What's the Best Kind of Rocket Fuel?
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- Опубліковано 23 сер 2024
- Chemical, nuclear, electric... what's the best way to get your spacecraft to a distant planet? There's a little more on this in my latest blog post: vintagespace.w...
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Scott Manley is just a scientist? NO, HES A GOD IN THE KSP COMMUNITY!!!
Joseph Jobo Licayan And he's also an astronomer.
Scott Manley is very good at explaining the science behind spaceflight. He's a great resource.
That's why I emailed him! He is definitely awesome. And we're working on figuring out that collab!!
Ed T. NecroBones Exactly Necro, Exactly
I wish I could give this more than one upvote!
Hay Bones, are MRS and SpaceY mods up to date?
Always. :)
Hellooo! I'm Scott Manley, and you're reading this in my voice.
Hullo*
Fly safe.
Chueels
Waiting for Scott Manley to actually come here and say hulloooo.
wrong
Scott Manley, the only person who can explain the physics of rockets AND help you with KSP :D
Loved the video btw
This is the most KSP video that doesn't ever mention KSP I've seen.
That last part of the video was almost as cool when there is a crossover between two of your favorite tv shows!
*two
ty
felipe morelatto yw
4:41 - "If the rocket explodes it might be really bad for the humans." lol
lol?
It's the Kerbal Style! *gnhihi
Have you ever considered collaborating with Destin at Smarter every Day? He really is a rocket scientist, and loves all things NASA :-)
Love your channel :-)
^
I think he's also a NASA employee which might cause him "not an official spokesperson" problems talking about topics dealing with NASA.
He is on sabbatical from his work with rockets, the military, and NASA. He's returned to school seeking to work on a PhD, I think. Maybe he's seeking a second Ph.D. In any event, I think collaboration with him would be awesome.
Speaking of Scott Manley, are you any better at playing KSP now, Amy?
Self ignition is a useful property for deep space propellants, but that is not the only, or even the most important, reason that hypergolic propellants are used. Another, very important, reason is that the most common hypergols, hydrazine, its derivatives and nitrogen tetroxide, are storage stable. The cryogens, including LOX, just don't want to stick around. If your mission plan is days, weeks, months or years, instead of hours, you need storage stability.
I guess you could call hypergols "stable" in the sense that they don't continuously boil away like cryogens. "Storable" may be the better term for hypergolic propellants since, as a rule, they are insanely corrosive and hideously toxic. Not the worst choice for an ICBM that has to spend decades in a hole waiting to launch on two minutes warning, but far less attractive in the booster stage of a space launch scenario where missions are planned years in advance.
Mylitla Nitrogen tetroxide, and the older red fuming nitric acid, are quite corrosive, but not so much that they can not be contained in proper metals. The hydrazine propellants are not corrosive to metals. In fact, one of the common uses of hydrazine is as a corrosion inhibitor in boilers.
We should not imply that the word "hypergolic" necessarily implies all of these propellants are highly hazardous. An early French rocket used red fuming nitric acid (nasty) and turpentine (not so bad). Most, but not all, hypergols are highly toxic. Some hypergols, primarily the nitrogen oxides, are highly corrosive.
The trick with RFNA was to add about 0.5% hydrofluoric acid to passivate the metal container. I guess compared to the overall nastiness of RFNA 0.5% HF doesn't change much...
NTO isn't exactly storage "stable". NTO tanks need air conditioning to keep below 70F. For a quarter of a century, we had Titan II missiles stationed in hot climates (Arizona, Kansas, Arkansas) in well-chilled silos... With neighbors worried at any time about red clouds of doom if NTO leaked.
Mark Holm Nitric acid is a byproduct of NTO reacting with water.
Random Hydrazine story... I was a retained firefighter some years back, and we got called out to a tanker involved in an RTC near a major Royal Air Force base in the UK. The driver of the tanker spoke very little English, and while this liquid was dripping from the tanker we were struggling to get the name of the substance in the tanker, let alone the safety data about it. I remember the manufacturer telling us on the pone "Guys, that tanker is filled with concentrated Hydrazine, sometimes used as a rocket fuel, it's extremely flammable, toxic, carcinogenic anyone near that spill is in immediate danger... you are at least 600 metres away from the tanker aren't you?". Instantaneously went from RTC to major incident in the blink of an eye: we were standing right next to the tanker in nothing more than fire tunics! The bollockings received by the RAF, tanker company, and our fire station were monumental.... luckily only a few gallons leaked out, but I remember that incident with much fondness when I hear the word "Hydrazine" :D I'll shut up now, and let Amy do what she does best!
