Making a new solid propellant formula

[@integza]

So this is what it looks like when you know what you’re doing

[@AlexW-]

But don't change the way you do your videos we like your .... mhmmm wild production style

[@Cloudsinmidair]

Hey, I wasn't expecting to see you here 😂

[@JohnSims-vl4wg]

HX-752 is dangerous bla bla, but tomatoes are disgusting anyway 😂

[@ultratorrent]

If you weren't showing us what not to do, Integza, we wouldn't even be able to appreciate Joe and his work at this point.

[@gavinblaedow9255]

lol I’ve been watching you both for years and you both have interesting and very different ways of approaching science 😂

[@DrewB0119]

BABE WAKE UP NEW BEPIS SPACE VIDEO DROPPED

[@E-dart]

Bepis is crazy

[@NeonNijahn]

I'm up I'm up!

[@eannamcnamara9338]

That's for waking me pookie

[@localsms]

It went from talking to the wife about fun rockets into fun facts about HX 752 and reproductive systems.

[@WSpace7]

“Bepis Space” 💀

[@shoitah]

The most underrated part of all BPS space is the videography. Stunning, professional work. Great job, Joey!

[@Brian-bk9qv]

Agreed.

[@trainedloser]

Absolutely, these are always top notch. I forget i'm not watching a big budget produced documentary.

[@fearlessgaming976]

He is musician and you can see his video music stands out from other channels music because he makes all of them and i think it is most underlooked aspect as people think he copy paste music of others .in reality it takes work forr 2 min music

[@leifhietala8074]

"Not a fun tangent," and yet PRETTY DARNED IMPORTANT so thanks for that, Joe. Good safety tip.

[@ConnorisseurYT]

yet another Joe Barnard video of all time. This one brutally shattered my kneecaps, thanks Joe 👍

[@BPSspace]

You are welcome!

[@Admeen3581]

To my FBI agent: I’m watching this for entertainment purposes only.

[@NeonNijahn]

Move along. Nothing to see here.

[@zchris13]

FBI doesn't care, the ones who might care are the BATFE

[@RustyMTB]

It’s ok FBI agents view my LinkedIn every so often. To my fbi agent this is just for funzies

[@william5931]

Just wondering why you need this knowledge. --Your FBI agent

[@NeonNijahn]

@william5931 I don't. I just watch videos about random shit all day. I won't remember this video an hour from now. I'm a sad lonely soul.

[@leomonk974]

7:31 this tangent is probably the most telling about your character. It’s an honorable one that in my opinion deserves way more recognition.

[@PatrickKQ4HBD]

6:45 ff, Thanks for including this part. Seriously. I don't think I've ever seen another presenter take on the issue so directly and yet politely. YOU SIR, ARE A GENTLEMAN AND A SCHOLAR!

[@robinvanderpal372]

absolutely, that was great.

[@mr-huggy]

Reliant Robin is also the car that Top Gear used as a space shuttle in their launching of a space shuttle.

[@mr-huggy]

By the way don't ever show it on KZbin it's an instant takedown.

[@Thefrontdoorscientist]

Joe should send a reliant robin to space. Using reliant robin

[@kender242]

kzbin.info/www/bejne/pnvHo5-Nh5KsfK8

[@BPSspace]

@@mr-huggy I KNEW IT - This is so validating lmao. I thought of mentioning it and just showing a photo but I figured I'd better play it safe and just reference the car instead of the Top Gear episode for that very reason

[@adaama4460]

It's also the car that Mr Bean continuously has altercations with in his Mini!

[@jpburned2414]

I grew up with harry, used to be best friends. Haven't spoken to him since middle school, but I've followed his rocket engine tests ever since and I think it's so cool that you're using his formula!!

