Solid Rocket Boosters (SRB) Slow Motion upon launch

[ApolloWasReal]

Wow, I'd never seen that shot of the igniter plume coming down the propellant star grain inside the SRB before. Amazing.

There seems to be a delay between the firing of the frangible hold-down nuts and SRB ignition, is that real? Or does it just take that long for the ignition wave to reach the bottom of the SRB?

[GeorgeEdo]

@ Membrane556

Thanks you for informing us...!

And yeah this has to be greatest SRB video...!

[Membrane556]

How they got these shots of the SRBs is an interesting story. The highspeed camera actually is under the launch platform inside a steel box and is hooked to a bundle of fibre optic cable sorta like what's in an endoscope.

There was a rotating quartz window on the end of the optic fiber with a wiper to remove soot .

The rotation also only allowed a portion of the window to be exposed at any given moment.

The same setup was used for those shots on the Apollo rockets.

[Elhombresombra]

@Membrane556 Thank you for sharing! It was a very clever setup, and not overly complicate! It takes a real genius to come out with a ELEGANT and simple solution to a wicked problem...

[plormitch]

Earplugs and a welding mask.?.LOL :)

[Elhombresombra]

together provide enough thrust to tear off all the 8 bolts, each one being 28" lenght X 3.5" in diameter, go figure the power of that thing...

[crazybastard82]

i wouldn't doubt that it could tear those bolts off, considering the millions of pounds of thrust that baby has. still, i had to laugh when you informed me about the nut catchers...those guys and gals at nasa really DO try to think of everything, right down to retrieving nuts for future study, lol. god, i love those people. i can't wait to see their launches of the ares v cargo vehicle. two boosters along with six engines should be an impressive sight.

[crazybastard82]

0:07

are those the explosive bolts that hold the stack during the twang being blown?

[Elhombresombra]

You are correct, there are 4 hold-down bolts for each SRB (so 8 total), in each bolt it's actually the nut that is blown. Each nut contains 2 small explosive charges, for redundancy, (at opposite edges of the nut) which are detonated simultaneously at T-00. Should one detonator fail, the other one is enough to fracture the nut.

[crazybastard82]

cool. i read somewhere that sometimes they give the nut halves to the astronauts for keepsakes after the missions... when seeing vids like this it is hard to imagine being able to find those nuts after the incredibly violent event of the srb ignition and liftoff.

[Elhombresombra]

Actually, the two halves are NOT allowed to go around freely! There is a "nut catcher" for each bolt, it looks like a "dome". The two halves of the nut remain trapped inside, and are recovered for later analysis. In one past mission, it was discovered that in ONE nut, ONE of the detonators had not fired. Anyway, one good detonator is enough to split open the nut, and I once read in a NASA document that, even if all 16 detonators failed to fire (virtually impossible), the 2 SRBs and 3 SSMEs

[jamcrane3]

@Elhombresombra

Fascinating!

[Elhombresombra]

@jamcrane3 Two or three years ago I found a short video (in the form of an animated GIF, I should have saved it!!!) showing one nut being fired on the test bench, very interesting and very rare! Should I succeed in finding it again I would inform you for sure.

[Elhombresombra]

@jamcrane3 Found! Look here: (3w dot) collectspace(dot)com/collectio­n/artifacts_sts_sts31fnut(dot)­html

[spudgunster]

@crazybastard82 My astronaut friend told me that the nuts are stainless, and are given to the astronauts, as you said. they are retained in the booster, and ride along the whole way up.

[kslifer1066]

no iwas the camera man, i had to wear earplugs and a welding mask to protect my ears and eyes

[sledger25]

@kslifer1066 you are talking bull... if you were the camera man standing THAT close to a launching shuttle, the heat would kill you

[peerless77]

I was the camera man, I had to wear earplugs and a welding mask to protect my ears and eyes.

[BackyardChemistry]

sorry, i'm afraid you're talking bull there. You'd have to have been in a bunker, or at least a mile away, same as everyone else. camera operator, perhaps, but you'd be dead if you were standin that close

[lithiumdeuteride]

The acoustic pressure is lethal 800+ feet away. We must be talking to a spirit. How's the afterlife?

Oh, right. There is no afterlife. What a joker!

[atlaniscolumbus122]

that was awesome thanks for that cool vantage point!

[Engine7601]

Nice video. Thanks

[ThePianoMan825]

Amazing

[r0ckt3hc4sb4h]

Too cool.