Don't you just love this chick, never at a loss on the topic, no matter what keep it rolling
Hi Amy,
Great job with all your videos. As a child of the space race I have been meaning to subscribe for a while now. I finally decided to because it is important not only to support Vintage Space, but to clear up a common misconception regarding the usage of the terms Rocket Fuel and Rocket Propellant: they are not one and the same, and cannot be used interchangeably just to improve ones’ prose. They are distinctly different concepts.
Rocket Propellant provides the inertial mass needed to push the rocket forward by virtual of the fact it is the stuff pushed out of the rear of the rocket: it does not bring any energy to the table. Rocket Fuel is what provides the energy needed to push the propellant out the back in the first place. In the case of chemical rockets, serendipitously, the same stuff acts as both fuel and propellant, and that is what makes chemical rockets so special: it is also the source and cause of confusion over the usage of two terms.
In the case of nuclear propulsion (NERVA), the atomic pile provides the energy and is considered the rocket fuel, while some fluid (like hydrogen) acts as the propellant when it is heated to high temperatures and expanded out of a nozzle to generate high directed velocities to produce thrust. Ion drives use Xenon gas as a Rocket Propellant (not fuel), and may not have any rocket fuel on board (no, the solar cells are collectors of energy, not sources, hence not really rocket fuel) -- in which case the rocket fuel is the sun.
So as a demonstration, imagine I am stranded in the middle of a becalmed lake in a row boat full of tennis balls but no oars. For some reason, I have a phobia about sticking my hands into the water, hence I cannot paddle back to shore. I do not look at all those tennis balls and think, ‘Aha, Rocket Fuel!’. No, I think, ‘Aha, Rocket Propellant!’. The tennis balls will not throw themselves over the transom: I will need to provide the energy for that. I can still feel lunch in my stomach and I think, ‘ Aha, Rocket Fuel!’. Yes, that burger in my belly is the rocket fuel needed to power my arm muscles acting as rocket engines, that propel the tennis balls acting as rocket propellant. Because propellant is precious onboard, rather than wasting propellant to change direction with an analogous RCS thruster, I use the same energy source (the burger in my belly), to stand-up and spin around, again using inertia effects to reorient the bow towards shore; that is, I use my own body as a reaction wheel. Hence, the most precious commodity on a rocket is propellant, not rocket fuel.
Even so, when speaking about chemical rockets, you should be aware of when to refer to it as a rocket propellant or as a rocket fuel, depending on the context. Technically, it is the propellant aspect that generates the thrust, and the fuel aspect that generates the power. Please use accordingly.
Sorry for the hair splitting, but you got me to finally subscribe!
Scott (and you) can be listened to for hours.
Love the channel!
2:12 That's a Titan II ICBM as modified for Project Gemini. The Apollo CSM SPS and LM used the same hypergolics as the Titan II: A-50 fuel and NTO oxidizer.
Wasn't expecting a Scott Manly shoutout, ksp seems so separated from actual spaceflight, despite its accuracy and attention to detail
Please tell me you'll follow up on the Project Orion episode with something about the Medusa craft. If you're not already familiar, the Medusa is a refinement of the original Project Orion, only using a massive ablative sail, with a cast-and-reel-in mechanism for harvesting electricity and smoothing out the acceleration from each nuclear pulse. It's estimated that the Medusa would be a more efficient nuclear pulse vehicle than the original Project Orion ship would've been.
We need a Vintage Space + Scott Manley colab
Leo Meyer we've had one or two but we need more.
A rocket actually does push against something - the mass-inertia of its own propellants. Both the rocket and the propellants have mass and therefore inertia, which makes them want to remain in a constant, uniform state of motion. Essentially the rocket and the propellants both push against each others inertia causing the mass of the rocket to go in one direction while the mass of the propellants go in the other direction away from a common starting point at the center.
