Living In Space, Future Rockets & Dark Matter - Supporter Questions Episode 13

[@didyouknowanime]

Thanks for the shout-out Mr. Manley! It was a pleasure, privilege and honor to work with you. Cheers!

[@RichMiniön-r2m]

Go away weeb

[@MrFaaaaaaaaaaaaaaaaa]

@@RichMiniön-r2m pls delete that. this is a good place on the internet

[@RichMiniön-r2m]

@@MrFaaaaaaaaaaaaaaaaa you are one soft boi, please come out of anime and onto reality

[@thef2pgamer500]

@@RichMiniön-r2m why though why do you have to be "the hard boy" let people be them self and leave dude. don't bother other people, if they want to become a weeb what do you care about them enjoying them self.

[@RichMiniön-r2m]

@@thef2pgamer500 the human race was made to came on REAL woman, not drawings behind a computer screen... come to reality, honour your ancestors, BE A MAN... THERE IS NO PLACE FOR SOFTIES ON OUT PLANET, ONCE THE APOCOLYPSE ARRIVES YOU WILL PERSIH AND WE WILL SURVIVE, but, you can still turn, do it now, while you still have time

[@bbirda1287]

Why we love Scott Manley, "I'm not a particle physicist, but..." proceeds to explain particle physics.

[@SystemBD]

It is actually important to mention that, because, while he might offer a good simplified model... as they say, "the devil's is in the details". You never want someone coming back to you saying "I used what you said, and now an entire city is on fire". Not without them paying you for it, at least.

[@oldmech619]

@@SystemBD Particle physics? That stuff is nuts. All kind of critters. Even things they call a particle Spin which is not spinning. As long as the math works, the bomb blows out.

[@ylette]

I feel like he knows everything.

[@jaakkopontinen]

Whole particle/quantum stuff is nuts. I'll never understand it like I would want to :( I'm a commoner and not that highly educated, there's a lot of basic stuff I'd need to rehearse to make calculations etc.

[@roninkoi]

Planetes is one of my absolute favorites! It really captures the passion some people have for spaceflight

[@NoNameAtAll2]

have you ever watched "space brothers" or "moonlight mile"?

[@roninkoi]

@@NoNameAtAll2 I think I've heard of space brothers, but haven't seen either. Thanks for the suggestion!

[@NoNameAtAll2]

@@roninkoi another one I just remembered that's slightly more into the future (but still has orbital mechanics, weightlessness and magboots(!)) - "Starship Operators"

[@TheZipsp92]

Toy Box DS-12

[@ryanwaege7251]

Agree, it's great!

[@williammodlin2621]

Your comments about the effects of neutron radiation reminded me of the joke we told when I worked in the nuclear power industry many decades ago. The joke is that the purpose of the neutron dosimeter badge is to record what dose you received before you died. We only used them when we entered the containment while the reactor was operating. Black humor, of course. Your videos are a highlight of KZbin. Keep it up, please.

[@ChemEDan]

Assuming that means it normally didn't pick anything up? Would it have been possible to prank a buddy? Like remove a film and expose it to sunlight or something

[@williammodlin2621]

@@ChemEDan Yes, it normally didn’t pick up anything. Neutron badges only respond to neutron radiation which doesn’t occur in nature (with the possible exception of a natural fission reactor, which has been posited). Pranking something like this would be a sure fire way to lose your job.

[@lewismassie]

"I can recommend [Planetes] to people who like anime and space" That's great because I've been trying to remember the name of it for weeks. Gonna watch that once I'm done with Cowboy Bebop

[@Lesesmo]

If you found yourself liking space anime, there's also the Space Brother, and The Vampire Cosmonaut-- these 2 flies real world rockets.

[@tarmaque]

If you end up liking _Planetes_ (you will) then try _Kurau: Phantom Memory._ The animation style is very similar, although it's less scientifically accurate.

[@dyingearth]

I also recommend the manga, which is also fully translated and published in United States.

[@archie4oz]

@@Lesesmo Space Brothers (宇宙兄弟) is like my favorite happy space series.

[@Jon6429]

Don't forget "Moonlight Mile"

[@CantankerousDave]

A little factoid about the anime version of Planetes: In scenes in cafeterias or control rooms where groups of people are in the background, every group's conversation is fully scripted. Every dang one, even if you can't make them out. They're normally just flagged as "walla" and the actors ad-lib indistinct speaky sounds, but nooooope, not here. We eventually decided it wasn't worth the trouble of translating and recording it all. Also, the screenwriter has a habit of writing all of his shows as if they were in feudal Japan, which is why Edel is hiding out at the space station and using it as an "enkiri-dera" (a so-called "divorce temple") so she can divorce her husband without his permission. In 2075. The head of the UN is the emperor, the head of their company is the shogun, and regional directors are daimyo who can kill their peasant employees without repercussion, etc.

