Interstellar Space Travel (Full Episode) | Startalk | National Geographic

DR. TYSON: From the American Museum of Natural History in New York City, and beaming out across all of space and time, this is StarTalk, where science and pop culture collide. Welcome to the Hall of the Universe! I'm your host, Neil deGrasse Tyson, your personal astrophysicist. And tonight, we explore the dreams and challenges of taking humanity interstellar. So, let's do this. So, introducing my comedic co-host, Godfrey. -Oh! -Alright. -Look at those biceps. -Also joining us is a good friend and a colleague, theoretical physicist, Lawrence Krauss. Lawrence! Lawrence has a very huge title, we will shorten it for this introduction, we'll just call him, Professor. -Paleontologist professor. -At Arizona State University. -Thank you, Neil. -Well you're a physicist, you're a physicist. You're astro, and he's theoretical. -Yeah, yeah, yeah. We totally got this. We got the universe in our hand, yeah. -You got the physicists locked down. -Your, your most recent book, you have several. The Greatest Story Ever Told - So Far. Came out this year. You're a deep thinker on all things deep space. -Thanks. -That's why we've got you. We're featuring my interview with engineer, physician, former NASA astronaut, Mae Jemison. -Wow. -And she, she's got. -Wow. That's cool. -She's got plans to take humanity, humans, on a journey to another star. But first, we discussed how she got started on her own journey to space, let's check it out. MAE: So many times, people think of, of themselves and particularly people who are in the public light as having this single dimension. And it's critically important to remember that there's a life before that that leads you up to the place you are. And then you have to continue on afterwards. And you know, so for me everything that I did before I ever went into space was just as important as going into space because that's what got me there. I worked in West Africa for two and a half years as the area Peace Corps Medical Officer for Sierra Leone and Liberia. Two of the least developed countries in the world. I'd worked in a Cambodian refugee camp. And so. -This is after you had gotten your medical? -Uh. Well, one was while I was in medical school. I worked in a Cambodian refugee camp. I worked with The Flying Doctors in East Africa. I was a busy medical student. -Okay. -Yeah. What I. -Wait, wait. And then you went into space? -There's more stuff before I went into space. -So, so. -Then you went into space, okay. -No, no, the reason why I'm bringing this up is because so many times people think you know you just appeared on the planet. -Mm. -At that moment that they knew you. -Hatched in that, in that circumstance. -And you weren't. -Mm-hm. -Right? It's all the things beforehand. So, my idea was that space exploration has many uses. And it will only come to fruition; we'll only know exactly how it should be used as we get more people involved. And so, it was literally because of my background of working in developing countries I was very excited about how you could use remote sensing in developing countries. How you could use. -Satellite remote sensing, yeah. -Satellite remote sensing. -How you could use satellite telecommunications to be able to get to places where telephone lines don't reach. Now I talk about medicine, but I'm really an engineer at heart. Right? Because I did chemical engineering as an undergraduate. And I also majored in African studies. So, you can sort of see how those pieces blend together and how you think about things and how you think through life. -Lawrence, should we require that future astronauts have that many dimensions going for them? In the move, The Martian, and in the book. -Yeah. -Uh, the main character is not only a botanist, but knew serious amount of engineering to keep himself alive. -And so, it seems pretty useful in situations like that. -Yeah, but I do want to remind you. That was science fiction. -Oh, damn. -Okay? But, you know, and I think the point is, what astronauts should be is tuned to the mission. So, they should be people who first of all can survive, which is a big part of it. And, and I think a lot of the astronauts have be, if you think of the lunar astronauts, became experts in what they needed to become experts in. Geology if they, if they could, that need to know how to do that. But I, I don't think in, in a mission that, that you really have to be a, a Jack of all trades, it really depends on the mission. If you're having a mission around a, around a star, you probably don't have to have expertise in geology, for example. -Or botany. -Yeah, exactly. So, I think astronauts are there to do a job, basically. And their skill should be tuned to the job. But they, you know, might have the wrong specs. Like Neil, as wonderful as he is, may not have the right specs because mass is the enemy of space travel. And if you look at Neil. -I think he just call, called me out. -Yo, he just called you out. -He just called me out. -He said you too big for a space capsule, man. -Duuuude. Yeah, I mean he's right. It, it, what is it? $10,000 a pound just to go to orbit. -Yeah, yeah, yeah, yeah. -Oh. -So. -Yeah, if you got. -I mean, you're, you're probably worth it, but it's still. -I wanted to be an astronaut. I did, but I was afraid, I'm not going to lie, I'm going to keep it real. I wanted to be, but there were no astronauts that looked like me until Guy Bluford came. -Uh-huh. -It was Guy Bluford who made. -Yeah. First black astronaut, yeah. -First black astronaut, Guy Bluford, then there was Mae Jemison. And my brother was like, "Why don't you want to be an astronaut?" I said, "Because I don't want to be the first person of color because they might put me in a wrong rocket." It'll be like, "Yo, why do I have a football helmet instead of a astronaut's helmet?" -No, uh. -"Houston, there's a problem." "No, just, just strap your chin strap, you'll be just fine." -No, no, no I know, I know what the problem is. You don't want to, you don't want to be up there saying, "Uh yes, NASA, no, NASA. Yes, yes, NASA." You didn't want to. -And I was like