This is why the Saturn V used kerosene instead of hydrogen in the first stage. The kerosene had much more mass than hydrogen. This allowed the first stage engines to produce enough thrust to lift such an enormous machine. This happened according to the equation F=MA, which states that the larger the Mass (with its corresponding inertia) being Accelerated then the larger the Force being produced.
Its a common misconception that the sole purpose of the propellants are to burn so as to produce heat and mechanical energy. In addition they also supply the mass-inertia that gets accelerated in one direction to produce the propulsive reaction in the opposite direction.
Found this - Tim Cole, Apollo-era kid and space nut
Answered Feb 22, 2015 · Upvoted by Robert Frost, Instructor and Flight Controller in the Flight Operations Directorate at NASA
Marshall Space Flight Center (MSFC) did consider using liquid hydrogen (LH2) for the S-IC stage, but the problem was the volume of the fuel needed to meet the performance specifications. They'd already reached the practical limit for the size of the tanks that could be built - as the longitudinal welded seams became longer, the distortion in the cross-section became more severe.
RP-1 doesn't provide as much energy per unit mass as LH2 but it is twice the density. The only way they could get the necessary total impulse from the first stage was to use the denser fuel.
The S-II and S-IVB stages could use the bulkier (but far more energetic) LH2 fuel once the S-IC had gotten the whole stack well off the ground.
Another factor was that they couldn't get the full benefit of the LH2 fuel at sea level, where the J-2 engines used for the upper stages operated relatively inefficiently. Used in the first stage, the RP-1 fueled F-1 engines outperformed the J-2 engines at sea level. The specific impulse figures are quite revealing.
Specific Impulse (s)
Sea Level Vacuum
F-1: 265 302
J-2: 200 425
They actually got the best possible performance for the Saturn V system through their selection of fuels for the stages.
I seen Amy in a documentary for the SLS and going to Mars the other day. She was only at the begining, she explained propulsion by sitting on a skateboard and throwing a medicine ball, and she should have hosted the whole thing :)
I have spent a lot of time at the Goldstone Pioneer site during my Army career and would love to learn more about the Pioneer missions please. Thank you Amy for the work you do.
I love it when two of my favourite Channels collaborate.
It's more accurate to say that it is not Newton's Third Law that makes the rocket move, but conservation of momentum. A force F can be described as F=dp/dt where p is the momentum, but if the momentum is constant (thus F=0), the rocket can also move, because the momentum of the exhaust gases must be equal and opposite to that of the rocket.
MolochBaal Yup other wise known as there is no such thing as a free lunch law
All of Newton's laws can basically be put into F=ma, which implies the conservation of momentum. Just calculate the mv from each side after subbing a=v/t and voila
But there should be a free lunch law. I would save so much lunch money.
THANK YOU. I was just about to post the same thing. Poor little momentum gets ignored so much, people go on about energy, force, acceleration; it is really about conservation of momentum.
my two favourite youtube people finally together! you should to more stuff in tandem!
yay my two favorite space youtubers working together! this video made me so happy
I did my bachelors in Electronics Engg. and your videos made me change my major to space flight mechanics in masters. :) Yo u are so amazzing.
Actually, there was research done based on NERVA in the late 80s/early 90s (an SDI thing) that had nuclear engines powerful enough to serve as a first stage, with an ISP above 1000s, thrust/weight ratio around 30, and half a million pounds of thrust. Project Timberwind, specifically the Timberwind 250. Really cool stuff.
Even before Timberwind, there was DUMBO, which was proposed around the same time as NERVA. It had speculative TWR in the region of 50, and an ISP around 850s.
Speaking of Nuclear, how about a video on Radioisotope Thermoelectric Generators.
Quite a few people think they are nuclear reactors due to the use of Pu238 as a heat source.
Love the videos Teacher!
The very same question I had! Let's see a video on deep space power generation :)
I assumed it was the heat from nuclear decay heated a bimetal which would generate eclectrcity.
That's exactly what it is.
A lot of people think think RTG's are nuclear reactors because of the nuclear reaction that takes place. It's worth noting that there are many kinds of nuclear reactors other than the common "pressurized water reactor".
I just wanted to elaborate on Amy's post (follow up with Scott Manly, too!):
There is a tri-fecta of options that you can choose when you choose/develop a space propulsion system:
You have efficiency, reliability, price; when engineering a system you can only pick two... and nobody ever wants to ignore reliability. As Amy said, the overall performance is stated by the specific impulse.