[@metachuko]

Regarding the first question, I'd like to see Scott do a video on rotating skyhooks. They might not eliminate the need for chemical launches completely, (and they'd obviously require being put in orbit by rockets,) but it seems like they could really cut down on the amount of propellant needed to reach orbit.

[@Xenos_Zeta]

I really love these hot-take questions series, really interesting and fascinating to think about. Thank you for keeping it up!

[@aBoogivogi]

The fusion rockets make little sense for orbital class vehicles, but it works perfectly well for an in-space ship

[@DavidOfWhitehills]

Ah, too late. That ship is already 20 years ahead and getting further.

[@KA-vs7nl]

Just 20 more years

[@Zacharysharkhazard]

I fully agree; Orbital-class vessels leaving Earth will likely always use chemical engines because of the sheer energy needed that they can produce, I think the only advancements there will be reusability and the efficiency of rocket fuel we use, whereas nuclear thermal/nuclear fusion vessels are great interplanetary transports to cross the vast oceans of space between planets and other celestial bodies, the same way you can’t dock a giant boat on the shore of an island, but take a rowboat from the main ship to the surface

[@isaiahphillip4112]

@@Zacharysharkhazard Chemical rockets like SpaceX's Raptor are already nearing their theoretical limits in efficiency. I think the real advancements will come down to material science. New materials that make lighter more durable rockets. But yeah fundamentally I think the vehicles bringing people to orbit in 100 years, 200 years, and beyond will pretty much look like SpaceX's Starship but made out of new age materials. Several times lighter, several times stronger, self healing, etc.

[@davisdf3064]

Well, unless we go coconuts and decide to throw safety out of the window, and do a Nuclear Salt Water SSTO or something

[@chrismiddleton398]

Dark Matter is the name of _a thing._ We can see it interacting; we can map where it is. Dark Energy, though, I think maybe is just the name of _a question._ Why is the expansion (apparently) increasing?

[@robhaver8704]

It's been said, still a thought as well, that not the expansion is increasing but only everything inside of it is moving away from their point of origin.

[@johnladuke6475]

Remember those people in the late 1800s who thought that there was an aether forming the fabric of space-time? I feel like these questions, once answered, will make our current understanding of the fundamental structures of the universe look as ridiculous as aether. In the future our need for dark matter and dark energy to plug the gaps in the theory will seem foolish in hindsight.

[@chrismiddleton398]

@@johnladuke6475 Disagree regarding dark matter. For why, see OP.

[@FastSloth87]

@@robhaver8704 Things are not simply moving away from each other, they're accelerating.

[@cinquine1]

@@johnladuke6475 There's quite a bit of direct evidence for dark matter, for example the bullet cluster lensing studies. It's not just a "we don't know why the math doesn't work" anymore, we can directly observe the stuff's effects and separate it from luminous matter. There's definitely _something_ there, even if the models also need to be revised that won't change. Dark energy though, yeah that's a complete wildcard.

[@arnoldloudly5423]

I really appreciate the approach you have to all of these subjects.....there is never any bluster in your answers, and the obvious depth of your knowledge never comes across in that weak insulting way that some experts seem to have. But mostly I really enjoy that you are genuinly enjoying yourself, and so obviuously doing what you love. Thank you.

[@Lucius_Chiaraviglio]

By the way, antimatter-matter reaction would generate neutrons: primary due to some stuff getting ejected before it could react completely, and secondary due to extremely high energy radiation knocking neutrons out of surrounding nuclei. Also, when talking about velocity and kinetic energy, it sounded backwards: I think you meant to say that kinetic energy goes with the square of the velocity.

[@nekomakhea9440]

My favorite idea for an alternative to chemical rocket ascent stages is the orbital ring from Isaac Arthur's Upward Bound series. It uses a pair of rings coupled together magnetically, like a maglev train and its track, for active support to keep it in orbit, with tethers hanging down from it to the earth for elevators to ascend. Active support means you can build it with common materials like steel and carbon fiber, rather than needing future-tech such as kilometres-long carbon nanotube cables.

[@HalNordmann]

Please, no actively supported structures.

[@SuLokify]

It looks good on paper but it's an incredibly hard problem. It's like trying to keep a high speed train the size of a planetary circumference running nonstop at thousands of miles per hour, in space. Many many orders of magnitude more difficult than anything we've ever done. Maybe in the far future :)

[@nekomakhea9440]

@@SuLokify So, about as difficult as the other alternatives to chemical rockets, like building a fusion drive, or perfecting carbon nanotube cable production for space elevators

[@joelkeddie9460]

The optical fiber market comment at 11:11 reminds me of the plot of the Artemis book by Andy Weir

[@ilyachaplygin8573]

Space Brothers is also worth watching. It takes place in present and shows a lot of space stuff. And the story is great!

[@alexanderkenway]

Never thought I'd see Scott talk about one of my favorite mangas Planetes (same guy who did Vinland btw)

[@stuartbrown1677]

Thank you Scott In my humble opinion you’re doing better than pretty well; I love it when your dialogue comes up as it’s always succinct and professional ! Merry Christmas to all your family and viewers Kind regards Stuart in Ireland

[@veramae4098]

Thanks for doing "Door Monster". It's how I learned about you! Subscribed.