[@whyevenotter1578]

Out of every channel I am subscribed to, I am by far the most excited when I see a new upload from this one. Amazing videos

[@timewing5501]

For those of you who don't know, 0:21 is a Pegasus rocket launch - an insane rocket that launches satellites into orbit by dropping a solid fuel booster from a plane. I used to be a flight controller for CYGNSS, a constellation of satellites launched on one of these boosters (and probably the one in the clip). Really cool to see it in the wild!

[@faxinspace]

12:21 Dude you got me so good i was like NO STOP then burst out laughing when you explained

[@JonahGreve-bn6jc]

A couple of months ago I found your channel from the time you talked with Tom Stanton in his video. I was immediately drawn in. In the next four days binged your entire KZbin channel. I got to the end and subscribed. You are an amazingly gifted person. I can't ever imagine knowing all the things that you do let alone teaching me them myself. I thank you for persevering through your scrubs and failures to continue to bring us all your incredible and inspirational work. I ask God to bless you with many launches in the future. May your skies be blue and your winds be low.

[@PatrickWilson47]

Awesome video and I enjoyed the tangent on the MSDS like I say at work “Better to be Safe Now Then Sorry Later”

[@AsmodeusInflect]

This is spectacularly well presented. You covered a complex topic in an approachable way - I wasn't lost at any point, and you hit the safety aspects effectively and concisely, and highlighted exactly why they're an important consideration which I love to see.

[@backpackerx]

We don't deserve the level of detail you put into these. The sheer effort that went into filming and editing that first two minute overview was amazing.

[@fullflowaerospace]

“woah that’s such a good chemical, it really makes life so much easier.. what could be bad about it?” “OH WAIT NVM”

[@mduckernz]

Azidrines are bad juju, yes

[@tompw3141]

-- every chemical engineer, ever.

[@ImieNazwiskoOK]

Everything!

[@James2210]

haha funny chemical go eldritch abomination

[@vigilantcosmicpenguin8721]

What could go wrong?

[@DrZeus108]

Oh wow I was not expecting this level of depth. I was completely engaged and I am sad it’s over. I am excited for the next one and hope it’s even longer with more great info. Thank you

[@Daan_Music_]

This is one of the best long term series in all of youtube. I cant wait to see where it leads and the amazing journey ahead. Keep it up!!! You're doing awesome!

[@jimurrata6785]

Really good brief overview of APCP. Id like to see you delve deeper into the more "flamboyant" additives like titainium flake, strontium, barium and the other colorful pyrotechnic nitrates and salts These might not have a place in a space shot where any properties that compromise ultimate ISP probably arent welcome. Lecithin is an emulaifier in the food context. It helps keep things from separating.

[@fabotond]

Iam having an Algebra exam in Feburary, and it makes me question my life choices... but watching videos like yours encorage me to learn that shit. You were one of my main inspirations to go and study engineering.

[@lonewolftech]

😂😂😂 algebra isn’t even hard it’s the trig, calculus, and other shit that’ll fuck you up in engineering. Just remember with algebra most of the formulas are given already you just have to learn to plug in data.

[@wardyosh]

As a researcher with a PhD in organinc chemisty I have had the conversation about chemical hazardous and risks many times . Through someof my hobbies hazardous chemicals have come up several times and trying to convince people that the dangers are real, and could have life long, debilitateing effects is shockingly difficult. Your explination of the hazardous of the chemicals your using was exelent, precise and struck the right tone. I cant stress enough how dificult that is to do, you rely are an exelent comunicator and I will definitly use this as an example the next time I have to explain similar risks.

[@timcovey7280]

I don't recognize said authority, As a garbage man I see hazardous organic chemistry everyday and know how to spell it.. What exactly do you research with spelling like this, We are doomed..

[@lonewolftech]

😂😂😂😂😂😂😂😂😂😂 much fail

[@curtiscapdeville6011]

You mention the use of MDI as the curing agent for solid propellants. Now I work at the solid rocket manufacturing plants in Utah where we all sorts of different propellants. And of all the formulations I know of, none of them use MDI as a curing agent. Also the curing agent we always went to in college was D.E.R 331 or DDI curing agent. Those are much more readily available and are not as toxic as MDI.

