxar it used to be called. It was taken by, yeah, by its like WorldView-3 satellite, which is an Earth observing satellite, but can obviously train its eyes on other satellites. And yeah, it's really, really cool. You know, there's a lot of mystery surrounding the space plane. Shenlong is the name that we have for it. We're not sure if that's the official name the Chinese government uses, but yeah, it actually took a really good picture of this thing that it was docked to another satellite with its solar arrays extended.

Mike Wall  [00:04:15]:
And we don't know what it was doing exactly, probably a docking test. We don't know what the other satellite is, if it carried it up there itself and released it to do tests like this of docking kind of rendezvous operations in orbit, or— what it's doing. But, um, yeah, it was, it was a rare look at what this mysterious thing gets up to in Earth orbit sometimes.

Tariq Malik [00:04:33]:
Yeah. And for folks who haven't seen the picture, so you have to imagine a miniature space shuttle, like the belly of a miniature space shuttle. So it's very small.

Mike Wall  [00:04:42]:
Nobody's on board though. It's all— there's nobody on board.

Tariq Malik [00:04:45]:
It's a robotic one. It's got clearly some payload doors that are open because you can see them behind the wings. And it's, it's got twin tails and then it's connected at the rear end with what looks like an engine pod or something like that. So it's very similar to like a mashup of the United States X-37B, where we have 2 of those, right? The Air Force— the Space Force runs those as reconnaissance and other platforms. And then the Sierra Nevada— Sierra Space, pardon me— their Dream Chaser, which has like an orbital module thing that sticks at the butt end of it.

Mike Wall  [00:05:20]:
Which still hasn't flown yet, though. That's the difference with the Sierra Space one.

Tariq Malik [00:05:24]:
Yeah. But now we know what they're doing, apparently. with, with, with China's space plane. And, uh, and, and I guess we have a new use case for Worldview right now. So,

Mike Wall  [00:05:34]:
uh, yeah, well, it's, it's, uh, it's, it's some good stuff. They— it's, it's been a trend recently to see more and more kind of in-space photos of satellites taking photos of other satellites, and that's ramping up as the kind of great power competition in space ramps up, and you see other satellites sort of, um, kind of going after, doing inspections of other satellites. This is like a whole new realm that's opened up in Earth orbit too.

Tariq Malik [00:06:00]:
Of course, you know, pictures can lead to other things. So we'll keep an eye on that for you, but hopefully we'll learn a little bit more about that space plane now that we have these pictures and everything. Speaking of space planes, this one reminded me of you directly, Mike, because, well, obviously you wrote the story, but Virgin Galactic has a new space plane For space tourism and other launches, their new Delta class. And you wrote all about its first flight from Arizona to New Mexico. And you were there at the first Virgin Galactic spaceplane rollout with the Enterprise way back when.

Mike Wall  [00:06:33]:
Yeah, a long time ago. Yeah. So this first flight of the new Delta class spaceplane, that's like their plane that's designed to fly more frequently and to really ramp up the cadence of their space tourism launches. It happened a couple days ago. They flew it from their manufacturing facility in Arizona to Spaceport America in New Mexico, and it didn't make the trip by itself. It was actually carried there by its carrier plane, which is called VMS Eve. It's an air launch system. VMS Eve, during flights of this thing, during space flights of this thing, will carry it up to about 45,000 feet in elevation, drop it, and then this new space plane, which is named like a Perion, Perion.

Tariq Malik [00:07:16]:
Apiron. A-P-E-I-R-O-N.

Mike Wall  [00:07:20]:
It's Greek for boundless. It was the result of a competition, a naming competition that they ran. They gave the public 4 options, and this was the one that won. Yeah.

Tariq Malik [00:07:29]:
Wow.

Mike Wall  [00:07:30]:
And so, yeah, it will be dropped at altitude and then turn on its rocket motor, go up to about 55, 60 miles above Earth, and Then glide back down again to Spaceport America.

Tariq Malik [00:07:43]:
And touch the sky, as Rod likes to say. There you go. So when would they start— resume, I guess, their commercial flights? Because they stopped to finish this plane.

Mike Wall  [00:07:53]:
Yeah, it's a bit— yeah, so their, their previous flight that was operational, their previous space plane, which was called VSS Unity, flew 7 kind of commercial missions from June 2023 to June 2024. Then they retired it. to put more of their resources into developing this new class, this new Delta class as they call it, which they think will be more, more productive and more capable, fly more frequently. But, um, now that they're at Spaceport America with the first one, with this new one, they still have to do a bunch of tests on it and stuff like that. They're saying that they hope to be up and running to start flying commercial flights in like the spring of next year.

Tariq Malik [00:08:29]:
So spring 2027.

Mike Wall  [00:08:31]:
So that, that would be nearly a 3-year gap between when, when Unity last flew and when this one starts flying.

Tariq Malik [00:08:37]:
Interesting, interesting. And they're They're going to build more Delta ships.

Mike Wall  [00:08:40]:
Yeah. They're already building a second one, and they're hoping that one kind of comes into service like a few months after this first one. And they've said they have plans to do more after that, to have like 5 or 6 or maybe even more. And so, yeah, as their long-term plan.

Tariq Malik [00:08:54]:
The more space planes there are, the more seats they have to fill. So let's hope spring's eternal for us space reporters to maybe get our turn in the hot seat. So we'll see. Well, thank you. Thank you so much for that and for those 2 looks, Mike. We do have a bit of a somber note, I guess, because we lost 2 icons of science fiction this week, of Star Trek. You can see my chair, big fan, with the deaths of Walter Koenig and Sir Patrick Stewart. Of course, Koenig was Chekov on the original series and of course the original cast films and the animated series, I believe.

Tariq Malik [00:09:32]:
No, actually, he was— Chekov wasn't there, but I believe he voiced some characters there. And Patrick Stewart was Captain of the Enterprise-D in Star Trek: The Next Generation. Just real sad to have it back to back like that, right?

