Space Exploration

Universe Today Interviews Author, Engineer & Technologist Les Johnson About the 8th Interstellar Symposium

This summer, experts in fields ranging from astronomy and astrophysics to astrobiology, astrogeology, and cosmology all convened at the University of McGill for the 8th Interstellar Symposium: In Light of Other Suns. In partnership with McGill, this event was hosted by the Interstellar Research Group (IRG), the International Academy of Astronautics (IAA), and Breakthrough Initiatives. Between July 10th and 13th, students, press, and space enthusiasts attended presentations and outreach events that addressed the big questions on interstellar spaceflight exploration.

To learn more, Universe Today sat down with NASA technologist, author, and engineer Les Johnson who attended the event and hosted many of its panel discussions. This included the public outreach event “Interstellar Travel: Are We Ready?” where he and a panel of experts (including Alan Stern, AJ Link, Prof. Philip Lubin, Erika Nesvold, and Trevor Kjorlien) discussed the technological, social, and ethical dimensions of traveling nearby stars. He was also a featured guest for the Science Fiction Author Panel, where he was joined by fellow SF authors Karl Schroeder, Eric Choi, and Sylvain Neuvel.

We covered some interesting topics in a relatively short amount of time. Among them was the recently-released anthology of short stories and essays, The Ross 248 Project, published by Baen Books in May 2023. This volume was the latest in a series edited by Les Johnson and professional engineer Ken Roy (inventor of the Shell worlds concept), to which I had the honor of contributing the essay titled, “”. The following is the transcript of the interview between Mr. Johnson and myself Symposiumliams), hereafter denoted as LJ and M.

The 8th Interstellar Symposium was held from July 10th to 13th at McGill University. Credit: Interstellar Research Group (IRG)

Matt: Can you give us a sense of the structure of the Symposium? How did things kick-off?

Les Johnson: A tradition of the Interstellar Research Group symposia is that we try to have classes before the meeting begins. These three-hour seminars taught by experts in their field are intended for the literate audience, but not necessarily a heavily-technical audience, because we offer continuing ed credits for teachers. So this year, we had three seminars, and they were a fairly good turnout.

There was one provided by Laura Montgomery, who used to be a space law person with FAA regulating spaceflight launches. And now she teaches space law. And she did a class all about space law: overview, past, present, and future. And so everything about the Outer Space Treaty, the Moon Treaty, and the new recently passed legislation in the U.S. that lets companies profit from asteroid mining and all that was part of her discussion.

And Alex Ellery, who is a professor of aerospace engineering, did a talk on self-replicating technology and how that might lead to space industrialization. So the whole idea of programmable von Neumann machines, though not as microscopic. And then, Brent Ziarnick, who is a teacher at the Air University, that they have for up and coming air force officers and space force officers, he teaches at that. He’s in the DOD. And he gave a seminar called the “Role of National Space Forces, and Security, Safety, and Prosperity through Space Exploration.” Which was all about how we’re going to evolve the Coast Guard-like aspects of the Space Force to protect the space lanes. So anyway, we had those three seminars that people attended before the symposium actually began.


“[I]n space, we run the very real risk that whoever gets there first, that they might set the rules of engagement that other people have to play.”


M: Now, in terms of what Brent was talking about, what do you see as the likely threats and scenarios, the things that we need to be discussing today to be ready for tomorrow?

LJ: I’ve had a lot of discussions with him about this. And he also wrote an essay for the anthology you and I are in. And he’s also writing a paper on this for a technical anthology that Ken and I are editing for Elsevier. So he’s given a lot of thought to this. And I think the big issue is, if you look at history on Earth, the nation states that are the first to do something set the rules for how the game will be played. So right now, there’s a big issue in the Taiwan Strait about freedom of navigation and what we consider to be international waters, whereas China doesn’t consider it to be international waters.

The norm is what the rest of the world currently does, which assumes it’s free passage in international waters because they were the first to get there. And in space, we run the very real risk that whoever gets there first – wherever there is, whether it be to a certain asteroid to a certain part of the Moon or otherwise – that they might set the rules of engagement that other people have to play by. And so I think one of the things we have to be careful of is making sure that the principles that we tend to hold dear – which are free travel, free expression, equal access to resources – that kind of thing is upheld by law. And part of how you do that is you set the precedent in space. So I think that’s what a lot of his talk probably was about who’s going to be the one to set the norms for how things are done.

