The #1 Reason Rocket Parachutes Fail

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[bunnybro]

"I may not be proud of everything I do, but it is a lot easier to be proud of something shiny" is, without question, the greatest sentence I have heard all year

[JustVinny]

'The meat is mission critical' a sentiment held both by Joe and engineers working on crewed missions.

[howa]

When you hit retirement age you should totally do some part time professoring at a University. You are great at explaining complex processes while keeping people engaged.

[PilotMan]

"BPS GPS" which may or may not be limited to 600 knots or 100, 000feet in altitude....The world will never know

[VisualBasic]

Joey trying to pass a radar array as a "meat holder" to the eyes of the powers that be is just hilarious.

[MarkEichin]

"If this connection fails we will *lose the meat* and that is *mission critical*"

... I love this channel :)

[quintuple_lained]

I really appreciate the honesty about the b roll but then also proving why it’s still good with the montage, honesty in art that doesn’t take away from the magic is a wonderful thing

[oliverniekrenz]

"Charged for the use of rocket parachutes" was what the auto-translated YT notification read on my phone 😱Thanks, YT, for this little heart-stopping moment

[feldamar]

Something to note with blackpowder! O2 in atmosphere makes pretty much ZERO difference in burn speed or reliability.
It's PRESSURE that's needed. The paper towel that holds it in place helps here. The vinyl tubing too of course. You don't need atmospheric pressure to do it, as it can provide it own...after it starts burning enough to do so anyway.
The blackpowder needs atmosphere/pressure to sustain itself. I think this is only true for blackpowder though as the o2 in the mixture is NOT chemically bonded with the mixture but merely mechanically close.

[fast-yijs]

WHY ARE YOU RUNNING YOUR HOT GLUE SO HOT ITS SMOKING

[ethanmiller]

Laboratory Machinist here. Your Al meat spike thing is really cool looking and would be fun and challenging to machine. I think I would have made the spikes from wire that was press fit into a plate with reamed holes. Then cut the wires roughly to length. Place a tube around the base to allow for melted wax to me poured around the wires and allowed to harden. Place in the machine the same way you did and run a few light passes before a few finish passes on the OD. Melt the wax away after machining. There are so many ways to get the same result, one thing I love about machining!

[Project-Horizon]

I was studying for my L2 this morning, and it’s great how much this video applied to that. Everything from twisting the wires to the emphasis on proper recovery, considering 75% of HPR flight failures are recovery-related. As always, thanks for the great info!

[leifhietala]

Homemade kaboomage, what could possibly go wrong?

Joe: "Let's find out!" Except no, because Joe has gotten to this stage of his rocketry career with a full complement of thumbs, and appears to be committed to maintaining that fine tradition.

[bjf]

You can de-pin most connectors (that looks like a JST, you definitely can depin those with a needle), so the wire colors can match your preferred standard.

[Oldman]

Your comment about making the connections so that they only fit the one which you wanted it to go reminded me of a 2013 Proton rocket failure caused by accelerometers installed upside down by mistake.

Knowing that this would have been a big problem, the designers of the hardware painted the sensors with an arrow that was supposed to point toward the front of the rocket or up (this way to space dummy). The wreckage was found with some of the sensors facing the wrong way.

Also knowing that obvious instructions aren't so obvious, the mounting point was designed by the engineers so that it had guide pins that matched up to holes in the sensor that would allow the sensor to fit only if it was oriented correctly.

Stupidity knowing no bounds, the sensors were recovered and found to be dented by the pins, having been forced into the mounting point probably by a hammer :).

[treelineresearch]

Potting the lipos in a soft silicone compound compound is something you might want to look at. I've used some 10 durometer platinum cure for potting electronics and it's tough but squishy, doesn't release any noticeable heat during cure, and as far as I know doesn't offgas anything corrosive. Mentioning brands on here seems to often make comments disappear but it's the yellow and blue company's stuff.

[wonjez]

11:16 What you are looking for is essentially a blackpowder motor with rapid burn and high gas volume. The trick to a steady downwards combustion is to compress the powder, so the pressure doesnt push the flame into the grains.

This will decrease burn speed, so you could increse the reactiveness of your compound, but then you'll always have hot ejecta. More powder will just set the chute on fire. The more traditional approach is a throat or a simple junction like on a fountain. That gives you a high pressure and therefore brings combustion speed back up. Now you have high pressure, but want a slow exhaust - the way to do it is to create a diffusor/maze. A lid or even some duct tape across the top with gaps to the side or a simple wound up acrylic tube does the trick. Imagine an airbag charge - large can with many holes.

Such a design will hold down any large chunks, increase pressure and slow the gas in the chamber down, which means more time for any fiery particles to burn up. Adjust the amount of holes to create the desired reaction speed. A maze structure also greatly helps with cooling, like in a cigarette.

The result: That intial puff at 11:03 comes close. Clean gas, due to high chamber pressure. If the powder was compacted and the tape had some more holes, it would've held on and moderated that inital pressure. After the tape flew off, the powder was merely burning and spewing out. Adding more powder would only make that worse.

Secondly, use a finer grain powder to reduce the burntime of any ejected particles. 10:44 almost looks like an agglomerate which is made to propell a mortar, the lose grain structure specifically allows it to throw itself up and fill the mortar tube to increase surface area and burn speed. 11:07, that's those grains spweing out like rouge SRBs.

[cje-Lg]

I really appreciate you documenting your all-government-watchlists speedrun.

[LeftoverAPCP]

The gaff tape/grubb screw retention is brilliant.

[MrBunnington]

Just wanted to let you know that I'm here because of Mr. Mark Rober. I'm now subscribed! I do enjoy your content and to know that you're self taught just completely blows my mind! From a very not self taught Engineer I have MUCH RESPECT for you 🙏. God bless and Godspeed to you and yours 🙏.