[@oasntet]

Lecithin is also an emulsifier, useful for getting fats to stay suspended in water. It's commonly found in nut milks to prevent separation, as nut extracts don't have whatever cow's milk has to keep the fat particles in suspension. It's also a pretty handy additive if you want to add something like peanut butter to a smoothie, or want to make a lower-fat ice cream at home without risking ice crystals growing everywhere.

[@SixOhFive]

Or want to make potent weed edibles

[@universalrockets]

You have no idea the happiness of seeing a new BPS Video

[@genxtech5584]

Your video series has come a long way Joe. Quality work here, you should be proud!! You may not realize it yet but you will inspire children today with science that will have profound impacts on our world in the future.

[@bennyfactor]

Always happy to see a new video for you, most of all because you do such a great job of explaining literal rocket science, but also because it means you didn't get a a visit from Raytheon or General Dynamics or whatever with one of those gigantic checks and some balloons with the caveat you don't get to make videos any more.

[@rrmackay]

years ago as an amateur rocketry member we mixed solid propellant using NH4MnO4 and powdered aluminum with a 5 minute epoxy as a binding agent poured into 2" diameter by 24" length solid rockets. It was wild because the epoxy would get very hot during the curing process. Scary stuff.

[@benjaminnevins5211]

These videos have been getting better and better!

[@the-witness8811]

You could get rid of those bubbles in the mixture using a sufficiently small concrete vibrator. This is how we ensure stable solid foundations with concrete. Just know it'll cause some of the more watery substance to rise to the top, since it is lighter. I also don't recommend using this method with any fuels that are sensitive to impact or jostling. Just an idea. Thanks for the videos man!

[@fdelacou]

Brilliant was an excellent choice of sponsor for that video! On the other hand, AG1 could have been one since it was also about chemicals that could neutered you! /s

[@tristanbergh8655]

Hey Joe, rocket scientist here, wish I’d had this channel available when i was studying. learn by doing - yes! The studies only touch on a lot of stuff which you’ve absolutely dived into and really got skilled in - i love your videos!

[@CDRaff]

It's fun how so many propellant mixture names are full of puns and easter eggs that reference each other.

[@macios502]

I love that when You read the script You are moving Your head so it looks more energic and a good way to cover the eye movement. Loved the video

[@mr.weirdo5756]

It`s such a joy to see how far you have come. From shooting your first test rockets to this, always blows my mind.

[@hvip4]

Man there are a lot of science, experimentation, engineering KZbinrs I watch. You're among those top of the line straight up madman. There are the popular science guys who are just using cool tools and materials like vacuum chambers, ooblack, ferofluids, liquid nitrogen to make experiments done a 1000 times before. Then there are awesome builders, creating jets, airplanes, plasma, laser, chemistry, high voltage experiments and many/much more. Very extremely cool projects, but mostly for themselves and KZbin, without a clear goal. And above that there are the madmen. Off the top of my head I can think of "Thought emporium" and yourself. Doing stuff that requires some brutal scientific research and dedication and a clear goal in mind. I am not an expert I have just been interested in this kind of content since the beginning of KZbin. I really appreciate what y'all are doing ❤

[@kreelaban3420]

Lecithin is actually an emulsifier. There is lots of it in chocolate. the more lecithin, the smoother and creamier it is. It is great for keeping fat soluble in your blood so you don't have a heart attack from drinking real perclorate mixtures accidentally !

[@AnthonyNolan-w5u]

Congrats, after more than 5 years you are my first youtube comment. Thanks for finally describing the full details of propellant design, interesting stuff. There's no protecting idiots from themselves anyway, if they are determined enough. Best you can do is explain why its dangerous instead of just giving them an instruction manual. Which you did. As a former research chemist, I'd have to disagree about avoiding toxic chemicals on principle (I've used much, much worse), but I guess I wouldn't want those in my garage. Nice channel. Good luck with the spaceshot!

