Hold Down Release Mechanism - The nuts & bolts that unfold a spacecraft.

[@JakeBiddlecome]

How KZbin's recommendation algorithm didn't show me this video a year ago is beyond me. Very nice explanation of these bolts. I had no idea how complicated these things were. Kind of amazing to me that mini explosions are sometimes the best choice for such delicate spacecraft.

[@derrekvanee4567]

Omg me too bra /sighed every internet warrior a sub and view ccash for yá

[@Ansset0]

Algorithms are doing fine on this occasion. Content is shooooty.

[@heshamyoussef8654]

I hate that algorithm hasn't made me know about you earlier.

[@hhyy3173]

I’m great full for knowing now ❤️

[@peterfireflylund]

So what you are saying is that the algorithm could have told me *six months* ago? Six months!?

[@heshamyoussef8654]

@Phil Lapino We all know that if you if you want twerking head to twitch

[@Random_192]

Yeah

[@vishank7]

This video is so well made! Amazing work man!

[@ReflectiveLayerFilm]

Thanks a like. Really appropriate it.

[@xzznnn845]

This video feels like it should've been made by a creator with millions of subs, i am surprised by the quality of this

[@ardendolas]

Very informative! I knew that these existed but not how they worked, thanks!

[@ReflectiveLayerFilm]

Glad I can help.

[@Declan-pg8cg]

If you like space tech, look up IRVE and HIAD.

[@AnupamVipul]

There you go again making High-Quality video Keep this up man

[@ReflectiveLayerFilm]

Thanks. I enjoy your work as well. Especially Rocket Monday and Future Friday.

[@ryuk2816]

Hello Anumpum vipul sir

[@erichschmidt8987]

What a great job with this video and narration. I’m a novice aeronautical engineer and I slept at a holiday inn so I found this amazingly informative. Can you do a video on how booster tanks adhere to the shuttle and how they’re discharged?

[@ReflectiveLayerFilm]

Thanks. Interestingly one of my other viewers asked about something similar a few weeks back. It's an interesting idea and I'll look into it.

[@Warriorking.1963]

What an amazing and informative video, truly excellent work. When I saw the title, I thought it was going to be about the hold down arms that keeps the rocket stable on the launchpad, but this was an unexpected and pleasant surprise.

[@ReflectiveLayerFilm]

Glad you liked it! Yeah, the thumbnail makes it look like it's about the rocket on the launch pad.

[@toweri_li]

@@ReflectiveLayerFilm Mee too. Why not make that video too?! :)

[@drspangle13]

@@ReflectiveLayerFilm That would be a cool video to do! It does always seem crazy to me that they can hold back a rocket in those initial phases, but I guess it's not that much more force than the rocket's weight, just, in the other direction

[@nagarjunkashyap5987]

Wow. That's a wonderful explaination with some great graphics. Pyrotechnics are really interesting.

[@lantose]

Great video; mot to mention the ingenuity by our space scientists! Everyone who has any appreciation for mechanics should watch and be informed of just how practical application can apply to almost anything! (Even if your not into space technology!)

[@ReflectiveLayerFilm]

Yes I'm always amazed how they the come up with this stuff especially given the conditions these devices must work under.

[@qwertyuuytrewq825]

Thank you! I never knew that NASA sometimes puts explosives on spacecraft. It could be a good clickbait title for a video if it contained "Nasa", "Explosives" and "Bolts" in some combination )

[@ReflectiveLayerFilm]

Yeah. Explosives deliver a lot of power relative to their mass the. But the trend in the industry is to move to the non-explosive kind. One big drawback of explosives is you can't test the actual bolt you're going to use since testing is destructive.

[@doodleboi7034]

This channels need attention,it really does.

[@mortkebab2849]

I would be interested in a video on the clamps that hold the rocket down until all engines have ignited.

[@oldspicey6001]

I thought that's what this video was about

[@craigrmeyer]

Your channel is just fantastic. This is the kind of real deal information I haven't found elsewhere. I'm really learning something here.

[@ReflectiveLayerFilm]

Awesome, thank you! I do try to cover things that aren't talked about or explained to a deeper level.

[@Southwest_923WR]

I almost stopped video within 30 seconds, title led me to believe it was about the "HOLD DOWN" machanism when engines ignite, but I stayed and it was very informative. Something I have v thought of, but not much. Good I stayed.

[@ReflectiveLayerFilm]

Awesome. Thanks for staying and watching the vid. Yeah I think the thumbnail is kind of misleading. I'll look into finding a better thumbnail.