These are best explained by two contrasting examples:
The highest performance, regardless to cost, is the Rocketdyne RS-25. It is a extremely complicated and efficient, proven system, that powered the SSME (space shuttle main engine) and was further refined for higher performance in the new SLS system. It uses difficult to handle cryogenic fuel and oxidizer with a highly optimized and efficient combustion process (hydrogen combusts rapidly and violently with only a small ignition event). Because of its complexity, the computer control is required to operate it in a controlled, efficiently, and safe manner. If you add these development cost with the costs associated with the development and use of materials that operate under these conditions, one finds a whopping 452s specific impulse in vacuum for an extreme price...! An order of magnitude or more than that of something by SpaceX or ULA or otherwise...
On the other hand, the Merlin engine from SpaceX is a reliable, inexpensive engine with reasonable performance characteristics. It burns the same fuel as some home heater and lamps use, which means it quite a bit safer to handle. You can store kerosene in your home, and, properly burned, it is not as dangerous and does not have a noxious exhaust (try storing liquid hydrogen in your house- it's explosive, super cold, and vents off flammable gas when it sits around heating up!). Also, because kerosene is a large molecule, it is not as reactive with oxidizer, so burns slower and needs less fine tuning to the combustion process, but with the penalty of less performance (when was the last time you saw a kerosene heater explode?). SpaceX can offer reasonable performance with the Merlin that is reliable and efficient, which allows non-state players the ability to launch payloads for a fraction of the price of a government-run program- but there are much more limitations of where and how the payloads can be delivered. Even though an engine offers a specific impulse of 304s, (about 66% of the RS-25), it does so at less than 1/10th to 1/100th the cost. The Saturn V used the same fuel as SpaceX's Merlin. If you throw in 60 years of evolution of engineering metallurgy, manufacturing processes, and computer modeling, you will note that SpaceX was able to squeeze a lot more performance out of the same fuel and oxidizer as NASA in the 1960s (one would come to expect this, however)
~~~
Regarding other propulsion systems such as hypergolic, ion, and nuclear: such systems are much more feasible for upper stage/high vacuum conditions, because of the efficiencies when not having to deal with atmospheric drag and the freedom to operate without ambient pressure. When you operate an emissive propulsion system, you need to expend energy to push away the fluid/gas (mass) that is directly obstructing the exhaust of the engine. Any extra work to move combusted material out of the engine is a performance hit, because you cannot liberate more energy from combusted fuel until the combustion chamber is voided of such products. Because of such, these propulsion systems generally not in the performance category to be able to lift anything off the surface of the earth. Gravity acts fast and hard, and you need to overcome a huge gravitational potential, with a massively weighted rocket (generally most systems that output how power in a short time are inefficient compared to refined long duration systems), in a short time. Since most of the payloads launched into space are for local planetary use, so the R&D applied to that technology is generally allocated to proven chemical propulsion systems. If the payloads need to go well beyond Earth orbit, then these exotic and novel propulsion systems are always an attractive option for the final stage.
Anyway, that's my two cents, lol.
C'mon, everyone knows sugar and potassium nitrate are the world's best propellants. :D
Super hot burn. ☠ Danger, Will Robinson!Danger!
Sir Can sugar and potassium nitrate still be good if they already made and stored years ago sir, I want to learn how to make rocket fuel for missile becoz my country doesn't have it, I want to help my armed forces to build mlrs, ground to air missile, ballistic missile and preferably for external threat defense. Since Rocket fuel is one of the most needed composition in building an effective missile defense
@@jokydee5694 it is one of the most accessible forms of propulsion, however, it isn't very efficient. If you want a good propulsion mechanism, use amonium perchlorate composite propellant. Recommend changing the fuel mixture to be fuel rich a bit into the flight so you dont explode during maximun dynamic pressure.
Di Lithium crystals... Well, it worked for Scotty... ;) lol
Best quote ever, "Scott Manley is as good as a rocket scientist"
Amy, it would be really cool to do a series on Dr. Robert Goddard and his theories and rocket development work and how it led to Dr Von Braun's work.
We should point out that Dr von Braun's work is not based on Goddard's work. Goddard was so secretive and paranoid most of his work went unpublished and people outside of the USA did not have access to it.