[@eannamcnamara9338]

It's awsome seeing how far you've come, from testing thrust vectoring with standard hobby motors to literally msking your own fuel for a space shot! Also eating the sugar really got me! Im telling you, BPS and Copenhagen suborbitals should team up, place your space shot on top of their spica instead of the capsule for a bargain bin vanguard rocket if you will lol

[@JustGoAndFly]

Very good video. Excellent pace, no irritating Adderall narration, super interesting stuff. What all KZbin videos should be!

[@lpngcf266]

I remember when you weren't feeling so good and you had to spot for a while. Glad this is where you are today!

[@dougyoud5944]

Nice work Joe! Looking forward to seeing the data on that motor my buddies found out at Black Rock desert last year :) hope it’s made its way back to you by now.

[@Lampe2020]

12:16 Wow, my heart stopped there for a second, until the thought that it might only be sugar came through my mind. And then you said it and I calmed down again **phew** XD

[@sashali6666]

Istg this man is the Nile Red of rocketry, I love it

[@Ryomensukuna0616]

Last semester I studied this things as rocket propulsion system had 5 units solid rocket pro, liquid rocket , hybrid then electrical propulsion ...damm it was ...main highlight was learning regression rate in hybrid and liquid rocket specifications...thou we couldn't study entirely but got an raw idea of rocket propulsion system as an aerospace engineering student...now after seeing this video I can literally remember wht I studied and can understand nowww more easier ❤... amazing mate....if in case you conduct some free online internship( mainly I am from India ) please notify us because you are an excellent teacher and scientists

[@IronAnt2008]

At school i was looking for new videos of you and now when I’m going to sleep you post.

[@CarsonUitermarkt]

I just love seeing the one upload per blue moon come from this channel. Hopefully some day you're able to reach said blue moon with these amazing rockets!

[@TheQueer23]

BONGO SPACE PROGRAM POSTED LETS GOOOOOO

[@billgaytes6845]

New to this channel. Amazed at what you are doing. While other KZbin's talk about rocket science you are actually doing it.

[@110Genesis]

I've been following your progress for a few years now. It's simply incredible and inspiring, honestly. Keep it up!

[@Arthur-rh9tf]

Holy crap, very impressive. Been a pleasure following you on this journey. Awesome work dude.

[@loganki5zyw]

Been here 4 years since I discovered u as a little kid. Still following with interest... Can't wait to see the space shot

[@kylecordes]

Watching your progress through all this has been incredible. I am so eager for the stage when you move on to liquid-fueled rockets, stepping away from working with these highly dangerous mixes in a workshop. Although liquid rockets are famously incredibly hard to make not explode, at least the dangerous stuff is only present at the test stand!

[@OtterSwims]

There's a youtuber making a liquid rocket made out of a beer keg which I'm eagerly awaiting the completion of, it looks really cool

[@willtheelectrician8184]

Bro, I don’t even need to see your thumbnails anymore. I just click as soon as I see BPS… Your production quality these days is phenomenal, I can’t believe you don’t have 2M subs yet.

[@CoronaFighter_]

my face when joe picked up the "ammonium perchlorate" and, without any context, just EATS IT-

[@johnholleran]

Great video, Joe- can't wait to see the rest of this series! Stay safe out there

[@-r-495]

thank you for the appropriate warning concerning the risk potential of the educts and thinking about the product and cleaning and disposal. intriguing!

[@-r-495]

I agree with ball milling for the AN. personally I‘ve worked with gas mills and far finer grain size range.