Mike Wall  [00:09:44]:
Yeah, no, it's really sad. It's just a reminder of the march of time. TNG was a big part of my childhood. I would watch that a ton growing up. Patrick Stewart, Jean-Luc Picard, make it so, was a big part of my early years. It's just really sad. Obviously, they both did more than just Star Trek. they were very accomplished actors over a long time.

Mike Wall  [00:10:07]:
It's not like all they did was Star Trek, but that's, that's our touchpoint for them for the most part. So it's just, it's just really sad.

Tariq Malik [00:10:14]:
Patrick Stewart was the guest of honor at the very first Star Trek convention I ever went to as a kid in high school in Sacramento. We drove like an hour out of town to go see it. And it was crazy. I thought at that time, to me as a kid, that you could watch someone on TV and then go see them in person. Like, I never knew that that was something that you could do. And Walter Koenig, by the way, like a great villain in Babylon 5, if anyone's ever like, has not seen that. He's like this great, like head of their psyops, kind of the Section 31 of that series. And very, very, very prolific on his own.

Tariq Malik [00:10:53]:
So we just thought we wanted to make sure that we took some time, you know, to— Yeah. To think about that and like the impact that Star Trek, I think, has had on us, on NASA and Like astronauts who have joined because of Star Trek.

Mike Wall  [00:11:05]:
And just, just on the popular culture in general, just to help get people thinking about what's possible, what could be possible in space. I mean, if you talk to a lot of astrophysicists, astronomers, spaceflight people, so many of them say that they grew up watching Star Trek or it was what helped them get interested in thinking about some of the stuff that they want to do. And so, yeah, it's, it's, it's had a really broad cultural impact across a lot of different places.

Tariq Malik [00:11:27]:
And it is the 60th anniversary of Star Trek at this point in time as we're recording this right now. And if you go over to space.com, by the way, From season— I think it was season 2, or maybe it might have been season 1 of Star Trek: Picard, when they brought back Patrick Stewart's character for 3 seasons on Paramount Plus. We have a great discussion of him talking about why Star Trek has resonated for so long. And it's about, in his words, like the hope message, the message of hope, and that we can all— that we're all in it together and that we can do mighty things. Yeah. You know, as, as we, uh, as we, if we work together and like put our differences aside, it's very, very kind of touching thing to go back on. It was written, he, he recorded it, I think in 2020 during like, you know, it was during the pandemic and during a different time, uh, with things, but it still resonates and hits maybe even more impactfully today with his passing. So just our thoughts go out to their families and everything and all the fans everywhere, you know, just, uh, you know, we'll, we'll have to remember them and maybe watch some of their, their work.

Tariq Malik [00:12:27]:
as, as things go on. So thank you very much. Thanks for sharing that, Mike. So for sure.

Mike Wall  [00:12:34]:
Yeah, sure.

Tariq Malik [00:12:36]:
And with that, you know, we'll have to turn off— turn on to a bit more positive things like exploring a moon pit on the lunar surface with this, this new mission and Dr. Than Putsik. So let's go on. We'll see— take a quick break. And then we're gonna head right into that. Thanks so much. And we are back, everybody, with Dr. Than Putzig, planetary geophysicist with the Planetary Science Institute, and the person who's gonna tell us all about lunar caves and pits and why they're exciting.

Tariq Malik [00:13:11]:
Than, thank you so much for joining us today. How's your day going? You know, how are things going?

Than Putzig [00:13:16]:
Oh, it's going just fine.

Tariq Malik [00:13:18]:
Great. Well, you know, for our listeners who maybe aren't aware, if you can just kind of share a little bit about yourself, your career, and then I've got a bit of a how you got interested in space question to come after that, just to give people an idea of who you are and the Planetary Science Institute overall.

Than Putzig [00:13:34]:
Sure. So yeah, I'm a geophysicist. I've been working in geophysics for many decades now. I actually started out doing terrestrial geophysics in the industry here, looking at targets on the Earth in the subsurface using active source seismic data. And then around the beginning of the millennium, I got millennium madness and decided to go back to grad school and switch into planetary science, still doing geophysics, but now on other planets. So up to this point, much of my planetary science career has been focused on Mars, actually. I do a lot of work with both thermal and radar data at Mars from orbit, trying to understand the surface properties of Mars. But I've developed an interest in the Moon of late, and with a great team of people, we put together this proposal to take some geophysics, uh, to the moon,

Tariq Malik [00:14:47]:
which I'm really excited to, to ask you all about, uh, in, in a minute. And I'm curious though, was the space part then— it sounds like from the way you described it that space was something you really got into later in life, but is that, is that correct? Or was it like— Kind of. That was always there in the beginning?

Than Putzig [00:15:05]:
It was always there. Um, I actually developed an interest in it, I think, very young when I witnessed the Apollo landings as a child. By the 4th grade, I was building a scale diagram of the solar system across the back wall of our classroom.

Tariq Malik [00:15:26]:
Oh, wow.

Than Putzig [00:15:27]:
And so I was very interested in planetary science from a young age. In the early '80s though, it was kind of the doldrums of planetary science. There weren't a lot of missions going on or new ones in the works. So I was kind of talked out of going into that for a career. So it's always kind of a hobby in the background. And then when I decided to make a career change in the late '90s, things had really turned around in planetary science. There were a bunch of new missions on the books and new ones that had been launched recently. So it actually looked like a very viable alternative career choice at that point.

Tariq Malik [00:16:12]:
Wow. And not just viable, but I mean, it seems like you're going to the Moon now, which is why we really wanted to talk to you today, because you're, you're the principal investigator on this Gimli mission to the Marius Lunar Pit, which sounds like something out of Lord of the Rings, I have to say. Can you kind of tell us about that, this payload? Now, you were— this was just announced, I want to say, like, like A few weeks ago, right?

Than Putzig [00:16:39]:
Yeah, it was announced on September 30th, actually. So this is a part of a NASA program to send robotic spacecraft to the Moon, kind of smaller missions that they want to do on a more regular cadence. So they put out this proposal for instrument suites to go to various Well, actually, you can pick the site that you want to go to.

Tariq Malik [00:17:09]:
Oh, wow.