what, what, because I didn't see any brothers. I said, "What does NASA stand for? Negros Ain't Supposed to be Astronauts?" -Well I asked astronaut, Mae Jemison, about her 1992 shuttle mission to low Earth orbit, MAE: It was a laboratory mission so we carried up a laboratory in the back of the, the space shuttle. And we flew on Endeavour. -Endeavour, nice, uh-huh. -Uh, right. So, it was a, it was a, it was a great mission. Um. -I think Endeavour now lives in Los Angeles, is that correct? -Endeavour lives in LA. -Yeah, do you, do you tear up when you see it on display at the California Science Center? -So, I went to the California Science Center, uh when they were actually unveiling it. And yeah, it's a, it's a strange feeling because it's sort of, uh. It's sort of saying good-bye to an era, but knowing that we have uh, more to do. -Oh, wow, that was cool. -So, so Lawrence, did, how did you feel at the end of the space shuttle era? -Meh. -Yeah, yeah, me too. -Me, me, me too. Well, so I, and all the people were tearing up. I said, "Why are you tearing up?" "Well, because it's ending." I said, "That's not why you're tearing up." Did anybody tear up at the end of Mercury? -I know where you're heading. Because they knew there was something there. -They knew there was something else. -Anybody tear up at the end of Gemini? -Yeah, no, no. -No. So here, we're tearing up, and they don't know why because there's nothing on the adjacent launch pad. -Yeah so, we got one of the space shuttles. We got the, well the Enterprise, which didn't go orbital but it was. -Yeah. Yeah. -Tested the, the uh landing uh aerodynamics. And so that one was strapped to the top of a 747, and flew right over New York City, and I was there when it landed at JFK. -And there it is. It's an actual photo. -That's amazing. -Uh, Enterprise. All the space shuttles are named after ships. Real ships. -Star Trek. Star Trek. Or sometimes Star Trek ships. -In this case, yes. Uh, Enterprise. That's a real photo coming over New York City. -That's, that's a strong plane. -Before they did mult, multiple bank turns just to kind of, here I am, you know. And then it came into JFK where I then saw it land, then there was a ceremony. -That's awesome. -And Leonard Nimoy was there as well. "Spock. Spock, I have." -No, no, no I think there was, there were two. -"That. Spock, it's the space shuttle you have to land. Land Spock. Mm." -You know, it was the fact that there wasn't anything next. But I also think that it was in, in some level, boring. I mean they, they were going up the distance between sort of closer than Washington is to New York. -Between to New York, yeah, yeah. And, and it's you know, it's not uh where no man or woman has ever gone before. So, the Orion spacecraft is supposed to have the capacity to take astronauts to Mars. And do, is that a realistic next for NASA? -I think it's not the next, I think it's a long way down the road. I think uh, uh, people talk about it, but I think it, Mars is, the you know, I have a lot of friends who think that we're going to be going to Mars the next decade and it ain't going to happen. -No. -It ain't going to happen I don't think. -It's so far. -I mean, just getting back to the moon is a problem for them. -Okay so, so whatever that is or isn't, Mae wants to go much farther than Mars. And so, she came to my office wearing a big button on her shirt, advertising her scheme to send humans to another star, let's check it out. -What's this? You, you, you, just. I'm taking this. MAE: Here, here, here, you can put it on. Put it on. 100 Year Starship. -I'm going to. -What's up with this? -100 Year Starship is about making sure we have the capability for human travel beyond our solar system to another star within 100 years. It's about pursuing an extraordinary tomorrow in order to create a better world today. It's by doing those things that we don't know how to do. That we get further ahead. Right? It looks good on you. But no, it's about using interstellar travel as a platform to push radical leaps in knowledge, technology, and um, public commitment. -Dr. Mae, we haven't left low Earth orbit since 1972, and you're talking traveling among the stars? -I absolutely am. -Did anyone snap some sense into you? -Well, you know, they tried to do all kinds of things to me when I was a little girl, and, and I said I was going to go into space, because there were no women in the US space program, no people of color going to space. -They must have thought you were crazy. -I just you know, I tell you, it's, it's up to you to make the reality. Now with 100 Year Starship, we're not talking about a specific mission date. We're talking about how do you make the capabilities exist? -No one organization can do it. But can we create and help to form in an environment where people tried to do bigger things? -That's what the moon shot did for our country, and the world. -Absolutely. -Just think about it, in 1901 when H. G. Wells wrote, First Men in the Moon. -It was less than seventy years later that we actually had a human on the moon. And back then, we knew how much, we knew so little about anything. Today, our technological arc is much steeper. Right? We know a lot more. So, it's not unreasonable to imagine that in 100 years, we might be able to have the capabilities. Now I'm not talking about Star Trek and warp drive and bending space-time, and all of that kind of stuff. -Maybe. Maybe. -Might be. I mean, I may be limiting us. But, we may be able to have the capabilities to think about it. And 100 Year Starship is about providing a platform to think outside of those ways we usually do stuff. Right now, staying within our solar system, we can do a lot of incremental kinds of technology to get there. But getting to another star requires that you open things up. -Lawrence, let's try to get a sense of the scale of this. -Yeah, sure. So, we, we just ran some fast numbers. So, if Earth were a basketball. -Then the moon would be about the size of a tennis ball ten yards away. Much farther than many people think, who only ever saw the Earth moon drawn in a book. -Because books aren't wide enough to actually