Artist’s impression of the orbital debris problem. Credit: UC3M

M: Yeah, I can see a lot of overlap with what Montgomery was talking about there and from what I’ve learned about space law from the Space Court Foundation and Space Generation Advisory Council. We need to set the precedents and establish rules ahead of time so that we don’t end up trying to figure this out as we go along and have a “Wild West”-type scenario.

LJ: Well, plus, from a national security point of view, right now, our Space Forces have a really good handle on what everybody in the world is doing in LEO, MEO, and GEO because we have spacecraft there that are watching everybody, and we have the capability from the ground to look up and watch everybody. And we know what everybody’s doing. Right now, in cislunar space, that capability doesn’t exist. And there is a Chinese lander on the lunar farside right now that we don’t have a clue what it’s doing.

And I’m sure that’s causing great consternation somewhere, not that it’s necessarily anything more than just a science mission, and they’re just doing science. But that’s not the point. The point is, there’s no way to confirm that’s what’s happening. And nobody really knows that that’s what’s happening. So you have to ask the question, “Hmm, how are we going to fix that problem?” And I’m sure that’s something that’s high on the list for the Space Force people.

M: Alex Ellery and I talked when I did an article on his work, and I immediately tried to rope him into doing a podcast on Von Neumann Probes, and he agreed. It helps that he’s a professor at my alma mater, Carleton University. I saw that Frank Tipler was there too.

LJ: Oh, that was great. I had a great time talking to him. I have some of his books that he autographed. I was a fanboy. His talk was a great way to start the symposium because he thinks big. Right. And his claim to fame, the whole Omega Point thing, and the fact that he believes that he has shown through the fundamental laws of nature that there will be a point in the future when we’ll be able to simulate the Universe and recreate everyone whose ever lived and ever will live and can live for eternity in that future.

And the fact that we exist now, he has a mathematical way of showing that that’s proof that we’re going to be successful in the future. And I have to admit, I didn’t really fully understand all of it. But he is really big on basically not just anti-matter, but this whole notion of how we understand the Universe and what that tells us about how the future clock of the Universe is going to unfold. And it was a really upbeat, optimistic, but incredibly technically detailed presentation. So I can’t do it justice in explaining it because I think there’s only one Frank Tipler. It was really a nice optimistic way to kick things off.

The next talk was given by another person you probably should talk to, Joseph Gottlieb, who gave a really nice humanities paper on the ethics and morality of “Should we explore space?” And he really delved down into the questions of, “Do we as a species have a right to export our species elsewhere? What’s the basis by which we’re going to make the decisions regarding that? And what are the philosophical presuppositions that go into that whole discussion?”

And his bottom line was “yes.” But he also made a point that there are other people out there that are of the belief “maybe” and some that are “no,” right? So there are different [opinions]. I’m not surprised there’s disagreement, but he makes a pretty compelling case in his presentation and in his paper that there is a good philosophical basis for space exploration and the expansion of the human species into space. So pretty cool stuff. It was very down to Earth after Tipler. (laughs)

Artist’s impression of the proposed Solar Gravity Lens telescope. Credit: The Aerospace Corporation

M: (laughs) Yeah, “let’s get back to things that are a little more… now!”

LJ: Yeah. Well, even stuff that was far out [like Claudio Maccone]. I’ve known Claudio Maccone for 20 years now. He’s the one who really – he and Greg Matloff are the ones that really got me sucked into the interstellar community. And Claudio is a mathematical savant. I mean, he’s just amazing. But his whole thing now is this whole gravitational lensing for communications and for looking at exoplanets. Now, you may have heard of the work that Slava Turyshev is doing at JPL on the exoplanet imager at the Solar Gravity Lens. Do you know anything about that?

M: Yeah. It was a little while ago, but I do remember that. Basically, it involves using the Sun as a gravitational lens to image exoplanets that would provide insane resolution?

LJ: Right. Yeah, there were two people at the conference who talked about that. One was Claudio, and the other was Victor Toth, who is actually a part of Slava’s [research]. He gave a talk in the afternoon, “Look before you leap: using the solar gravitational lens to explore exoplanets.” That’s where he really delved into the whole exoplanet imaging kind of thing. Claudio actually talked about using it as a communication system, kind of the Galactic Internet.