[@streetwind.]

RE: non-chemical launch systems - wasn't there a company some five, six years ago that wanted to use microwave beamed power? A ground station was supposed to project a microwave beam at the belly of the launch vehicle, where it hit a heat exchanger, and that in turn heated hydrogen to levels similar to a NTR. I forget what they were called, though. Never went anywhere. But hey, if you haven't yet made a video on this concept in your almighty backlog, maybe that's an interesting enough topic for a future video? :)

[@coyotech]

Escape Dynamics

[@Technichian462]

Yep. And the vehicle lifted had the weight of an aluminium pie plate. A very small pie at that. About a 3" pie plate.

[@skylerlehmkuhl135]

I remember this being a thing in the KSP Near Future mod.

[@MysticalDork]

I don't recall if it was a different company, or the same company trying slightly different technologies, but I also remember seeing a demo of a beamed-power launcher using a pulsed IR laser system to create an air plasma for propulsion, rather than microwaves. It was also pretty small-scale, I think the test articles were less than a foot in diameter and reached a few hundred feet of altitude in the video I saw.

[@CheshireNoir]

There was also a proposal in the 80s for laser launch. You freeze a block of water in the bottom of your rocket, then flash heat it to steam with ground based lasers. I think the problem ends up being that you can't get more than a few pulses before you have difficulties shooting through your own exhaust plume. There was a writeup in Jerry Pournelle's "A step further out".

[@markolson4660]

Regarding Rosetta, a big reason for terminating space missions with prejudice is to terminate its budget. As long as the spacecraft is alive it consumes money and, eventually, competing projects needing the same money force an irreversible shutdown. (Planetary protection is also a handy excuse for closing down older probes such as Cassini.)

[@tarmaque]

I'm still mad that they didn't just slow Cassini's orbit into the rings so we could get close-up pictures of the particulates before they ripped it to shreds.

[@null090909]

10:59 Thank you! This is painfully true for manned missions, where the only outcome is getting less bad at manned missions. Automation, on the other hand, has greatly benefited from the space money.

[@LA-MJ]

Expanse doesn't use fusion in the atmosphere. Unless the objective is to "glass the planet". Furthermore most fusion craft are not atmosphere worthy. Except light corvettes, conveniently for the plot no doubt

[@richcaloggero3424]

OK, but you still need shielding for the people actually riding in the ship.

[@noop9k]

@@richcaloggero3424 Neutron radiation is quite vile but it is not true than neutrons are harder to shield from than energetic gamma rays, given enough space. You need to use multiple materials for the best effect though.

[@davidturpin9135]

Then how did they land on and take off from Ilus?

[@SeaDemon25]

@@davidturpin9135 yeah if they dont use fusion how are they landing and taking of using only 1 stage

[@subumohapatra]

Scott your a great communicator and from physics, appreciate your videos alot. Minor correction is warranted here. Neutron need light z material to shield and gamma need high z materials. So technically from mass prospective neutron shield can be light (water/hydrogen) but gamma shield are heavy (lead). Unwanted neutron activation is bad that can generate bad gammas.

[@noop9k]

Yeah, neutron shielding not that hard, just different (bulkier) materials.

[@grn1]

Can't most gamma be blocked by weak electromagnetic fields? I just tried looking it up and got a bunch of BS articles pushing anti-radio pseudo-science/products. Pretty sure Nuclear Fusion reactors use EMF to contain the reactions.

[@martylawson1638]

My two favorite rocket alternative launch concepts are Laser Heat Exchanger concepts, and sub-orbital docking with a roto-vator that's re-boosted electrodynamically. The laser launcher gets you all the benefits of nuclear thermal without the radiation issues. (and might give you a free re-entry heat shield) While the roto-vator is more metal than most sci-fi and just has some boot-strapping and control problems to figure out. Agreed that fusion rockets for earth launch are probably a no-go with Deuterium or Deuterium-Tritium fusion. With Helium 3 or Proton Boron I bet it could be made to work. Both those fuels trade a large increase in confinement difficulty for a dramatic simplification and weight reduction in the rest of the reactor because they produce far fewer neutrons.

[@matteodelgallo1983]

By "roto-vator", do you mean the concept commonly known as a skyhook?

[@martylawson1638]

@@matteodelgallo1983 Basically the same. Though you can make a sky-hook that doesn't rotate. Makes docking with the hook harder and isn't practical in an atmosphere, but still has a lighter cable than a ground attached elevator cable.

