How hard is it to keep rocket fuel in space? Which is better, a lunar base on the surface or in orbit? How would a space station look like in a binary planet system? And in Q&A+, could we launch a probe into a black hole? 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. Alright, let's get into the questions. Geohondo, is it problematic to keep rocket fuel in space for extended time? I hear hydrogen escapes no matter what, but I don't know if that's true. Yeah, this is one of the biggest problems with space refueling. So this idea of space refueling, like up until this point, rockets have to carry all of the fuel on board for their entire mission. And when you think about something like, say, New Horizons that launched from the Earth, flew past Jupiter, did a flyby of Pluto, flew past AirCoth, another Kuiper belt object, and still has a little bit of fuel in the tank to probably see another target, it had to carry all of that fuel in all of its stages. And it doesn't even have an ion engine. It had to use a regular old chemical propulsion system to make that journey. Everything else, right, is just you put the fuel on the rocket, you launch it into space, it completes its mission. And even when you go back to the Apollo missions, right, you had Saturn V, you had the three propulsion stages, you had the command module, the landing module, each one of these little modules had its own little fuel tank and its own little rocket to be able to allow it to complete its mission. And one of the big ideas that several of the aerospace companies have been suggesting, and the big company for this actually has been Lockheed Martin back in the late 90s, early 2000s, they were starting to pitch this idea of fuel depots in space. And the idea is really elegant, right, that if you are able to launch your spacecraft into space, it doesn't have to be that big if you aren't going to be carrying very much of your fuel. And if you're going to be carrying people, it can be a very safe rocket. Something that is designed 100 percent to just carry humans to space safely. And then you can refuel at one of these fuel depots. Now, today, you're going to have to launch rockets that will refuel the fuel depot, which will be a different thing. But they can be sort of more cargo spacecraft. They don't have to be as safe as the ones that are for carrying people. And then your say your human mission to the moon or to Mars or whatever goes into space, goes to this field depot, replenishes this fuel, and then it can carry on its entire mission. And you've got all of that capacity for fuel, the fuel capacity that you use to just get into orbit. You can now fill it all back up again and pretty much go anywhere in the solar system with that fuel. And then, of course, the other mission that you've probably heard a lot about is the SpaceX Starship, the human landing system. But just like in general, SpaceX has been thinking about how you can do orbital refueling. And a lot of their long term ideas really depend on orbital refueling. If you want to send humans to Mars, you launch this thing, it uses a ball of fuel to get into orbit and then meets with the field depot, replenishes its fuel, or you have other Starships filled with fuel that meet up with it, replenish its fuel, you fill its fuel tanks. And now you've got a spaceship that is completely filled with fuel and you can easily make your journey to Mars. So the idea is very elegant. And in the far future, once we have, say, mining water off of the surface of the moon or once we have asteroid mining, then the fuel depot makes a ton of sense, because then you're not having to bring up that fuel from the surface of the Earth. You're bringing that fuel from some other location out in space, where you haven't had to get out of Earth's awful gravity well. The idea makes a ton of sense. And it is absolutely inevitably our future. But the challenge is that cryogenic propellant systems like liquid hydrogen, liquid oxygen, or even liquid methane, these are Trixie and can escape. And that you have there's a lot of other technical challenges you have to deal with in, you know, when you're in in weightlessness, the fuel is floating around inside your tank. And so you have to use pressure to be able to kind of push the fuel in a certain direction. There's various solutions to be able to solve this problem. But as you said in your question, it's hydrogen that is the worst. And that is the, you know, probably the most useful propellant component that you're going to mine water, you're going to break it into hydrogen and oxygen. You're going to store the hydrogen under a compressed liquid form in your fuel depot. But the atoms of hydrogen are so small, molecules, if it's H2, but hydrogen is so small that it's able to get out of almost every kind of containment. And when you're out in space, your fuel depot is going to be going through cycles where it's going to be getting heated and cooled. If it's in orbit around the earth, and it's going to the shadow of the earth. And so all of the metal is going to be expanding and contracting. You've got to be able to come up with a fuel storage system that can handle that. So people are working on solutions both for the storage of cryogenic fuel, as well as transferring cryogenic fuel. There have been test experiments installed on the International Space Station. The Chinese, just recently, with the last couple of months, tested out a refueling spacecraft that would try to deliver fuel. In this