Than Putzig [00:17:10]:
And then they go through the process of selection. So now this instrument suite has been selected. So we don't actually yet know when we're going to launch and who's going to provide the launch. So NASA will then contract with commercial providers to provide Both the launch vehicle and the landed craft, the lander and the rover that we requested.

Mike Wall  [00:17:40]:
So do we know then, do we have like a sort of window? Like, I know you don't know exactly when you're gonna fly or with which provider, but is this gonna be in the next 5 years, the next 10 years? What's your best guess?

Than Putzig [00:17:50]:
Yeah, right. So as part of the proposal, you're given a timeline, and we were given a 4.5-year timeline. So around the 4-year mark is when the launch and landing is to occur, and the whole mission really. So it's just a 2-week mission, 1 lunar day,

Mike Wall  [00:18:11]:
and

Than Putzig [00:18:11]:
we'll be carrying out all of our investigation during that 2-week period. So if things stick to schedule, then we're looking at a launch and landing approximately in 2031.

Mike Wall  [00:18:27]:
Great. And so could you just tell us a little bit about what this payload, Gimli, will actually do? It'll be on a rover, right? So will you be like traversing what you think is the lava tube that lies kind of around this pit and just seeing the extent of it, trying to map it out with ground penetrating radar, that sort of thing? What's the actual science that's gonna be

Than Putzig [00:18:47]:
done? Yep. No, yeah, you got it in one. Basically, it's not fully determined yet that lava tubes exist on the Moon. Hmm. There's a lot of circumstantial evidence, both from imagery that has imaged these pits that look like a collapse feature potentially into a lava tube, but not necessarily. There are other means of forming such collapse features even in volcanic terrains. kind of a tectonically driven process in a very isolated cavity. So really, we're trying to ascertain whether it's that style of pit or if it's actually a collapse pit into a lava tube.

Than Putzig [00:19:38]:
Wow. So we're bringing multiple geophysical methods to do that survey, as you're alluding to, over the area adjacent to the pit. to try to see if we can detect the void space at depth.

Mike Wall  [00:19:54]:
Cool.

Than Putzig [00:19:55]:
And so we're using 3 different methods. One is active source seismic. So that's sound waves, essentially. Another is the ground penetrating radar. These are radio signals. You emit the signal and it goes into the subsurface and bounces off of interfaces and comes back to the same antenna. And then the third method is a gravimeter, which measures very tiny changes in gravity as you move around. So if there's a void space down there, you'll see a drop in the gravity as you're passing over the lava tube.

Tariq Malik [00:20:39]:
And I should point out, so the, the, the, the name of your, your investigation is the Geophysical Instruments for Marius Lunar Pit Pit investigation. So, that's where the Gimli comes from. And I think, Mike, and you hinted at this earlier, but for our listeners who don't know, you're looking at the Marias Hills Pit as like your target. And a lot of our listeners may not know that there are— I hope I'm— am I pronouncing that right? Is it Marius or Marius? Either way.

Than Putzig [00:21:08]:
It depends on tomato, tomato, you know.

Tariq Malik [00:21:13]:
you know, they may not know that there are these hills there, let alone that there's these pits that, that, that could be this tantalizing lava pits, or even why having like a lava tube on the Moon would be important. So sure, if you can describe like, what is this, this, this pit? When did we find it? How large is it?

Than Putzig [00:21:30]:
Yeah.

Tariq Malik [00:21:31]:
And why, why, why do you care about finding these lava tubes themselves, despite the fact that they sound inherently awesome?

Than Putzig [00:21:40]:
So the Marius Hills Pit was discovered I forget the exact year, maybe not quite 10 years ago, on a spacecraft called Selene that had a high-resolution imager. And you need a fairly high-resolution imager to identify these pits and distinguish them from craters. The diameter of the pit is only 50 meters. Okay. So roughly 150 feet across. And it's— you can tell that it's different from an impact crater in that you don't have the rim surrounding it and the ejecta blanket that is associated with impact craters. Also, the walls of the pit are extremely steep. And there appears to be an overhang a few, maybe 20 meters or so down in the pit, which tantalizingly could be associated with a lava tube.

Than Putzig [00:22:55]:
But again, these other types of collapse pits can also have overhanging edges. So that's not a diagnostic of it being a lava tube.

Tariq Malik [00:23:06]:
Okay.

Than Putzig [00:23:08]:
So, yeah, so the imagery of this pit, you know, is how it was identified from that orbiter camera. And then some other instruments have also been passed over the pit area and identified suggestions from a radar sounder in orbit. For example, that there may be a void space down below that's more extensive than the pit, quite a bit more extensive. But to really dial that in, you need to go to the surface.

Tariq Malik [00:23:47]:
Okay, great. Well, I think we're gonna pick it up right there and, and I guess go to a surface of our own. Oh, that's a really bad one, John. And I'm so sorry. We'll take a quick break and we'll be right back to talk about what we can find on the surface of with this, this instrument, what it might mean for future astronauts on the Moon. Now then, when I was reading the NASA description of your, your project with PSI, you know, for Gimli, the part that gets me really excited is, is how you say that confirming the void space— I'm quoting now from like the NASA description— confirming these void spaces could shift the future of habitat planning Yeah, right. And, and, and that these, these areas could be ready-made shelters that could, you know, for astronauts on the Moon to protect them from deadly ionization— ion— oh my gosh, I can't say it— ionizing radiation and micrometeoroid bombardments. That sounds like our future living on the Moon, all built out of getting the ground truth, if it will, if you will, from Gimli at this, at this pit itself.

Tariq Malik [00:24:54]:
And, and I'm kind of curious how how that connects, right, from Gimli and the work that you're hoping to do in 2031 to, you know, lunar astronauts taking refuge or even just building a home inside a lava tube on the moon.

