Heat Shields, VASIMIR and Hydrogen Peroxide - Supporter Questions Episode 11

[@danieljensen2626]

I like how your recording setup is basically something most people could throw together (with the purchase of the large ring light and a single square of audio foam) even though you have more than a million subscribers. But your videos are great so obviously there's no need to get any fancier!

[@zenklok2233]

When he talked about his DJ equipment, it sounded like rocket science

[@mirien7277]

Scott: magnetic confinement nozzle Me: understands Scott: spherical needle Me: a what?

[@bazedjunkiii_tv]

i got the point - still i don't get why ppl are so hyped about straight tone arms. whenever i played on a turntable with those it was most likely i swiped them across a record on a regular which left some nasty scratches on that precious vinyl.

[@aliquander]

it caught me completely off-guard, I was like wth, we swithced to a whole new level I can't even...

[@vector824]

I was tracking with him until then. He totally lost me.

[@HermanVonPetri]

@@mirien7277 Haha, true. I was trying to imagine what design of needle could possibly be described as spherical. But a needle is by definition long, slender and pointed so it seems like a complete contradiction in terms. Turns out, the tip is like the ball on the end of a ballpoint pen. But it isn't really a sphere, so _hemispherical_ might be a better term (they are also called conical.)

[@RCAvhstape]

RE. launching through the eye of a hurricane: that was a key plot point in the awesome film Marooned, where an Apollo spacecraft was stranded in LEO, unable to deorbit itself, and NASA had to figure out how to mount a rescue mission. The film was scary enough that it influenced NASA's decision to have a spare Apollo-Saturn IB stacked up for rescue during Skylab missions.

[@averageeclairenjoyer3010]

That movie is also said to have influenced Soyuz-Apollo program, as it was shown to Soviet scientists who liked that it portrayed Soviet space program as good guys (Boris Chertok also claimed it was a "commercial" of sorts to get funding for Space Shuttle program). Interestingly, the book that movie is based on was already published in Soviet Union, with foreword by cosmonaut German Titov, who was name-dropped in the book. The book, by the way, has some really inaccurate portrayal of Soviet rocket, which is described as having tandem configuration, and the ullage and stage separation motors are mentioned and explained even though rockets from R-7 family had neither.

[@Allan_aka_RocKITEman]

FWIW: The question posted on screen listed actor Gregory Peck's name, so I presume the person asking had seen *MAROONED.* BTW, I thought the _XRV_ was cool...👍👍

[@bobqzzi]

Saw that in the theaters when I was 8. Scared the bejebbus out of me. Remember it clearly

[@goingballisticmotion5455]

Trivia: The author of the book the movie was based on also wrote the book Cyborg, which became the TV series "The Six Million Dollar Man"

[@RCAvhstape]

@@bobqzzi The scene where the astronauts are talking to their families, believing they are probably not going to make it, was pretty stark and horrifying. Gene Hackman's did a great job of portraying an astronaut who was at the end of his rope mentally.

[@richardwild4322]

I am the Harbour Master for Scapa Flow, most of the WW1 fleet were raised after the war. Some do remain here and are the few wrecks from the war that can be freely dived as they are not war graves. The running joke here is that the German Admiral was supposed to have said "I said subtle retreat, not scuttle the fleet!"

[@patricks_music]

It’s interesting the people that follow Scott’s page. How did you decide on your field of work?

[@zenith828]

It seems like you are the Deputy Harbour Master since 2019. Did you get promoted?

[@scotarg1973]

When told well, with German accents and narrative of the situation etc, the "subtle retreat" joke is hilarious! My dad tells it well. 🤣

[@scotarg1973]

@@zenith828 That's just not good enough. How can we believe a word of what this guy says now?! Unless he believed that it wasn't necessary to explain whether he is the deputy or if he has been promoted. Like, maybe it's not important to his comment and it's extremely unlikely that anyone is going to fact check because nobody cares. Mr Wild was wrong.

[@robertrjm8115]

Although your joke works well in English, no so well in Scotts brogue, bust as the Admiral spoke German it doesn't work at all. Still, its a good joke but alas not reality.

[@shehulsuratwala2684]

No fancy video cameras equipments but pure rich knowledge delivered. Thank you for your hard work Scott.

[@rougenaxela]

10:55 It's worth noting that reflectivity and emissivity are inversely related material properties, and emissivity in the wavelengths associated with black body radiation affects how efficiently something can cool itself radiatively. To keep a surface as cool as possible, you actually want it to be dark in the wavelengths predominantly corresponding to black body radiation at the temperatures you need to cool it down from. In regimes & wavelengths where a surface's own thermal glow is brighter than it's surroundings, you actually want it to be dark/absorbant, but in other wavelengths/regimes where the surroundings (which could include reentry plasma) are brighter than your surface, want it to be light/reflective. No one material is ideal for staying cool in all regimes and environments, but this can be worth considering. In any given regime there are ranges of wavelengths where you're best off being dark and other wavelengths where you're best off being light, when it comes to staying cool.

[@HanSolo__]

Neat!

[@AsbestosMuffins]

Low background steel isn't needed because they switched from atmospheric oxygen to liquified oxygen for most steel production, so no radioactive contaminates

[@fokjohnpainkiller]

Finally someone answered why it isn't needed anymore. I knew this, but I didn't know WHY, good stuff

[@kineteks77]

Does liquifying oxygen somehow remove radioactive contaminants or does that imply the source of the liquid oxygen is not the atmosphere?