represent it accurately, so we have this, this warped sense of it. So, ten yards away. And Mars on that scale would be a mile away. -And the nearest star would be twice the actual distance to the actual moon. -It's just. -On that scale. -It's, it's a big place. -So, it seems undoable to me. -Well, I think it's a real challenge. And I think that it, I'm as you, we may talk about it, I think there are ways you could imagine going to a nearby star, but the human part of it is the hard part. I think that, that it is an incredible challenge to imagine getting to a nearby star in, in any human lifetime. -Yeah, but I'm saying. So, sure, we'll have medical people looking at the, we'll talk about that later in the show. -Yeah. Yeah. Sure. -And I agree that, that, that the equipment has to get you there. -You, you don't have humans running alongside Flintstone-style, you know. Uh. -But you know, even, even the equipment has got to be vastly different than the equipment today. And it's hard to imagine that. But. It's worth imagining, I think it's worth thinking about it. And you know uh, the question is, is it crazy, I think. And, and, I really think the answer is that she's not crazy enough. -Ooh. -I, I, I really think you got to be more crazy than that. -Well, we'll try to conjure up a plan for reaching another star when StarTalk returns. (applause). DR. TYSON: Welcome back to StarTalk. We're talking about what it would take to get humans to another star. with astronaut and deep space dreamer, Mae Jemison. I asked her, why not something a little easier, like Mars? Check it out. MAE: I love Mars, um. -Nobody doesn't love Mars. -I love Mars. But, think about Mars and the generations that are going to be working on these things. Even since we were kids, we've had something on Mars. We've seen Mars close up. Right? -Everybody who, most of the people who are alive today were born after we landed on the moon, is no big whoop. You know why we was like, "Ooh, the moon shot. You know, ooh, that we went to the moon." A lot of, you know, when I talk to college students they say, "Yeah, yeah, that's cool." -We've had stuff roving around on Mars since most people were born. Right? -Mm-hm. Mm-hm. -Up close. We did samples; Vikings did samples when I was in school. -It's, it's not, it's not really the next frontier. -It's not the next frontier. -Even going, we've had, you know, we saw the pictures of Saturn. Right? Everybody remember when we first saw the Saturn's ring, we were all like, "Ooh, Saturn's ring." -Close up. -They've seen this like it's just a regular old thing. -This is just a thing. -It's just a thing. -Yeah, just Google it. It's there. -Right. But, but going outside of our solar system. -Doing something that we can't do, that's what grabs you. -You know, I would go to Mars in a heartbeat. Right? I'm like, I. But, it's not the most difficult thing that we can think of doing. -So, Mae is, Mae is saying. -That kids today are just completely unimpressed. -Right. -By the missions to the moon, and the Mars rover. -Been there, done that. -Done that, yeah I know. -And I'm, how can anyone not be impressed by landing people on the moon? Or flying through Saturn's rings? You're, you're in front of the public all the time. -Right, right. The thought of a spacecraft going past Mars but not landing on it is pretty sad. And is, reminds me of this. -Sad? -Yeah, it's pretty sad. -Just a fly-by of Mars. -That's just whack. -But we've landed rovers on Mars. -Forget the rovers, we want to be on Mars. I mean, it reminds of me a gif, check it out. -Oh! Oh, is that Pluto? Cause, yeah. That's a fly-by of Pluto. -Is Pluto back in the planetary system? Wasn't it considered not? -No, and get over it. Okay, so now. -Whoa! Damnit. -Now, me and Mae go back. -Okay? So, I could, I could talk about her stuff if I have to. And I did. Alright? So, I, I had to, I had to ask her, you know, it seems a little bit out there for her to be, run around talking about a mission to send people hundreds of trillions of miles into space. -I mean I got, I'm agreeing, I mean, you know. We, we, we're, we're resonating here, right? -Which is, yeah. It's unusual. -Yeah. So, I called. I called her out. It's a little bit unusual. I call, I had to call her out on it, let's check it out. What else could you expect someone to think? Alright? Here's Mae Jemison, she's been in space, and now she wants to go to the stars. That's just kind of weird, okay. MAE: You know the first thing I had to do, was to get the woo-woo out of it. That's a technical term, -The woo-woo. You know what it is, like you said, Mae Jemison want to go to the stars, okay. That's kind of weird. -Right, right, right. -That's the woo-woo. -So, to really start to think why might this be a reasonable proposition? -So, what you're doing is, you're not building a spaceship. You are saying, here are the challenges that such a mission confronts. Wouldn't it be interesting to solve those as a thought experiment? As, or as, or in real, really solve them, and look at how it applies back to the rest of our lives. And so, you would have a moon shot without actually going to the moon. -Well, you know, yes, but let's be clear, we want to do it over the stars. Because if you pretend that it's not for the stars, then people lose interest in some ways. But, it's about capabilities. We can't set up a launch date, until you know some things. -Like I've had people sort of say, "Well, what's the technology world about?" I don't know, because we don't know what the hell the technologies have to be. I mean, let's be serious. We could have a capabilities map. Right? Which we know certain things have to exist in order to do that trip. And so, let's work on the capabilities we'll reassess in ten years, or twenty years, or thirty years. And then, you might be able to start this other thing. But it's really about how do you transform life here on Earth? How do you use this as a platform to push? Because again, we would be on the moon. You and I would be sitting having this conversation in a lunar base, or Mars. Right? If there had been commitment and people understood how this could