[@ZenoFranco]

Thanks for making this video - I was trying to explain explosive bolts used on the Saturn V rocket stages, and this really helped to make it clearer for him how these work.

[@juantelle1]

how come I've just discovered this channel??? This is great. Subscribed.

[@ReflectiveLayerFilm]

Thank You.

[@Anothy]

Excellent work on the video. I've always wondered how those releases worked.

[@prvashisht]

Wow, an amazing channel with so few subscribers. You deserve much more :D

[@ReflectiveLayerFilm]

Thank you so much 😀

[@yan3073]

Oh man, this video is so informative on such small but essential parts of the rocket! May I suggest that make a video about thrust vectoring of SRB and what does it mean of "running out hydraulic fluid"?

[@ReflectiveLayerFilm]

That's a good idea. I'll look into it doing one in the future.

[@Stiderspace]

great video and explanation about something that most probably think is extremely mundane and boring

[@twofacedmctwoface4876]

Thank you for a simple and concise explanation.

[@lazeecam3467]

Finally, peace! I always wanted to know this. Thanks

[@alexandresen247]

On the JWST program these are called NEAs (Non-Explosive Actuators)

[@basfinnis]

Really interesting stuff. Thanks. Shame I didn't see it before. YT keeps recommending rubbish and missing good stuff which is frustrating.

[@jaypanchal5042]

Man I really can't thank you enough! I wonder how many papers would I have to read to understand this.

[@ReflectiveLayerFilm]

Thank You. For this video it took about 3 papers(links in description) for me to understand what's going on. The main challenge in doing these videos is going through the many other papers that have basically the same info and nothing new.

[@EnergyWell]

Very good DFX! Just enough to digest and remember.

[@ReflectiveLayerFilm]

Thanks. I appropriate your comment.

[@doggonemess1]

I knew an engineer who had a few explosive bolts on his desk. He used them as paperweights. I'm really hoping they were inert.

[@toreyweaver9708]

This is very fantastic! You did a great job on this. I learned several new things!

[@ronaldtartaglia4459]

I can watch this stuff all.day.😊

[@jmautobot]

Fantastic topic and video! Very unique

[@quinsomnia4934]

Thank you for this!

[@pradeepj8268]

Great channel. I was just wondering why I didn't get any of our videos recommended until now just like others. PS : I didn't get any apps in google Play when I searched for Reflective layer. And also the link for play store in channel discription isn't hyperlinked.

[@ReflectiveLayerFilm]

Thanks for the sub! I'm not sure links are clickable in channel description but I did add a google Play icon link in the Links section.

[@Spaceflightinc]

I love the way you explained how these systems work. Can you do a video on the space shuttle SRB seperated?

[@ReflectiveLayerFilm]

Interesting topic. I'll look into into it. Can't say if or when I'll be able to put into the production timeline.

[@Declan-pg8cg]

Oldschool:"Your bolt ain't tangible until it's frangible"

[@bryanstellfox8521]

The channel "Operational Facts" stole a portion of your video. I have reported them. You worked very hard on this video, and it shows. Very informative!

[@ReflectiveLayerFilm]

That's my other channel.

[@bryanstellfox8521]

@@ReflectiveLayerFilm OMG hahaha sorry for the mistake, I just didn't want your hard work stolen!!

[@ReflectiveLayerFilm]

No problem. I appreciate you notifying me. I have that other channel for short videos with no story and just a focus how a single piece of tech works.

[@hussainali9999]

Great work, thank for sharing

[@while.coyote]

I bet IKEA could design some really good space-bolts.

[@lohikarhu734]

The title shown in the graphic talks about losing a tight grip...it's kind of funny that a lot of Americans are misspelling "lose" as "loose", when "loose" is kind of correct here, being the opposite of "tight" ...okay, it's kind of an abstruse connection, but still ;-) A nice, clean, simple handling of pretty important, and interesting, subject!

[@ReflectiveLayerFilm]

Interesting. Yes it could go both ways and still be correct.

[@mudkatt2003]

lots of copy cat space youtubers out there these days, but I think you're doing alright kid. I have never seen a video on this topic and your info and delivery were pretty good. Keep em comin'.

[@ReflectiveLayerFilm]

Thanks

[@josephastier7421]

Nice thing about non-explosive mechanism is that you can test them before you fly them.

[@ReflectiveLayerFilm]

True, True.

