Slow motion video of model rocket engine underwater doesn't end well


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What? I think this ended exceedingly well.


I’ll have to watch later. But why not a smaller A motor? Go big or go home, I guess.


Start at 3:20


Incompressible substance, glass, explosive. Seems like it ended exactly as expected.


Yeah, my first thought was along those lines. A D12 motor pack is something like $15 these days. An A8-3 would have done the job just fine.


The idea of an underwater rocket goes way back. Flip to page 6 of this 1962 Estes newsletter:

(The rest of the newsletter is pretty interesting too. Vern Estes is still alive and active in the hobby; he hangs out at the Ye Olde Rocket Forum and answers questions about the olden times.)


That’s really cool, Stefan! Thanks for posting.


Wondering if a Tempered Glass or Polycarbonate Tank would have held up to the Ejection charge?


Speaking of rockets under water. Ever heard of a Gyrojet?

It was a gun which shot bullets propelled by rockets.

It was a neat idea, but never really panned out. It was inherently inaccurate. And, oddly enough, because of the time for it to get up to speed, if you were real close it wouldn’t hurt you.

They did make a version for underwater called the Lancejet, but it was even less accurate in water.

If you think they look kinda cheap and stamped mettally - that is because they are. They had very little recoil and didn’t have to contend with anything near the pressures of normal bullets.




Yes, I think we had these in Gamma World.


I learned about Gyrojets from a Larry Niven story. Fascinated by the idea.

They regularly turned up in SF war games and RPGs back in the day. FREX the paleo-SF-miniatures skermish game “Star Guard,” still in production, put gyrojet pistols and scaled-up “cone rifles” in the hands of militias and security details. (More upscale forces had laser rifles.)


Leftover from their previous video… and well youtube so MOAR BOOM! MOAR SPLOSION!


Does anyone know what exactly is that “sound of light reflecting off glass” at 5:47?


But famous in its own way.


I’m speculating that it was added in post-production just for ‘effect’ - a little artistic license if you will.


Wow, wasn’t aware of that! I faded from the hobby after the Aerotech factory burned down, their product disappeared locally and it seemed like the hobby stores also shrank their line of Estes. Such a cool hobby, sorry to see it shrink, great to still have the pioneer around!


He didn’t know it had an ejection change? That’s what the -5 in the engine type means: 5 seconds delay.


I liked the spacey music during the slo-mo section but I would’ve gone with this:


Estes, Ind. is kind of schizoid. Most of their sales are of simple, often pre-made, rockets sold at discount stores.

But they turn out a few really challenging kits a year, often of really high quality. Some scale models (like a Little Joe II I got for Xmas and really need to build one of these eyars), and some nifty Sci-Fi looking things. The Chief Designer these days, John Boren, has a CAD system and 3D printer and laser cutter, and uses them!

He hands out at Ye Olde Rocket Forum too. On this thread, a guy posts pictures of two scratch-builds, and John responds that he’d like to use one of the ideas. (I mean, MAN, just look at that Starship Avalon. That’s primo Sci-Fi shit right there.)