[@topsecret1837]

@@kineteks77 I would assume that radioactive contaminates could then be filtered from liquid oxygen, since they were mixed well in the atmospheric gas with nitrogen but not in Oxygen as a liquid.

[@-danR]

@@kineteks77 All LOX comes from the atmosphere, yes. So unless there's some kind of specialized isotopic fractionation involved, it doesn't make sense.

[@-danR]

@@topsecret1837 That would make sense. There are no long-lived radioactive O isotopes, to which I alluded.

[@DocHuard]

As to painting, paint and coatings add weight. While this doesn't seem like much, it adds up. They quit painting the external tank on the shuttle and saved 800 pounds. Interestingly, some have a questioned whether or not that paint helped reduce the foam shedding that plagued later shuttles.

[@williamblack4006]

According to John Chapman, NASA's external tank project manager at the Marshall Space Flight Center (MSFC) in Huntsville, Alabama: the white paint did not prevent foam from popping free of Columbia's fuel tank during its first two launches.

[@simongeard4824]

Similar issues came up in WW2 regarding the benefits of painting aircraft with camouflage vs leaving them shiny metal, with the result that later generations of long-range bombers and escorts opted for bare metal to reduce weight and improve range.

[@HalNordmann]

This is one of the reasons I don't like Starship. A winged flyback/aluminium construction Heavy-lift Vehicle from NASA's SPS study has similar payload to Starship, yet only 4000t mass when full (less than simply the mass of fuel for Starship)! And that is even with some mass reserve! If you want cheap lift to LEO, you build something like that. Steel may be cheap, but it is simply too heavy. And in spaceflight, mass is everything, every gram counts. The weight limits on rockets are far more strict than the ones on airplanes - and you don't see any airplanes made of steel, do you?

[@Slicerz717]

@@HalNordmann maybe you are right, but I think Starship with new generation high strength steels with great properties against corrosion, fatigue, etc. Starship is only gonna get lighter compared to composite or aluminum Starships. If steel work its tps should be also lighter compared to later ideas. Time will tell. However isnt always about best performance. He is always about cost.

[@HalNordmann]

@@Slicerz717 Good performance makes good cost, since you spend less on fuel. Again, you don't see many airplanes made of steel.

[@DrDeuteron]

Re: Low Background Steel. When you say "work with low radiation hardware", it gives the impression you're talking about radiation sensitivity (damage), which is ofc not the case: hardware is much tougher than people, and modern steel is completely safe. We're literally talking about "background". If you have steel plates in your neutrino / double-beta decay / axion detector, where your signal may be 4 events per month: you simply cannot have Cobalt-60 gamma rays appearing at 2 events per month. Even though Trinity was 14.5 half-lives ago, and 99.996% of Co-60 has decayed, the problem is that Avogadro's number is HUGE. A single microgram of Co-60 in 1944 will yield 4 event per second in 2021. That is huge background.

[@KatyaAbc575]

Wow, I never really thought about radioactive decay in equipment interfering with measurements. Very interesting addendum, by the way.

[@DrDeuteron]

@@KatyaAbc575 they also use low potassium glass in the phototubes too, and those experiments 4000m down a mine shaft? The rocks are full of thorium and all that, so they basically need to make it a clean room. In a working mine. Not easy. (I've never worked on one of those...it's just hard...you got to earn you neutrino Nobel prize). Look at Ray Davis. He detected 40 argon (from neutrino + Cl) atoms per month in a swimming pool full of cleaning fluid, when the Sun was supposed to make 60 (afaik). 40 atoms, in a pool. Have you ever tried to clean a pool?).

[@jonahbrame7874]

Dang those numbers are wild.

[@bottlekruiser]

Scott: parks a space station in an industrial zone Also Scott: "fly safe!"

[@OlleErikssonL]

An idea for a future video I would love to watch: how inertial guidance was used to guide early rockets like the V2 to their target.

[@atl5305]

And then how sextants were used in space.

[@jackroutledge352]

Yeah, you could do a whole series on space navigation. ICBMs use star sightings for example. Incredible technology considering it was developed in the 60's

[@philcanny6356]

Good call!

[@brianarbenz7206]

14:51 Drew may have been prompted to ask this by the movie "Marooned," which came out in 1970, showing the crew of a fictionalized Skylab mission being rescued (well 2 of 3 were saved) by a Soviet-U.S. effort that featured the American launch through the eye of a hurricane. It was dramatic and true to NASA technology, but had enough cliches to get it sent up to Joel and the robots on the Satellite of Love in MST3K. (It was shown there, and heckled, under its re-release title "Space Travelers.")

[@glenn_r_frank_author]

I think the "black heat shield" question may have been been better phrased "black Thermal Protection Tiles"... thinking the kid's question was referring to the black tiles used on the shuttle and starship not the shields on capsules.

[@nothke]

Yeah I also found it weird that he didn't mention Space Shuttle as that was my first association with "painted black"

[@Aaron-zu3xn]

yeah ..smart kid though

[@peteranderson037]

@@nothke Maybe he thought that it was a reference to a Rolling Stones song. "I see your yellowish-red tiles and I want them painted black."

[@TheJttv]

That kid was born after the shuttle

[@limiv5272]

@@TheJttv So was I, what are you getting at?

