Hypersonic Planes & Getting Too Close To Rockets - Supporter Questions - Episode 15
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- Опубликовано: 11 июн 2024
- Another handful of questions in my backlog, not that I have answers to all of them, but I like reading them and trying to answer what I can. This month we have questions about biological contamination, hypersonic flight, Mars bases, asteroid impacts and more.
The specific question asking thread is here:
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"If you were within 100 yards of a Shuttle launch, the heat and blast would kill you. If you were within 400 yards, the sound pressure levels would kill you. And if you were within a mile, the gators would kill you--those low-frequency vibrations really rile them up." --Charlie Bolden, in his pre-ride (recorded) spiel for the Shuttle Launch Experience at KSC
That's gold :D
Oh man, I've had that quote stored in my memory for so long and had no idea where it came from! I must have heard it when I visited KSC at 12 years old, 10 years ago. Thanks for this bit of info!
At NASA Stennis, I was watching a single engine test on A-1 from B-2, about a distance of 1 mile. The test lasted only a few seconds before a brilliant flash told us the engine had failed. I stood up bent over to grab my chair and three pieces of one of the pump blades flew over my back striking the wall behind me. The three of us watching on the external staircase dove for the door into the B-2 test stand as metal parts rained down on the cars below us.
Love that quote from Charlie and the "ride".
He was my commanding general in 3rd MAW back in 2000
I'm so happy to hear that you're learning to fly. As a professional pilot and flight instructor I really look forward to following your progress.
Fly safe. Literally.
@Bobb Grimley "safe" is a flat adverb and is perfectly acceptable (as is "safely")
As a private pilot I'm also pretty interested, I hope to hear more updates from him
@Bobb Grimley Scott gets this *deliberately* wrong every episode.
As another pilot I agree, but we need to get him to understand that you don't land at high speed and stop on a dime following an Immelmann turn.
I absolutely recommend he get his basic aerobatics endorsement as I do to every pilot. Nothing else teaches a pilot to handle and recover from adverse or unexpected attitudes.
Great video Scott! I always enjoy your content. Extra info on how loud a rocket is:
- The sound power of the Saturn V rocket was about 204 dB relative to 1 pW. You'll find reports online of it being 220 dB, but that is incorrect and seems to stem from a random website that doesn't cite anything.
- However, the sound power is not the same thing as the sound pressure level (SPL), which is what correlates to how loud a person will hear it. The SPL decreases with distance, and Sally McInerny published a paper in 1992 that said that the measured SPL 81 meters away from the rocket was about 164 dB. This is very loud, but certainly not loud enough to kill you or light your hair on fire as you'll sometimes see in online forums. It would definitely damage your hearing though.
- Contrary to popular belief, there is actually no limit to how loud a sound can be. The rarefactions are in theory limited by vacuum, but in practice never even come close, even if the compressions exceed atmospheric pressure. This is because at such high amplitudes, you have nonlinear wave behavior, which means that you don't have sines and cosines anymore. The compressions can be many times atmospheric pressure even though the rarefactions never approach vacuum. Fascinating stuff.
We've got a paper in review right now that is specifically all about the sound generated by the Saturn V in the hope of clarifying a lot of misinformation about how loud rockets really are. Wish it was finished with review so I could share a link right here!
Would love to be involved in any conversation on rocket acoustics! I'm on twitter as @AerospaceMark.
Awesome thank you for the clarification to my question! Im surprised you can stand so close to rockets of those size as long as you have great hearing protection.
@@jesserutt7413 You're welcome! Thanks for asking it!
Forgive my ignorance, but what does "204 dB relative to 1 pW" mean? How does picowatt relate to dB (if pW stands for picowatt as I would assume)?
I thought there was no sound in space.
@@turun_ambartanen Great question! When you take a value and put it into decibels, you follow an equation like:
decibels = 10*log10(value / reference_value)
The "reference_value" has to have the same units as the "value" so that all of the units cancel out inside the logarithm. The 204 dB relative to 1 pW means that we are putting the total acoustic power into decibels and using 1 picowatt as our reference value.