[@aidenhennings8]

Cool video man, I can't wait to see where you take this! One small but very important correction, the aluminum does NOT act as a fuel in the propellant. Fuels expand into hot exhaust gasses that take up tremendously more volume than their solid original state when they are burned. Aluminum does not do this at all. When it oxidizes, it does not expand and does not get hot enough to even turn into a gas. It's real purpose is to release lots of heat as it oxidizes, which in turn expands the exhaust gasses and increases pressure, therefore producing higher thrust as the gasses exit the nozzle with greater force. In this way it acts very similar to a fuel (both ultimately work to increase the pressure of the exhaust gasses) but do so in very different ways and have different side effects as well. In apcp propellants, the fuel is the binder, but also unintuitively the AP as well. When AP breaks down it releases the needed oxygen to oxidize and all that good stuff, but the molecule also breaks into a burnable fuel. This is why AP is such a great choice as an oxidizer, even though there are plenty of solid oxidizers that are better at releasing lots of oxygen, which on paper sounds better.

[@vyznev]

AFAICT, there really doesn't seem to be a clear consensus on what "fuel" means in the context of solid rocket propellants, and many seemingly authoritative sources (e.g. www.ncbi.nlm.nih.gov/pmc/articles/PMC8587658/) as well as less authoritative ones (e.g. Wikipedia) seem to classify all reducing components of the propellant mixture (other than trace additives, perhaps) as "fuels", if they don't simply use the words "fuel" and "propellant" interchangeably. For bipropellant liquid fuel rockets, there's a well established distinction between "fuel" and "oxidizer", those being the two liquids stored separately and mixed and ignited in the combustion chamber. (And yes, aluminum _has_ been tried as a liquid fuel additive; see e.g. Clark, John D. (1972), _Ignition!_, p. 180.) In solid rockets, however, the propellant is all one more or less homogeneous solid mass, so that simple distinction does not apply. The various substances making up the propellant grain can certainly still be classified using chemical terms, e.g. as oxidizing, reducing or inert, although - as you note - this classification isn't perfect since a single substance such as AP can contain both oxidizing and reducing parts. However, "fuel" isn't really a term used in this chemical classification. The closest thing, perhaps, is "reducing agent", which metallic aluminum certainly is. Anyway, while gas generation is certainly an important (arguably _the_ most important) aspect of rocket propulsion, AFAIK there is no concise and established term for "a substance producing a gaseous exhaust when combusted as part of a rocket propellant." And even if there was, it would presumably have to include both oxidizing and reducing compounds, since both can and do contribute to the exhaust gases. Part of the complexity here is that the actual composition of the exhaust depends not only on the individual elements and compounds present in the propellant mix, but also on their ratios and on the temperature and pressure of the combustion process. While we can certainly say with fair confidence that e.g. aluminum pretty much always gets exhausted as solid particles (of aluminum oxide or, if combustion is incomplete, aluminum metal) while e.g. hydrogen and nitrogen pretty much always end up as gases (H2 / H2O / N2 / NOx) in all but the most fuel-rich (sorry, reducing) combustion conditions, other elements such as oxygen and carbon can go either way depending on what (if anything) they end up reacting with. And even when a combustion reaction produces gaseous products, that doesn't necessarily guarantee an increase in pressure: for example, the combustion of hydrogen with oxygen (2 H2 + O2 -> 2 H2O) has gaseous products (at typical rocket engine temperatures) but actually decreases pressure, since three gas molecules go in but only two come out. The heat generated by the reaction, of course, generally more than makes up for it, but that's still a big part of the reason why hydrolox rocket engines pretty much always run very fuel-rich: you get a much better specific impulse if most of your exhaust is uncombusted H2 rather than H2O. (The other reason, of course, is that _too much_ heat tends to be bad for the engines.)

[@adamszalkowski8226]

That sugar and water with food colouring in the background looks mighty professional 😉

[@MarcusHouse]

Super interesting Joe. Thanks for making this.

[@nathanguyon7620]

I love this series. Side note, always wondered what kind of difference if any using regular aluminum vs. ball milling your own and mixing the propellent under an inert atmosphere. The oxide layer is super thin, but freaking resilient stuff. Dunno, just popped into my head after years of not thinking about it thanks to this vid.