He says that what we need to do if we’re going to send a colony or a settlement ship to Alpha Centauri, and we want to have high-bandwidth communication from there to home, you can’t do anything about the speed of light with the lag time. But you can sure do something about getting the communication strength up. So you have high bandwidth because bandwidth is determined by the size of your antenna and the size of your receiver, and the power of your transmitter. And it turns out that not only does the Sun act as a gravity lens for light, but it also acts as a gravity lens for radio.

We shouldn’t be surprised because both are photons, right? They’re just different energy. So if you take a spacecraft with an existing transmitter that’s not gigawatts but might be hundreds of watts, and you put it at the Sun’s gravity lens point that aligns with Alpha Centauri. And you put another one in the Alpha Centauri system so that it’s at the point where it looks back at Sol (our star). You have two nodes. And then you send whatever data at Alpha Centauri that you want to send back to Earth to the Solar Gravity Lens satellite that they have. And then they use this very modest transmitter to send it back or back to Earth, and the Solar Gravity Lens focuses all that energy back onto our receiver.

So you no longer need a gigawatt transmitter to get high bandwidth. You can do it with just a conventional few 100-watt spacecraft transmitters. So it’s sort of the equivalent of imaging, but you’re doing it with radio, and you have a communications network. And Claudio postulates that, given the amount of time that the Universe has existed and how long it takes spacecraft to travel these distances, even if we have cultures that are spreading throughout the galaxy at some small fraction of the speed of light, they’ve had a long time to do it.

The reason why we may not be picking anything up on SETI is because these different civilizations are all talking to each other from the gravity lens point. And there’s no leakage. And in order to join the network, you have to get one of them to recognize that you’re there and beam something to your surrogate Solar Gravity Lens region. So it’s potential that we could send a probe to the Solar Gravity Lens with a radio tuned to SETI frequencies and suddenly find out there’s somebody else out there.

And Claudio really developed that mathematically and did a very, very nice job. Showing that it’s not only possible but how it could change our paradigm of doing SETI and how there might actually be a galactic internet that we just haven’t got a cell phone to tap into yet. So that was one of the more mind-expanding lectures of the morning.

The 8th Interstellar Symposium was held from July 10th to 13th at McGill University. Credit: Interstellar Research Group (IRG)

M: The event you were part of, “Interstellar travel, are we ready?” There was a lot of “who’s who” there. Right off the top, Alan Stern and Phillip Lubin were both there and bringing quite a bit to the table. And you yourself, you were hosting?

LJ: Yeah, I introduced all the panelists: AJ, Allen, Phillip, and Erica. And then Trevor was like the MC. He’s apparently a popular host in Canada, and he does this kind of thing all the time. He’s witty and personable, so he interacted with the audience and had a list of questions. And we on the panel kind of batted around the answers. Some were specific to us, and some were general. And it all centered around this notion of – “How do we plan for something that’s far out?” “Why are we doing it?” “Can we really afford to do it?” And, “What’s the scale that it will be?” And there were differences of opinion.

We had a few points of disagreement, notably between most of us and Philip Lubin. Phil had just done a recent cost analysis, just in energy costs, of how much it would cost to send an interstellar ship. And that caused quite a discussion. Because I personally, I think it’s an irrelevant number because by the time we do this, what is the energy price going to be? And what is money going to be? So there are some definite differences. Erica and AJ really brought the perspective of “Who’s going to go?” and “How do we decide who goes?” and “How do we make this community less ‘pale, male, and stale’?” which I thought was very valuable.

Erica [is] a successful social media podcaster kind of person, and AJ is really big on working to get diversity into space, and the space thinking, and space workforce. So it was, it was really a nice interplay between technical, social, and political kinds of discussions, and it was the most well-attended public outreach event we’ve ever had. The audience had over 400 people in it. So it was really awesome. Yeah.

M: Was there any consensus when it came to this event? Was there any sense of, “Yeah, we think we are,” or “We’re gonna have to wait and see,” or…?

LJ: No, we’re not ready (laughs), and it’s technology that’s the prohibitor. We’re really not ready technologically. But we did conclude that being ready, at least for small robotic missions, is within reach. With the work that Breakthrough Starshot is doing and the spin-offs that might come from that, we all kind of envisioned that it might be possible to send a robotic probe within the next 100 years, give or take. So we’re not as far away from being able to do that as I thought we were when I began my career and looked at interstellar stuff like 20 years ago.