Another common reference value is for the sound pressure level (SPL), which takes the acoustic pressure at a given location and converts it to decibels. That reference value is 20 micropascals.
The reference values usually have some significance behind them. For example, the 20 micropascals used in the SPL calculation is roughly the smallest pressure that a human can hear. When you do the math, this results in an SPL of 0 dB being equal to the quietest sound a human can hear (forgetting for a moment that all humans are a little different). You can actually have negative decibel values too, which mean there are sound waves that are smaller than 20 micropascals.
In short, 1 pW is the reference value for sound power. It's usually important to specify what your reference is because sometimes people use different references, get different decibel values, and that can lead to confusion. The 220 dB sound power you'll find sometimes online for the Saturn V does not correspond to any frequently-used reference value for sound power.
Hope that helps!
"Better bang for your buck" -- Scott is so used to throwing puns in there that he's doing it without even thinking now. 🙂
Study hard, and go fly often as possible, perhaps twice a day on 3-4 days a week. You'll learn & retain the lessons MUCH better! And you'll get it done quicker. Rapid, repetitive retention is the way to go!
Fly Safe!!
Can confirm. Seriously. Also, use Sheppard Air study guide products for the FAA written exams, which are notoriously fickle. Also also, get about 100-150 hours under your belt as a private pilot *before* you go for your instrument rating.- A CFII / long time fan.
Get your night endorsement. Totally different world in the dark.
@@randyz1592 PPL in the United States includes the night endorsement! He's right, though. Totally different feel. Super fun and spooky flying, though.
@@randyz1592 Night endorsement USED to be a mandatory part of the PPL curriculum. It should still be thus.
And you are completely correct, night flying is great fun, as long as you're flying around populated areas with lights, or a full moon! Flying in total darkness over un-populated areas or open water will make the sweat roll down your back. At least until you get IFR certified and stay current!
@@walter2990 Fly Safe? I see what you did there. :-)
For the guy who asked about the chances of hitting an asteroid, know this: After New Horizons swung by Pluto and onto the rest of the Kuiper Belt, the snowman that it later flew by was mostly along its path, but after that, researchers weren't able to find anything else that the probe would have enough fuel to do a flyby of. That's how sparsely populated asteroid belts really are.
Another way to think of it is that most planets are (likely) made out of such belts that have collected over time, so the total mass of a belt is likely to be somewhere in the planet range, which is not a lot spread over such a huge area.
@@RaistlinMajeren Wouldn't the total mass of a belt be significantly below the planet range, to explain why it hadn't accreted into a planet?
@@patheddles4004 Likely, yes (though I understand that other things can come into effect), the point is that it is very unlikely to be more than the average planet, and spread over an entire orbit that obviously amounts to almost nothing per km^3
@@RaistlinMajeren Cool cool, we're agreed then. :-)
...comparing asteroid belt and Kuiper belt is meh. Completely different scale.
2-3 AU compared to 30-50 AU. There is just so much more space out there. (grows to the power of 3 with growing distance)
"Being a DJ, the really good bass, you can feel it, but still not damage your hearing... but... What was I going for? Uh... " Scott, there's other thing BETWEEN the ears which matter quite a bit too.
Awesome to hear! Learning to fly is one of the best things I’ve ever done. I hope you enjoy it as much as I did!
No, dont fly planes.. its dangerous. - An AMP
Pilots love to quietly let others know that they’re pilots lmfao
@@jacobreuter oh man it’s not quietly. If I don’t mention it at least once every 6 minutes, I may have a stroke
@@silversrayleigh8980 driving is more dangerous
Same here, starting CPL training in summer. Oh, and I can't shut up about it either!
Great to hear you’re learning to fly! I’ve been a pilot since 1988. I have taken up people who have used simulators and it seemed as if they’d been flying all their lives. Your sim time will prove to be very valuable. Good luck. Fly safe!
His understanding of energy and flight in general will also come in handy; who says KSP isn't worth the time? lol.
Good to hear you are learning to fly, been flying for 44 years now! Hope you can have the same fun in your flying. FLY SAFE!