affect our world. Because every group of people around the world have looked at the stars and wondered what they were. -Yes. You want to tap that energy. -It's, it's, it's, it's. It's, it's sort of fundamental to us. -We just have to get the woo-woo out of it. -Get the woo-woo. -So, Lawrence, you're a little aloof about what is described here, but you are actively on a project to send stuff interstellar. -Yeah, yeah, but it's not aloof, I'm sort of below it. I'm trying to do something that might be realistic. -Maybe. And in fact, Mae's on it with me. She's on the, she's on the. -So what's, what's that project called? -It's called Breakthrough Starship. -I've heard of that. -It was funded by Yuri Milner and a few other billionaires. And, and Stephen Hawking's on it, I'm on it, a few other people. -On the board. -Of trying to figure out how to send a, a small spacecraft, one gram spacecraft. -That would be a very small spacecraft. -Very small spacecraft. To the nearest star, twenty percent the speed of light. -Now you got the gonads to be calling that a spaceship. -Yeah, but you know what? It could do all, all of it in principle, all the things a spaceship can do. It can send information back to us, it can maybe take pictures. -Does this exist yet? -No. And that's. -What? -No, but hold on. -Theoretically. -But. No, but the difference. -He's a theoretical physicist. -Theoretical, man. -But the difference is it may exist. Its pushes. It, it, it's something that doesn't exist now. And it, it may never exist, but we think maybe ten to fifteen years of R 'n' D may allow us to do that. And that's already at the limit of human capabilities, and it's so much easier than sending you to the nearest star. -I think we have an image of it. Talk me through this, what's this? -Okay, so the idea. -Is that it's, it's, that's the actual sail, which is a meter across, around a square meter. -And the idea is that to take about 10,000 lasers on the ground and direct them. -What could go wrong? I mean I have to say the more we work on this, the harder it gets. -Look at those lasers. -But you know, we have. -What happens if a plane flies through those lasers? -Yeah, no kidding. It's even worse if a satellite does. But it's a, and in fact, that's a real problem. But the idea is we never, we never developed those lasers, they have to be coherent and go through the atmosphere and be able to push that thing, it takes two minutes to get it to twice the distance to the moon. -Two minutes? -Two minutes. -Damn. -To get up to twice the distance from the moon. And then you lose it. -Using just the pressure of light from lasers? -Just the pressure of light. And that's how long you have, after that, you've lost it, so it pushes every aspect of human technology right now. -Whew. -But so, so in all fairness to what you just said, it pushes our technology, but all these are technologies you can, you can imagine them. -Yeah. You could imagine. -It might be possible. They don't violate any laws of physics. -Right. Right. -And so, if you get, if you, if you get this to twenty percent the speed of light, you can get to the nearest star in twenty years. -That's the idea. And so, my hope is that you know, trying to remain healthy, just like you. -Because ten years are already be. -We're all going to be dead by that time. -Twenty years of, of, of travel, and then you got another four years to send the, the picture back. -So, it's like thirty-four years. So, I'm hoping to be around when that's. -So, you'd be like, "It finally made it." -And then. -And then die. -My, my. My worries it's going to, it's going to be blurry because the planet's going to move, you know and that will be the big problem. -Damn. Where is it? -Because the idea, you know, as you know, that, what really makes this exciting. -Is that there are, we've now discovered what may be a habitable planet around the nearest star system, and that makes going there much more interesting. -We'll get back to that in another segment. Coming up, we'll take your questions. -Hey. -On the science of interstellar travel, when StarTalk returns. From the American Museum of Natural History. We're exploring the challenges of sending humans on a mission to another star system. And we're doing that with engineer and former NASA astronaut, Mae Jemison, MAE: Let's just talk about energy, right? So how fast can you go? -Currently, I mean, I did the math on this. -Go, go ahead. -You take the fastest thing we've ever launched. And doesn't even have people on it. And you aim it towards Alpha Centauri. It would take. -Keep going. -The Alpha Centauri system. It would take; you know, 50,000-60,000 years. -Exactly. -Somewhat longer than a human lifespan. -It's, it's somewhat longer than we've been able to cave paint well, even. Right? -Exactly, back. That's, that's longer than since we've been cave painting. Yeah. -Right. So, we, we have to go much faster. -Which means that we have to generate these tremendous amounts of energy, store them safely, and control it. But you, that means you can't do chemical. You can't. -Chemical energy will not do it. -Chemical energy is out. All that fire and flame that comes up under the shuttle or Blue Origin in it. -It looks good. Looking, it looks good. -It looks good, but it's not going to do it. -Just to be clear, so chemical energy are molecules that have energy stored in them. You break apart the molecule, or you bring together molecule, uh, atoms, and energy's released. -And then you aim that in a way so that you thrust forward. -So that's, that's everything you see. But if we were going to try to generate the kinds of energy that we would need to get to another star in fifty years or something reasonable in a lifetime. -So, this is a tenth of speed of light. -A tenth of speed of light. -At four light years away, it's forty year, forty year trip. -So, you're going to have to, we're going to have to do at minimum a fission safely. Right? Which powers atomic plants and things like that where you break atoms apart. Or, you're going to have to do fusion, which is what runs the sun. Right? Which the sun generates energy, which we don't