SpaceX's Crew Dragon Spacecraft Exploded Because of 'Corrosive Bullets' and Leaky Valves

Yesterday SpaceX released a report on their analysis of the '4/20' Anomaly that destroyed their Crew Dragon spacecraft during a ground tests. It was the result of oxidizer leaking into the wrong part of the plumbing and then being propelled through the system as fast as a bullet.
Raptor Engine images by Jack Beyer



  • Spacex sucks, but at least the taxpayer doesn't have to waste money on space crap anymore.

    Mike WongMike Wong26 วันที่ผ่านมา
  • SpaceX dodged a bullet with this one.

    Chris MusixChris Musixหลายเดือนก่อน
  • We had a catastrophic failure would have destroyed the rocket and killed all the crew. We installed 60$ burst disc were sure that is our only problem. Ok who wants to ride into orbit 😁👍

    Ronald 240BravoRonald 240Bravo2 หลายเดือนก่อน
  • Looks like someone didn’t fly safe.

    TheThirdManTheThirdMan2 หลายเดือนก่อน
  • The technical term for pushing the fuel through the piping into the check valve is fluid hammer. This can cause a piping failure at a valve or at an inadequately supported piping elbow. In my professional life I have seen piping move several feet due to fluid hammer, only the piping was supported to take the hammering.

    captfjparkscaptfjparks2 หลายเดือนก่อน
  • Say it with me ALUM IN UM

    Squinty KostiukSquinty Kostiuk2 หลายเดือนก่อน
    • I'm sorry. I'm a scientist.

      Scott ManleyScott Manley2 หลายเดือนก่อน
  • ..... Ms paint 😂😂😂

    Christo ThaliyathChristo Thaliyath3 หลายเดือนก่อน
  • Baddaboom!

    TheThirdManTheThirdMan3 หลายเดือนก่อน
  • So what are the benefits of using burst discs instead of check valves?

    Dr. TranDr. Tran4 หลายเดือนก่อน
  • It would seem having a valve that opens rapidly instead of modulating was the main culprit but not even mentioned. Maybe the engineers there should have asked their local plumber about rapidly opening/closing shutoff valves and the pitfalls of check valves!

    Pete FPete F4 หลายเดือนก่อน
    • @Scott Manley G'day @Scott Manley Yes that's a good point, but we're not talking about the Janitor finishing his hamburger and then wandering out with a Stillson wrench to turn the valve on. A valve that "gradually" opens means milliseconds in order to control the pressure wave front. From your report, the NASA recommendation was for burst valves to be used, and at least that indicated they were considering the shock wave (indeed used that property to perform a function). It seemed by their design, the implications of the pressure wave weren't even considered by the designers, and the proof was in the pudding. ... In this case the pudding exploded. Not exactly a handy design feature for something intended to save the crew! How fast do you want your crew fried as both the "rescue system" and the rocket are exploding? After any accident there are always people like me who will come out with "Coulda ... Woulda .... Shoulda"; those of us in the aviation industry deal with it constantly. That may grate the current generation where everything is always "awesome", but I feel that's the price to pay when dealing with other people's lives/money. I sometimes get the impression the team there are making it up as they're going along. That's fine when building video game; how many there are putting their hand up to sit on top of the candle when they light it? Would you? Obviously all just my personal opinion.

      Pete FPete F4 หลายเดือนก่อน
    • @Pete F OK, so how slowly do you want an emergency escape system to operate when your rocket is exploding?

      Scott ManleyScott Manley4 หลายเดือนก่อน
    • @Scott Manley Scott thanks for replying, but from what you mentioned it was the OPENING of the valve in the pressurising gas that caused the "obstruction" to be propelled along the fuel line, causing the damage. This is a very basic and known problem and a first year apprentice plumber would be aware of that issue (as would any home owner dealing with "water hammer"). Obviously I know nothing more about the system than what you described (very well incidentally), but it appeared there was no good reason to have the pressurising system's valve operate so quickly. Pressure shock waves in hydraulic systems is nothing new, neither is the fact that check valves leak. Fluid Dynamics is a first year engineering subject, at least down here in Oz. I thought this failure was a face-palm moment and I'm literally embarrassed for the engineers involved.