[@willjackson7982]

Hi Scott, My Grandpa actually worked at NASA since the Apollo missions and ran the lunar receiving lab. I got to go to his lab and it was deep underground and he got to be one of the first people to test the moon rock for what the elements where in the rocks. The lab walls and equipment was made from steel forged before any nukes and was sources from old WWII ships. Funny to hear about this again.

[@Error6503]

When I was doing my physics degree in the 80's, a lecturer said some of the experiment equipment was expensive because it had to be made from old sunken battleships. That's about the only thing I remember from university.

[@Tim67620]

The H2O2 question reminded me of the old rocket tests on the Isle of Wight that are available on KZbin. You pour a small amount on anything organic and it bursts into flames. The guys handling it were well covered up. Also, the Government cancelled the Black Arrow program before the last rocket was launched but they lit it up anyway and now we still have Prospero!

[@mikerichards6065]

Curiousity Droid has a nice video about the UK space programme at: kzbin.info/www/bejne/fHmleHSvfrprftk for anyone who is interested in learning more.

[@r0cketplumber]

I worked with 90% peroxide at Deep Space Industries in 2017-2018. While removing the small (65-lb thrust) engine from the test stand one day, I didn't have a Tyvek smock on and nearly fumbled the engine, bracing it against my belly as I caught it. A few seconds later I felt a sting from a few drops of the HTP, quickly doused myself with water, pulled my shirt off, and rinsed off the HTP. I developed a welt with the characteristic white subcutaneous oxygen bubble formation, but my shirt was undamaged and I had only a modest mark by the next day. 90% peroxide requires respect but not paranoia. 98% is a different beast. With that engine I demonstrated that peroxide of 70% or more can be burned without any catalysts by direct injection, provided your torch igniter is robust.

[@Tim67620]

@@r0cketplumber Respect mate. Black Arrow used 86% KZbin shows the British Rocket Black Arrow in development and final launch. It is called "Once we had a Rocket" They poured some Hydrogen Peroxide onto some grass and it burst into flames. Organic products would ignite. Was your shirt man made? Anyway, that was a close call. I agree H2O2 is not that dangerous if you take proper precautions. Hydrazine and Dinitrogen Tetroxide are both much more dangerous. What pisses me off is the way the Government pulled the plug. They didn't know what to do with the rocket. Who expects a new rocket to work first time? That was the last of 10 years of shutting down British innovation because we were going in the EU and had to please the French.

[@sudazima]

@@rydplrs71 anything over 68% orso is an explosive danger and your not allowed to posses it without a license as far as i know..

[@mememaster147]

@@sudazima AFAIK it's not that it's an explosion hazard, it's cos you can make explosives with it like TATP.

[@WayneTheSeine]

Love your videos Scott. Always a pleasure to watch and I always learn something...usually a lot.

[@AnonymousFreakYT]

8:40 - And because I expect people will ask - when he talks about the "bladder tank", that's generally how the ullage thrusters fuel tanks work. The ullage thrusters had separate propellant tanks, that were either bladder-lined (so the bladder would shrink and squeeze) or pressurized. So you had these "pressure-fed" small thrusters that would be used to add some small acceleration enough to push the propellant in the main tanks back to be able to light the main engine. (Or the ullage thrusters could just be a pressurized cold gas directly.)

[@advorak8529]

Or solid rocket motors. Saturn V as just one example. Also: piston with a spring.

[@PAZags]

Thanks Helium Road. I saw the movie "Marooned" on TV, circa 1972, when I was a wee lad, and thought it was fantastic! I thought of it instantly when Scott read the question. Perhaps Scott should watch it and critique it for technical accuracy. It had an experimental Von Braun style boost glider atop a booster that was to be pressed into service as the rescue vehicle.

[@robertrjm8115]

Scott, I very much enjoy your presentations and the scientific accuracy and details (especially your program on Lagrange points and Chernobyl) . Now on to a personal question, following on from Katharina N's question: " What is your favourite dram? I only see a While Label on your shelf. As a proper Scot there must be a single malt hidden somewhere! " On to a more scientific / technological topic: Seeing heat tiles fling off during or sitting askew after a static fire on Starship , I feel there is still a very long way to go for this rapid, reusable space craft. Or is it that the underlying stainless steel structure of the body and its "simplified" cylindrical shape is much more forgiving compared to a similar loss of tile or leaking protection in the space shuttle. The catastrophic failure on challenger was due to the plasma penetration into the wing space leading to a breakup from inside. Would love to hear your thoughts. PS: greetings from near "home" i.e Edinburgh on a stormy/rainy autumn day. And "Stay Safe"

[@erikreddington461]

Ladies and gentleman, take notice, This is how you update a theme and channel. Classy sir. The music, new formats (show types) better quality, but same old reason we show up, YOU! Thanks Scotty so Hotty.

[@Libertylute]

Vegas! Yesss! Used it for every one of the several hundred music videos I have posted to KZbin (none under this username, though). Very flexible and versatile software.

[@michaerun]

It was my understanding that the modern steel as a small amount of Cobalt 60, because the lining of the smelting system is doped with Co60 so that they can monitor its thickness remotely. So, it is likely still an issue.

[@JahLuvzU]

"The complicated things I try to do for you, people." 8:01 is a nice juxtaposition to the complicated things You are explaining. Also, explaining them well.

