how are military solid rockets ignited, same as ours?

[soopirV]

I was reading up on the sidewinder AIM-9, and wasn't able to determine how they are ignited...is it just an ematch-like igniter?

 

[Zeus-cat]

Copperheads!

Actually, I would think they would use something very energetic to ensure ignition. They can't swap out the igniter if it fails!

 

[rharshberger]

Copperheads!

Actually, I would think they would use something very energetic to ensure ignition. They can't swap out the igniter if it fails!

Copperheads WITH a chunk of Blue Thunder added...😀

 

[rstaff3]

Head end pyrogen plug per their spec sheets.

 

[Steve Shannon]

Like rstaff3 said. Something like this:
https://www.eba-d.com/assets/produc...n-CapabilitiesSht-Web-Low-Res-For-Gen-Use.pdf


Steve Shannon

 

[ECayemberg]

I lit my Sidewinder motor with a Firestar igniter taped to a 6' stick and probably augmented with scrap propellant. It lit easily and pressurized immediately. Nice motor.

But yes, the military version is a bit different as far as ignition goes. Doesn't take much to get that propellant going!

Eric

 

[stealth6]

Well they used to use Q2G2s, but.........

s6

 

[soopirV]

Like rstaff3 said. Something like this:
https://www.eba-d.com/assets/produc...n-CapabilitiesSht-Web-Low-Res-For-Gen-Use.pdf


Steve Shannon

Thank you to you and Rstaff3 for the needed details, and the rest for the laughs! I had assumed (hoped?) that the military had something more elegant (and of course expensive) than an e-match, but couldn't find any specifics!

 

[Steve Shannon]

Thank you to you and Rstaff3 for the needed details, and the rest for the laughs! I had assumed (hoped?) that the military had something more elegant (and of course expensive) than an e-match, but couldn't find any specifics!

It's quite different from an ematch; higher current (nobody wants a Sidewinder going off accidentally), matched to the 28 volt DC aircraft power bus, less sensitive to physical and electric shock.
The new head end igniter system from Aerotech shares some features.

 

[mpitfield]

Like rstaff3 said. Something like this:
https://www.eba-d.com/assets/produc...n-CapabilitiesSht-Web-Low-Res-For-Gen-Use.pdf


Steve Shannon

I want one

 

[Steve Shannon]

I want one

There's this:
https://www.rocketmotorparts.com/Low_Cost_Head_End_Initiator/p1577809_16501656.aspx



Steve Shannon

 

[ECayemberg]

...except I was serious:

[video=youtube;nylUXEGtpgU]https://www.youtube.com/watch?v=nylUXEGtpgU[/video]

unless I'm mistaken in that the O25k is a commercial HPR version of the Aim-9 motor

 

[Incongruent]

unless I'm mistaken in that the O25k is a commercial HPR version of the Aim-9 motor

According to Wikipedia, the engine is a Hercules/Bermite MK36 Solid Fuel Rocket.

 

[rstaff3]

https://www.orbitalatk.com/defense-...Sidewinder_Fact_Sheet_Approved_April_2015.pdf

Since orbital/ATK builds such, I'd be surprised if they outsourced them.

 

[Steve Shannon]

According to Wikipedia, the engine is a Hercules/Bermite MK36 Solid Fuel Rocket.

Orbital ATK makes three different motors for the Sidewinder series of Missiles:
https://www.orbitalatk.com/defense-systems/missile-products/sidewinder/

Data sheets which show nothing about the impulse or burn time are linked to the page.


Steve Shannon

 

[Incongruent]

Does anyone know what "MK 36" means? It's listed in the name (with parenthesis around it) of the first sidewinder variant and in the name of the rocket motor.

There's also this: https://www.govconwire.com/2016/07/...-for-sidewinder-block-ii-missiles-production/

I think I'll be backing out of the conversation a little, since I'm quite confused right now.

 

[Steve Shannon]

Does anyone know what "MK 36" means? It's listed in the name (with parenthesis around it) of the first sidewinder variant and in the name of the rocket motor.