really know how to do well. Are we going to have to use antimatter? Each one of these are orders of magnitude more energy. So, if we started to be able to do even a little of that, look how it would change life here on Earth. If we were able to do it safely and store it. -Access to energy. -Access to energy, which is one of the things that's fundamental about uh, people's quality of life. And this is a good. -More power. -More power to the people. -Scotty, we need more power. -We need. We need more power to the people. -So Lawrence, uh, were my calculations about right? Tenth the speed of, yeah. -In, in this case, you, you got it right, yeah. -So, uh would you say this exercise rules out chemical propulsion? -Of course, yeah. I've written about it at great length in, in one of my books. -That's why we have you here so I, we know we didn't have to read the book. -Yeah. Exactly. But the ideas that with chemical rockets like we now use to get to that kind of speed, you'd have to use more fuel than there is mass in the entire visible universe. -Whoa. -It's just amazing to think about that. It's the, it's the big. First of all, mass is the big enemy of space travel. But really, the key question is, how fast can the fuel leave the rocket ship? Because. -That's the recoil that you're getting off with. -And. And that, that determines how fast the rocket can go. And the problem is that stuff that comes from chemical rockets may appear to go fast, but compared to the speed of light, it's pretty slow. -Alright. So, the options of getting let's just say to, to Proxima B. -Uh, the planet around Proxima Centauri in the Alpha Centauri system. If you're not going to do chemical rockets, but you want to get there in a time before a person dies. Okay? So, what are the ways to do it? -Well, you, you know, there, with fuel aboard the rocket ship, as far as I can see there's no way to do it. Because part of the problem also is that if you had fuel, you have to accelerate that fuel. That means you need more fuel, and then it, it. It, it, it, it. -It's the famous rocket equation. So, she mentioned fission, but fission is not particularly useful. We use fission on rockets right now, but usually just to power the experiments. Because it's not particularly effective at making things go very fast. Even fusion, the, the, the stuff comes back out the back at about one percent the speed of light. So even fusion, which we can't do on Earth. But if we, if we could, even fusion would, would still require an immense amount of fuel. So, having fuel aboard a rocket ship. If it's, if it's. -Okay, how about antimatter? -Well, antimatter's even. I mean it sounds nice. But if you take all of the antimatter we produced in particle accelerators over all of history so far, it's not enough to light up a light bulb. -I mean, the problem is that we can't find antimatter. -Is that right? Are you sure about that? Did, did, did you check your numbers on that? I checked my numbers on that, as a matter of fact, and I got them right. But uh, but. -Theoretically, yeah right. -No, but. I mean the problem with antimatter is it's hard to find. It takes a. And what's worse, it takes a lot more energy to produce the antimatter than the antimatter itself. So, antimatter is not a practical uh tool to even. Even though by the way, it is the most bang for your buck. If you wanted to in principle do it, you take matter and turn it into radiation, you can't do, ever do better than that with fuel. -Hundred percent conversion? -Hundred percent conversion so it's the best you can do. -Okay, so how about solar sails? -Well that's, the idea that's one of the reasons we're thinking about solar sails for the Breakthrough Starship. Because if you don't have the fuel aboard the ship, then everything changes. In this case, the fuel is on Earth or in the sun. Because light, even though it doesn't seem like it has much of a kick, does have a very small kick. So, with this one gram satellite, you could imagine a solar sail that's one meter. But if you wanted to, to have a real spacecraft, you'd have to have a solar sail that's the size of Texas, or something like that. And then there's a problem. The problem is, maybe over a year or three months to a year, you might be able to accelerate it to one tenths the speed of light. But if you want to land on the planet, you got to stop the darn thing. -You got to slow down. -And it just takes just as much. And where do you, how do you do that? So. -And you don't, you don't want to go to Alpha Centauri just for a flyby. Yeah. -Well with a, with a one-gram satellite, you might, but not if you had a human being. You don't want them to just keep going. -Okay, so how about we have a system, a gravitational system where you keep getting sort of slingshots? -Oh, okay. Now we. -And you accumulate them? -We've done that for the solar system, that's how the Voyager spacecraft went. -The Voyager, the, 40th Anniversary of the launch was August 2017. Yeah. -And it's an amazing thing. It's the first object humans have ever sent out that is leaving our solar system. -But that had a multi-pool cushion shot around four planets. -And that, and, and that is stuff it couldn't have done otherwise. We couldn't have had rockets that would've made it fast enough to go through the solar system in a human lifetime, except it used that kick. Because if you, if you just go around a static object, you come out with the same speed as you start with. -It's just symmetric. -And the object is moving, then when you go, and you basically pick up some of the motion. So, you go around the planet. -You mean you're stealing some of its energy. -It's called a gravitational slingshot, so that's great for the solar system. The problem is, there ain't a lot of big objects between us and the nearest star. So. -Okay. How about in, in Star Trek IV: Voyage Home, they did a slingshot around the sun. -Yeah, and they went back in time. -They went back in time. -Yeah, I know. And you know what that is? Science fiction. -Alright. That brings us to cosmic queries! -Hey! Hey! Hey! Alright. Tonight, we take your questions on the physics of