[@ScumfuckMcDoucheface]

haha I like your name, and your art. **nods** =)

[@tundramanq]

Lead is like the steel. We grabbed up as much of the sheet lead from the walls of the old VA hospital demolition at Kirtland AFB for SNL's detector shielding. Very low background.

[@jamesowens7176]

7:50 Saturn V second stage (S-II) had 8 ullage motors for the Apollo 8 mission, but they figured out they didn't need that many, so it was reduced to 4 by the time of Apollo 11. Apollo 15 and onward launched with NO ullage motors on the S-II stage. I surmise they were deemed unnecessary using data from the previous flights, and NASA was reducing every ounce of mass it could in order to get the moon buggy on board. The third stage (S-IVB) still had ullage motors, though, as Scott mentioned.

[@BarryRowlingsonBaz]

The eye of a hurricane is very low atmospheric pressure so your atmospheric-tuned rocket engine nozzles won't be so efficient! But then getting through the thinner atmosphere might mean lower max-Q...

[@hydrochloricacid2146]

To be fair, most atmospheric engines are designed to reach peak efficiency during ascent and are in effect underexpanded at launch

[@Nuovoswiss]

The minimum pressure in the eye of a hurricane is only 15% lower than it normally is, which is equivalent to having an altitude of ~2 km. Most first stages are optimized for altitudes higher than that, so it should be a net increase in performance.

[@brandonhamilton833]

"The complicated things i try to do for you people". We love you Scott!!!

[@st3althyone]

Delightful as always Scott, love your channel.

[@roadwarrior6555]

I like how Scott doesn't apologize for potentially mispronouncing names. As long as it's not intentional, it shouldn't matter.

[@kindlin]

He outright waves it away. He's long given up hope of getting people's names right.

[@cyborghobo9717]

About the question about colour of heat shield . If you talk about the heat shield of the Space shuttle and similar designs , i believe it's because of the black body radiation. Heat radiation of black objects is very intense , this would contribute an advantage for after reentry cooling of heat shield .

[@-danR]

I was surprised that Scott didn't go into the black-body radiation effect, which I felt was what the original question was looking for.

[@ckdigitaltheqof6th210]

5:53 "lunch" vehicle.. ? 11:45 could have mentioed to the kid, the temporary albat heat shields could implament color, which could last for re-entry, since they were assumed to last forever on a X-15a craft, at horizontal mesosphere travel. The topic of 14:56, if you launched the rocket beneath a ground surface through a hatch lid , you can while the hurricane Eye is zenth. 2:40 was hard, but if you use spike-boosters or cage net in M-drive form, its feesable at low results, Vasimr, to become more effective then chem rocket, require nuculear amp, the booster would actually look like a sheet plank & not a booster funnel at all, but thats beyond humanity to explain modernly.

[@SRFriso94]

I would like to add to that point about the RapVac on the Falcon 9: 1. The cost of basically developing a new second stage from scratch is not insignificant, and SpaceX will be looking to phase out the Falcon 9 once Starship becomes operational. 2. SpaceX would also have to have a major overhaul of the ground support equipment, whereas now they can just use the same propellant between the first and second stages. 3. The Raptor is more efficient than the Merlin, yes, but it's also more powerful. This is a good thing on Starship, which will have an enormous dry mass, but the Falcon 9 second stage is designed to be light, and in real terms, the Merlin Vacuum is already _way_ too powerful to make for a practical second stage engine. For the reason they didn't develop a different engine to begin with an make the Falcon 9 a better rocket, see points 1 and 2.

[@erictheepic5019]

To give additional context to point 3 for anyone wondering, the Merlin engine has such a high minimum throttle compared to the mass of the second stage and payload when nearly depleted of fuel that some burns done late in flight are barely a second long, if that. It's the equivalent of pressing Z and then X in KSP to do a really short burn. Only in the real world, it takes time to start and stop an engine.

[@SRFriso94]

@@erictheepic5019 Yes, that. Then again, it kind of works out with the Crew Dragon. The Atlas V needs that dual-engine Centaur to make sure it has enough power for the shallower launch profile it has to follow with the Starliner.

[@DavidVermeir]

Didn't SpaceX get money from the USAF to investigate using the Raptor as a second stage engine on the Falcon 9?

[@AnthemAnimation]

@@DavidVermeir that seems like a dumb idea if the Merlin is already overpowered. What would be a cool thing to look into is a Raptor first stage, you’d only need 3 engines, since each can lift ~200,000kg, and the falcon 9 weighs 549,054kgs. It’ll save on complexity and ease of reuse, and even if it doesn’t pan out, it surely would provide good data and knowledge about adapting the Raptor to platforms besides Starship

[@owensmith7530]

What you want for a better Falcon 9 second stage is a cryogenic engine with higher specific impulse. Lack of this really hurts Falcon 9 for GTO or beyond earth orbit missions. Something like the Vinci expander cycle engine from Ariane 6 would be great, same combustion cycle as the RL-10 but a modern design and higher thrust.

[@rauladdams5709]

Thank you! Q and As always grab my attention. Extra thanks for really showing off your room. That was unexpected and neat :)

[@Habakouk77]

It would maybe make more scence to build a Metalox or a Hydrolox secon Stage for falcon heavy to serve ultra-high velocity-Missions like Parker Solar Probe. With the limited specific impulse of Kerolox, you just can not get as high velocitys as Delta v Heavy for example, no matters how light your payload is.

[@corynardin]

Your can also use vanes inside your tanks to control where the fluid is in zero g.