A Beautiful woman talking about space stuff. SUBSCRIBED!
3:39 Thanks a lot for the video. I would like to add, that the specific impulse is in first approximation the exaust velocity.
I would love to see you do a collaboration with Scott Manley, the combination of space science and space history would be epic.
Scott Manley helped me be a better KSP player. KSP helped me learn more about different kinds of rocket fuel. Also I love you channel for both the technical, and the human aspect of historic spaceflight. It's the human aspect that makes me post the same question on all of your videos and it's this. What can you tell us about facial hair and the space program? Did NASA have rules and facial hair in space? How did astronauts shave their faces without getting stubble in all the instruments? etc.
Amy Shira Teitel & Scott Manley team up. Nice!
One of your best presentations! Good physics: succinct explanation. Brava.
Always wanted to hear you talk more about nuclear space propulsion. Orion, NERVA, VASMIR and others.
you two are my favorite space nerds! I love it when you team up
I never considered watching Scott for non-ksp videos. The science ones are cool, but I subbed for ksp
I actually asked my parents this question when I was 6. I used to read a LOT about Gemini, Mercury, and Saturn before the Shuttle program.
Finally the NERVA project gets some spotlight! In my opinion, that was the closest we ever got to an manned interplanetary mission. Had they developed that, imagine how far developed nucleae engines could be today!
I recommend reading Ignition! by John Clark. It's informative and funny. The book is out of print but you can find it as a PDF via Google. His description of chlorine trifluoride as an oxidizer is memorable.
Excellent intro to fuel types! And I love the retro cover art (or whatever you call it) of you on a rocket complete with 40s hairstyle.
Amy definitely needs to get better at KSP.
I'd watch an Amy does KSP series.
I actually learned that the rocket pushes off the gases, and the gases don't quite push off air to move the rocket! Thanks Amy!
The shuttle program began way back in the 1960's with the testing of many strange-looking space gliders. Would like to see more about this...
What could possibly on the poster that warranted blurring it out?
Something copyrighted
Check at 5:01
@@gok0o ASU?
Hi Amy, just found your channel thanks to Scott Manley and I think your videos are great, keep it up.
Excellent and informative video. +1 for Scott Manley, that dude is my hero. I also want to point out that this video is way ahead of SciShow Space that totally botched explaining nuclear propulsion.
You can also use a nuclear reactor to generate electrical power to run an ion engine.
This is probably the best option for deep space propulsion beyond Mars orbit. Because ion engines have better Specific Impulse than nuclear thermal engines. But sunlight intensity drops off like 1/r^2 as you get farther from the sun, making solar power panels too inefficient.
And I think that idea is totally Vintage Space because Ernst Stuhlinger (one of Werner von Braun's associates from Peenemunde) wrote a now forgotten book (Ion Propulsion for Space Flight) laying out all the technical arguments. That book was published in 1964, before the first Saturn V launch.
You are definitely a scientist the way you told about rocket is amazing keep it up good luck
Hi Amy! You mentioned in your live video from the Museum of Flight about rocket models. Have you looked into paper models. you would be surprised how good these models look. Just print cut and glue! No painting and you could build some of them in just a few evenings.
This is the only thing I could find on fuels I really needed this because I really want to get a A on my science project so thank you
Vote 1 Scott Manley and Vintage Space collab
TimmyOz Kerbals meets Amy's cat.
SixDasher alternatively, re-enact the Apollo missions with RSS and the KSP multiplayer mod
Okay, you got me. I was thinking of subscribing and then you brought in the Manley factor and sealed the deal. Great vids
Cheers! Still working on editing the monster video we shot, but it's going to be good when it's live! Really think you guys will enjoy it!
Love the new title screen animation!
Being a physicist, I would argue it isn't Newton's Third Law, rather it is conservation of momentum that makes a rocket engine work .
The RD-0410 is the only nuclear engine I know of that was declared operational. It had an Isp of 910. Woot!