[@vyznev]

10:20 Nitpick: "power law", not "exponential". I know it's kind of confusing, because there _is_ an exponent involved. But in the formula for the burn rate, the chamber pressure is not _in the exponent,_ and so the relation between the burn rate and the chamber pressure is not exponential.

[@waylontmccann]

Joe man, I love that naming convention. Great work!

[@hugacreeper69110]

It’s been really cool seeing the scale of your projects evolve over the years nice work!

[@lit_for_20]

you make all of this sound so easy to understand. i wish some of my teachers would've been like this

[@leggo0]

Joe you are so amazing at explaining and breaking down complex concepts.Always look forward to these videos!

[@chiranthanreddy1271]

Been here since the days of Signal R2, Nice to see you go for spaceshots. May the skies be clear and winds be low!

[@fledglingrockets]

Waking up to a new BPS video is the best feeling! (I only now realized how similar our logos are)

[@ltpinecone]

Another excellent video! Humor, science, and outstanding videography! I also really appreciate your emphasis on safety. Great stuff!

[@Evan_gg345]

Nice video, just a quick thought, would paraffin wax be a good combustion depressant? The aluminum fuel has an energy of 31.8 MJ/KG, but paraffin has an energy of 42 MJ/KG. This would increase specific impulse due to extra heat energy and also lighter exhaust products (co2 and water over aluminum oxide). I know this would slow the burn, so maybe in small percentages on an upper stage🤔

[@thatstarman42]

YOU TAKE THE HTPB, IDP, ALUMINUM AND MIX AND ADD THE PER-CHLOR-ATES! YUM! 🎶

[@Copesthetic-Aesthetic]

A dead straight concrete tunnel. 3 miles long. Pointed on a slight upward trajectory from start. To avoid unnecessary lateral g forces. Reduce atmosphere slightly. Install mag-Lev rails around the outer diameter of the tunnel. Accelerate whatever you like into space. Weight would not be a problem. I think lead lined space ships might be nice.

[@blakeparker8282]

Love the videos I love rockets and the science behind how they work big or small rockets

[@bofhorg]

16:08 in/s, g/mol, K, psi and ft/s together on 1 page... mixing imperial and metric resulted in an extra crater on Mars if I recall correctly

[@transistor754]

great stuff as usual... vibrate the motors on loading... thixotropic... also the surface area increases along with the diameter of the burn area....

[@TeaRex]

Taking a break from studying for my Thermal Rocket Propulsion exam after getting wrecked on a question about a Solid rocket motor and what do I see in my recommend. More solid rocket motors. My life is a sick joke haha Edit: in my textbook it's De Vielle's equation as well, guess that needs updating

[@Djbz91]

Great bit on toxic chemicals really informative 👍

[@ZoonCrypticon]

@15:40 lecithin is in most margarines and cheap chocolate brands as emulsificator.

[@thom7440]

Great video, Joe! Looking forward to future vids where you explain more of the technical stuff

[@justinrobinson9524]

Thanks Joe for the great video as always

[@Core-Frisk]

Bps is the sole person that has saved so many of my projects

[@albertstebbins7590]

Same for me and I only make Lego

[@fabian1150]

Thanks for all your effort! Never thought that I get so interested in this topic but here I am and I can't wait for the next video :)

[@Streetcarsaturdayshuntsville]

Prolly my fav tech video Love the openness of knowledge Can’t wait for more vids on this motor!!

[@Turcian]

BPS finally owning up to its name and doing propulsion stuff 💥 🚀

[@BirnieMac1]

It’s worth noting that MSDS risks being lower is specific to the GHS classification system; that sadly despite being the international standard, isn’t always implemented so it’s important to check which system they’re rating it off Otherwise love your work; you’re spot on, working with nasty chemicals isn’t worth it 99.9% of the time I miss having access to a fume hood after switching to engineering

[@winter5945]

Man, the B-roll on this video was insanely beautiful.