[@frankoforte9040]

The Falcon is allready flexing a lot...especially against other rockets.

[@CheshireTomcat68]

Just get a Longbow archer to show them how to use the flex! :-)

[@casacara]

So long as you’re not trying to go on a high energy trajectory, at least.

[@JohnyG29]

already

[@railgap]

@Scott Manley - WRT avoiding bubbles in fuel lines, are you familiar with phase separation devices? (mostly using a very fine stainless steel fabric which resembles satin; once the fabric is wetted, surface tension across the tiny openings does not permit bubbles to pass) for some applications, I believe they can eliminate or reduce the need for a g nudge, but I think they have limits to how high they flow liquids (improved with increased surface area, obv). Martin Marietta was using them in Titans and spacecraft in the 70s and 80s for sure...

[@StephenByersJ]

Thanks Scott for actually making me not feel so bad about the state of my desk -- very similar situation here!

[@Wunderbolts]

Despite myself having a later gen iPhone, I never would've guessed that the (what I would consider) high quality video you were putting out was done with an iphone.

[@dsdy1205]

1:56 I feel like this question stems from a misunderstanding of the reasons an Epstein drive is impossible. Yes, it needs to be extremely efficient, but the only reason it needs to be that efficient is because of the main problem surrounding Epstein drives, which is that you're passing *the entire power output of present-day humanity* through a small engine package in order to get the sort of ridiculous performance you need to zip around the solar system a la the Expanse. Usually if your engine is anything less than 99.999% effcient that results in gigawatts of waste heat vaporising your engine and the rest of the ship, which is why Corey said it "runs on efficiency". But before we start dealing with that we have to find a way to cram literal terawatts of power output into a small ship first, and it's not clear you can do that short of just letting off nukes behind your craft. VASIMR is essentially a fancy way of heating a gas with microwaves and then redirecting the plasma through a magnetic nozzle out the back. The microwave antenna used for this can only support several megawatts of power, you're going to need a million times more power to make it anything near Epstein drive level. That's not to mention it needs an external source of power to run all this, which is actually probably the main reason it hasn't gone anywhere.

[@cyborghobo9717]

The problem of fusion drive isn't waste heat . There is a thingie called breamstruhlung radiation . It occurres when high energy electrons hit magnetic field and decelerate emitting x-rays due to law of conservation of energy . The hull of an engine absorbs it and gets overheated .

[@dsdy1205]

@@cyborghobo9717 that's...waste heat.

[@cyborghobo9717]

@@dsdy1205 it's slightly complicated . The proper term would be parasite heat .

[@dsdy1205]

@@cyborghobo9717 It doesn't need to be; whatever energy doesn't go into producing thrust becomes waste heat, be it bremsstrahlung or neutron radiation, fusion igniter low-temp heat, plasma impinging on the craft, or anything else. All these forms of heat are not useful and a good fraction of them might deposit themselves on the craft, which is bad.

[@tomgucwa7319]

Is that someone's name ,or a German compound word ? Can u decode it for me brum...

[@PotentiallyAndy]

To the person with the 8 year olds heat shield question. Please encourage him as much as possible to explore the sciences, asking that question at 8 years old is fantastic :)

[@jrt818]

Questions I got from a 50+ year old. Why don't people in the southern hemisphere fall off? Why doesn't the Nile river flow down into Africa instead of up?

[@running4john]

Thanks for the room reveal! A little concerned that I didn't see a door, though... Blink twice if Jeb is holding you captive!

[@--cs3]

That bothered me too. He either has a secret door somewhere, or he comes in through the window, or a trap door in floor/ceiling. Or the door was in the middle of the wall to his right and he didn't show us enough of that wall. I dunno...

[@colinritchie1757]

Ullage - from the brewing industry - Beer and Rockets what a great combination

[@JM-cv7nv]

I thought the black color of a heat shield actually helps with maximizing black-body radiation... that being especially useful on a reusable craft with tighter heating margins.

[@EstorilEm]

I think he just focused on the capsule coloration, but indeed I think you’re correct and also I believe Scott even did a video about this (why the space shuttle had portions which were black vs. white)

[@trolleyfan]

"Could a rocket be launched through the eye of a hurricane?" Well, *someone's* seen "Marooned..."

[@andyalder7910]

Would like to see your explanation of JAXA's Quasi-Zenith Orbit, in particular why the orbit is asymmetrical rather than a simple figure 8.

[@dhart1951]

Great grousing around 8:00, I loved that. I'm a fan.

[@hagerty1952]

8:00 The Korolev didn't, as a rule, use ullage thrusters on his boosters. He preferred to spool up the next stage while the lower stage is still firing. This is why there's an open trusswork between stages on boosters like the R7 and N1 (to let the exhaust out) leading to that distinctive "Soviet rocket" look.

[@kneekoo]

Scott, please make a playlist with the supporter questions. They're great episodes well worth having their own place. :)

[@williamarmstrong7199]

Interesting stuff. Good questions great answers.

[@kirkwagner461]

Rocket launch in eye of a hurricane. It was done in the movie "Marooned." Thus it's doable! (That's how things work, right? Done in movie means it's doable for real?)

[@KnightRanger38]

The only way I can see it being viable would be if the rocket was launched from a silo. Even then, the eye of the hurricane might not be large enough for the rocket to launch through.

