How Bad Is a Rocket Launch for the Environment? | Q&A 475

How much pollution does a rocket launch produce? How does a gravitational assist really work? What new tech is being developed for space food? And in Q&A Plus, how will human bodies adapt to low gravity? All this and more in this question show. It's time for the question show. Your questions, my answers, as always, wherever you are across my channel. If a question pops in your brain, just write it down. I'll gather them up and I will answer them here. I'm still in this echoey room. Alright, let's get into the questions. All right. This question comes from Patreon, Brian Rodriguez. How polluting is a rocket launch like Starship and what will probably be improved in the future? Will we still need a lot of power to reach escape velocity? You know, a rocket like Starship is a giant skyscraper-sized, really tank of fuel, and it's filled with liquid methane and liquid oxygen. And when you mix those two together, ignite them, you get carbon dioxide as one of the outgassing. So it's water vapor, and carbon dioxide is a greenhouse gas, and so it's water vapor. But you're definitely adding a big chunk of of greenhouse gas to the atmosphere, but. So relatively speaking to the amount of greenhouse gases that are added to the atmosphere every day, it is a drop in the bucket, right? There are tens of thousands of flights going across the entire planet every day. Each one of them is dumping almost as much carbon dioxide and so on as one rocket launch. So the actual amount of carbon dioxide released from a rocket is a drop But it's not nothing, right? And the other question is, is what the exhaust of rockets do to higher atmosphere? We know that rockets, you know, the lower atmosphere, they're contributing carbon dioxide, but but they can also be putting some of these. gas is up into a place where our regular atmospheric effects just can't reach. And we still don't know. I mean, so one possibility is that this can actually increase sort of the darkening of the atmosphere and other possibilities that this can can cause damage to the ozone layer. So this is still a part of significant study. And then the other issue is that when these rockets come back through the atmosphere and they burn up, they're delivering metal particles. high up in the atmosphere and same thing. So these can potentially damage the ozone layer, these can potentially sort of offset global warming, they can actually cause global darkening. So, so we just don't know. And like, you know, before you're like, Oh, we should just do that. Well, you know, unintended consequences are a thing. So the amount of energy required to get you into orbit just comes down to the rocket equation, that there's no way around it, that if you have a certain amount of mass, you want to put that mass into orbital velocity. 28,000 kilometers per hour orbiting around the earth, you need a certain amount of energy. You can like measure it from first principles. You know the speed you want to go, you know the gravity of the earth. You can calculate the amount of calories required, joules of energy required to get your mass moving at that velocity. And then any rocket that's going to be built is going to have to essentially consume that much energy. So there's kind of never going to be a free lunch way for us to be able to really knock down the amount of energy that's required to get to orbit. The hopefully future sustainable way that we do this is that we have a space-based manufacturing system. So instead of launching an entire rocket and carrying computers and booms and antennae and robotic arms and so on, all we do is just carry the people. Everything else is already up there in space, gathered from asteroids, harvested from the surface of the moon. It never has to inflict its pollution on planet Earth. Kyle Miller, were you surprised at how fast the Rubin Observatory had already discovered its first dwarf planet candidate in our solar system? No, I'm not surprised. I'm surprised. You know, it is a quantum leap in ability to observe. The entire sky, it is so fast and it is able to resolve down to such a faint magnitude that it discovering other objects out there in the solar system was a given. I mean, they were predicting, forget the number, like 75% or more of all of the asteroid discoveries will be coming from Vera Rubin. That is just an absolute powerhouse in finding things here in the solar system. And we've seen this pattern before. So when the very large telescope came online, which is the big observatory down in Chile, it's four eight meter telescopes that can act as a interferometer. When those came online, astronomers found a bunch of dwarf planets. And that was because the new most powerful telescope had arrived. And now By scanning the plane of the ecliptic, astronomers were able to turn up all of these additional planets. That's how we got Eris from Mike Brown. And Mike Brown found a bunch of others. So we got Haumea, we got Makemake, we got Quaoar, and Sedna? Anyway, and so whenever a new telescope comes online that is significantly more powerful than everything that came before it, then you're going to find a bunch of new stuff. And so, no, it's absolutely not surprising that it found... Dwarf planet. And I wouldn't be surprised if there's a bunch more that are already known that just people are working through to the data. I mean, this has been this kind of running. Not joke, a meme, whatever. Like, where are all the Vera Rubin discoveries? And now they're coming. We got the new dwarf planet, and we reported on another interesting discovery this week where astronomers found the Trojan asteroids for Neptune. And so NASA's Lucy mission is going to the Trojan region for Jupiter. We know that there are Trojans around Saturn. We know that there are Trojans around Uranus, but