Maybe a few billion years ago, Aliens sent a robotic exploration probe to our solar system that accidentally crashed into Earth, and did a lousy job of decontamination of that probe :D
Congratulations! Getting my pilots license was an experience that I will cherish forever! Especially my first solo.
17 hours into getting my Private license also! SO much fun!
Good luck from a CPL
I am so happy to have some Scott Manley in my life today! I really need it with everything going on. Thank you.
Congratulations on starting your pilot's license! I flew firefighting helicopters in your neck of the woods the last two years.
One of the best times of my life was learning to fly. I hope you enjoy it as much or more.
Great to see Scott! I’ve been flying for 30 years, and it still thrills me every time I fly! Good luck!
I love you Scott. Got me into KSP, furthered my knowledge of physics, and you have a beautiful voice. Fly safe
I'm so happy to hear you're following up on this and going for your PPL. I wish you all the best !
There's only one thing to wish for Scott really: "Fly Safe!" ;)
Your videos began my interest in aerospace. I contribute my career in commercial aviation to you. It's nice but also funny to see you getting your pilot's license after I did.
That’s so cool you’re learning to fly. I’m almost done with my private pilot license so I was pleasantly surprised when you held up the flight computer because I have the same one sitting on my desk next to me
The E6-B flight calculator is an analog marvel!
I found learning how to actually fly is way easier than in a sim. I always crash in a sim, never crashed in a real plane! Just do what you're trained to and you'll always...Fly safe!! 👍👍
Survivorship bias :p
huge difference of no fear of death and fear of death. I can fly better IRL than in sim but I can land better in sim than IRL.
@@ChemEDan 🤣
Couldn't agree more Scott. 30Hz and below is REALLY where it's at!
I’ve been 200 meters from an RS-27, it was almost painful but one of the coolest experiences in my life
RS-25?
@@user-lv7ph7hs7l Nope,RS-27. I actually worked on the RS-25 at rocketdyne in the 80’s though
@@Red5 Delta! I forgot about Delta... well super cool in any case. Seeing Discovery launch in 99, visiting the US is one of my fondest memories. We got as close as you can get after accidentally meeting some NASA contractors watching the launch. I did my duty as a 7 year old and employed full puppy dog eye mode and it worked :)
Perfect timing! Busy working on a research project proposal for my final year aeronautical engineering degree! Doing research into air powered rocket motors!
Air powered? As in air as the working fluid?
Awesome to hear about you getting your license. You’re Scott Manley. Fly safe!
Be safe flying. Just remember, you cant reboot. I know.
Welcome to the sky Scott! As a newly minted pilot myself I can say it is very awesome!
Thank you for making the time to do this Scott.
Congrats on flight lessons! Nothing as thrilling as a deep dive into the FAR/AIM!
I'm glad your using a manual E6B computer. Big believer in learning the long way to solve problems before using electronic E6B. I meet people today that can't do long division without a calculator.
Hell, for the last few years I've met people that can't read unless whatever is written is printed. Good luck with flight lessons, I loved every minute of mine. I don't know your age but if you are over 40 you might need to practice extra on the landings. I've noticed people have a hard time landing after this age. Let us know if the flight sims. helped or harmed your actual flying. If you think of it, be sure to let us know how many 5 to solo and to get your ticket. Thanks again.
49 according to Wikipedia
regarding the asteroidfield: just think about earth and moon beeing way closer to each other than any asteroid.
Well, they still plan flight paths to control possibility of hitting the Moon.
funnily enough I have been thinking the amount of videos you have been making have been just fine. Every time I see a video I'm kinda like, "another Scott Manley video already!"
My understanding is that the largest difficulty with SCRAMJET engines is that they don't really know how to make them able to fly slowly, which is necessary to go from stationary to takeoff to actual desired speed.
You essentially two sets of engines for such flight, so as to get up to speed
The bigger problem is they're very weak, heavy engines. You end up needing a huge scramjet to keep your craft going and save some oxygen weight, and you have to have extra engines for different speeds, or you cold just stick on a tiny but powerful rocket engine that works at any speed.
control at these speeds is also a huge problem
@@DrWhom And that's not even getting into the problem of atmospheric heating. Flying at hypersonic speeds is like applying a blow-torch to the front of one's vehicle for hours on end
@@alexv3357 DeLorean had that covered! lol
(and CyberTruck will, too, presumably)
Scott Manley 2021: Fly safe!