Than Putzig [00:25:11]:
Okay, so, um, some of the theories about lava tubes on the moon, um, include a wide range of sizes. You know, the dimension of the lava tube is not well understood. Um, the pit doesn't necessarily probably define how big the lava tube might be. And the size estimates range from just a couple tens of meters up to hundreds of meters in diameter of these lava tubes that can go on potentially for hundreds of meters or even many kilometers. So they represent enormous potential space that can be utilized. And there's several things about these potential lava tubes that make them attractive as a potential habitat. Of course, there's the protection from the micrometeorites and the ionizing radiation that you referenced. But in addition, the temperature inside of the lava tube is thought to very constant and actually quite temperate, on the order of 17 degrees Celsius or about 60 degrees Fahrenheit.

Tariq Malik [00:26:33]:
Oh, that's kind of like caves on Earth, right? Like they're a little bit more like easygoing.

Mike Wall  [00:26:38]:
Yeah.

Than Putzig [00:26:38]:
Yep, exactly. And so that— there's a similar temperature regime expected for the lava tubes on the Moon. So So, you know, all of these factors combine to suggest that, you know, these could really serve as, you know, large-scale habitats potentially for, you know, colonization. So, of course, you know, the lack of clear understanding about the dimensions of lava tube sort of holds that back. You can't really plan to it if you're not really sure if you're going to have, you know, a few hundred cubic meters to deal with or many tens of thousands.

Mike Wall  [00:27:30]:
Yeah.

Than Putzig [00:27:31]:
Um, so in order to— for NASA and other organizations to be able to plan to make use of this resource on the Moon, we really need to figure out, well, how big are they really?

Tariq Malik [00:27:43]:
Yeah.

Than Putzig [00:27:43]:
Um, and, um, you So the Gimli really would be the first step in that, to get to the surface with geophysical methods to see if we can detect and determine the cross-sectional diameter and characteristics of the lava tube from the surface. The next step, which will be a big jump in cost and complexity, is to actually go down into the pit in some way. And that could potentially be done robotically as well. There's an interesting project out there called— that NASA has funded called the Lunar Underground Explorer, and this is actually to send up essentially a hovercraft, robotic hovercraft, with a tether down into a lava tube should we demonstrate that they're— That

Tariq Malik [00:28:44]:
Oh, wow.

Mike Wall  [00:28:45]:
Wow.

Than Putzig [00:28:45]:
And that device could potentially go up to a kilometer or more down the length of the tube and fully characterize a large section of it that would be then a potential habitat.

Tariq Malik [00:29:02]:
Wow.

Mike Wall  [00:29:03]:
Mike? Yeah. I mean, this kind of goes without saying. People will probably know this, but we should probably just kind of state it clearly that the reason that we are so interested in underground habitats on the moon is because there's no atmosphere to speak of. It doesn't have a magnetic field. So all this protection that we enjoy here on Earth from the kind of dangers of space are like, they don't really exist on the moon. It's just like, it's kind of nakedly exposed to the vacuum of space. So yeah, it's just a much tougher place to set up shop than even Mars would be. Yeah.

Mike Wall  [00:29:35]:
Yeah. It just, I mean, that's, yeah. I mean, people listening to this probably know that, but that's just why.

Than Putzig [00:29:38]:
Yeah. Right. But not necessarily, right? You never know. It might be tuning in. And yeah, we make— when folks like me are close to the problem, we don't even think about those aspects because they're already in the back. Yeah.

Mike Wall  [00:29:54]:
And I'm just curious too about the sort of timeline. I mean, Gimli is 2031 if all goes well, and then maybe follow-up kind of exploration with this, this kind of other— this, this, this robot that might go into lava tubes. Does, does this timeline potentially line up with NASA's Artemis plans? I mean, and also Artemis is looking more at the South Pole. Do we know about like any lava tubes in the south polar region? How does kind of Gimli mesh with what NASA already is trying to do with Artemis?

Than Putzig [00:30:23]:
Sure. Well, I mean, effectively, it's— the intention is to do it in parallel. You know, there's a big push to send astronauts to the moon and start establishing a moon base there in that south polar region. And there's many good reasons for that. Notably, there's permanently illuminated areas next to permanently shadowed areas, and you can use the permanently illuminated areas to generate solar power. You might think of this South Polar Moon base like bases on the Earth, like the base Antarctica, where, you know, at McMurdo is where they send a lot of people, right, to do things, right? But a lot of them don't stay at McMurdo. They go out in sorties around the entire continent of Antarctica to do experiments and, you know, carry out scientific studies, etc. So, you know, think of the lunar South Polar Moon base in that sense, where you may then send sorties of astronauts to other places around the Moon, including these mid-latitude or low-latitude areas that host many of these lava tubes or potential lava tubes.

Than Putzig [00:31:57]:
So far, there hasn't been any clear evidence of lunar rilles and the kinds of volcanic terrains that potentially would host lava tubes. in close proximity to the, um, the lunar south polar region. You know, it's part of the, the lunar highlands, the heavily cratered terrains that were, you know, presumably volcanic at one time, but a lot of that's been overprinted by later bombardment.

Tariq Malik [00:32:25]:
Can I ask then, what, what makes a lava tube in the first place? I mean, and are these ones that you're hoping to find and explore on the Moon with Gimli and, and, you know, the imagery that we've had to date, are they kind of like one-for-one for what we see on Earth where there are lava tubes from actual volcanoes, uh, that are, that we, you know, that are active now? Or are they like a fundamentally different kind of, of lava tube or cave or that kind of thing that work just because the Moon is a different place?

Than Putzig [00:32:57]:
Sure. No, I mean, there's, there's certainly, there are differences due to the, the different environment and the gravitational field of the Moon and the lack of atmosphere. These are all factors that are going to contribute to differences, including the potential size, right? But qualitatively, it's effectively the same process we're talking about. So I'm sure most of your viewers have seen footage of active volcanoes in Hawaii or Iceland or other places where you see Lava flowing, red-hot lava flowing across the surface. So in many cases, that lava will start to cool while it's still flowing, and it'll effectively roof over. And then, so there'll be like a solid surface formed at the top. But the flowing lava below will continue and flow effectively in kind of a self-made pipe in the subsurface. And as the event that led to the eruption of the lava sort of tapers off, it's in many cases the lava will continue to flow and empty out from that underground pipe effectively, leaving a cylindrical conduit that, you know, carried the lava out to wherever it ended up eventually.