      Pete FPete F4 หลายเดือนก่อน
    • Do you have time for a slow opening valve if your rocket is exploding?

      Scott ManleyScott Manley4 หลายเดือนก่อน
  • psi really? Use real units man.

    Ensign RageQuitEnsign RageQuit4 หลายเดือนก่อน
  • There is a mystery on the 600 psi disappeared from the He tank. It has been tremendously compensated by the perfect quality of the graphics.

    MatteoMatteo4 หลายเดือนก่อน
  • Its Tony Bruno

    dragondragon4 หลายเดือนก่อน
  • corporations can only afford to deliver profit..

    Mark PhelanMark Phelan4 หลายเดือนก่อน
  • I believe they haven't killed anyone on their tests yet. but some have

    MoebiusMoebius4 หลายเดือนก่อน
  • I would love to see a video what would happen if a rocket just ascended vertically. Straight up no trajectory

    Michael TuckermanMichael Tuckerman4 หลายเดือนก่อน
  • Can the pressure system not be brought up to operational pressure slowly so the N2O4 in the lines doesn’t arrive like a bullet?

    Steven SmithSteven Smith4 หลายเดือนก่อน
    • Scott Manley ah, yes well there’s that point. I’d forgotten this was for an escape system. Can the plumbing not be prefilled with an inert buffer? Wouldn’t that prevent the bullet effect of leaked oxidizer without having the untestable burst disk be a part of the mechanism?

      Steven SmithSteven Smith4 หลายเดือนก่อน
    • How long do you want to wait in an emergency abort?

      Scott ManleyScott Manley4 หลายเดือนก่อน
  • I would think the psi in the Helium tank would be higher. ie: my air tank (scuba) holds 3k psi. (not to compare per use)

    C SMITHC SMITH4 หลายเดือนก่อน
  • exploded because of lack of foresight. Blame it on a valve like an oil rig? No purge valve, no trap in piping, no sensors behind or after valve to test pressures, detect oxidizers in helium? Plz Even a hobbiest at the drag strip installs a purge valve on their NOS system for safety.

    Prove Me WrongProve Me Wrong4 หลายเดือนก่อน
  • What about doubling up the check values? Having 1 Check value, then another right after it? You could even add a sensor of some kind in-between the check values and before it. A sensor type that can emit a scanning signal of some kind that is non-reactive to the materials used. If a leak is occurring in one check value, hopefully the second check value can ensure that it wont get very far and the sensors can detect the problem long before device activation.

    Double M.M. BunnyDouble M.M. Bunny4 หลายเดือนก่อน
  • Thank you Scott Manley!!

    John O'DriscollJohn O'Driscoll4 หลายเดือนก่อน
  • So, Scott, why are the valves replaced by the burst disks, and not supplemented by them by, for example, placing the burst disks between the LF/O tanks and the check valves? These are both relatively low-cost parts, in the context of a rocket engine, but each protects from different kinds of failures, and importantly, these different kinds of failures occur at different times.

    Dashiell BarlowDashiell Barlow4 หลายเดือนก่อน
  • Great news! The silence was worrying me.

    Admiral BobAdmiral Bob4 หลายเดือนก่อน
  • 1080p, full HD resolution in MS, you killed it Scott! The best!

    Pavlo PerevoznykPavlo Perevoznyk4 หลายเดือนก่อน
  • im impressed with the super draco bell you managed to make in paint. lol

    Branden WilliamsBranden Williams4 หลายเดือนก่อน
  • Hmmm... So titanium under the right circumstances can act as catalyst? Actually this accident can open new avenues.

    MinonianMinonian4 หลายเดือนก่อน
    • Not a catalyst; a fuel.

      jimW133jimW1334 หลายเดือนก่อน
  • The one way valves go back to default closed position to stop fluids going back down the pipe, they are usually spring loaded to auto shut when the pressure drops to below spring force etc, but of course can be motorised

    Nick HardyNick Hardy4 หลายเดือนก่อน
  • Come on it was 4/20 they were all smoking that maryjane. This is just a coverup. But great breakdown, it really helps when everything is simplified down like this.

    Riley FenleyRiley Fenley4 หลายเดือนก่อน
  • The sooner Spacex gets rid of the helium pressurization systems with Starship the better. It has caused so many headaches.