case, it just delivered fuel to itself. But, you know, in the future, you'll see that we have seen servicing spacecraft that have been launched and have docked with target spacecraft. But right now, the only really official plan is what SpaceX is going to be doing and not even a fuel depot. So they're going to be launching the human landing system into orbit, and then they're going to launch other starships that are going to have to dock with the human landing system and transfer it to it. And then it's going to travel out to the moon and bring the astronauts to and from the surface of the moon. So this is the dream for long term reusability space exploration. But there are a lot of technical challenges. And I always sort of use this as one example of why space exploration is going to be so hard and that there are all these little tricky things that we have to work out. How do the astronauts eat? How do they drink? How do they breathe? How do they go to the bathroom? What do we do? We waste. How do we deal with the medical issues? Long term space exploration is going to be very challenging. And yet if we can overcome this and bring out the best of us, so let's do it. It's time to shatter all the new five dollar patrons and above Dave Bundy, David Boris, Darryl Griffiths, Sigurd, Chris Richardson, Astrophysics, Mark Shores, Ashok, Flight Path 35 and Michael Prude. Join the club at Patreon or ComSush Universe today. Through D2. Would a lunar base or space base be more effective for reducing the cost of space exploration? It really just depends on our level of infrastructure. So when you think about a space base, like say we've got a space station that's orbiting around the Earth and we have spaceships coming and going from the space station. And then the space station has refueling capability and then people go off into space. And instead of putting it in low Earth orbit, why don't we put it at the Earth, Moon, L1 Lagrange point, which is this balancing point, gravitationally between the Earth and the Moon. And so once you're at that point, then you can head off into the solar system and you don't have to no longer have to escape a lot of the Earth and the Moon's gravity. Or if you go to the L2 point, which is on the far side of the Moon, now you're like right at the very edge of being captured by the Earth and the Moon and takes very little propellant for you to then head off into space. So if you put your station down on the surface of the Moon, then if you want to leave the Moon, you're still going to have to fight the Moon's gravity before you head off into space. So that's the downside. But the upside is you have access to solid ground stuff that you can mine off of the surface of the Moon. You had access to the permanently shadowed craters on the Moon that you can supply water and so on. And when you think about 2001, they ran their mission off of the surface of the Moon, which was pretty cool. And they went off to, was it Europa? Where do they go? Jupiter? Yeah. From there. And so you could imagine one possible future is that we have a base on the Moon that is people are able to then launch off the Moon. You have to pay to get out of the gravity well of the Moon, but is less than trying to get off the gravity well of the Earth. And the other possibility is that we will have this base out of the L2 Lagrange point and that that will be the waypoint, the true gateway to the rest of the solar system. And then eventually both will be there. Both will make a ton of sense and we will maintain them and use them as ways to get out to the rest of the solar system. That they will be fuel depots, they will be hotels, there will be logistics hubs, communications hubs, and they will provide in general stores that will provide people with they need before they head off into deep space. Visto Tutti, are we capable of launching Voyager-class probes out of our solar system today? For sure. You know, the most recent spacecraft that was sent on an escape trajectory was New Horizons. And New Horizons did a flyby of Jupiter, but it didn't do a flyby of Saturn or Uranus or Neptune. And it is on an escape velocity. It's not going as fast as the Voyagers were. And so it's never going to catch up. It's moving in a different direction for the Voyagers, but it will never catch up in distance to the Voyagers. They are always moving a little bit faster than New Horizons. But still, we have the capability to send an interstellar mission without having this grand alignment of the planets. But that was amazing. You know, when you think about the fact that you could send one mission to do the grand tour to go past Jupiter, Saturn, Uranus, Neptune and give us close up images of all of those for the first time in human history that you've got to see Uranus and Neptune up close. Absolutely amazing. Now we have to send missions to those worlds on their own because they're not lined up. You can't do gravitational assist to line them up again. We won't be able to do that again for 150 years or something like that. So we have to do this the hard way. But NASA is working on a mission called the interstellar mission. And so this would be to send a mission rapidly out into interstellar space, out beyond, say, the Kuiper Belt, out into. A region where you're really experiencing the combined solar winds from all of the other stars that are out there. You know, the kinds of observations that the voyagers are making as they just run out of power with instruments that were