[@wesleyashley99]

On the orbital refueling the advantage of using rotation is that thrust is only needed to start and stop the rotation but if you don't use rotation thrust must be maintained the full duration of the fuel transfer. The disadvantage is that as the fuel transfers mass from one vehicle to the other the center of mass moves a lot and rotation automatically centers on center of mass. This is the reason for a counterweight but a counterweight big enough would be very expensive to get to orbit. I hadn't heard of the membrane idea but had thought of using a sealed diaphragm to separate liquid and gas but the problem is that some liquid is always boiling off and would build up gas on the wrong side of the diaphragm.

[@A2nthop]

So nice of Planetes to get a shoutout! It's a great hard sci-fi anime set in the near future about orbital debris! Somehow, it's increasingly relevant today.

[@A2nthop]

@@linyenchin6773 No, different animes. Planetes predates Space Brothers.

[@scubasam4255]

going to be interesting to see the first factory in space, i still picture how fast we can build big shipping container boats feel like we just need the first smelter and the first factory will follow. with everything exploding out from there quickly with the first factory machining the machines needed for other factory stuff etc etc

[@bhaskararaka]

Honestly this is why I don’t pursue aerospace engineering. Sure aerospace engineers are always needed, but you will need adjacent industries to flourish too once Orbit is easier to access

[@oldmech619]

11:51. No, there will never be anyone living in space. Ask Chris Hadfield about the long term exposure ex: eyes. There is also way too much space debris.

[@TheEvilmooseofdoom]

I would think the first true manufacturing will be done on the moon.

[@scubasam4255]

@@oldmech619 would space debris collection work, if say they used big magnetized sheets of metal that are soft enough grade that when punctured they don't create any more extra pieces and just get a hole but slow down the piece of debris that hit it? and yea I don't see people living in space for awhile maybe not ever but I want to see us pumping out massive things into space with robotic factory's someday hopefully

[@oldmech619]

@@scubasam4255 Enough space debris can never be collected to ensure safe long space endurance. Machines can live in space, not humans. Soon, there will be no humans in space. Absolutely no reason for man to be in space. Except to prove we can. And that is very costly.

[@toweri_li]

@12:21 "There's people way up in the arctic circle..." About 30% of Finland's land area is located north of the Arctic Circle. On year 2019, there were 178,522 Finns alone living in Lappland - which is mostly north of the Arctic Circle. So yes. There most definitely are people in the Arctic Circle!

[@gajustempus]

a friend of mine works in both the space industry and majored in metallurgy. Right now there're plans on constructing a foundry in space. Not necessarily because of zero gravity, but due to the fact it's the easiest and cheapest option to manufacture in vacuum. Sure, they've got variants of that on earth as well, but to generate a vacuum as pure and entire as out there, the pumps need to run at least 2-3 days and KEEP running to maintain the real vacuum. That's ENORMOUS amounts of energy required.

[@midship_nc]

And the compressors that are capable of doing so are extremely expensive to operate/maintain.

[@TheEvilmooseofdoom]

A foundry in space? Wow, that's going to introduce a lot of problems. I'd do that on the moon so you could at least use more conventional methods. :)

[@gajustempus]

@@TheEvilmooseofdoom that's the long-term plan. But for short-term and first experiments, that's the best way to do it. Plus, there're also applications for creating new alloys in both vacuum and low to near-zero gravity, as SOME metals wouldn't mix properly on earth (because of their different density. Like oil you try to mix with water. But: No gravity, nothing that pulls both apart, therefore you can keep the metal emulsion mixed until the alloy hardens). Imagine a steel beam made of steel foam for example - it would collapse on earth during creation, but is perfectly stable when it's hardened. Yeah, material experts have some crazy ideas already. All they need is the stuff being sent into orbit so they can start.

[@LuciFeric137]

Youre on a roll, scott. How about the Higgs Antiparticle drive? Production of Higgs antiparticles negate the mass of the ship which will accelerate to lightspeed.

[@daleamon2547]

Scott. We used reciprocating pumps driven by a closed cycle He drive gas for both the LOX and kerosene sides of the Lynx's engine.

[@edrasa9003]

Ed Knudson in Ajijic, mx Scott: Nothing to do with Lagrange Points but, I just finished the Saturn V launch tower, it was a night mare. I got it almost compleatly built and had it colapse when I tried to move it. --Start over, I stripped it down to the lower base plate and leveled everything. From there I built it to the first all grey level, made sure that was level and super glued the entire thing. I then built to the start level of the tower and leveled that, again the super glue act. I then built the tower in sections of four levels and went through the same drill. It is solid as a rock and perfectly plum. I also used needle files to loosen up the fit on many parts so the moved freely during construction. Made life much easier. You are right. It ain't LEGO. Hope this is useful..

[@acanuck1679]

Scott: Thank you for putting to bed the notion that there is (presently) any feasible alternative to chemical rockets for launching humans (and other delicate payloads) from Earth into Space. More generally, thank you for doing these question shows. They are quite enjoyable. Merry Christmas, Happy New Year and... Good sir, we bring salt for your meat, logs to keep your fire lit and a good single-malt to warm your New Year's Eve! (Hogmanay)

[@dsdy1205]

them bots be lernin'

[@davisdf3064]

Oh no, Scott Manley is trying to show his rocket to me D: Jk

[@OsirusHandle]

Wow never expected to see Planetes here. Definately one of my favourite anime.