    The SphinxThe Sphinx4 หลายเดือนก่อน
  • As usual, a quality video (even with MS Paint) full of great info, and explained in a way that everyone can understand. Thank you Scott.

    Murray BallMurray Ball4 หลายเดือนก่อน
  • Why not keep a bit of helium pressure in the lines at all times?

    Benjamin BrooksBenjamin Brooks4 หลายเดือนก่อน
  • Lucid Explanation. Thank You.

    bruce bagnolibruce bagnoli4 หลายเดือนก่อน
  • by adding bust disk spacex will be making the thrusters a one time use right? one time per flight till the disk can be replaced?

    Ben NaylorBen Naylor4 หลายเดือนก่อน
    • No but it was originally designed to propulsive landing and what not just a escape system the system can leave orbit and reenter the atmosphere if the second staged malfunctioned in orbit the draco thruster can do alot more just be used for escape system

      Ben NaylorBen Naylor4 หลายเดือนก่อน
    • because you're planning to use the escape system multiple times in the same mission?

      Phoe PhoePhoe Phoe4 หลายเดือนก่อน
  • Most importantly, we now know that there is a spy inside spaceX

    Dakilang MaginooDakilang Maginoo4 หลายเดือนก่อน
  • Well, seems like The old school engineering firms such as Boeing , Lockheed and Northrop know something after all.

    kenya catholickenya catholic4 หลายเดือนก่อน
  • As stressful a job as it would be to try and figure this out, it's gotta be incredibly rewarding to piece it together and find the answer. Never doubted the SuperDracos for a moment.

    mycroft16mycroft164 หลายเดือนก่อน
  • Wait a minute? Aren't the superdracos supposed to be in-flight restartable?

    Joshua HudsonJoshua Hudson4 หลายเดือนก่อน
    • nope, abort only

      TheBackyardChemistTheBackyardChemist4 หลายเดือนก่อน
  • This has been documented for decades. It’s known as the “Taco Bell Effect.” When high pressure gas accelerates a soft blob of material directly through a one-way check-valve apparatus, causing an unexpected blowout. Every taco tuesday, someone experiences this effect.

    NarcissistectomyNarcissistectomy4 หลายเดือนก่อน
  • 02:34 ,,something werent quite right'' you told at the start on the video they know exactly what went wrong... seems to me they actually dont now anything^^ in my opinion this ,,something werent quite right'' should be the main thing to look after or am i wrong??

    marvin luthermarvin luther4 หลายเดือนก่อน
  • so it is Space X causing the helium shortages in the US.

    james corvettjames corvett4 หลายเดือนก่อน
    • Nah, it’s economics. In the 90’s politicians started selling off the strategic helium reserve, that meant it wasn’t profitable to harvest helium. Now supply can’t match demand.

      Scott ManleyScott Manley4 หลายเดือนก่อน
  • 3:55 I think you meant to say "Minecraft Fire" 😂

    MinecraftPhenom08MinecraftPhenom084 หลายเดือนก่อน
  • Wouldn't another method of preventing this problem be to use an automated gradual opening of the pressurant valve? Burst disks can't be a final solution if they want to have multiple restart capability... Furthermore, what if part of the burst disk breaks off and blocks a passage downstream? I know they aren't supposed to, but then check valves aren't supposed to leak either.

    travis dunntravis dunn4 หลายเดือนก่อน
    • @Scott Manley Good point. I'm beginning to understand why my spaceX application was turned down xD

      travis dunntravis dunn4 หลายเดือนก่อน
    • There’s no such thing as a gradual opening when your booster is already exploding

      Scott ManleyScott Manley4 หลายเดือนก่อน
  • It's a good thing that this happened at this stage. Fluid dynamics under loads and interactions of different types, gets very complicated.

    Jett Jo johnsonJett Jo johnson4 หลายเดือนก่อน
  • I hope NASA won't Need Another Seven Astronauts.

    John NyJohn Ny4 หลายเดือนก่อน
  • So they intend to blow up the space station next , spacex extreme fireworks company .

    guy foxguy fox4 หลายเดือนก่อน
  • Excellent explanation. I come here for good info, and am never disappointed. Thank you!