never really designed to do this job. What if you could do a much better understanding of how the sun interacts with the rest of the stars in the Milky Way? And so we can see future missions going on escape trajectories at some point in the coming years. And of course, if you want to go to the solar gravitational lens, that is 550 astronomical units from the sun. If you want to do that in a human lifetime, you got to go fast, which means you're going to be on an escape trajectory. So any mission sent to the solar gravitational lens will be on escape trajectories. In fact, people are still proposing that we could do missions to do flybys of Omuomua, Borisov, three Atlas, even. But, you know, if you took a Falcon heavy, stripped down, did a bunch of gravitational assists, you could catch up with Omuomua in 50 years. So we still have the ability to to provide close up images of even some of the interstellar objects that have come through the solar system if we have the will, which we don't. The light runner, if we lived on a binary planet system and built a large space station at the Berry Center, would it be zero G in the middle of it? Yeah. Yeah. So I'll give you sort of an analogy, which is imagine going inside the earth. So if you went down to the middle of the earth, you would be weightless because you would be pulled at equally in all directions from the mass of the earth. You would be floating around. In fact, if we dug a hole through the earth all the way through up to the other side and you jumped into the hole and there was like no friction and there was no air and you fell down, you would accelerate as you are going towards the center of the earth. And then you would experience this weightlessness as you got closer and closer to the center of the earth. And then your your momentum would carry you all the way up the other side to, you know, your eyes would peek out of the other end of the hole. Then you would fall back down and just oscillate back and forth. And so if you had a binary planet system, an ideal binary planet system, which is impossible, which we'll get into in a second. You had two planets orbiting around each other. Then if you were positioned right in the middle of those two planets orbiting around each other, you would experience weightlessness. And the the space station would require the minimum amount of fuel to be able to maintain that position. And the you sort of imagine it kind of it's like a Lagrange point that you are at the top of this gravitationally unstable point requires very little fuel to remain at the top of that point. But once you start to drift away, then you can imagine such as if closer to one of the planets or the other, you start to accelerate towards that planet. And then things go haywire. But that is the sort of idealized platonic version of that. But the reality, of course, is that the planets aren't going to be the same mass. You're going to have the influence of the star, the influence of other planets that you are going to be perturbed just by all of these gravitational interaction. That it doesn't take much for oscillations to set in and for you to start to to end up in a chaotic orbit between the very center of these two objects. And you will eventually crash into one or be kicked out of orbit or whatever. And it's that same thought process you should use to imagine the unstable Lagrange points. When you think about L one, two and three, which are lined up between the star and the planet, that those three points are gravitationally unstable. You can hover in that region with a minimum amount of fuel. But once you start to drift away from that idealized position, then you will sort of fall out of that gravitational well. And there is no perfect place you can be because there's always the interaction between the other bodies in the solar system. Johnny Appleseed, what could we learn from launching a probe into a black hole? Well, the problem with a black hole is that nothing can get out of the black hole. No information. You know, the probe is going to be trying to sending home information about going into the black hole. And that information is going to be trapped inside the black hole because you have to exceed the speed of light if you want to be able to send a message out of the black hole. And you can't go faster than the speed of light. And so there's no way to communicate information from inside the event horizon to outside. And it might be that there is just never any way that we can understand what's happening inside the event horizon, because it's not just light, gravitational waves, neutrinos. Nothing can get out of the black hole. But it would still be an absolutely worthwhile mission to send. I mean, we would get a ton of information about the environment around the black hole before the probe crossed the event horizon and the signal stopped. And we would not be able to find out what happened to it after that. All right, those were all the questions that we had this episode. Thank you, everyone, who asked your questions into YouTube comments. Everybody who joined me for the live show, we record that every Monday at 5 p.m. Pacific time. So if you want to join us for the next live show, and then it's going to be a break for a couple of weeks. So definitely come and join us. I'm going to respond to a comment about why astronomers are trying to disprove God. But first, I'd like to thank our patrons. Thanks to Abe Kingston, Andrea Pagretti, Brian Bodie, Karen Chukhaka, and