[@neithere]

It felt like 5 minutes, as always. Thank you, Scott!

[@glennbeck5138]

Regarding the refueling question it brings to mind a product used in automotive racing applications to avoid fuel starvation due to fuel sloshing in the tank. Holley Hydramat. I’m not familiar with the technology used but the problem being solved seems very similar.

[@will3346]

Funny to see a GaTech aerospace slide in one of your videos. Gives me some anxiety, I spent a lot of time looking at those this past semester.

[@craig4811]

Thank you Scott. Happy holiday!

[@oopsadaze]

THANKS for Being SMART, We Need More SMART PEOPLE.

[@michaelbindner9883]

The key to cheap space is to get ice into orbit. Start with making steam in the middle if the ocean and sending it up a pipe to where it condenses. Next to the pipe, have a track for containers plus a power line system and solar. At the point if condensation, make lox and hydrogen chilled for loaded containers of ice and propellant and load it into a magnetic catapult, launching it toward a depot in orbit for processing for more fuel and for orbital good production.

[@CraigLYoung]

Thanks for sharing and Merry Christmas 🎅

[@magnemoe1]

3:45, having to get to close to the object for the gravity assist, the famous -300 km Tylo flybys :)

[@markiangooley]

Antiprotons plus water is a great propellant. Getting and containing the antiprotons is the problem, obviously. Maybe a facility in a somewhat close solar orbit could serve as an antiproton factory but… so many big unsolved problems in the way.

[@runningray]

I for one love your mad ravings. Fly safe.

[@bethmetal4544]

"Go drinking whisky with Scott Manley" is my newest bucket list entry. Whisky #8 "Tell us about black holes Scott!" 🤣❤

[@18robsmith]

I'd even supply a couple of bottles for him to add to his collection.

[@mrwilliamjoel]

Planetes is cool - another great hard sci fi space anime is space Brothers, really granular focus on a near future lunar program

[@zeux5583]

or the currently airing "tsuki to laika to nosferatu" which is a more or less historical retelling of yuri gararins flight. it even is science fiction - more or less everything sciencey in this show is based on real world science and the fictional part is, indeed, fictional

[@thirteenthandy]

Parker Solar Probe "touched" the sun this week. I understand the distinction as you previously explained, but would you be able to show us a comparison of what altitude a satellite in Earth orbit would be touching a similar volume and intensity of Earth's atmospheric particles? What kind of Earth orbit could it be compared to based on what the Parker probe is running into? I imagine it's not as simple as looking at the distance to diameter ratio.

[@eaglestdogg]

It's kinda hard to compare planetary atmosphere with stellar atmosphere as the composition and mechanics of both are very, very different.

[@thirteenthandy]

@@eaglestdogg Of course. That's exactly why it's a question to me. Even though it's not a clear comparison, is it possible to show for instance that the level of energy and mass that the probe is running into right now could be compared to an Earth orbiting satellite in geostationary orbit, LEO at 400km, etc? Or perhaps two different comparisons could be more accurate, for instance the number of particles that Parker is running into could be compared to one Earth orbit while the particle energy it's running into could be better compared to a different/lower Earth orbit...

[@thirteenthandy]

@@hmJgyinPlM That literally doesn't help at all, lol. I don't have any background to understand the practical difference between those numbers or the different types or energies of the particles in question. This is why it would be cool to see some graphics on the topic.

[@zacharybennett3249]

@@thirteenthandy The sun is basically a giant ball of plasma (think of an electrically charged type of air) and the parker solar probe touched the part of that plasma that the sun has a "direct" influence over. Its like being in a spacecraft and entering the earths atmosphere enough to tell that your craft is being pushed back by the Earth itself and not just a random gas cloud you're floating through.

[@thirteenthandy]

@@zacharybennett3249 I understood that on my own, and Scott does a great job describing it in more detail. That doesn't eliminate my question. The ISS feels drag from the Earth's atmosphere. Is Parker hitting anything like that? Less? More?

[@ShawnHCorey]

The holy grail of rocketry: the neutrino rocket. It shoots neutrinos out the back. Its exhaust velocity is just under the speed of light. And since neutrinos rarely interact with normal matter, there is virtually no blast from it. You can stand next to the rocket without danger.

[@E9X330]

In that case let's invent a neutrino cannon, so i can shoot people I'm mad at without getting into the legal ramifications of killing anybody

[@g.f.martianshipyards9328]

If you managed to produce enough neutrinos to get meaningful thrust, they're probably gonna be dangerous. You'd need to find a way to emit a ridiculous amount of energy pretty much solely as neutrinos, and I have no idea if that's even possible.

[@richcaloggero3424]

And because they interact wiht matter very weakly, how would you accelerate them. They also have rediculously small mass, so how would you get enough of them to accelerate your payload.