Scott Manley 2022: Land safe!
I just started my PPL training as well. Very cool to see you doing it too!
Good luck from a CPL!
My professor, Dr. Scalo, works on hypersonic flight! His small LLC uses super computers to calculate fluid mechanics of hypersonic flows on bodies for the military. So applying Navier-Stokes theorem and lots of dimensionless analysis.
Good luck with your pilot training! It is a lot of fun with small aircraft!
Love your channel... And the E6B. I’m a Commercially licensed pilot.... Have fun learning to fly! You have all of the instincts and skills so why not?... It would make an awesome video series! BTW, your first solo flight you will never forget... PLEASE remember that a lapel mic head in your headset with the correct recording parameters will record your audio really well... Pro tip! Worked like a charm for me before RUclips... Seriously WAY PRE-RUclips... Duck tape may have been used... lol... 😎🖖 Have fun and fly safe! Extra story here... I really like the “X-Plane” flight and development sim for realism back in the day and actually met Austin Meyer (X-Plane’s developer) IN PERSON while taking care of an airplane he assembled while it sat on my (KGMU) ramp. His parents were there too, flying with him... Talk about proud parents!!! Mr. Meyer was so cool about everything no one else knew who he was until he left...
Yeah! Congrats on the flying! Would love to see a video after your done comparing/contrasting between the SIMS knowledge and actual IRL piloting.
[slightly tongue in cheek]
- "I can put planes down." - As a commercial pilot friend once told me, "Getting the plane down on the ground is not hard. Doing it without losing your license, is a whole 'nuther ball game."
- When you learn to fly, DO NOT take up music. I enjoy your videos, and would like to continue viewing them live.
Fly real safe.
Love the questions and answers videos. Thanks Scott.
Glad to hear you are learning to fly. Celebrating 50 years since my first solo flight this year. It has been awesome. I know you will enjoy it.
What a deliciously funny IKEA instruction kit for the JWST at 13:33 Doubtless extra actuators and pins can be ordered from IKEA if they are found to be missing when reaching L2!
During the 60's we lived in Woodland Hills near the Rocketdyne plant. Just up the road was the Santa Susana test facility where they tested the Atlas and J-2 rocket engines. Tests there shook the ground and lit up the skies in the SF Valley. We had friends with a cabin on the edge of the Southern Containment Area and were able to sneak into the area several times to watch test fires from about 1 mile away. It was stupid to do after the 1964 meltdown of the nuclear reactor but we do not have cancer yet! NOTHING compares to the sound and flames of a rocket test! No comparison to what your liver feels like as it vibrates along with the rock in the caves we hid in to avoid the guards in the jeeps.
For what it worth: I have many interests and several hobbies and so subscribe to quite a few - a bunch- of various RUclips accounts. But, “Oh good! A Scott Manley!” actually just came out of my mouth. Thanks for that.
Hey Scott, glad you're taking up flight training. You're gonna love it. Speaking from my experience, when you land from your first solo flight, you're gonna have a smile on your face that will last for the rest of the day, if not longer. Fly Safe!
Here is a fun question: The UN has a need to build a rocket ship to L3 and pickup the precious package, and have deemed a minimum crew of 3. You get to build the vehicle out of all already made parts from anywhere, describe your rocket.
(The manufacture people are so good it'll all just bolt-on like in Kerbal without concern for compatibility)
Scott, the flatpack in space is a *very* good idea.
Less space required volume wise for hauling. A small cargoship hauling materials to build half a station, because it's so compact. Volume space is an important factor that we usually take for granted.
In space, smaller = efficient.
Glad a fellow DJ is flying safe. Fly safe please Scotty because your videos keep me sane as I launch capabilities.
I'm a CFI, CFII, MEI that taught for the ATP rating. Make certain to fundamentally understand your IFR training prior to entering an aircraft. Use the MS or XP sims for nav training.
Oh...and probably don't fail to go on to get your IFR rating....fly safely. The IFR rating makes you a better pilot.