Trojan asteroids had never been seen around Neptune until now. And so researchers went through Vera Rubin data and they found these little dots that were in the right position to be trapped in the L4, L5 points with Neptune. And so now Neptune's Trojans, like that's a big story. We got two of them last week, new dwarf planet, new Trojans. And so. So the, the astronomers are catching up with all of, all of these data with the pipeline. And I think we're going to see a lot more discoveries. Like I, I suspect we'll have as many stories mentioning Vera Rubin as we do with James Webb, just because there's so much in there. It's time to shout out all the new $5 patrons at above, Ron Culmer, Stovepipe, Ronak, Girolamo Castaldo, David Woodland, Santa Mozzarella, Bob Laskiewicz, Derek Pilkington, Donalo Flynn, and G. Sean Gorlay. Join the club at patreon.com slash universe today. In Dogenmore, how does a gravitational assist work? From a planet, would it have to be in the direction of its orbit? What about from the sun? Don't you just lose speed coming out of the gravity well at the same time? Right. Okay. So this is a puzzler. And I think a lot of people have had this exact question. When you kind of think through it, you're like, wait a minute, how does gravitational assist work even? So you've got a planet, right? Like Jupiter. And you've got a spacecraft that's approaching Jupiter. It's falling into Jupiter's gravity well. And you're picking up speed. This all makes sense. No problem. But then you go past Jupiter and now you're falling out of Jupiter's gravity. Well, it is pulling you back. It is slowing you down. And so you would expect that the speed that you go in. To, you know, begin falling into Jupiter is exactly the speed that you have when you're leaving Jupiter again. And if there was no other objects in the universe, that is exactly what would happen. You know, you can imagine you dug a hole through the earth, directly through the center of the earth, and you jumped in the hole. And if there's no air, you know, there's no air resistance, no friction, you would fall all the way down through the earth, you go faster and faster and faster, you get through the middle of the earth, and then you would go the other way and you'd be slowing down, slowing down, slowing down, and you would just land on the other side of the earth. And then if you didn't like hang on, then you would fall back into the earth. You'd just be going back and forth inside the earth. So that's the same thing that's happening to you from the gravitational assist. And that absolutely is part of the process, right? You are approaching one of these giant planets. You're getting closer and closer. You're speeding up. And then as you move away from them, they're pulling back on you. You're You're slowing down. So where do you get the boost from? Well, that comes from the orbit. The planet going around the sun. And so, you know, think about how we are here closer to the sun. We're orbiting around with the earth at 30 kilometers per second. And we aim ourselves so that we get close enough that Jupiter's gravity can start to pull on our spacecraft and pull it up to Jupiter's orbit. So the, the thing that you get is not the falling in and out of the gravity. Well, the thing that you get is the getting pulled up to its orbit. And that is something that is, that is the bonus. And so you, um, and there's like other tricks you can do as well about firing your rockets and so on as you get really close to the, to the planet. But essentially you are stealing a tiny little bit of Jupiter's orbital. momentum around the sun. So you pull Jupiter a little bit closer to the sun and Jupiter pulls your spacecraft a ton up to its orbit. And so you can do the opposite, which is that you can actually slow yourself down, go in the opposite direction. And so you are adding a little bit of velocity to Jupiter, which Strangely, it raises its orbit a little bit and slows it down. Um, and. In exchange, you are losing a bit of your velocity as you're falling inward into the solar system. And sort of like the... The idea that I really love of this that's related is people talk about how life on Earth is only going to survive for the next, say, half billion to a billion years because the sun is heating up. Well, if you could move the Earth away from the Sun, then you could keep the temperature in perfect balance. And so what you do is you have an asteroid that you're sending in this orbit and goes around Jupiter, steals a little bit of velocity from Jupiter. A little bit of momentum from Jupiter and then falls back into the inner solar system, goes around the earth, gives a little bit of that to the earth, speeds up the earth, causes the earth's orbit to raise a tiny little bit so that it's farther away from the sun. And then you just keep doing that over and over again. And this idea of gravitational assists, I mean, you can do gravitational assists across a bunch of planets in the solar system. You can do gravitational assists with black holes if you can get to them. They're the perfect objects to try and do gravitational assists with. It's a cool idea. And of course, if you've ever played the Kerbal Space Program, you can do these gravitational assists. You can actually do them on your own, which is very cool. HFN Noble, are there any interesting research being conducted on food tech for space? Yes. Oh man, is there ever research being done in food tech for space? This is a gigantic problem. Uh, where you've got like a whole bunch of issues that are all coming together. So, you know, when you've got a mission to the moon, you have to carry all of the food that the astronauts are going to eat. And it's a lot of food, but you know, how much food are an astronaut's going to eat in a week, right? Not a ton or the food on board the