interstellar travel. And I got Lawrence Krauss here. So, the two of us, we should be able to knock this one out of the park. Alright Godfrey, what do you have? -Here we go. John McCormick from Keene, New Hampshire... -That is a very good question. Because in fact, most people don't realize it takes just as much energy to slow down as it does to as, as it does to, to speed up. -Yeah, we have, we have in our head a car on a freeway. -And you know, you, you use energy to speed up, and you pull off your accelerator, and the car automatically slows down. -But in space, exactly. In space, it doesn't. There's no friction. -Yeah, tire friction against the road and air friction is slowing the car down, without you even doing anything. It's an issue. Right. Next question. Go. -Christopher Judge from Sarasota, Florida... -Ooh. Ooh. -I think I'd want to travel to whatever planets are orbiting Betelgeuse. -Whoa. Why? Why, why is that? -That's the star the, that's the left shoulder of Orion. -Oh wow. -Loosely translated from uh, Arabic is, "Armpit of the great one." Uh, it's Betelgeuse. Betelgeuse is a super-giant. -Betelgeuse? -Betelgeuse. It's a real star. -Yeah, it's huge. -But it's huge but why would you want to go to such a big star? -Because, because I would want to go in a planet, I want to watch the thing collapse and then explode as a supernova. And. -If I. And I would do that and die doing it. -But it would be what a way to go. -What a way to go. -I just want to be close up eyewitness to one of the greatest detonations the universe has ever known, a supernova. -In the armpit of Orion. -Yes. Alright. -That's it! That's all we had. -Coming up, we imagine the life of a space pilgrim on a journey to another star, on StarTalk. We're talking about the science of sending humans on a journey to another star. And we got physicist, friend and colleague, space enthusiast, Lawrence Krauss. And he's here to help us assess the physics challenges, but we needed even more help if we're going to send pilgrims to space. And joining us now to assess the biological challenges is biomedical engineer, Ronke Olabisi! Welcome! -Hey! -Welcome. You're assistant professor at Rutgers University, and you got your own biomedical engineering lab. -Yes, I do. -This is a beautiful thing. And you work with Mae Jemison, on her 100 Year Starship. Thinking about how to send humans to another star, and what it would take to have them survive such a trip. So, she and I discussed some of these challenges on an interstellar journey, let's check out the clip. -Some people say, "Take humans out of it." But no. Leave humans in because that pushes the platform. Imagine what you have to do with sustainability. Right? Because, if you get to going fast enough, that you could get there in 100 years or 50 years, you're not going to slow down to pick stuff up, right? You're going to have to carry everything with you. -There's no filling stations. -No filling station, no grocery stores. -No stop offs. -No Quik Mart. No, nothing. -No, uh-uh. You, you're going to take it with you. -No Whole Foods. -No. What we going to do, no. And once you get there, you're probably not coming back. So, everything you take has to be sustainable, which means we have to understand things like the micro-biome, in the soil, which is what fixes nitrogen and other things for plants to grow. Because we're going to have to grow our own food. We're not going to be able to uh, you know, store enough food. You can't freeze dry and all that kind of stuff. You're going to have to have a whole bunch of people onboard. -You can't bring silos on your trip. -And, and it doesn't make any sense, right? So, you're going to have to, because every silo you bring, every extra packet you bring, is more energy that's needed in order to get you to .1 light speed. Right? -So, so think about it. What does that mean? We, it means we have to make tremendous strides in understanding sustainability, right? Clothing. You can, right now when we go up into space, people carry the clothing with you. We had a textile and a design professor who came in and said, "How many people in this plenary session can sew? We got a few hands up. He said, "The rest of you all can't go. Because we're going to have to make our own clothes." Everything that we do starts to change. Think. -Space pilgrims. -What about them? -Pilgrims had to do everything themselves. -But, but everybody, I mean our history, we had this wonderful planet that supplies us with so many things. So now we're going to have to understand enough about it to be able to recreate some of that. -Ronke, do you think you would make a good space pilgrim? -Absolutely. Uh. On a scale of one to ten, eleven. -Whoa! -Wow. Whoa, whoa, whoa, whoa. -I think because she's right. Right so the, the pilgrims had to do everything, right? Um. I have advanced degrees in aeronautical engineering, mechanical engineering, biomedical engineering. I'm like. -Yeah, but can you sew? That's apparently the. -I mean, sort of. Like I'm, I'm like a dreadlock MacGyver. -Oh, where's the duct tape? Right, right. So, so what, what specifically does your research focus on? -So, I do tissue engineering. Uh, and regenerative medicine. And those two fields are interchangeable. But um, some people... -Tissue engineering, you mean biological tissue. -Mm-hm. Yes. -And so, the goal of tissue engineering is to make organ donations a thing of the past. So, instead of all these people dying on waiting lists, instead I scrape some cells from your skin, mix it up with a scaffold and the right combination of growth factors and grow you a new heart, or liver, or lung, or whatever you need. -The way she said that, she like, eye of newt, wing of bat. -I'll, I'll just scrape up cells. -Put some salt in there. -And out comes your heart. -You're going to get a new leg, don't worry. -And it beats in my hand. -Wait, wait. Almost ready. Little more sugar. -Okay. So, so Lawrence, whatever it is or is not possible, surely this research will have benefit. -Of course the research will be useful here on Earth. I think it will be much more useful here on Earth than it will in space. I