I was thinking it was 200 to 300 years. We might actually be within 100 years of our first robotic probe, which is amazing. So the answer is, “Technically, we’re ready.” I think AJ and Erica might take issue with us being socioeconomically, sociologically, and psychologically ready. But that’s an important question, “Are we as a culture ready to do this?” And I think there’s some legitimate debate to be had here.

Project Starshot, an initiative sponsored by the Breakthrough Foundation, is intended to be humanity’s first interstellar voyage. Credit: breakthroughinitiatives.org

M: I was wondering about that very thing. I would assume the psychological and sociological impacts that such a mission would have had to have come up. So, did they [say] we’re ready that way, or they do they not believe [we are]?

LJ: They believe we’re on a path to being ready and that we should try to do it. They were not negative. They were questioning our readiness today but not doubting that we will if that makes sense.

M: Perfect sense. And so, the thing that we’re not ready for, I take it then, is we cannot foresee crewed interstellar missions within our lifetime?

LJ: Well, here’s where you have to be real careful. There were a lot of students in the audience who were 40 years younger than me. So when we say our lifetime, whose lifetime are we talking about? In my lifetime? No way. Robotic missions in my lifetime? No way. Robotic missions in the lifetime of a baby born today? Maybe. I don’t think a 40-year-old is gonna see it. I think a two-year-old might.

M: Well, that counts me out.

LJ: Sorry (laughs)

M: I should point out that they’re doing a lot of good work in longevity cures these days. So, I wanted to definitely get into the science fiction panel. And it was you, Karl Schroeder, Eric Choi, Sylvain Neuvel?

LJ: They’re all Canadian science fiction writers except me. And Karl Schroeder has written quite a few. He’s written a lot more stuff than I knew about. And I saw it, I really, I’m going to read some of his stuff. Now. We had side discussions because he and I have a common interest in developing planetary sunshades to mitigate climate change, and he and I’ve been talking about that offline. But this panel is centered a lot in a direction that I kind of inadvertently, well, probably not inadvertently. I did steer it that way, a bit, maybe a bit too much.

And that is how science fiction has changed. It used to be optimistic. And today, it’s very pessimistic and dystopian. And why? What does that mean? And is that a good thing or a bad thing? And or is it something we ought to try to change? And we had a lot of audience interaction with the younger people. And there are quite a few younger people at this meeting, more younger people than we’ve ever had, who were explaining why they think dystopian. And then me and Carl and the others telling them, “Well, your generation has challenges like every other did. Roll up your sleeves and get busy, right?”

And we all agreed that the tone of the literature can set the tone of the culture and that it’s been negative for too long. The pendulum needs to swing back to people writing about futures where we can actually solve our problems. And so we had a lot of discussion about that, not a lot about the writing process or what it means to be a writer. We did talk about some of our works, but it was primarily the philosophy of directions of where we are in science fiction.

The Ross 248 Project, by Les Johnson and Ken Roy (eds.) Credit: Baen Books

M: Well, that certainly sounds interesting. So was that sort of the main subject, the tone of science fiction today versus [the past]?

LJ: That’s how it ended up being. There were other questions asked, but most of them centered around that, and that’s what got the most audience interaction.

M: During your panel and also the public outreach event, did The Ross 248 Project come up?

LJ: Oh, yeah. I made sure it came up. It came up in the science fiction panel, and they had 10 copies of the book for sale in the room. And they sold out. I wish they’d had more. I think they could have sold twice that many. So yeah, I did. And a lot of people who said they couldn’t get it told me they were going to order it. So I think they will. Yeah, came up. Are you kidding? I had a copy up there with me! (laughs)

M: I wish I could have been there. I’d have brought my copies too.

LJ: Well, our next meeting will be in Houston. And June of 2025.

M: I think my schedule is clear. (laughs)

LJ: Believe it or not, I had to put it on mine to make sure it stays clear.

M: Les Johnson, thank you so much for joining us, and best of luck with your future endeavors.


Matt Williams

Matt Williams is a space journalist and science communicator for Universe Today and Interesting Engineering. He's also a science fiction author, podcaster (Stories from Space), and Taekwon-Do instructor who lives on Vancouver Island with his wife and family.

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