[@frogflyer79]

Thank you for a really informative video

[@TennisGvy]

Really appreciate this video. Do you have any animations or simple explanations of how separation systems work such as clampbands or lightbands?

[@ReflectiveLayerFilm]

Thanks. I don't have anything on clampbands but I plan to do a video on satellite deployment in the near future. So I'll probably include it in that video. Thanks again for watching.

[@ReflectiveLayerFilm]

I now have a video on Lightbands. kzbin.info/www/bejne/j6q3Zql7htGoeNk

[@TennisGvy]

@@ReflectiveLayerFilm haha wow, you remembered. I actually already watched it! Super helpful, thanks

[@SA-ow9yo]

To each of this type of video there are one million is stupid stupid stuff on on KZbin.We need more off this type of videos for kids.

[@haris9858]

well this just popped up in my recommendations.. insta sub, keep up the good work! :)

[@ReflectiveLayerFilm]

Awesome, thank you!

[@michaelthompson9548]

Fantastic video!!

[@PassportAdam]

When the Webb finally get's into it's parking orbit and begins unfolding, I'm going have anxiety for the entire time.

[@ReflectiveLayerFilm]

Yeah me too, but from time it launches.

[@kdshak4904]

The way I read it, JWST will not stay in the “parking orbit”. Immediately after separating from the vehicle, It will initiate deployment continue doing so as it speeds towards L-1 point destination. Scariest part is to “unfurl” the tennis court sized sunshield. The rest of the deployment steps are pretty routine type. Really nice video. Well done. 👏👏👏

[@mortkebab2849]

Pretty good effort for such a small-sub channel.

[@ReflectiveLayerFilm]

Much appreciated!

[@Avida-l7s]

Binging your content 🥳

[@SteveBakerIsHere]

Thanks for that! Very interesting - it would be nice if you could also talk about the re-usable couplings that SpaceX use for these kinds of things in their spacecraft.

[@ReflectiveLayerFilm]

Interesting suggestion. I did a quick google search "re-usable couplings SpaceX" but came up empty. Could you give me a link to start with? Thx

[@codak29]

So interesting.

[@ashwinraghunath]

Thank you so much for making this :)

[@ReflectiveLayerFilm]

No problem 😊

[@yidetao5623]

This is such great content!!!!

[@vedprakashsharma2388]

Great explanation...

[@chrisrigoni]

Thank You 🙏✌️

[@balajimundhe6102]

Thank you.

[@SevenDeMagnus]

Cool

[@tvp-rbe-betterworldstem7535]

informative! keep it up please)

[@TecSanento]

But the explosiv version does create significantly more space Junk and Debree?

[@altaloma7789]

The two devices outlined here are but two of a plethora of other release devices used to deploy spacecraft mechanisms. Not all spacecraft releases are accomplished using pyrotechnic or burnwire devices. The Spacecraft Mechanisms field is a very wide discipline where specialist engineers must demonstrate solid and well thought out engineering as well as prove their designs through rigorous test programs. It is not a easy profession, as it evolves constantly and requires lifelong study to remain proficient. When very expensive spacecraft and satellites rely on all of their mechanisms to work perfectly, it compels those building those devices toward serious and resolute endeavor.

[@ReflectiveLayerFilm]

Thanks for the additional detail. I'm hoping all of the HDRM on Webb work as planned.

[@altaloma7789]

@@ReflectiveLayerFilm Those of us who worked on Webb live in fear of it because the expectations have been boosted so high. It was originally designed to go up on a Titan heavy, but the move to an Arianne caused everything to go into draconian mass reductions after many of the mechanisms had been designed. Add having to deploy under cryogenic conditions made everything painful. Keep your fingers crossed...

[@ReflectiveLayerFilm]

@@altaloma7789 Wow! I didn't know this about the launch vehicle switched. I always wondered why NASA was using a European launcher for its flagship spacecraft.

[@amirm3621]

Super cool. Did you know spacex use this for crew dragon and wich of them use? Thanx alot

[@ReflectiveLayerFilm]

Crew Dragon doesn't seem to have parts that unfold once in space. So it may not use release mechanism at all.

[@kozzmik]

Good video but you could have explained the explosive train better. After all, if all three stages are triggered inexorably by the first stage then the last stage is as sensitive as the first, so what's the benefit?

[@ReflectiveLayerFilm]

Yeah. Good point. I notice after I made the recording and some of the video timeline was already in place.