    Gustav LessingGustav Lessing4 หลายเดือนก่อน
  • this theory doesnt add up-

    Jack SmithJack Smith4 หลายเดือนก่อน
    • I agree.

      guy foxguy fox4 หลายเดือนก่อน
  • Didn't that really clever guy invent a testable check valve, ya know the one Elon Musk named his car company after...

    Michael McAdamsMichael McAdams4 หลายเดือนก่อน
  • " don't want your liquids flowing back into your gas section. At least it might cause burping..." If they flow all the way back to the Y-joint you're going to get a hell of a burp. They're hypergolic! Yikes!

    jfan4revajfan4reva4 หลายเดือนก่อน
  • This is so ironic, as Tesla invented a one way vale that cannot fail. Someone tell Elon!

    The EnglishmanThe Englishman4 หลายเดือนก่อน
    • "this cannot fail" is usually a phrase found in the category "famous last words"

      Jim PanseJim Panse4 หลายเดือนก่อน
  • Very simply explained and diagramed. Nicely done

    givingus5givingus54 หลายเดือนก่อน
  • Corrosive bullets. **sweats in Elite Dangerous experimental effects**

    Queen NidusQueen Nidus4 หลายเดือนก่อน
  • Would have to agree that Rupture Disks are way more reliable than Check Valves. Not reusable but could be easily replaced between tests. Failure for the win.

    Likely candidateLikely candidate4 หลายเดือนก่อน
  • This happens when I eat Taco Bell.

    jw33jw334 หลายเดือนก่อน
  • Thanks for explanation. BTW Dragon2 doesn't have to worry about busy parking at station because it uses the old Shuttle PMA2 docking port which nobody uses. (but still has to take appointements to make sure they schedule crew rotations etc).

    Jean-Francois MezeiJean-Francois Mezei4 หลายเดือนก่อน
  • Scott, your quick and simple responses and explanations are amazing and still manage to be great quality. It’s a bliss to have them.

    sunkid86sunkid864 หลายเดือนก่อน
  • Man you do a great job Manley!

    Scott DorflerScott Dorfler4 หลายเดือนก่อน
  • What is burst disc and how does it work.

    ArnisArnis4 หลายเดือนก่อน
  • I would guess frame shift drives are immune to this problems?

    martin masangamartin masanga4 หลายเดือนก่อน
  • Great video man was able to comprehend all of it :D

    Jonathan MartinJonathan Martin4 หลายเดือนก่อน
  • No isolation valves behind the check valves? Odd....

    A. I.A. I.4 หลายเดือนก่อน
  • When your blood flows backwards through the venal valves, trouble.

    Cby 0530Cby 05304 หลายเดือนก่อน
  • Nice job explaining this.

    MikeGamerGuyMikeGamerGuy4 หลายเดือนก่อน
  • Nice ms Paint skills, lol. Thumbs up!

    ian5576ian55764 หลายเดือนก่อน
  • No one was hurt. This is why we test.

    SteverRobSteverRob4 หลายเดือนก่อน
  • No one ever said reinventing the wheel would necessarily be easy.

    Dale ComerDale Comer4 หลายเดือนก่อน
  • Thats a rough couple months for Mr. Musk

    jason archerjason archer4 หลายเดือนก่อน
  • Ok, so the Mars Observer Failure Investigation Board concludes that Nitrogen Tetroxide had leaked past the check valve and either reacted with the titanium or caused some other problem. Yet, Spacex writes ”It is worth noting that the reaction between titanium and NTO at high pressure was not expected. Titanium has been used safely over many decades and on many spacecraft from all around the world..." . Someone help me out with this contradiction...

    Saumya CowSaumya Cow4 หลายเดือนก่อน
  • Do not worry, Werhern Von Braun had same problems in 40`s. You get it... or contact me, I can send you to Mars and back.

    Jone ArmyJone Army4 หลายเดือนก่อน
  • Only in aerospace could moving vehicles between parking spaces once every 3 months be called "very busy"!

    Jonathan LeeJonathan Lee4 หลายเดือนก่อน
SpaceX's Crew Dragon Spacecraft Exploded Because of 'Corrosive Bullets' and Leaky Valves