Commander Bialock, Darkfinger, David Guilton and David Matz, Eric Lindstrom, Evan Dot Probe, James Clark, Janice Smith, Jeremy Madden, Jim Burke, Jordan Young, Josh Holtz, Marcel Suntz, Michael Purcell, Nord Space, onestepheranimals.org. Please follow me if you had VBrick6994, Ryn Kitey, Richard Williams, Sean Sargent, Stephen Finlaymanly, Team 49, Telsoaps Canada, Vlad Chippell, and Wolfgang Klotz, and Zeldemore Galactic competitor, who support us at the master of the universe level and all our patrons. All your support means the universe to us. So I got this question. I get this kind of question quite a bit. So I'm going to sort of interpret it a little more wider than I think was asked. General Cirque. So they want to waste billions more on a new telescope to try and disprove God. James Webb shattered the Big Bang Theory. Maybe we should spend this money on, I don't know, beating China to the moon or maybe building new nuclear reactors for clean, cheap energy. I mean, almost anything would be better than another space telescope at this point. So I get this question quite a bit. And I think there's sort of like two versions of this question. So I'm going to tackle the why are astronomers trying to disprove God part first and then I'll tackle the why are they spending money on stupid research part second? So first, why are astronomers trying to disprove God? They're not. They're they don't they're not trying to prove or disprove God. All astronomers are doing is using their telescope, looking out into space and describing and trying to understand what they see. And there is this natural limit to how far astronomers can see, which is about three hundred and forty thousand years after the Big Bang. And this idea that astronomers are trying to disprove God does not come from astronomers. It does not come from scientists. You ask a scientist that even like an evolutionary biologist, why are you trying to disprove God? They're like, what? Just an astronomer. Why are you trying to disprove God? They don't they have no idea what you're talking about. This is a talking point from people who are religious because the evidence that astronomers and scientists are discovering about the universe does not necessarily line up with some readings of religious texts. That should not be surprising, especially when often religious texts will disagree with each other about their creation myths or whatever. And obviously, if you have sort of locked down your worldview to a very specific interpretation of a book that was written several thousand years ago before modern technology, you know, if you were a believer of Greek myths and you believed that Zeus was up on top of his mountain hurling lightning bolts down. And now we understand how lightning bolts work. Then you might see this as an assault on your on your proof of Zeus, right? Your belief in Zeus. If we have a perfectly natural explanation for where lightning bolts come from that don't require Zeus, then if you were an adherent of Zeus, you're going to feel like this is an attack, but it is not an attack. And that there are plenty of people out there, plenty of religious people who will who are scientists and they don't feel any collision between the discoveries they're making about the universe and their personal beliefs about the supernatural. They are perfectly complementary to them. And that this says more about a person who is unwilling to be sort of open minded about what's out there in the universe and sort of be flexible to change their worldview when new evidence and new information comes in. So no one's trying to disprove anything. They're just trying to examine nature and just tell you what they find. And if you don't like what they find, that's on you. It's not on them. But this question that we always get as well is like, why are people spending money on James Webb or another space telescope or whatever when they could be doing engineering, developing fusion reactors, being China to the moon, whatever. And, you know, the whole point of research, of basic research, of just investigating nature is that we don't know. We are just curious. We don't know where it's going to lead. Now, we live in this modern society where we have all of the technology with the Internet. We have lasers. We have we have satellites. We have like I could just go on for a thousand years describing all of the technologies, the transistors, microchips, radio waves, all of this. Right. And these all came from somebody just interrogating nature. Someone just going out and going out. Wonder how this works. I wonder what is the underlying mechanisms of how this part of the world, the universe works. And then later on, someone says, I bet we could do something with this. We could do some kind of engineering solution or whatever. And it has always been that case and it will always be that case. And so the things that people are investigating right now, some of them are going to pan out. Some of them will be dead ends and some of them will completely revolutionize what the future of humanity looks like. And we don't know which ones it's going to be. And so we have to just let the process continue. When I think about how money is being spent, we're looking at tens of billions of dollars being spent to arm and kill people in various wars and conflicts around the world. Let's decrease that and focus instead on getting along, trading and investigating the world as we find it around ourselves. All right, we'll see you next time.