Have fun learning how to FLY SAFE!! I'm confident that I speak for most of us when I say we look forward to your aviation adventure updates!
I've always wanted to learn to fly. Bucket list item.
Flying into Gross Field. Learned at KSTS a number of years ago. Cheers from Sonoma County 😊
You're awesome Scott, keep it up. As a Canadian glider pilot, and mesmerized by practically anything space related, your uploads can add to my day in a great way. I look forward to your experiences with the FAA 👍
You'll make a fantastic pilot in these skies 🙂
Yay !
You mentioned the Skylon !!
If you haven't heard of it before, you should check out the BGRV. (Hypersonic boost-glide weapon tested on an Atlas ICBM. Discussed in the book, "Engineering the Space Age - A Rocket Scientist Remembers".
Good luck with your pilot's license. It's a good challenge to take on. As much as we all want to see your progress, don't let it distract you from learning and flying safely.
Hello Scott Manly…love the content. All of it. Every bit of it.
You know…the lot! Thank you for keeping this up.
@Scoot - big fan of Russia 🇷🇺
Live with it now
Congrats on flight training! I'm sure you'll do great!
IIRC, pressure waves have a trough limit when it pulls a complete vacuum, but no limit on the crest. The max limit is only for non-distorted decibels.
I think there might be some kind of upper limit when the pressure is so great that it condenses the gas, but I'm not so sure.
You were quoted in The Economist the other week in their starship article
You never know you might join the ranks of the aviation RUclipsrs.
Great to hear you're learning to fly! I recognize the ol' E6B, or "Wheel of Doom" as some of us called it! The Flight Simulators are fun, but I'm sure you'll find that actually flying a plane is nothing like it! Looking forward to hearing that familiar "Fly Safe!" spoken from the cockpit!
Very glad to hear about you learning to practice what you preach and FLY SAFE as a private pilot!
Just started flight training in December! Good luck to you, Scott! Keep the blue side up and as always, fly safe
That's great Scott. Definitely fly safe.
AWESOME! Airplanes are amazing! Waiting, when i can do own PPL
That was a delightful episode, Scott! Thank you.
That JWST Ikea meme is awesome.
Good for you Scott!! It's tons of fun.. especially night flight! The ASA CX3 flight computer is really handy for VFR pre-flight planning and enroute ETE, ETA and ground speed calculations! Its flight plan function rocks!
"A perfect landing starts with a perfect pattern!"
It's great to hear that you are learning to fly! With your background and comfort in science (plus your "Fly Safe" motto), learning will be easy and fun. As for loud noises from rockets, that reminded me of side window buffeting in cars. Some cars, especially ones with rear side windows with large vertical edges, can develop a really loud, low frequency resonance. A car at speed has lots of power available to power those 15-60 hz pulses-like a huge whistle!
While being blind does give advantages in perspective, one of the biggest regrets I have is being pretty firmly groundbound. One of my most memorable, most treasured experiences was being able to take the controls, briefly, in a little four-seater Cessna. Feeling the way the plane moved in three dimensions as I maanipulated the controls was an experience like no other.
Then there are those awesome folks who do the powered paragliding. Imagine being up "there with almost nothing between you and the power of gravity. What a visceral sensation that must be.
I think the only thing greater than that would be flying to space.
Please keep us informed about your journey to the sky, and of course, fly safe.
I guess we should be the ones saying "Fly safe" to you too now!
Another pilot wishing you congratulations and fly safe!
Great to hear you are getting your PPL. Flying an aircraft is relatively easy, the hardest part is all the theoretical things to remember.
0:57 I'd sure like to see *that* approach plate!
So excited that you're getting your pilots lisence! Good luck Scott!!
I've been a subscriber for years, and a CFI for 20 years. Good for you to get your license! Good luck 🤞
Congrats on the flight lessons!!! It's challenge, but extremely rewarding! Can't wait to see an update on that.
I could listen to these question and answer videos for hours if you did all of them at one Scott. I am always amazed at what I learn when I get to watch your videos.