Than Putzig [00:34:43]:
Interesting. And so this same process is going on, or had gone on at least, presumably many millions of years ago on the Moon. And so it's thought then that there are these, these tubes underground that we're desperately trying to prove the existence of.

Tariq Malik [00:35:05]:
Great. Oh, well, well, I think that Mike and I are both interested about how stable and safe they would be to be, you know, for astronauts. But we'll have to get to that in our next section. So we'll take a break to get stable ourselves. I thought that was a lot better. And then we'll come right back with

Mike Wall  [00:35:21]:
Mike So, um, if everything goes well, if sort of Gimli does find that this pit is part of a lava tube and we're able to kind of access it, what, what are the— what would it be like to actually live in one of these things? I mean, I mean, first of all, how, how do you access it? I assume people aren't gonna be like rappelling from the skylight into the deep into the pit. Like, would you have to find where it starts, where it's— where the slope is more gentle and you get in there? Would it be a stable place? Is there any risk of like a collapse or something? Yeah, so from an impact or something like that, or just a sense of what it would be like to actually build a habitat in one of these things and live inside it. What are your thoughts about that?

Than Putzig [00:36:04]:
Sure. There's several potential ways of providing access for humans. Actually, the idea of rappelling into it isn't— I wouldn't totally rule that out. My understanding is that some folks at the Jet Propulsion Lab in California have actually looked into doing that robotically with essentially a rappelling spacecraft.

Mike Wall  [00:36:33]:
Wow.

Than Putzig [00:36:34]:
And there may be some safety concerns trying to do the same with astronauts, and so you may want to seek other means of getting in. In principle, you could fly a spacecraft directly into the pit and land it. at the bottom.

Mike Wall  [00:36:51]:
Wow.

Than Putzig [00:36:53]:
Other possibilities are to find where there's an entry point kind of more at ground level. And in this case, the pit sits in what's called a lunar rille, which is kind of a valley that's thought to be at least a partially collapsed lava tube. The pit sits in a very shallow part of the rille, which is why we think there's an intact lava tube down there. But other portions of the rille further afield are more pronounced topographically and may offer a means of ingress into the lava tube. We won't be investigating that. They're a bit too far away for the timeline on our mission. Yeah. But that's certainly a possibility.

Than Putzig [00:37:47]:
And then a third idea is that one could install an elevator either at the pit or actually carve out a hole somewhere else along the way, maybe where the roof of it is thinner. Mm-hmm. And install an elevator essentially down into the lava tube to move people and equipment down in there.

Mike Wall  [00:38:15]:
It's probably one of those things where once you've established the contours of the pit, where it goes and all that, then you can explore it and find a place where you could maybe get some people in there to break through the surface where it's closer to the surface and you could actually have an exit point that's more accessible and so forth.

Than Putzig [00:38:33]:
Yeah, absolutely. And so that, you know, the follow-on spacecraft would presumably like carry some sort of LiDAR Or laser mapping of the interior of the pit. And certainly you want to identify any areas where it may be unstable so that you can either avoid using those areas or reinforce them in some manner.

Mike Wall  [00:39:02]:
Cool.

Than Putzig [00:39:04]:
So as I mentioned, from the orbital imagery, we get Kind of lower resolution, but we can see the pit wall extending down, I think, maybe 20 to 30 meters depending on which side of it you're looking at. So that suggests that the roof is, you know, at least about that thick in many areas. Mm-hmm. So you also touched on a question about safety and within the lava tube and whether impacts might knock a hole in the habitat once it's established. It's not completely outside of the realm of possibility, but if you have a couple tens of meters of roof above you, it'll be very unlikely that a meteorite or Asteroid large enough,

Mike Wall  [00:40:09]:
yeah,

Than Putzig [00:40:10]:
it would impact right at that lava tube, um, to, to break through.

Mike Wall  [00:40:15]:
And, and you're, and you're still probably safer underground in that situation.

Than Putzig [00:40:18]:
Absolutely.

Mike Wall  [00:40:19]:
Yeah.

Tariq Malik [00:40:21]:
Well, can I, can I ask just about, about this kind of lunar living? You know, if we find, uh, a substantial lava tube that the, the signs hint to that could be at, um, at this, this pit itself, and it is, let's say, 20 feet deep. Obviously, a couple of astronauts with a pair of shovels aren't gonna be able to dig all the way through, or I would assume. I don't know how astronauts— yeah, how tough they are.

Than Putzig [00:40:46]:
Given enough time, they could probably do it.

Tariq Malik [00:40:50]:
So what would be involved? Because you would, you would need equipment to punch through, drills or whatever. And then if you're gonna build a habitat, you either need to have modular stuff, I would assume, to put in, or Or would you seal the whole thing off yourself and then have an International Space Station-sized or football field-sized interior space that you could walk around in shirtsleeves and that kind of thing? Is that, is that the kind of thing that's possible with, with a space like this?

Than Putzig [00:41:15]:
Yeah, I do. I think the latter, you know, sealing it off, yeah, is, is probably the most likely scenario. I mean, in principle, you could potentially seal off like 2 ends of a segment of the lava tube But you need to do a test to make sure that it's actually airtight on its own. If it's not, then you basically build an airtight space within there. And you wouldn't need to worry about micrometeorite bombardment. So you could potentially, say, do an inflatable habitat in there within the lava tube. Yeah. Something that would be a lot less challenging than building a habitat on the surface that also will need to protect against at least some level of radiation and micrometeorites.

Tariq Malik [00:42:12]:
Oh, I can see that. So it'd be like a giant whoopee cushion underground on the Moon that you fill up, and then it's nice, you got a nice membrane all around the sides, you don't have to worry about, I guess, patching up the walls. So that sounds cool. That sounds really cool. You know, I think you mentioned about Gimli and like its range. Do you plan for it to be able to totally circumvent the pit itself as part of that mission? How long do you expect it to run after landing, I guess, depending on what the surface conditions are like for the rover that it's riding on?

