What's this tank on the Titan IIIC SRB?

[Lexif]

As the title says, I looked at photographs of the Titan IIIC, which has solid fuel boosters as its first stage. There's a tank visible on the side of one of one booster in each picture, it's painted orange near the top in this picture:

(Click for full resolution)

I guess the other booster has one on the far side as well. It seems to feed into the nozzle of the engine on the booster. I wonder what it's for?

Thanks in advance!

Edited February 7, 2014 by Lexif
included picture

[astropapi1]

Yeah, I've also wondered what that thing is.

Also, is that a Gemini mockup on top?

[Lexif]

It's a mockup of the Manned Orbital Laboratory (MOL), reusing the Gemini 2 capsule that was flown unmanned for a suborbital test flight and recovered.

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

Edited February 7, 2014 by Lexif
clarified my post

[Fuzzy Dunlop]

I'm betting It has something to do with the steering. On the Titans with SRBs the core engine wasn't ignited at launch so that couldn't be used for thrust vectoring.

[Kryten]

As the title says, I looked at photographs of the Titan IIIC, which has solid fuel boosters as its first stage. There's a tank visible on the side of one of one booster in each picture, it's painted orange near the top in this picture:

https://upload.wikimedia.org/wikipedia/commons/8/88/Titan-3C_MOL-Gemini-B-Test_3.jpg

I guess the other booster has one on the far side as well. It seems to feed into the nozzle of the engine on the booster. I wonder what it's for?

Thanks in advance!

I'm pretty much sure that's a 'Secondary Injection Thrust Vector Control System'; effectively a tank full of extra fuel to inject into the nozzle, changing the thrust vector. I've not seen anything that would confirm this, but it looks very similar to the same system on other rockets (e.g. India's PSLV), and I've seen vague references to the SRB's having 'advanced thrust-vector control systems'.

Also, is that a Gemini mockup on top?

That's no mockup; it was (and is, it survived the flight) an actual gemini re-used from one of the early uncrewed test flights. The stripy thing directly underneath is a mockup of a military spacestation that was supposed to be serviced by an evolved gemini (MOL), but was cancelled not long after that flight.

[Fuzzy Dunlop]

I know the Indian PSLV (Polar Satellite Launch Vehicle) vectors its thrust by injecting a solution of Strontium perchlorate into the nozzel of the solid first stage. This was stored in strap on tanks like the ones on the Titan SRBs.

[Lexif]

I'm pretty much sure that's a 'Secondary Injection Thrust Vector Control System'; effectively a tank full of extra fuel to inject into the nozzle, changing the thrust vector. I've not seen anything that would confirm this, but it looks very similar to the same system on other rockets (e.g. India's PSLV), and I've seen vague references to the SRB's having 'advanced thrust-vector control systems'.

I think I also saw a reference to the solid stage having thrust vectoring capability, but I can't find the page now. So that just might be what it's for. I guess that provides steering in only one axis, though? Or do they internally inject the stuff into different ports in the nozzle depending on the steering impulse needed?

[Kryten]

I think I also saw a reference to the solid stage having thrust vectoring capability, but I can't find the page now. So that just might be what it's for. I guess that provides steering in only one axis, though? Or do they internally inject the stuff into different ports in the nozzle depending on the steering impulse needed?

I don't know anything about this system specifically, but some definitely do have multiple ports; PSLV uses the same system for both pitch and yaw.

[astropapi1]

Oh, so that's MOL? I thought it would have looked cooler from all the articles I've read about it. Kinda looks like a PVC tube.

Shame the Gemini program got scrapped. It had lots of potential.

[DerekL1963]

I think I also saw a reference to the solid stage having thrust vectoring capability, but I can't find the page now. So that just might be what it's for. I guess that provides steering in only one axis, though? Or do they internally inject the stuff into different ports in the nozzle depending on the steering impulse needed?

My guess is is seperate ports, Polaris A-3 used helium gas for TVC on the second stage.