think you actually have to be bolder. And I think you should, you don't want to print organs, I think you want to print people. The whole point I would argue of getting people to distant stars is, is, is to get, putting them on the journey is not the important part. In this case, the journey isn't the, is the big deal, it's just boring. Why, why... -Oh wait. So, so you want to send the ship without people, then print them when you get there. -Yeah. That's much better because then you don't need them on the way, and you don't have to keep them alive. That's why I say it's not; they're not being bold enough. Why, if you want people there, why, but why, why bring them all the way? -So, you, you, you encode their genetic identity in some way. -You could code, yeah, you could do many different things. -And then print. -Print them. And you can have a little computer teach them, you can, you can imagine all these things. -Okay. So, you know how you were saying it's impossible for us to get there, as a physicist? -I didn't say it was impossible, impractical. -You were saying it's, it's very, very, very, very, very unlikely. -That's the difference. -I'm telling you it's very, very, very unlikely we're going to print people up, as a biomedical engineer. -He can't shake the, he can't shake the. -He can't shake the theories man. the hypothesis. -I think you're, but you're missing the point. -For instance, if we had never sent people to the moon. We wouldn't have developed the water filters that we did that benefit us now. We wouldn't have developed. We have insoles because they needed insoles on the moon. We have sunglasses, we have GPS satellite communications because they needed to communicate with people. So, when you, when you include humans. -Okay, so we agree. We, oh, you're saying the human part of that brings a whole other dimension of discovery and invention. -Yes. Exactly. -And I don't think, none of us, none of us are denying that. -Yeah. I think that's true. And, but that's true in the solar system, too. I think it's a big challenge. -Okay. So, what it seems to me, is that you each have ambitions of going far. You don't want to send people. But if. -I want to get them there. But when you accomplish your technologies to do so. -It doesn't seem to me it's going to make much of a difference of how we live life on, here on Earth. Whereas if she accomplishes what she wants, we could all be living differently. Because she's printing our heart, and a limb, and our neural systems. -Well. -And all you have is a post, postage stamp. -Hold on. You don't think it's going to. -With, with laser light up its ass going the tenth of speed of light. -You don't think it's going to affect life on Earth if you can make people? Uh, from scratch? You don't think that's going to affect life on Earth? -That's your plan. -No, that's, I mean that's. -No, that's not, that's not in your, that's not in your Starshot plan. -No, no, no, not on the Starshot run. -I'm saying that if you want to make that challenge, that's the extreme challenge. Well coming up, former astronaut, Mae Jemison explains why space is for everyone, when StarTalk returns. We are featuring my interview with former astronaut, Mae Jemison, who is now leading a bold project to figure out how to send humans beyond our solar system. I asked her, why humans haven't reached a planet in our own solar system yet? MAE: I was really irritated when I joined the astronaut program. Because, I figured when I was a little girl, by the time I got old enough to be an astronaut, I'd be hanging out at least on Mars. -At least. -At, at least on Mars, and I wouldn't have had to be a crew member, I could just be a scientist working on stuff. -Mmm. -And so, the reason we're not on Mars now has nothing to do, from my perspective, with the engineering. It has more to do with the public commitment. And that's the reason why we have to bring all those pieces and so many different people in, and include them in things. It was a lack of public commitment as people didn't see why it made a difference. I was a little girl; I had grown up on the south side of Chicago. I'm running around telling grown folks why it was important for us to be in space. Uh, no, I'm serious. I was running around telling grown people. "And you see, we can do this on the moon, and we do that and stuff." But so many folks were left out. When you look at the space program, there were lots of people involved, but publicly when you viewed it, a lot of people felt like they didn't belong. And in fact, I'll have to get you a T-shirt that says, "Space isn't just for rocket scientists and billionaires." -Mmmm. -That's our other motto. -That's the job we have to do. That's how you get public commitment, when folks understand that this is not just for this peculiar group of folks. Right? It's much deeper than that. -Nice. -So, Lawrence, do you, do you agree with her? Or you think we, we should have been much farther along? -I think that's one area where I do agree. I think we could have been a lot further along in a lot of ways. But in the exploration of space, again, we could have done a lot of non-human exploration. But even in the human exploration, I think the Space Shuttle program got us caught up in doing things that really NASA as, as we're now learning, doesn't have to be the ones to do. I think in near Earth orbits, we've now learned that private industry, like SpaceX and other groups can, can do that effectively. What NASA should be concentrating on are the things that private enterprise can't do. The things that don't have a business model. And, and I, and therefore, I think it would have been, everyone would have been a lot more excited, and I disagree with her about the fact that kids wouldn't be excited about. If, if people were landing on the moon today, kids would be excited about it, they really would, there's no doubt it. -Oh, yeah. -And so, I do think we, that, that that twenty-year effort, if you wish, of, of focusing on near Earth orbit, which may have been necessary at some level to get industry involved, uh, held us back. -Ronke, uh, can you help me understand