Than Putzig [00:42:47]:
Right, yeah, so our Kind of our goal mission is to essentially rove out to the pit, do imaging of the pit wall, because we really want to understand the stratigraphy of the material that overlies the pit and potential lava tube. And then we'll carry out the geophysical survey at some Distance away from the pit, probably 1 or 2 pit diameters away. And then we'll come around the pit to the far side later in the lunar day, which is 2 weeks long. The Sun, just like on the Earth, the Sun goes across the horizon the other side. So now the other wall of the pit will be illuminated and We'll go to image that. If we still have time, we'll do another geophysical survey on the far side of the pit from the first one, again, to see if we can identify the other end of the lava tube. And then at the end of the mission, we'll kind of close the loop around the far side of the pit and then head off toward the edge of the rille.

Tariq Malik [00:44:11]:
Wow.

Than Putzig [00:44:11]:
That broader valley that the pit and presumably the lava tube sits in the center of. And so the point of circumnavigating the whole pit is we don't know for sure that the lava— that if there is a lava tube, that it will necessarily be aligned with the rille, the bounds of the rille. So we really need to go kind of all the way around the pit in order to fully ascertain that there is or there is not a void space extending away from it.

Mike Wall  [00:44:44]:
Oh, that's very cool. And, um, no, this is something that I think I wanted to ask at the very beginning, but I didn't. Did you guys formulate the name of the mission because you're Lord of the Rings fans? That's right.

Tariq Malik [00:44:57]:
I'm glad you asked that question.

Mike Wall  [00:44:59]:
Did you— yeah, did you backronym it to make it Gimli, or did that just sort of— Okay.

Than Putzig [00:45:05]:
So I did read The Lord of the Rings, you know, the whole series back in the '70s and maybe into the '80s a little. And I did watch the movie, certainly. I wouldn't say that I'm a rabid Lord of the Rings fan by any stretch.

Mike Wall  [00:45:26]:
No.

Than Putzig [00:45:27]:
But I'm certainly aware of it and I really enjoy it. So basically, the way that I arrive at acronyms typically, I prefer acronyms that are descriptive of what you're doing and that it has to make a clear statement about what the purpose of the project is.

Mike Wall  [00:45:51]:
Yeah.

Than Putzig [00:45:52]:
And so I just take words like geophysical instruments, And Marius, the location where we're going, and lava pit. And I kind of arranged them in different orders to see if something interesting falls out from an acronym standpoint. And I really kind of got lucky with this one. And this one took a little more effort than a prior one that we came up up with. And that was for Mars. We were doing a study to try to figure out where the subsurface water ice is that's closest to the equator, potentially to be used as a resource on Mars by future astronauts. And so we started writing down words like I do, me and And my deputy, who's also the deputy on this project, Gareth Morgan, we started just writing words down and we wrote down, okay, what are we doing? We're doing subsurface water ice mapping on Mars. And then we were done.

Mike Wall  [00:47:08]:
Swim. Swim. Yeah. Nice. So

Than Putzig [00:47:12]:
that one was easy. It just sort of fell out of the sky.

Mike Wall  [00:47:16]:
Gimli just works on many levels, right? Because—

Tariq Malik [00:47:18]:
oh, go ahead. Sorry, Mike.

Mike Wall  [00:47:19]:
No, I was just gonna say Gimli is a dwarf in Lord of the Rings, and dwarves live inside the mountains. They mine underground, all that. So it just, it just works on many, many levels. I was

Than Putzig [00:47:29]:
just— Yeah, no, I, I— when it, when it came to us, yeah,

Mike Wall  [00:47:34]:
uh,

Than Putzig [00:47:34]:
you know, we took a poll of the team to, to see who wanted which, uh, wanted to go with which title for the project, and that one won hands down, you know, because of those associations. It, it just works really well, and we're looking forward to maybe using some other Lord of the Rings references as part of the mission.

Tariq Malik [00:48:02]:
Yeah, even the name, like Marius, is very close to the Mines of Moria. There you go. But I did have a question about the— oh, go ahead, go ahead.

Than Putzig [00:48:12]:
I've been joking that I would like to rename the pit the Eye of Sauron. I don't know if the IAU will go for it though.

Tariq Malik [00:48:25]:
Well, you can always apply. But we'll come right back after a break to ask a little bit about the team and the institute as well. and how you do these missions. So thanks, stay tuned, and go nowhere, as Rod likes to say. So then, you know, so this is a really exciting mission. It could lead to the really even maybe perhaps more exciting, like, civilization under the moon's surface or whatnot, which I think is really cool. It's very— it sounds very much like Moon Is the Harsh Mistress. They live underground, I think, in there as well, if memory serves.

Tariq Malik [00:48:57]:
I could be wrong about that, but, but I was very curious about how The mission came about from you and your team at PSI. Like, like, for people who don't know, you know, like what, what the Planetary Science Institute is, how these missions and these teams come together there. Like, how did you, as an institute, you know, organize everything to try to bid for this, this slot, and then, and then execute it as a science campaign?

Than Putzig [00:49:27]:
So the Planetary Science Institute is actually, we believe it's the world's largest group of planetary scientists at one institute that's not governmental. And we're organized a little differently than a lot of research institutes. It's really in a lot of ways, it's kind of a collective, right? We all have a— all of the scientists that lead proposals and activities have a lot of autonomy. So we fabricate our own ideas about what we want to do, where we want to go. We put the teams together. The Institute provides the support from an administrative standpoint to deal with the whole effort to put the proposals together and submit them to NASA. And, you know, there's an internal review process that's done internally, and that's all done by us collectively. And then once the selections are made and we win, then the administrative arm of the Institute, you know, jumps in to help deal with all of the contracting and all of that stuff.

Than Putzig [00:50:52]:
to ensure that things go smoothly. So yeah, there's not like a, you know, kind of a top-down approach to deciding what we're going to propose. Mm-hmm. It's really kind of a grassroots effort at the Institute to come up with these ideas and that, you know, the best ones kind of rise up to the top. And, um, they, uh, and then they, you know, hopefully that, you know, a good number of them get selected and, and keep us all afloat.