[@MartinWillett]

In the movie time was mission-critical. In the real world such a high-risk would be unlikely to occur. It would only be worth taking such a chance if lives and national pride were both at risk.

[@mikerichards6065]

One of the tragedies of the demand for low background steel is that many sunken warships that are designated war graves have been badly damaged or destroyed by illegal salvage..

[@Ugly_German_Truths]

Civilian graves in most communities are cleared away after 50 years at most. The War has been over for 76 years, seems long enough to declare graves as untouchable.

[@hydrochloricacid2146]

@@Ugly_German_Truths this is always up to personal opinion but I don't really think we should be treating war graves in the same manner as we treat the average grandma's stomping grounds

[@Ugly_German_Truths]

@@hydrochloricacid2146 Why not? Lots of grandmas get senselessly killed by "warriors" in their little kerfuffles. And it takes often more courage to withstand a crisis in peacetime than to go to war.

[@sh4dy832]

If we're even unburying humans after 30 - 50 years, we sure as heck can reclaim resources from inanimate objects that have sunken over 50 years ago. It's not like leaving them down there would be of any use to anything sentient, at worst you steal the home of some fish.

[@Markle2k]

@@sh4dy832 OK Mr. 70 year old. We think gramma has been taking up that land for long enough. We need it for a mini-mall. We're going to dig her up and chuck her in the landfill. Got a problem with that?

[@donsample1002]

The 1969 movie _Marooned_ had NASA launch a rescue mission through the eye of a hurricane

[@wpatrickw2012]

In the movie Marooned, they launch the rescue ship through the eye of a hurricane.

[@nerdwatcher4273]

You are officially the recipient of my first ever KZbin question/comment! Here it goes: Is anyone putting serious effort into the space crane concept? Are we getting anywhere near close to feasibility with today’s materials and Starship’s lift capacity?

[@frankgulla2335]

Great answers to some great questions, espcially about your favorite number.

[@HPA97]

The eye of a hurricane to launch would be a cool sci-fi setting where there is hurricanes everywhere and you can only launch when you are in the eye.

[@JoePinball2006]

Already been done in a film called "Marooned"

[@GuntherRommel]

The worst thing about your channel is that it took me until very recently to find it. Wonderful content.

[@Chantillian]

Kudos to 8 year old Dorian for being so inquisitive!

[@danielwallace5730]

Katharina coming in clutch with the questions we really want to know the answer to.

[@johnmiller8884]

WRT putting raptors on the second stage of Falcon 9. From what I hear, those engines are perhaps 80% more expensive than Merlins. The second stage motor is the single most expensive one-time use part already and from what I understand make up quite a bit of the per-launch costs. There is an economic reason to not put raptors on an unrecoverable second stage. So can the second stage be recovered you ask. There were plans to try, but recovering something from orbital velocities pretty much demands a heat shield. Falcon 9 is a massively successful design, but it is also a dead end. The future of SpaceX is invested in the fully recoverable Starship.

[@MrJonathandowns]

Flexing rockets? I can't imagine that, I have never had a rocket shake itself apart in KSP from being too wobbly. Nope, totally not a thing that happens to me.

[@UndercoverPirate69]

Still rocking a G15. Had one too and it lasted very long. Still have it, but the left side of the space bar restraint is broken off by FPS nerd rage making it very noisy to use. Even programmed my own display stuff back then.

[@sparkparkful]

It makes me happy to see you have all 4 NASA Lego builds

[@chrischen82]

Question: (additional to Joerg Wimmers question) Hey Scott, I think Joerg was referring to the heat shield tiles of Starship and Spaceshuttle as well as X-37B heast shield. Those are black ceramic tiles and even though they have a white/grey-ish colour when backed, they get coloured black for a specific reason, right? ++ How about Arca Space these days? Did they get any further? Best regards, Chris.

[@lent6114]

It would be interesting to compare the challenges faced with the first human lunar landing and return with the current Martinis project. The advances in computing, propulsion systems, materials, and communications would seem to make things an order of magnitude safer and easier. Yet, still a huge endeavor. Compare and contrast would be interesting, IMHO.

[@lent6114]

*Artemis

[@peterbunnell2373]

@ 14:53: The Gregory Peck reference is from the movie "Marooned".

[@ElmojitoYTjop]

A quick note towards the heat-shield discussion: when entering at low velocities (e.g. from LEO) the heat load is rather small and re-usable heat shields can be used and they are usually black to maximize their black-body radiation. Making them reflective would do no good, as there is basically no radiative heat. At higher velocities re-usable heat shield become increasingly impossible and stuff like PICA (phenolic impregnated carbon ablator) is used. This is meant to burn off, so any paint would quickly be gone anyway. At even higher velocities, where radiation becomes the dominant source of heat (e.g. the Galileo probe entering Jupiters atmosphere at a whooping 48 km/s), the heat load is so high that any reflective surface would burn of in a mere matter of milliseconds, no matter how reflective it is.

[@dansegelov305]

Hey Scott. I have a question for you. Given that the bow shock of a re-entering spacecraft heats and disassociates atmospheric gasses into plasma, and that plasma is therefore electrically charged, is there any scope to using electromagnetism to repel the plasma forming a cooler boundary layer over the windward face of the vessel, removing the need for a full heat shield?

[@theblackswan2373]

Hay Scott a couple of questions: 1) What do you primarily use the 3D printer for? 2) Has anyone ever even proposed a variable geometry rocket engine nozzle? I can’t really picture how it could be done but….. P.S. Not that Black Swan 😀

[@arthurfarrow]

Was not launching a rescue vehicle through the eye of a storm in the novel 'Marooned'?