what she fully means by, "Space is not just for rocket scientists and billionaires?" -So, for instance, there is this thing called the overview effect that a lot of astronauts have described when they go into space. And it's this transcendental feeling of seeing the Earth from space. You know, everybody describes how, you know, all the wars and all the conflicts that we have seem petty after that. And if you realize that simply traveling the planet, just going backpacking through Europe changes your perspective, right? If space travel became as affordable as say a first-class ticket, and everybody had the overview effect, what would the world look like, if people were like, "Why are we fighting?" -Just send Congress a first, a first class. -One way, one way. -One way. -For me, that's the, that's the most important reason, for me. -Yeah. But I think it's, the, but the problem is as you just said, it, it. That in some ways, it's always at least, if you're pushing the edge of the envelope, it's never going to be for the average, but you need people who are going to survive. As you said, you got the skills, most, most people don't have those skills. And I think you're always going to send a subset of people who are either more capable of surviving, or, or working that environment, or, you know, a first-class ticket isn't for everyone, either. -So, Ronke, where will the 100 Year Spaceship be forty years from now? And I choose forty years because this is the 40th anniversary of Voyager, the Voyager One. It's been going for forty years, it's left the solar system. So that's kind of a benchmark sort of timeframe. So, add 40 years now, where is 100 Year Starship? -So, that's a really hard question because. You know, come in. -No, it's an easy question, you mean the answer's hard. -Yes. It's, it's an easy question, with a hard. So. What I would like to see, I would like to see that we've managed to, in some way, put a mammal that doesn't hibernate into a hibernating state. And that can help us incrementally get there. That can help people who need medical assistance who can't make it unless they're put in hibernation. There are so many applications on Earth that that would help as well. I would envision seeing data from your nano-craft coming back. Uh. I would envision that actually more people... here had the overview effect and that it changed our world for the better. -But the best part, and maybe the thing that Mae was hitting and you're hitting is if you're a scientist, the real answer to that question, what's going to be done, happen in forty years, is I don't have the slightest idea, because that's the best part about science, is the discoveries that you can't anticipate. -That's why we do it. -Because it's the, it's the surprises. And that's why it's worth keeping going. -Godfrey, where do you want to be in forty years? -Dead? I don't know. What? -You ain't that old. -No, wait. You know what? In forty, forty years, I would, I would love to be part of this technology, you know. I would. -Maybe on your little gram. -Keep working out, shedding those pounds. -Your gram ship, just like, you know what I mean? I don't know. But I mean I would love to be part of. Hopefully, there will be like what she's doing, we can get younger. -Would you go? Would you go? -That would be cool, get younger and then travel again, that would be awesome you know. -Oh, I see. Just, just, just not die. Just never die. -Just not die. Just not die. -I hope you're working on that. -Yeah, if you're printing up organs, you don't have to die. -But, you know. Would you, would you want to go on a one-way mission? -But would he what? -Would he, would he, would you want to go on a one-way mission with you? -I want, I want to come back. -No, I'm coming back to Earth. -It depends how old I am. -I didn't finish Game of Thrones. -It depends how old you are. -Yeah. If, if. -I didn't finish it. -If I'm ninety years old. -Then a one-way mission from. -Definitely. -Yeah, yeah. -No, no. No, I'll tell you why. Because if I'm 90 years old and you're on a one-way mission, and then you die in space and then you didn't learn that they figured out a way to live to 200, just saying on Earth. So, no. So, I do a lot of reading of the history of science in texts written in the day that people were making discoveries. And there is no end of people saying, asserting what is not possible in the future. And then just have them made look foolish by clever engineers, brilliant scientists born after them, who are thinking in different ways. So, what I do know is, if you live in a culture where a subset of your fellow citizens are thinking about 100 years from now. Thinking about traveling where no one has traveled before, we could all run behind them and say, "No, that will never happen, you could do that, I suppose." Does that mean you want to stop them from thinking that way? I, I don't think so. Whether or not they succeed, some stuff is going to get invented out of that. There'll be patents. There'll be insights, there'll be discoveries. There'll be new vistas created by it, even if it's not the intended destination, you'll be standing in a new place. And you might be in a position to ask a very different question than you even imagined possible. Because real advance in our civilization, as Lawrence said, comes from places you can't even predict. There are discoveries that come in from the side, from below, from above, and you never saw it coming. And it's those discoveries that make it essentially impossible to predict what we'll be doing 50 years and 100 years from now. So however pessimistic I occasionally am, I will never stand in the way of people dreaming about tomorrow. Because in fact, they may be the only ones whose discoveries will help us assure that we can become better shepherds of our own civilization. And guarantee that tomorrow will not only be different from today, but better. That is a cosmic perspective. This has been StarTalk! Godfrey! Ronke! This has been StarTalk; I've been your host, Neil deGrasse Tyson. As always, I bid you, until next time, to keep looking up. Captioned by Cotter Captioning Services.