Manley WILL fly
Scott, your an ambassador to space news and technology. That is as important as the scientists to keeping pace and growing interest and investment flowing.
Nice! Grats on the flight training. I got my license in 2001 and have only flown 2 hours since then and I might never fly again but it is just about the best thing I have ever done! Can't wait to follow your progress.
I had many many hours on Microsoft Flight Sim starting from when it was just a vector graphic of Meigs Field until FSX (yech). Longest flight was a Piper Cub from the southern tip of South America to Arizona. Another flight in the Cub was from New York City to Los Angeles just following road maps.
Good luck with the PPL did mine nearly 50 years ago, favourite place to fly is Scotland’s Western Isles.
Q. How do you know when there is a pilot in the room?
A. He’ll tell you 😂
Hey! I resemble that remark... 😄
The Skylon model looks like Trust SSC minus wheels!
Another entertaining and infomative video, thanks Scott.
To the Saturn-Cassini angle, the insertion path was charged so the craft passed in the least dense area of one of the gaps between rings. They turned the large solid reflector dish from its main antenna toward the prograde path until past the ring. During the crossing, the craft recorded a fantastic rattatat of micro-impacts at inter-planetary velocities.
Really exciting your going for your PPL! Got mines 2 months ago and have been slowly racking hours visiting my parents. It’s the best thing ever but it is expensive. Good luck! Remember right rudder!
All the best on your way to your beginners license. It is the start of a very interesting, and at times, challenging journey.
Congrats on the decision to get your Private Pilot Certificate. I may be biased as a CFI, but flying is one of the greatest pure joys in life. Interesting you mentioned the NASP/X-30. I did a couple research papers on that on back in college. Fascinating idea at the time.
Good for you!!! But nothing is better than eating a greasy cheeseburger or burito and taking a real airplane out to the practic area and do some spins. or rolls..and the turbelance bumping you around is priceless!!! And your ears popping afterwards... Is great!!!
@Scott - Have a blast learning! As a record-setting pilot who loves mentoring others, I'm happy to put you in touch with folks in your local area. Stick with it, and I hope we get to follow along in your journey here via YT!
Also: As a sailplane pilot, I am being completely unbiased when I say that gliders/sailplanes are the best way to practice engine-out landings. ;-)
Pioneer 10 went through the rings if I recall correctly and was hit by some debris but continued functioning. Used to understand how much shielding is really needed for all future missions
Actually that was Pioneer 11. Pioneer 10 only flew by Jupiter.
You should really check out Space Engine Systems. They're based in the same city I live in and from what I can tell are trying to build a cargo/crew hypersonic vehicle that use ramjets for propulsion.
Good luck Scott!!
Low frequencies definitely cause hearing damage, it's a common misconception that it's just high frequencies that cause hearing damage. Low frequencies can also lead to detached retinas after long exposure so do be careful out there :-) Love the channel Scott, thanks for your efforts
I agree. I think current thinking is any sound that can shake the basilar membrane hard enough/long enough is going to cause chronic damage, irrespective of frequency.
I'm a 73 year old with work related hearing damage due to spending many years working with and around Power Presses. So far as I know the sound they produced is mostly low frequency, although I'm not an expert on this, but I have tinnitus and have difficulty following a conversation in a noisy environment.
As an example of experiencing low frequency sound waves one of my abiding memories is a display by a Royal Navy F4 FG1 Spey Phantom in the mid 1970's who ended his display with a Re Heat climb out with the burners pointing directly at the crowd line. The sound was experienced as a resonance in the chest that felt very strange. At the other end of the spectrum I recall high performance 2 stroke racing motorcycles in the 1960's that would make your teeth 'Buzz' if you found yourself facing the ends of the exhaust expansion chambers.
Love that you’re learning to fly! Can’t wait to see you in the sky Scott!
awesome to hear you're getting some stick time! best of luck.
Cool project! My dad is a former helicopter pilot and my cousin was a commercial airline pilot.
A major variable in pad damage is whether you have solid boosters on your rocket. Their exhaust includes high-speed aluminum and hydrochloric acid. I worked on a Titan pad in the late 90s, and there was time devoted to launch pad repair after each launch before we started the next build.