[@chrissartain4430]

Manley Scott, great answers today thanks

[@BeardyBaldyBob]

I think Scott is catfishing us with that photo of some fresh young chap on his patreon! 😳😂

[@Clematisch]

0:47 this is also called "Discord Light Theme"

[@advorak8529]

Yep, Scapa Flow, Ernest Cox (of Cox and Danks, a salvage company) had the largest private navy, only sunk once. IIRC, during a miner strike in in the 1920s, they got quite some coal out of the bunkers of some of the ships. ... A few are still down there --- not that they did not blow huge holes into all of them, opening the engine spaces to get the more valuable materials there.

[@mgscheue]

Fun to get a look at your work area. Your desk looks like mine. And I have a Prusa printer on the way. Didn't think of using it as a platform for my Lego ISS!

[@kirkwagner461]

QUESTIONs: -Which beers/whiskeys pair best with which games? And which is the primary choice? Do you say "I'd like some Jamesons. That means I'm playing Kerbal tonight!" or "I'm playing Kerbal tonight, that calls for some Jamesons?" -Have you ever visited the Wright Patterson Air Force Museum on Dayton, Ohio? Great stuff there. Do a vid? -Have you ever visited either of the Smithsonian museums near or in Washington, DC? (Air and Space is on the national mall, while the Udvar-Hazy Center is in nearby Chantilly, VA. I live nearby and both are great.)

[@semvosem8852]

Hi Scott, you videos are always interesting. Appreciate your work - it gives great results. Question: can you please talk about how SpaceX installs and removes engines on SN20 and BN4? It seems to be done from outside of the ship, and done quite fast. I am wondering how all it connects to fuel, electricity and control lines.

[@sm3ttz]

Jolly good fun the last questions about a bit more personal stuff!

[@johnrymszewicz]

Do any rocket engines take advantage of liquid oxygen's ferrous properties? It seems like a good idea to me esp concerning ol' muskie's flipity flop maneuver and lighting those sea level raptors.

[@LTVoyager]

Have you ever done a video on the Van Allen radiation belts and how astronauts got through them without health issues?

[@kefkaZZZ]

3:18 So you’re saying that the Proton Torpedo (a ball of condensed protons in a warhead) from Star Wars would really be a high energy storage option?

[@gajbooks]

Absolutely, but still nowhere near nuclear. That's basically just an ionized hydrogen blob. Now, a Star Trek photon torpedo with antimatter... That would be good storage. Or get a few Jedi for infinite power generation via Force.

[@TheBackyardChemist]

@@gajbooks Depends on how tightly you can cram the protons together. What is the fission yield of one atom of element 10 000 ?

[@hagerty1952]

Regarding heat shield color for non-ablative systems (like the Shuttle's tiles or Dyna-Soar's columbium panels), the ones that see most of the heat are black because it increases their black-body coefficient, allowing the surface to radiate heat away better. That's not the same as "reflecting" the heat, but rather getting rid of it once it has been absorbed by the surface. BTW, columbium is not black by itself, so there was a coating of silicide applied to make it look so sinister.

[@paulgrosse7631]

As you say, the steel radioactivity problem is not that much of a problem any more. However, there is a problem if you want actual wrought iron. Lots of things are called wrought iron but wrought iron is a material, not a style - often, so-called wrought iron gate are made from mild steel. Actual wrought iron was made originally from blooms in a furnace that did not melt the iron - this was how it was done in the middle ages - and things forged from that. Actual wrought iron is a composite material with a lot of silica strings in it so it is a bit like a glass fibre composite material. Forging wrought iron takes skill because of all of the silica in it and when it rusts, it has a distinct thread-like nature. If you ran the bloom furnace a little hotter so that it actually melted the iron, the iron would drink up the carbon that was around it and make pig iron. This is what comes from blast furnaces. Pig iron was until less than a hundred years ago, then put into a hearth furnace and the carbon burned out of it. This made mild steel but unless you added the silica, you didn't get the composite. An American made a process that added silica to make synthetic wrought iron because the physical properties of wrought iron are so much better than just plain mild steel. You can still get wrought iron - the stuff made from bloomery furnaces has a distinct 'small bits of charcoal' look to it and is called charcoal iron. The later wrought iron is more common and you can get companies like Topps to make it from old anchor chains and so on. I get the feeling that most charcoal wrought iron is being made for KZbin videos nowadays.

[@chris.heffernan]

I used to use 35% peroxide at work. Nasty stuff, great question.

[@metachuko]

I don't know why, but the hurricane question really cracked me up. Maybe because I'm picturing some Hollywood screenwriter trying to work the scenario into a script.