[@FinnBuildsThings]

Wish I had this skill and brain power, I’m just now using fins with mobility but even that barely works. Keep this awesome stuff up!!!!!!

[@aculleon2901]

Awsome stuff man. Beautiful shots.

[@NathanLewisVideos]

Your quality is just better and better, also i want that starlink sweatshirt

[@chicken_punk_pie]

IDK why but that slice at 17:47 looks TASTY

[@KevinJonson]

Ever consider doing a video with one of the chemists KZbinrs on how to test and purify your input materials? There has to be a way to verify the quality of the stuff you're getting before jamming it into an explody tube.

[@ZoonCrypticon]

@11:00 I wonder, that the surface of the solid propellant towards the burning core doesn´t play a role in the equation.

[@derpyter]

What do you use to protect your combustion chamber and how? I assumed you use phenolic but I can’t find any flexible sheets? So how do you take a solid phenolic sheet and shape it into the cylinder shape to fit into the combustion chamber? Or do you just use phenolic paper? I don’t know and I need help with that.

[@tec4303]

THANK YOU for talking about safety!!!

[@chaosopher23]

Sutton has a good-sized section on this. I'm considering a Karmann breaker, and so far, OpenRocket says a 3-staqed rocket powered only by N-5800 can go that 100 km line. Since I want to get it back, the upper stage has a graphite nose cone and cargo bay and fins. The rest is carbon fiber, 4.024" off the shelf. As for recovery? I'm still working on that, but Regallo is a very attractive method. I'll build an Estes BT-80 size, first. I'm learning a lot, here. Keep up the good work!

[@Arek_R.]

2:54 He's so sweaty it drips down from his glove. Can't blame him lol

[@gottabweird]

I'm so curious to see what adding both a catalyst and a burn suppressant would do.

[@mduckernz]

This is a legitimate thing to do sometimes - some suppressants act more on the n parameter, rather than a, and so if you want a fast burn but for it to be fairly insensitive to changes based on pressure - this is most often useful with grain geometries that have quite big surface changes throughout the burn, which you don’t want translated into thrust differential - then you can select one that acts primarily on n, and then add a burn rate catalyst that primarily acts on the a parameter; for APCP, red iron oxide is a traditional and still excellent choice for this.

[@mduckernz]

The resulting propellant will be one that doesn’t have “swingy” burn rate, and a burn rate that can be tweaked as required by adjusting the amount of burn rate catalyst. Keep the suppressant at a fixed value and simply tweak the catalyst, thereby tweaking the a parameter.

[@mduckernz]

I have used this strategy to “tame” a propellant based on sodium chlorate and platinum-catalysed casting silicone as binder. Typically, chlorates have too high of an n parameter in their propellants made from it, but it can be tamed through suppressants to a value where it is actually usable (though I much prefer APCP… this was more of a “huh, I wonder if I can get this to work…” than a “this is a good idea” haha) I used a variant of suppression techniques, but the ones that ended up working the best were low molecular weight amides. IIRC, without breaking out my old research notes, I ended up using glycine or phenylalanine, because it was effective in low quantities and was readily available, and didn’t screw up the binder chemistry. Without suppressants, the measured n was about 0.65, far too high for comfortable development, as neutral grain geometries (surface area barely varies throughout burn) would be pretty much a hard requirement. WITH suppressant, between 0.38 and 0.45 (depending on the exact one, between those I had deemed viable and potentially worthy of further testing), which is still a bit high but very workable.

[@mixsmasher]

Can we appreciate the stop at 18:08? That is actually stunning it looks like a nuke on a test stand lmfao. Of course it is sad that it went kablewy but cool as heck!!!!

[@jamesmnguyen]

You almost got me when you ate the "Ammonium Perchlorate".