Mike Wall  [00:51:28]:
I've always been struck by— you, you have to have such patience as a space scientist, right? Because you can come up with ideas and you got to go through all the vetting processes, the approval processes, and then you've got to wait for a ride to space. And, and depending on how far away your target object is, it could be years and years. It's just Did you appreciate what you were getting yourself into when you went back to school 25 years ago or so?

Than Putzig [00:51:54]:
I didn't know really in detail, but I had worked in the industry in several different capacities, both as just a regular geophysicist dealing with data and analysis, kind of analogous to a postdoc or early career researcher in planetary science.

Mike Wall  [00:52:14]:
Yeah.

Than Putzig [00:52:15]:
And then I got into more of a management role where I had a whole bunch of people reporting to me on different projects. So I was doing a lot more of that administrative aspect of it. And then that job kind of blew up when a merger occurred, and I found myself working as an independent consultant. where you do everything, right? From paying the employee to, you know, going out and finding the customers that you're gonna do the work for.

Mike Wall  [00:52:51]:
Yeah.

Than Putzig [00:52:51]:
So I think that actually set me up pretty well for success as a planetary scientist, where you kind of work through all of those different aspects of the business. So now in terms of, you know, specific to this, this was actually the 4th round of these so-called PRISM calls, these, you know, payloads for sending to the moon. And me and much of the team that ended up winning here proposed to all 4 of them. So we've kind of been through the mill on learning. Yeah. what is, you know, viable to put into one of these proposals. And often it takes, you know, a few attempts at a given funding program before you kind of dial in exactly what it is they're looking for, because every program is a little different. Yeah.

Than Putzig [00:53:54]:
And this one is interesting in that you're really trying to marry both a science team and an engineering engineering team together, um, to, you know, propose the development of these instruments and then eventually their integration with NASA-selected commercial providers.

Tariq Malik [00:54:11]:
How large is your team then? Is it— and is everybody based out of like the PSI headquarters in Arizona, or is it distributed based on like how we're all remote today here?

Than Putzig [00:54:22]:
No, I'm actually speaking to you from, uh, the PSI office in Lakewood, Colorado. So I lead up this office. We're a small office with half a dozen staff or so. The headquarters in Tucson has several dozen people, including all the administrative folks down there and a number of scientists. So we're a very small, lean team, as you need to be for these particular for this program. Mm-hmm. So, you know, named people on the project are not quite a dozen. So we have not quite half of those at PSI, both in this office, there are 3 of us here, and a couple from other— that work remotely from other locations.

Than Putzig [00:55:16]:
And then we have our team at Honeybee Robotics that's going to be building the US contributions to the project. In addition, there's a team in Norway that's going to be building and supplying the radar instrument. Oh, wow. And then we have folks at Boise State University in Idaho that are helping with the active source seismic component. The gravimeter lead is at Johns Hopkins University in Maryland. And then we have a scientist, a lunar scientist at Johnson Space Center as well.

Tariq Malik [00:56:06]:
Yeah, I was going to ask, like, the next steps. It sounds like building the stuff between now and 2031 is going to be very, very key. Um, but, but I— something just dawned on me, uh, that is, I don't know what an active source seismometer is. Are you like shooting slugs into the moon to see like what's inside, like in Jurassic Park?

Than Putzig [00:56:27]:
Or, uh— Not quite, but close. So, um, so I mentioned there's a lander and a rover. Um, and on the lander, we're going to have a kind of a heavy device that goes— is put down on the ground, and then it will impulsively hammer on the ground.

Tariq Malik [00:56:51]:
Oh, wow.

Mike Wall  [00:56:52]:
That's cool.

Than Putzig [00:56:53]:
And so we'll do that many times in a row and then add up the energy that comes from that as recorded at ground motion sensors both on the lander and

Tariq Malik [00:57:08]:
It is like Jurassic Park. That's how they find the bones. Right.

Than Putzig [00:57:10]:
And so these ground motion sensors, they may also pick up non-active source or natural sources like moonquakes or a nearby impact of a, you know, a small object. They're not really designed for that. They're more— these kind of ground motion sensors are designed to be used with a specific nearby well-known source. So they don't have like the sensitivity of the, say, the ground motion sensors that were sent to Mars on the InSight mission, for example. But they do just a fine job with the active source and down to the, you know, 100 meters or so depths that we're trying to explore.

Tariq Malik [00:58:05]:
That's awesome. Well, I guess, uh, uh, I think— oh, Mike, Mike.

Mike Wall  [00:58:09]:
Oh no, I just, I just, I just had one more question. Sorry, sorry to keep you here so long, but, um,

Than Putzig [00:58:13]:
no worries.

Mike Wall  [00:58:14]:
Yeah, um, so these are, these are potentially very good places to set up shop on the Moon, and you were talking earlier about how you've done a lot of work with Mars too. What, what are the prospects for lava tubes on Mars providing the same sorts of kind of habitation accommodations for astronauts? Is— has, has Has that been studied to the extent that Moon lava tubes have been or are about to be? What's the status for Mars?

Than Putzig [00:58:39]:
Right. They're often investigated in parallel or even within the same project. Some people will do comparisons of lava tubes on different planets. There may even be lava tubes on Venus, for example.

Mike Wall  [00:58:56]:
Yeah.

Than Putzig [00:58:57]:
Oh, wow. Though that'd be a bigger problem given the surface conditions. As far as habitat use. Right. So yeah, there's been quite a bit of work to identify similar kinds of pits on Mars. And like with the Moon, they tend to be found mostly in these relatively recent volcanic terrains. Mars does have a thin atmosphere and it's a little better at dealing with the issues of the ionizing radiation and small impacts. You know, the real, really worrisome micro impacts that occur frequently on the Moon, they, they don't really go happen on Mars because the atmosphere is thick enough that they'll burn up on the way in.

Than Putzig [00:59:54]:
Mm-hmm. And of course, at the Earth, we don't worry about them at all for the the same reason with our thicker atmosphere. Yeah, but as with the Moon, there's the circumstantial evidence of the lava tubes on Mars and not a definitive demonstration that they— there actually are these subsurface void spaces.

Tariq Malik [01:00:17]:
Well, that's why we need Gimli 2, right?