Thank you for brining up the Orion project, I am really looking forward to that video :)
Same reason why handgun fired will recoil backwards. If fired in outer space, the force of the exhaust gas will cause the person holding the gun will go backwards. There is no need for an atmosphere, or for some background to oppose the force. Recall, the NY Times had to retract their statement that one of the early rocket designers argued that a rocket would work in outer space. The Times tried to make a fool of the person ( can't remember if it was Goddard), but had to make a retractaction over 50 years or so later that the paper was wrong. I have to give credit to the newspaper for finally coming to terms with the truth. I am not endorseing the paper at all by making this comment, just a fact. Thanks Amy for always making things easy to understand.
We love you Amy
Hi young lady. Thank you for a very good episode. I just wanna say I think antimatter will be the answer to interstellar travel. We have a way to go before we can achieve that but I am confident we can do that. On another note I posted a question to you on a different video of yours about the Saturn V. I wanted to know how the F1 engine was ignited. Well I found out it was with the use of hypergolics! Thank you for investing so much of your time and effort for this worthy topic. I grew up in the space age and it was glorious. Mercury, Gemini and Apollo were a part of my life as a young man and made me pursue science in all it's splendor!
Amy - just found your channel! I've spent several hours just going over a lot of your videos! Great content! I've even ordered your book! :^)
Back to questions about cool old tech! Since you love the Saturn V, maybe some info on Pad 39? Talk about the underground safe room? The slide wire escape system? The access tower and the service tower? How about the mobile launch system and how it was developed, why and the technologies for and against using what was still used through to the Shuttle era and on to the developing SLS monster rocket.
I did a video on the rubber room ages ago: ua-cam.com/video/cGnhUUbgrU4/v-deo.html
The slide wire is one I want to cover bust kinda forgot about - thanks for the reminder! I have been wanting to dig into launch pads a little more... one of these days!
Request for future episode: The Little Joe abort tests for Mercury and Apollo. The A003 mission was notable in that the LES acted on its own to save the spacecraft when the booster broke up.
I really appreciate you covering the physics at the beginning. Was it you who pointed out that Goddard used to put his rocket exhaust above the fins because he thought they needed to be pulled to work?
Great video, looking forward to those future episodes :) Keep being awesome!
I believe your specific impulse is low, watching your videos is more and more fun / helpful with less invested to click on the video. :)
Amy, could you please do a video on or series on the selection of the early astronauts and the rest pilot culture. You could explain the reason Ike chose test pilots and why they were critical to the success of Apollo. Thanks and love your channel.
Nice glimpse of the refurbished F-1 gas generator test!
Great job, thanks Amy. I did ask if you could delve into nerva a few months back. I thought it would be up your street being a early nasa project at all :).
Would love to see you and Scott team up on some videos. Maybe he could do a video chat type thing taking you through the basics on ksp. Recreate some vintage space missions etc.
If people really want the rocket to "push" off of something, I like to point out that it's pushing off it's own fuel. If we take the rocket and fuel combined system, the center of mass never actually moves, it's just that on one end there's a bunch of uninteresting combusted fuel/oxidizer on one side and a rather more interesting rocket with probes or people inside on the other.
I know you know this, and this video was more about fuel types, but something to consider when explaining.
Scott Manley! He is so cool!
Yay Scott Manley!
While Amy is totally correct about a rocket accelerating due to its reaction to the hot gas leaving the rocket nozzles, the escaping gas does have to contend with atmospheric pressure. If I remember my propulsion class correctly, usually at lift off the jet of hot gas is overexpanded, and leaves the exhaust bell pretty much in a nice cylinder. However as the rocket gets up into thinner air you see the exhaust plume spread out greatly due to the flow being under expanded in the bell. The length of the bell is optimized only for one altitude, usually about half way through the total burn time of that stage.
Random fact / bit of calculation: When using photons as reaction mass (i.e. using a laser as a rocket), the thrust is proportional to the laser power via the speed of light. So, to equal the S-IC's thrust of 33 megaNewtons with a laser, you'd need about 10 petaWatts. The interesting part is this: lasers developed for inertial confinement fusion research (such as at the National Ignition Facility) are just a little ways into the petaWatt range. So, for extremely short lengths of time, on the order of nanoseconds, those lasers are producing a total thrust that is of the same order as the Saturn V first stage! That sets the scale for how tough it would be to take a significant payload from the ground into orbit purely using a laser rocket. Your laser would be so intense that you might well cause nuclear fusion in the ground below the rocket!
Amy have you been to the air and space museum in Huntsville Alabama ? Spectacular.