international space station. You know, they want their food to be fresh. And they want their food to be nutritious. And the problem is that over time, food becomes less nutritious, and it definitely becomes less fresh, and so you have to rely on canned food. And so this causes morale concerns with the astronauts on board the station, on board your mission. And so the solution is better food. And so on the International Space Station, they actually have a little mini farm where they grow fresh vegetables. They can grow salads. And not very much, but like enough to get like a little bit of an interesting, and they do a ton of experiments, but also they can eat this stuff, which is great. Right. And so then for the really long duration journeys where you're going to say Mars, you know, three years, then you're starting to see a nutrition degradation over time. And so they need to come up with the kinds of foods that can survive and still provide enough nutrients. Three years down the road. The other thing that's really interesting is that astronauts, they're, because of this fluid redistribution, we've talked about this, that they get, you know, a lot of fluids in their head, their sense of taste goes away. And they report that the kind of food that they eat is very bland. And so NASA has a food kitchen and they are working on recipes that the astronauts enjoy eating that gives them the kinds of spices that they want. The Chinese space agency have been doing a lot of this as well. There was a recent story, maybe it was like a year ago, year and a half ago. So on the Chinese space station, they gave them a, was it an air fryer? And they were able to make like barbecued chicken wings on the station, which they loved. And so you can sort of imagine, you know, can you deliver interesting food? Can they grow some of their own food in space? It is a bottomless. Food challenge. If you're on Mars and you're trying to grow your own food locally, it's poop potatoes, but what about protein? Is it crickets? Is it mealworms? How are people on places like Mars going to be able to get enough protein to survive? Is it soybeans? Who knows? So this is something that we just don't know a lot about. Think about the Biosphere 2 experiment where there was this closed environment and these people were sealed up in this big building and were trying to grow enough food to keep themselves alive. And they were running out of food. They weren't able to keep up with what the requirements were. So we don't know very much about how to sustain a closed ecological system. And yet... Some kind of future long-term existence out in space, whether it's a base on the moon, a base on Mars, is going to require us learning more about how to grow food, how to preserve food, how to enhance and enrich food. There's so much work to be done. Did you know you can watch the same video with no ads and get a bonus question over on Patreon completely for free? We call it Q&A Plus. And this week's bonus question, how will the human body adapt to low gravity? I'll put a link down in the show notes. All right, those are the questions that we had in this episode. I'm going to do a follow-up on the recent video that I posted about the AI slop. But first, I'd like to thank our patrons. Thanks to So earlier this week, we released a video where it was actually a portion out of a live stream that I was doing where I was sort of just talking about my experience in watching YouTube and how I'm noticing that a lot of creators are now switching to using some kind of generative AI to write their scripts. And I think it was interesting, the response I got to that video was overwhelming. Clearly a lot of people feel the same issue that I do, but a lot of the responders If the thumbnail looks like AI, if I hear the AI voice, I hear the, you know, then I'm out. But the thing that I'm talking about is more insidious than that, which is that creators, many of which that have had channels for a long time, like a decade. Have switched over to getting the AI to write their script for them and then they're just reading out the script because that is easier and that's the part that I was sort of shocked and surprised and sort of discovered unhappily that this was happening because I was looking at creators that I had enjoyed their videos and then I started to feel suspicious and then I checked on on Pangram so People were wondering if that video was an ad for Pangram. It's not. You know, I'm asking people to disclose. And so if it was a video ad for Pangram, then I would have had to have disclosed it. In fact, YouTube requires that you disclose if your video is an ad or contains sponsored content. So no, this is just like a natural. I have this tool that I found that is helping me figure out what's real and what's not. A lot of people were like, you know, get over it, old man. Old man shouts at the clouds. I'm not concerned about my career. We've got an incredible community of patrons who follow us, who support us every month, who want real human journalism. I'm concerned and grieving as a viewer that I will, I love YouTube. I love watching YouTube videos and I don't like feeling deceived. And that was the feeling that I was having. I was feeling deceived. You know, obviously the person's not going to say I. Thought it would be a lot easier if I just used AI to write the script to this video, right? And, you know, please continue watching my video, even though I put in a fraction of the work. And, you know, they're not really my ideas anymore. That's what I'm feeling sad about. Not worried about my career. I know that until the robots literally crush our bones, there will be a demand for human-created content. Bespoke, organic, just the way Grandpa used to do it. Which is me, I guess, soon. Alright, thanks for watching, and we'll see you next time.