[@ShawnHCorey]

@@richcaloggero3424 You don't accelerate them. Normally they are created at very high speeds so that's not a problem. The biggest problem is they are created heading in a random direction. They need to be created travelling in the same direction, more or less.

[@TheEvilmooseofdoom]

They're so nearly massless you wouldn't get much thrust.

[@GaidinBDJ]

I'm laughing at the Rosetta question. It's a hell of a thing to see an age of technology where

[@Br3ttM]

When it isn't designed to land, but to be as light as possible, and it has important but fragile things sticking out all over, that's enough. To actually be useful, you need the power and communications to both function.

[@ProperLogicalDebate]

Only sufficient shielding I can think of is straight down through the launch pad and the Earth. Probably hard to keep it pointing to the pad. Also what damage?

[@Pratanjali64]

I love your videos so much Scott. I'm sorry I'm not in a position to contribute to your patreon. I do recommend your channel quite often on the Outer Wilds subreddit, since many people there have an interest in real-world rocket science.

[@kiltedskipper]

Scott. Would using MagLev (electric linear motor) technology be viable to getting space craft a boost in propulsion off the launch pad, essentially allowing more propellent to be used to increase its speed and less to just get the vehicle started?

[@HalNordmann]

Look up NASA's Maglifter concept - it is exactly what you are talking about.

[@grn1]

I'm guessing the main issue is that most rockets rely on internal pressure to keep their shape/wouldn't be strong enough to survive the forces/kinds of forces. Reusable rockets are presumably stronger though and may be able to handle the forces of a maglift (I hope that made sense). Another issue to consider is how the magnetic forces would interact with things inside the rocket, the more powerful the magnet is the more powerful (and most likely the heavier) the shielding would have to be so we'd have to figure out what the best balance is and whether it's actually worth it.

[@simongeard4824]

People talk about RocketLab "moving" into fields peripheral to their core launch business - but they've actually been into that side of things almost since the beginning... they announced the Photon satellite bus barely a year after their first successful Electron launch, and acquired Sinclair less than a year later to support that. So they've never really been looking to be just a launch provider...

[@dr4d1s]

You fracken killed it as usual Scott!

[@sleepib]

My favorite hypothetical alternative launch method is the launch loop. Rockets can have impressive RUDs, but I'm pretty sure inertia supported megastructures can top that.

[@1KJRoberts]

A-a-w-h, Scott! 'Ya threw shade all over 'Back To The Future'. How will I ever watch it again armed with this new knowledge? Wait! I'm gonna build a time machine with my Citroen...

[@INSIGHTSAU]

As always. Brilliant video.

[@larrybuzbee7344]

Fluids have been manipulated in a controlled manner in microgravity using acoustic forces only. Carbon nanotube 'forests' applied to a surface have been shown to be highly efficient electro-acoustic transducers/'speakers'. It could be possible then using very lightweight elements to create a modulated acoustic field inside propellant tanks that would corral all floating globules and push them gently to the transfer pump intakes at the back or bottom. Once transfer begins the momentum of moving tons of fluid keeps stuff in place. Or not.

[@yo.aj6391]

Thanks for answering my question!

[@MichaelWilliams-fm9mw]

Came for the science, but appreciate the Scotch recommendation ; ) Will definitely procure & sip on a bottle of the green label. Cheers!

[@proto_hexagon5649]

1:40 instead of that use Fusion to make energy on close loop and get energy/electricity to RF and make plasma to thorw away any gas you have stored but at much more speed.

[@veramae4098]

Many, many years ago my future brother in law graduated with a maths degree. Brilliant. In job interview fair at U of MI, a man identified himself as being from NASA, and interested in hiring David to help with development of nuclear engines. David was ecstatic. Never heard from the guy again. Oh, but a few weeks later some FBI agents met with him asking questions about this "NASA" guy. Never heard anything more from FBI either. Questions in life .

[@anthonylipke7754]

Solar ion drive blimps seem slow and low mass. I think you mentioned beamed power that seems like it could work. rotating tethers seem fun. Is any hypothetical metallic hydrogen energy non chemical? Computing in space might work solar power and big cold sink.

[@joshbeaulieu7408]

Hey Scott, is there any reason that they don't use bladders inside of fuel tanks to facilitate fuel transfers? Instead of spinning the spaceships would it be feasible to squeeze the fuel out of one bladder into another bladder using a mechanical system or gas pressure?

[@magellan6108]

With gravity assists, as much as an object gains velocity, how does this affect the object giving the gravity assist? If the same object is repetitively used to get a gravity assist, won't that object's orbital dynamics be affected by the cumulative effect of imparting energy to these passing object?

[@magellan6108]

AM or now?

[@superakman14]

Speaking of anime and space, a new anime just finished , called "Irina:The vampire cosmonaut". It is basically what it says in the title, focusing on the soviet space program.