Than Putzig [01:00:19]:
Yeah, Gimli for the— we'll just change the M from Marius to Mars.

Tariq Malik [01:00:26]:
There we go.

Mike Wall  [01:00:26]:
There you go.

Tariq Malik [01:00:28]:
Can I ask, I guess, because we're just about at the end, your rock collection then is amazing. I'm just curious what they are on the side there by the window, and is it just like your favorite bits as a geophysicist, or is it something that you use for your students and folks you work with?

Than Putzig [01:00:51]:
This actually all started 26 years ago. I mentioned that I had worked in industry and then I went back to grad school. I actually took a year off in between those and I traveled around the world. And just as I was getting ready to go off on this adventure, I met this woman through work, you know, one of my clients. And she said, hey, Could you actually, you know, pick up some sand samples as you go around the world and send them to me? Because I collect sand. And so I copied her.

Tariq Malik [01:01:34]:
Yeah.

Than Putzig [01:01:35]:
And I said, you know, I sent her the samples she, she wanted, but I also started collecting my own.

Tariq Malik [01:01:41]:
Oh, wow.

Than Putzig [01:01:42]:
To this day, I, I still collect sand. So the kind of the back row of the jars you see see in here, those are all sand samples from around the world.

Tariq Malik [01:01:50]:
Oh, wow.

Than Putzig [01:01:52]:
And then I've also picked up rocks on various field trips that I've been on in the last 26 years. Yeah, I think actually some of them are even earlier. There's one down there, this one here.

Tariq Malik [01:02:13]:
Oh, that's awesome.

Than Putzig [01:02:14]:
Which, as you can see, is a fossil. It's a rock. It looks like a shell, right? And it comes from Yemen.

Tariq Malik [01:02:25]:
Yemen. Wow. Very cool. That is amazing.

Than Putzig [01:02:27]:
A colleague of mine at Shell Oil Company went on a trip there, a work-related trip to do oil and gas exploration. And he came back and gave me this as a gift.

Mike Wall  [01:02:40]:
Wow, cool.

Than Putzig [01:02:42]:
At that time, I was working with, you know, the seismic data that they acquired in Yemen. Um, so it was a very meaningful, uh, gift, and it was a consolation for the fact that I wasn't part of the, the folks that got to go to Yemen.

Tariq Malik [01:02:56]:
Oh, wow. Well, and now, now you can design, you know, maybe you can add a sample return part for Gimli so you can get yourself some sand from lunar That would be amazing.

Than Putzig [01:03:07]:
Yeah, a rock, and I'll write Marius on

Tariq Malik [01:03:10]:
it. There you go. Is there, um, is there any other like upcoming news from you or the Gimli team that we should be looking out for as the mission develops or as PSI, uh, you know, proceeds with, with some of their, um, uh, their other ongoing projects?

Than Putzig [01:03:24]:
Um, well, so we've got kind of a, a staggered start. Um, NASA selected 3, uh, different projects from this same round of these PRISM calls. One of them has started immediately. Ours is actually not really kicking in until about a year from now, beginning of October of next year. So we're kind of— it's actually kind of nice in that I don't have to drop everything and immediately start working on this project. 'Cause it's gonna take more or less a full-time effort on my part.

Tariq Malik [01:04:04]:
Yeah.

Than Putzig [01:04:06]:
So, you know, this gives me a chance to kind of wrap up some of the other projects that I'm working on and kind of hand off some things to other folks to pick up. So in the interim though, we'll certainly be having discussions about what what the priorities are for ensuring that we get all these instruments built and delivered on time, and then doing the background work for the science investigation. We're also trying to get the word out about the project too. For example, I'll be giving talks in public forums here and there going forward as we are going through this lead-up period.

Tariq Malik [01:04:58]:
Great. Well, thank you. Thank you so much then for your time. I think we're just about at the end of the time we had for the episode. But, and thank you all, everyone listening for joining us today for episode 234, which we're calling Living in Lunar Caves. And maybe, you know, with Gimli and the dwarves, if you're game. And then where is the best place for people to keep up with you and your work as you are gonna go through it? Is it at the PSI website? You got socials?

Than Putzig [01:05:23]:
Yeah, definitely. psi.edu. Is how you get in touch or, you know, see what's going on at our institute. We will have a website for Gimli shortly, but that hasn't been put together yet, so I won't give you a URL for that. But it'll, it'll be linked into the main psi.edu website.

Tariq Malik [01:05:49]:
Great, so we'll be on the lookout for that. And remember everybody, you can drop us a line here directly at @twis@twit.tv. That is twis@twit.tv. We welcome your comments, suggestions, and of course, we always need new space jokes. Sorry for the lame one today. New episodes of This Week in Space publish every Friday on your favorite podcatcher. So wherever you are listening to us, that's where you're gonna find us. Make sure you like, you subscribe, and go tell your friends.

Tariq Malik [01:06:16]:
We need more space people. We need more reviews. Rod likes 5 out of like stars or thumbs up or whatever. Just, you know, So whatever you do for Rod, just like add extra ones for me, please. And then you can always head over to the website at twit.tv/twis. That is twit.tv/twis. And by the way, oh, really quickly, what about Mike? Mike, where can they find you, by the way?

Mike Wall  [01:06:41]:
The space.com website. I'm on X as well, but I very rarely post over there. But yeah, just like go to the space.com homepage and search for me. I pop up pretty quick.

Tariq Malik [01:06:52]:
I did it in reverse. Yes. And you can find me at space.com as well, @TarekJMalik, on all of the socials, the Instagrams, the Twitter— what is it, Twitter? No, it's X now. That's right. And if you like video games, you can find me on YouTube @spacetronplays. And of course, again, twis@twit.tv or for, for This Week in Space. And as we're recording it, it is Halloween Eve. So happy Halloween to all you folks out there, you spooky ghosts and ghouls and I guess zombie astronauts.

Tariq Malik [01:07:28]:
Let us know what your costume was for this year. Maybe we'll talk about it next year. And we'll see you all then. Thank you, and we'll see you next week. Thanks for watching.