[@DanHelfrichGP]

The first stage is only able to be activated by the electrical pulse, which is relatively easy to inhibit. The third stage is protected by the other stages from stray environmental influences that otherwise might set it off, but is extremely responsive to the pressure-heat pulse when the device is fired.

[@kozzmik]

@@DanHelfrichGP That makes no sense. You "inhibit" an electrical pulse by not sending one in the first place.

[@DanHelfrichGP]

All pyros that I have ever used are capped with a shorting plug until it's time for them to be fired. That device inhibits inadvertent voltages arising across the leads due to stray RF or ESD.

[@james112680]

Thank you for your video! At 1:45, can you say what the structure on each side of the inner parts of the fairing closest to the spacecraft? It has a black background and maybe grounded metalic tape in horizontal sections? I was just wondering what that was for

[@ReflectiveLayerFilm]

It looks like the sound absorption paddings used to minimize the vibration transmitted to the spacecraft from the rocket during launch.

[@Miniatures-And-More]

Thank you so much for the video , Can you help me in understanding How a rocket boosters are released ?

[@ReflectiveLayerFilm]

The side boosters are first released by explosive bolts, then a separation rocket pushes it away from the main rocket. This is how it's done on the Ariane 5. www.esa.int/Enabling_Support/Space_Transportation/Launch_vehicles/Boosters_EAP

[@Miniatures-And-More]

@@ReflectiveLayerFilm Thank you so much for this information , Actually i am working on a scale model of a rocket with side boosters , so i usually make the models with exact ( or Nearly ) the same kind of fastening , fabrications etc. But in spite of my extensive search i was unable to find " How the Boosters are fastened to the rocket ? And how they are exactly released "

[@rong1924]

“James Webb space telescope will be...as of 2020...” Hehe

[@GregorShapiro]

Are there any examples of HDRMs that have failed and restricted the usefulness of spacecraft?

[@ReflectiveLayerFilm]

Can't think of a direct HDRM failure, but the motor that unfurled the high gain antenna of the Galileo spacecraft failed to do so when commanded. This caused a serious reduction in it's data transmission rate.

[@parkershaw8529]

It is well into 2021 now, and the Just Still Wait Telescope is not unfolded yet.

[@TecSanento]

This mechanism seem so overly complicated - are simply motorised screws too complicated?

[@ChucksSEADnDEAD]

The satellite would have to power those motors while folded, which means only satellites with radioactive generators could power the system. Plus you could have the issue of the metal in the screw and nut lock together in the vacuum and seize the motor.

[@TecSanento]

@@ChucksSEADnDEAD last point gets me but the first - don't they have batteries Tobe powered while at the night side?

[@ChucksSEADnDEAD]

@@TecSanento Sure. But now if something goes wrong and the panels do not unfold, the battery might not charge again.

[@TecSanento]

@@ChucksSEADnDEAD but this is the same for these explosive charges because they need energy to activate as well

[@ChucksSEADnDEAD]

@@TecSanento Sure, but it's a quick discharge like the flash from a camera.

[@JeanClaudeVanDabs]

"And another one" - Dex DFX

[@ReflectiveLayerFilm]

Thanks.

[@DmitryGrigorev]

Is this the voice from DSC world tutorials?

[@ReflectiveLayerFilm]

No, this is Dex DFX

[@DmitryGrigorev]

@@ReflectiveLayerFilm what is Dex DFX?

[@ReflectiveLayerFilm]

@@DmitryGrigorev I'm Dex DFX

[@westhuizenarchives2614]

The nuts on any astronaut/cosmonauts is enough to hold down any early rocket designs. The reason they made heavier and more powerful rockets is to carry the nuts of these astronauts/cosmonauts.

[@Jkauppa]

em-railgun acceleration sled, combined with solar and nuclear acceleration, ion and electric pulse jet

[@Jkauppa]

rely on hope only, have screw detachers, spring motorized

[@Jkauppa]

you could also burn a fuse to detach, direct arc melting

[@Jkauppa]

not the only way, multiple paths to making it work

[@assassinlexx1993]

This also helps in not making more space junk.

[@yelectric1893]

Wow

[@Yutaro-Yoshii]

7:18 looks kinda overcomplicated for its job, why don't they just have a piece of nichrome wire connecting two parts of the spacecraft? It's much more light weight and fewer things to go wrong.