[@NoNameAtAll2]

of course they would display soviets with a vampire -_- do the "soviets" bully main character (s) too?

[@CuteLittleNeko]

I just finished it myself. There's apparently more ongoing in the novel.

[@kennethsalyers3809]

still awesome moving forward!

[@zrebbesh]

If you want rotation in a system you needn't spend propellant for it. Use a pair of counter-rotating gyroscopes. Spin them up, then turn the axles end-over-end in opposite directions and magically you get torque from precession. Once you're rotating fast enough, you spin the gyroscopes down, which produces no net torque, and you're still rotating.

[@spinmaster4348]

Another point is that the Gamma ray is no less tricky thing to deal than neutrons, if you would like to totally rely on matter-antimatter annihilation to propel your spacecraft to an admirable speed, you’d like to be at least several kilometers away to your main engine.

[@spudd86]

What about Proton-Boron-11 fusion? There's a couple fusion projects that if they work might be able to run that reaction, in that case the only paths that produce neutrons are side reactions. (Example is the Polywell concept, depending on how well it works, it at all, it might be able to run Proton/Boron-11 as fuel).

[@wumpusthehunted2628]

There have been some non-chemical suggestions involving beamed power (like masers) heading up propellants. Ideally te would have the Isp of NTR engines (hot hydrogen). They would likely need to piggyback on military tech, which makes it more difficult.

[@blackhawks81H]

Laphroaig is a very good choice... My favorite "everyday sip" is the good old Lagavulin 16. Other favorites are Ardbeg and Bowmore... Starting to see a trend here? Lol

[@MervynPartin]

Regarding the radiation shielding that you mentioned, gamma rays are the hardest to shield, as they are attenuated, but not stopped by anything, really. Lead or concrete can be used. Radiation still passes but gets weaker depending on the thickness, and the material used. Make the lead or concrete thick enough and you get practically down to background levels. Neutrons, however, are quite easily shielded with hydrogenous materials like water, paraffin wax or polyethylene, or again concrete due to its high water content. Water of course, is used as a moderator in PWRs to slow fast neutrons to thermal velocities. The concrete used in shielding commercial reactors is very effective at shielding. Shielding is just one of the methods used to reduce radiation dose. Others are keeping at distance from the source of radiation, and limiting the time of exposure. A combination of all 3 gives the best protection.

[@Dave5843-d9m]

Check out the turning radius of SR-71. It was huge. Hypersonic aircraft (drones or otherwise) seriously struggle to change direction at all.

[@JohnSmith-cs5ce]

There are aneutronic fusion reactions with different fuel, but they are even harder to achieve than deuterium-tritium one.

[@andrewharpin6749]

Re Fusion engines + Neutrons. With a D + T reaction yes, they produce lots of neutrons, neutronic fusion. But there is also aneutronic fusion such as H + PB11 or He3 So it's not exclusively a Neutron issue.

[@franklinz8098]

For the last couple of years, anime sci-fi is basically 40% VRMMO, 30% post apocalypse, 20% AI becoming human, 10% science vs magic, and 0% space.

[@thoji215]

Being a space and anime lover, I would love to see a very good space anime.

[@razvanmazilu6284]

@Scott Manley• this is not Scott Manley in case it's not immediately evident.

[@chikitronrx0]

The Irina Vampire cosmonaut girl was good enough. I hope it gets a second season. It's from this year, this season.

[@kevinmcenhill2656]

Random question here. The Atlas rocket is famously held together with pressurized fuel tanks. Vent the tanks of a standing rocket and the whole stack comes down. That's all fine and dandy when they were being actively used in the Mercury program or as alert ICBMs but how do the static display rockets in museums stay upright?

[@HalNordmann]

Either they are kept pressurized, or they have additional structure installed inside. These hard-to-handle baloon tanks are also used on Starship, which is one of big problems with it.

[@Br3ttM]

Dinosaurs used muscles and ligaments to keep their bones together when they were using them, and museums put up (replicas) of their fossils with wires and metal holding them together.

[@gardnep]

Isn’t orbit assist speed ultimately limited by e=mc^2, hence the black hole scenario. Mass is converted to energy and disappears up its own fundamental orifice.

[@kenhelmers2603]

These are fun :) Merry Christmas!

[@spinmaster4348]

Actually, there was a program called “Dumbo” which is also a SNTR like “Nerva”, but having a much much much higher TWR of like 70 or so. This could have been made as a radiation pouring nuclear booster stage, if you managed to ignore the tremendously large propellant tank or the stupidly low Isp of other propellant types.

[@SteveChisnall]

19m44s Fine mesh? What about some sort of "wick" that draws the fluid along its length via *capillary* action instead of using surface-tension?

[@alan2here]

It seems like these rockets use up as much fuel in the first 50 meters moving at a crawl as they do to getting nearly out of sight. Maybe they could be assisted with a mechanical spring/throw/push to get them moving fairly quickly, with the rockets kicking in a few seconds later than usual. So like a "rocket jump" in a game but the other way round, a mechanical jump to help the rocket rather than (equal and opposite and an explosive blast) to accelerate a mechanical jump on the way up.