There's also this: https://www.govconwire.com/2016/07/...-for-sidewinder-block-ii-missiles-production/

I think I'll be backing out of the conversation a little, since I'm quite confused right now.

It's just a common designation, which stands for Mark 36. It's like a version number.

 

[Steve Shannon]

https://en.m.wikipedia.org/wiki/Mark_(designation)

 

[DavidMcCann]

They're ignited by the sheer anger of the pilot at his target

 

[Worsaer]

Adapting these to HPR Head-End-Ignition (HEI), as Aerotech is pursuing, also requires some thought to safety. If you review the linked PDF, you'll see a schematic that requires two independent 'arm' inputs plus a 'fire' signal to initiate ignition. For a two-stage configuration, with HEI for the upper stage, this adds an interesting margin of safety.

https://www.e2v.com/resources/account/download/28

 

[Steve Shannon]

Adapting these to HPR Head-End-Ignition (HEI), as Aerotech is pursuing, also requires some thought to safety. If you review the linked PDF, you'll see a schematic that requires two independent 'arm' inputs plus a 'fire' signal to initiate ignition. For a two-stage configuration, with HEI for the upper stage, this adds an interesting margin of safety.

https://www.e2v.com/resources/account/download/28

Absolutely correct! Although we don't require that many inhibitors, we still require that whether the igniter is inserted head end or aft end the connection of the circuit that powers the igniter is required to be made either at the pad or at a preparation area that is away from uninvolved persons and must not be armed until the rocket is on the pad and near vertical.

 

[ksaves2]

Two words: Zirconium and Boron.

https://en.wikipedia.org/wiki/Pyrotechnic_initiator

Three words: Don't go there.

Kurt

 

[Worsaer]

Two words: Zirconium and Boron.

https://en.wikipedia.org/wiki/Pyrotechnic_initiator

Three words: Don't go there.

Kurt

Help me understand Kurt. BKNO3 is used for rocket ignition, isn't it?

 

[UhClem]

Help me understand Kurt. BKNO3 is used for rocket ignition, isn't it?

Rocket motor igniters come in at least two parts: initiator and pyrogen. The initiator is the (usually) electrically activated bit that kicks things off. Usually a 1 Ohm/1 Watt device. (Must be able to withstand the application of 1 Watt for 5 minutes without doing anything.) This is followed by a pyrogen which does the heavy lifting of generating heat/gas. Popular pyrogens are BKNO3 and Magnesium Teflon among others.

There may also be an integrated arm/fire device with safety features that receive very careful review.

 

[ksaves2]

Help me understand Kurt. BKNO3 is used for rocket ignition, isn't it?

Yes BKNO3 is used for ignition. I've been told the zirconium can be very dangerous and powdered Boron is quite pricey. That's where "don't go there" came from as far as hobbyists are concerned. The government, NASA and the military have the means to do what they want and pull it off.

It's ok to click on the link, just don't get any ideas of trying to reproduce what the "big boys" do as it's not fun getting hurt. MTV igniters are doable and reasonably safe as long as one is well-versed with the safety of dealing with magnesium powder. Raw viton can be hard to find as one can't just chop up a cured viton gasket and get it to dissolve in anything. Teflon is easy to find. A first dip with a commercially available product is advisable and then the MTV. Note, I didn't discuss proportions here so not violating the rules. Oh, the commercially available igniter kits are reasonable too if one doesn't want to mess with the hassle of looking up recipes and trying to acquire the components. Or if one just flies certified loads, just use what's provided (except
I think I have to use my own igniters for Loki loads which is fine by me)

I realize the original question is, "What does the military use?" I just want to caution it isn't necessary for a hobbyist to attempt to emulate it, that's all. Kurt

Kurt

 

[Worsaer]

Thanks Kurt, got it. I assumed you were talking about safety concerns, sorry.

I noticed the instructions on the component available from RCS (made by Triton Space) that we may see in wider use in our hobby some day, and BKNO3 was included (below). Your point about cost, availability, and practicality of BKNO3 is well taken.