[@ReflectiveLayerFilm]

That particular design in the video has a load rating of up to 42.2 kN(9500lb) and its release time is very predictable. Doing the same with a nichrome wire with the same amount of loading will require a relatively thick wire which will require a tremendous amount of current to vaporize it. Heating it up and depending on thermal expansion would not be reliable enough. The mechanism in the video is basically a force amplifier. You can read more about that faster from the link below esmats.eu/esmatspapers/pastpapers/pdfs/2013/chang.pdf

[@Yutaro-Yoshii]

@@ReflectiveLayerFilm Thanks for the explanation! One thing that I don't understand though, is why do they need 4 tonnes worth of load rating just to hold some solar panels.

[@ReflectiveLayerFilm]

4 tons is probably not required just to hold solar panels in place. I just gave the max ratings of these devices. Devices like these are also used in detaching landers from spacecraft. Keep in mind that that when it comes to releasing stuff in space it's not just the mass of the solar panel, high gain antenna,etc. You also have to considers the maximum G-force the spacecraft has to go through during launch and that could be up to 6 times the mass of the thing that's being released.

[@Zorlof]

Just open the thing and pack it into SN22.

[@shannonparkhill5557]

does the bolt just become spacejunk?

[@ReflectiveLayerFilm]

Yes if the ejection trajectory is directed away from the earth.

[@julesdomes6064]

@@ReflectiveLayerFilm Actually the two parts of the bolt are usually trapped in the structures to avoid having them flying around, potentially causing problems.

[@ReflectiveLayerFilm]

@@julesdomes6064 That makes sense. Thanks.

[@julesdomes6064]

@@ReflectiveLayerFilm No problem. Great channel you have here! Very informative. Important that KZbin contains this type of info, and not just BS from science deniers and conspiracy theorists.

[@clayz1]

Cant they unfold the Webb Telescope in low earth orbit, then send it on its way to its parking orbit once all the unfolding kinks are ironed out? That way we have a chance to reach it to repair something.

[@ReflectiveLayerFilm]

That's a good question. My guess is that if they unfold in LEO it's going to require more fuel because you first have to establish the LEO. It's also possible that Webb may not have its center mass along its centerline when unfolded. This would mean that more than one rocket engine is needed to fly straight. These are just my guess.

[@phalanx3803]

that could work if we still had a space shuttle but we dont.

[@klausvogler6710]

Too much "stuff" in LEO. The few particles that are around (and requiring ISS to reboost periodically) would damage/contaminate the sensitive equipment which is protected in the folded state. Only far out is the paricle count low enough to unfold it.

[@CraigCholar]

If everything was unfolded first, including the mirrors, wouldn't a rocket ignition have the potential to knock things out of cirtical alignment? Better to keep everything locked down tight during any boost phase, and hope for the best when it's time to unfold.

[@phalanx3803]

@@klausvogler6710 that's another good point. a tiny Flick of paint did some nasty damage to one of the viewing ports of the ISS to something as sensitive as a JWST the damage would be devastating. Even folded up any sort of debris strike would be nasty if I'm not mistaken orbital velocity a flick paint would be like a 22LR anything bigger like a nut or similar size object would be worse than damn .50 cal.

[@burntsider8457]

What's a "foe word?"

[@ReflectiveLayerFilm]

What do you mean?

[@Ansset0]

Sound quality is very similar to what I can experience while having quality time on the bloody throne. Look at the authors considered benchmarks in the VERY precise area..

[@jaykandari]

RIP ears.. at the beginning of this video. warning use HEADPHONES.

[@joedoe3688]

Who in their sane minds would release a bolt in space with 28km/s speed, so it can penetrate like a bullet the next satellite?

[@k1ng401]

I wonder if any real engineers left a spacecraft in orbit unfolded while they had a bit of a nap and woke to realise the batteries had gone flat and there was now no power to unfold the solar panels…like I’ve done in Kerbalism.

[@benschroth7717]

Unfold; not unfolds.

[@ReflectiveLayerFilm]

Thx

[@alexprokhorov407]

For some reason Russians like HDRMS

[@MeaHeaR]

é Power-Phull Aadmé untt AuRát SâHîB 👳 🔫

[@mikejudge942]

Algorithm

[@bestamerica]

' oh no... stop watch at 150... lousy computer animation cartoon edit video... why why this video bad shake shake shake

[@bestamerica]

@Mudkip909 hi M... ' video edit did lousy video move shake by a person edit use the computer... not rocket

[@dannyrodger491]

STICK TO YOUR TITLE

[@nisheethrastogi]

The vocal background not helpful.