FWIW: I do not have the exact quote in front of me, but Arthur C. Clarke wrote - in THE LOST WORLDS OF 2001 - that Project Orion/nuclear pulse propulsion is the only known way to get a very large single stage spacecraft into Earth orbit.
+John Murphy → AFAIK there is currently *NO MATERIAL* available with a high enough tensile strength to form a structure *that long*.
+John Murphy → Agreed. When it IS developed, it will lead to a MAJOR DECREASE in the cost per pound {or kilogram} of placing stuff in Earth orbit.
Very beautiful, great speaker, and very knowledgeable. Loved the video and look forward to viewing more of your videos.
Why is that poster blurred out in the background?
You forgot compressed gas propulsion. All you need is a tank full of a compressed gas and a valve to control the flow. A lot of the EVA astronaut jet packs use this kind of propulsion. Simple and extremely safe/reliable.
Also (in the case of astronaut jet packs) there is no hot "flame" to possibly impinge on and damage a spacesuit.
I think space x want to use unburnt methane for rsc
Thes is called cold gas thrusters and usually has abysmal specific impulse. (20% of chemical rockets at best)
Barcel That's why we fill our compressed air rockets 1/3 with water. The extra mass expelled is great for lifting heavy payloads.
And also garbage thrust. Plus, a gas tends to takes up more volume than a liquid or solid.
Orion project (the old one) could be the most insane project of space exploration history!!
You basically summed up the entire first half of my EPQ...
I loved your talk for Spacefest at the museum of flight and i wanted to thank you for your inscription about live streaming from mars! Loving the videos and... again did you get to go on the FFT? :)
my favorite part was when you said that the Dyno-saur was named for its dynamic souring, not because it was destines to fail, that was great.
Great intro and your best hairdo yet.
What's with the poster in the back?
Ohh I am very much waiting for a Project Orion video. It sounds like the setup to a bad sci-fi disaster movie.
Thanks for all your hard work Amy. Great channel!
You or Scott Manley should look at different types of rocket nozzles, bell nozzles and aerospike nozzles. Also I'd like to learn more about the Lockheed x-33 if there's any more info out there.
AST, how many different forms of chemical propulsion did the Saturn V employ? Can you cover why each of those choices were made for the various stages/modules? Thx. Keep up the good work!
You should find the book Ignition! By John Drury Clark. It is a history of the development of liquid rocket fuels. In particular the chapter on halogens is entertaining and illuminating on just how bonkers you had to be to do practical rocket science in the 50ies
soooo cool that you and scott got into contact and shared smth on youtube :D keep that up
A "like" just for your new graphic!
Awesome Video! BTW why are you blurring the poster in the back?
Would you please do a show about Aeronca's contribution to NASA . They built heat shields for Apollo and parts for the space shuttle , Gemini and Air Force One.
Amy, great coverage of the very different fuels and methods of propulsion. I have an idea for a future episode that builds on the fuels discussion. We've all seen the exhaust plume morph and grow as a rocket ascends through the atmosphere, especially with the Saturn V. What causes this and what are we actually seeing? Thanks!
The growing exhaust plume width is due to the decreasing atmospheric pressure as the launch vehicle ascends.
Most first stage or booster engines are designed to be exactly expanded or slightly over expanded at the launch pad. That means the plume goes straight out, or sometimes slightly contracts as it leaves the nozzle. Watch a video of the space shuttle engines lighting up on the pad and you'll see that slight exhaust plume contraction. But at high altitude the ambient pressure is less and the nozzles are "underexpanded" so the plume expands more after it exits the nozzles.
The point of the converging/diverging nozzle is to convert static pressure to exhaust velocity.
The more your nozzle expands at the opening, the faster the exhaust and the lower the pressure.
But if you go too far you run into two bad effects. Your nozzle can get too big and heavy, and you can get flow detachment before the end of the nozzle bell which can damage the nozzle.
why the sloppily blurred and pasted poster?? you want us to notice
Did you make this video on an impulse? Specifically, what caused you to put this video up? Was the momentum of your channel conserved?
Well now that this video is over, I'm gonna go play some KSP.
Amy, can you explain why different fuels are used in different stages of the Saturn V? What makes one type the right choice at one point in the journey but not another? Thx.