[@donsample1002]

1969, _Marooned_ A rescue mission to save some astronauts stranded in space is about to be scrubbed because of a hurricane bearing down on Cape Canaveral. Just as all hope is about to be lost the weather officer notices that there's a good chance that the eye of the hurricane will pass over the launch site during their launch window... Based on a book by Martin Caidin, who produced some fairly hard SF, and was the guy responsible for _Cyborg_ which got turned into _The Six Million Dollar Man_

[@Teekles]

A rocket launching through the eye of a hurricane sounds like mediocre action movie and I love it

[@sylak2112]

A lot of youtubers: Fancy camera, expensive Microphone, fancy background, large crews, Crazy animation edtiing. Scott "aaah I use a phone and a point and shoot, and look at my office it's a cool mess" . Guess what, that all we need! Feel more authentic. Speaking of Awesome point and shoot (yeah that sony is neat indeed), I'm a big fan of Panasonic ZS/TZ series. I discovered those in 2009 with the TZ5. My Galaxy S10 is great, but I want a Zs100 now. it has a bigger sensor (not DLSR size, but DSLR are a pain to carry while travelelng for not that much gain for my use). as good as phone are, they are still things a dedicated camera, even a point and shoot, are better at. Thanks for the video

[@Alexander_Sannikov]

can the black heat shield color be related to black body radiation being more effective from, well an actually black body? i remember from uni course than any brighter albedo than black is less effective at radiating heat, although i never understood exactly why. the simple explanation says : "bodies that absorb more radiation also emit more radiation because they are better coupled with EM field". but this connection is not clear enough to me and the actual rigorous proof is non-obvious. and when you see reflective materials used for things like thermoses and thermal blankets, it's exactly for the opposite: to reflect as much heat as possible and to radiate as little heat as possible.

[@GreenJimll]

Question on heat shields: Starship is obviously struggling with its prototype TPS tiles, but back in 1980s as a kid I saw Starlite demonstrated on Tomorrow's World and it was mentioned that NASA had looked at it as a heat shield. Whilst the Starlite recipe was taken to the grave, have any thermal protection systems been based on similar carboniferous tumescent materials? Could something Starlite-esque be used on Starship or does SpaceX's planned rapid reuse preclude it?

[@retrorocketuk]

Talking about rocket fuel, I immediately spotted the bottle of White Dog on your top shelf :D. I discovered the drink myself on a holiday to the Grand Canyon some years ago, and now pay terrible UK import prices to always keep some around for just the right occasion.

[@Psi105]

If your running short of questions create a channel on your discord for non-patreons to ask stuff. You'll probably get lots of stupid questions but i'm sure some will be good. You can set a 1hour between post limit to stop that channel getting flooded

[@barefootalien]

For the asteroid warning... it depends on how big. Really huge ones we'd need decades or centuries of notice for, but fortunately we know about all of those, and it's entirely reasonable to actually _have_ that much warning. For smaller ones, actually, I think a few _weeks_ would be fine. There've been some results lately that suggest that nuclear detonations can actually do quite well at redirecting asteroids, and I don't think it'd take that long to mate a thermonuclear warhead to a Falcon Heavy or the like. Would it have all the super-tight safety and testing stuff done we want for launching expensive satellites? No. But so what? We just need it to have a reasonable chance of successful launch, and then we can prep several to increase the odds. This is existential stuff; money is no issue. We're confident at this point that we know of all the region-killer asteroids and above that are in normal, stable orbits in the inner solar system. Apophis was the only scary one, and that's been eliminated as a threat within the last year or so. City-killers might still come around, though we believe we know _most_ of those, but those aren't that hard to deflect. The real danger is extra-solar objects, or high-eccentricity objects... but those often contain a lot of volatile materials that off-gas and create bright tails as they approach the sun, so are pretty easy to spot. The truth is, the era of existential danger from asteroids is all but over now, barring a freak incident like a hyper-fast extra-galactic object moving retrograde through the galaxy hitting us, but that's even less likely than a gamma ray burst or other extremely-low-probability doomsday scenarios. Does that mean it's time to cut funding? Absolutely not. But right now, asteroids rank pretty far down on the list of existential threats to humanity and/or large chunks of our civilization, below climate change, coronal mass ejections, nuclear war, and pandemics, at the very least.

[@ecoriskprojects9783]

I seem to remember that both the Gemini and Apollo spacecraft had heat shields that were white. The Mercury heat shields were a brownish color as seen on the unflown spacecraft exhibited in the Smithsonian.

[@nicholasmaude6906]

The reason why the Black Arrow was cancelled is because short-sighted bean-counters with no imagination in the UK's treasury department came to the idiotic conclusion that there was no commercial application for it. I sincerely hope that once they were proven wrong they were dismissed from their jobs.

[@lawrencedoliveiro9104]

13:42 And no doubt there will be those claiming it’s all a political hoax or some kind of conspiracy, the threat is overblown etc etc. And threatening or committing actual violence against those trying to solve the problem. (Not something I would have seriously suggested a couple of years ago, but recent events, you know ...)

[@stevecrye]

I still use Vegas! Started with Vegas 9, now Magix Vegas 17 and an AMD card for the compatible GPU. Another great one!

[@eddyer3393]

well A deep hole with water in it but that is not important now. Scott, I just wondered if you ever go trout fishing? It seems to me they are vary protective of their lure's - the golden wiggler for example is kept in the : fly safe.

[@tavshedfjols]

High Test Peroxide was used in German experimental submarines, as well as British, Soviet, and US subs after the war. It was reacted by passing through a platinum mesh/screen and the resulting oxygen and high temperature steam was combined with diesel fuel and ignited to power a turbine. They were very fast but liked to explode, and the HTP had to be stored in rubber bladders outside the pressure hull which was a fairly dangerous way to do things. The Soviet boats were arguably the closest this got to mass production. Semi-related IDK, it's interesting.

[@miles2378]

The Submarine Kursk was lost do to a leak from a Peroxide fueld Torpedo.