So, spinlaucnh but less kick...

[@alan2here]

@thank you :) That looks potentially great, and hilarious.

[@Br3ttM]

The rocket can't handle those forces, and adding weight to increase strength means you need more fuel to go the rest of the way. Also, you want to make sure the engines are working correctly before you leave the pad, so you don't go up 100 feet and fall back down with no time to react and a full tank of fuel to have explode. There are videos of unmanned rockets doing that.

[@jdmillar86]

It seems very tempting but in practice it always seems to turn out better to just make your first stage a little bigger. Especially if you are recovering your booster SpaceX style - how much cheaper would it make it to just shrink the reusable part a little bit?

[@brucebaxter6923]

Two questions about speed n launch 1) how do you stop the vehicle rotating? 2) how do you absorb the energy of the counterweight plowing into the ground?

[@brucebaxter6923]

@Scott Manley• That’s cool. Lots of people have new things at Christmas. What does that have to do with spin launch?

[@Sparra2629]

Hey Scott, what about closed cycle gas core nuclear thermal rockets for exiting the atmosphere?

[@owenclark7210]

Hi Scott. In regards to the question you had about large numbers of people living in space - check out Allen Steele's book 'Orbital Decay'. Ostensibly it's science fiction (first published in 1989), but it presents a scenario of a large group of construction workers living in space building giant solar power satellites.

[@Br3ttM]

As long as orbital construction comes before there is so much automation the humans aren't needed, that could be a motive to get more people in space. And if you can build without humans, then you don't really need to worry about costs, so the reason just becomes "Why not?"

[@loadmastergod1961]

I need to learn kerbel. Maybe that instruction que is worth doing once I download it again

[@dudermcdudeface3674]

Glad to hear from another person who appreciates Green Label. You're literally the first other human being I've heard mention it.

[@milolouis]

Just brilliant as ever! The black hole bit I need to look up 4:40. So I could escape a black hole as my propellant gets accelerated by it?

[@lordcirth]

You cannot escape once past the event horizon, but you can get a gravity assist at a safer distance.

[@billmilosz]

I used to like Glenfarclas- when I drank it in the 1980's it was a tremendous bargain in single malt.

[@thundercactus]

Ha! +1 for Laphroaig! Their quarter cask isn't just an oaked whisky, it's drinking the lumber yard! =D

[@homairi79]

hey Scott, greetings from Poland. Also, what do you think about recent Tabby star developments, more unusual dimming and other strange behaving stars around it?

[@reformCopyright]

Scott Manley drinking game: Take a shot every time Scott says "anyway, ...".

[@tarmaque]

Are you mad, man? Alcohol toxicity is a thing.

[@bandiras2]

Recommended hard scifi and close to reality space related animu: "Space brothers", "Rocket girls", and of course, "Magnetic rose". The last one is a bit fantasy, but still a magnificent piece of art.

[@cashhue941]

Space Brothers is fantastic! Also oddly enough, Irina The Vampire Cosmonaut from what I've seen so far. In so far that it's highly inspired by the Soviet side of the space race.

[@NoNameAtAll2]

"moonlight mile" - forgotten unfinished (in anime, despite having 2 seasons) portrayal of construction worker sent to space

[@GreatistheWorld]

had to add Royal Space Force: Wings of Honneamise!

[@klankowski]

in your background you have a model of the Saturn V launch tower. looking specifically at the truss design, why do you think SpaceX opted for the inverted truss design for StarShip launch tower?

[@uuzd4s]

Possibly the Vertex of Awesome!

[@jab9934]

2:05 why are gamma rays easier to shield than neutrons?

[@richhagenchicago]

Fusion might scale up nicely for a large prolonged thrust rocket because the reactor size would be fixed for a given power and you could have a larger fuel tank. The shielding thickness and mass would therefore be fixed as well. With a large craft you could make a larger percentage of your mass fuel as compared with the mass of the reactor. You would just have to run it for a larger percentage of your trip and your acceleration would of course be lower. Heck, fusion power is only 30 years away . . . . . . . . . .

[@TheEvilmooseofdoom]

What are you using for reaction mass though? The fusion by products or a different working fluid?

[@FreeRadicalX]

OMG didn't expect to hear the name of my favorite Scotch (Laphroaig) on your channel, but I suppose I shouldn't be too surprised at a Scotsman talking Scotch!

[@thanksfernuthin]

I don't think he meant gravity assist with one boost. I think he meant boosting over and over.

[@Br3ttM]

It depends on how much time you have to do repeated passes, and the planets available to use. There's a limit to how much you can gain from each assist, and once you exceed the escape velocity of the star system, you only have the planets ahead of your trajectory to use one more time.

[@thanksfernuthin]

@@Br3ttM Right. I think something like that was the answer he was looking for. And maybe a speed of light percentage.