[1.12.5] Bluedog Design Bureau - Stockalike Saturn, Apollo, and more! (v1.14.0 "металл" 30/Sep/2024)

[CobaltWolf]

  On 7/12/2023 at 3:10 AM, septemberWaves said:

What are the two spikes next to the rocket motor nozzle? I've noticed something like that on several of the solids in BDB and I'm wondering what it's for.

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I believe it has something to do with igniting the SRB - though I thought usually the ignitor was at the top. A lot of the STAR motors have them.

[Richmountain112]

Maybe it has to do with shutting down the engine once the burn is complete, as to avoid overshooting.

Where is the Shutdown assembly?

[CobaltWolf]

  On 7/12/2023 at 4:40 PM, Richmountain112 said:

Maybe it has to do with shutting down the engine once the burn is complete, as to avoid overshooting.

Where is the Shutdown assembly?

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Most SRBs don't have them in real life. You either adjust the amount of propellant or shape your orbit differently to use a set amount of delta V. The shutdown on the BDB solids is a gameplay consideration to make them more useful, since I don't expect players to spend weeks/months planning a mission and shaping the trajectories haha.

  

  On 7/11/2023 at 4:33 AM, Brainpop14 said:

HYPE! Want so badly! Any word on how soon?

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  On 7/11/2023 at 9:04 PM, RocketBoy1641 said:

My guess is we should be thrilled if we get it for Christmas.  If sooner: Insert gif of guy handing Cobalt buckets of cash!

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I won't give an ETA, since work hasn't even begun on texturing the lander or getting it in game. I'd say before Christmas though. (Also, I am still looking for more people to sign up to the patreon)

 

Here's an update on the orbiter, though:

Edited July 12, 2023 by CobaltWolf

[biohazard15]

  On 7/12/2023 at 4:40 PM, Richmountain112 said:

Maybe it has to do with shutting down the engine once the burn is complete, as to avoid overshooting.

Where is the Shutdown assembly?

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IRL most SRBs don't have these. The closest thing to a "shutdown assembly" would be blowout ports on Minuteman III's third stage. IIRC there was a plan to add similar feature on UA-1207s for Titan IIIM MOL flights.

[Richmountain112]

  On 7/12/2023 at 5:01 PM, biohazard15 said:

  On 7/12/2023 at 4:40 PM, Richmountain112 said:

Maybe it has to do with shutting down the engine once the burn is complete, as to avoid overshooting.

Where is the Shutdown assembly?

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IRL most SRBs don't have these. The closest thing to a "shutdown assembly" would be blowout ports on Minuteman III's third stage. IIRC there was a plan to add similar feature on UA-1207s for Titan IIIM MOL flights.

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  On 7/12/2023 at 4:57 PM, CobaltWolf said:

 

  On 7/12/2023 at 4:40 PM, Richmountain112 said:

Maybe it has to do with shutting down the engine once the burn is complete, as to avoid overshooting.

Where is the Shutdown assembly?

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Most SRBs don't have them in real life. You either adjust the amount of propellant or shape your orbit differently to use a set amount of delta V. The shutdown on the BDB solids is a gameplay consideration to make them more useful, since I don't expect players to spend weeks/months planning a mission and shaping the trajectories haha.

 

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That makes sense. SRBs can't be shut down once turned on.

[CobaltWolf]

  On 7/13/2023 at 12:41 AM, Richmountain112 said:

That makes sense. SRBs can't be shut down once turned on.

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There were studies back in the day for SRBs that could be shut down (and reignited!) using an extinguisher system. I don't think it made it very far, I think it was mostly a result of experts trying to push the capabilities of SRBs past what was needed.

[septemberWaves]

  On 7/12/2023 at 2:39 PM, CobaltWolf said:

I believe it has something to do with igniting the SRB - though I thought usually the ignitor was at the top. A lot of the STAR motors have them.

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Thank you for the explanation. This diagram makes me think that the position of the igniters near the engine bell is important for the ignition sequence; perhaps putting it at the top causes problems with the gas expansion immediately after ignition?

EDIT: looking at this a little more closely, you can sort of see that the void space in the middle of the propellant curves to a close before it reaches the top. That probably explains why the igniters are close to the bottom. The igniters are shorter near the engine bell than they would have to be if they were at the top.

Edited July 13, 2023 by septemberWaves

[Starhelperdude]

  On 7/13/2023 at 1:26 AM, CobaltWolf said:

There were studies back in the day for SRBs that could be shut down (and reignited!) using an extinguisher system. I don't think it made it very far, I think it was mostly a result of experts trying to push the capabilities of SRBs past what was needed.

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I remember hearing about some small upper stage solids that could cause such combustion instabilities through an to me unknown way that the combustion stops

did such a concept ever exist?

[RocketBoy1641]

On the matter of shutdown; some SRBs have a thrust termination system where they dump thrust either equally for and aft (net 0 thrust) or dump through side vents in a way that ends forward thrust.  The later seems more reasonable with PAMs/kickstanges and similar things that you can't burn toward the top of the stack.

 

I don't think they are all that common b/c it is cheaper to have less working pieces and push less mass (unspent fuel).  Restart options would take a lot of extra weight and complexity unless you use a solid/liquid hybrid.  Those are an interesting lot.  You have fuel or oxidizer as the solid and the liquid is the other.  Cut the liquid and the reaction dies.  Restart with hypergol or Tea-Teb.

[CobaltWolf]

  On 7/13/2023 at 11:47 AM, Starhelperdude said:

I remember hearing about some small upper stage solids that could cause such combustion instabilities through an to me unknown way that the combustion stops

did such a concept ever exist?

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  On 7/13/2023 at 2:17 PM, RocketBoy1641 said:

On the matter of shutdown; some SRBs have a thrust termination system where they dump thrust either equally for and aft (net 0 thrust) or dump through side vents in a way that ends forward thrust.  The later seems more reasonable with PAMs/kickstanges and similar things that you can't burn toward the top of the stack.

I don't think they are all that common b/c it is cheaper to have less working pieces and push less mass (unspent fuel).  Restart options would take a lot of extra weight and complexity unless you use a solid/liquid hybrid.  Those are an interesting lot.  You have fuel or oxidizer as the solid and the liquid is the other.  Cut the liquid and the reaction dies.  Restart with hypergol or Tea-Teb.

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Here is the image I was thinking of about it, I don't think I have a study document or anything.

[Pappystein]

  On 7/12/2023 at 4:57 PM, CobaltWolf said:

Most SRBs don't have them in real life. You either adjust the amount of propellant or shape your orbit differently to use a set amount of delta V. The shutdown on the BDB solids is a gameplay consideration to make them more useful, since I don't expect players to spend weeks/months planning a mission and shaping the trajectories haha.

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Very True,  In fact, the only SRB that I KNOW has a thrust termination system beyond the general "Shatter the SRM hull and it will go out" form of thrust termination is the UA-1205Gen2, as seen famously on the "KH-10" mockup launch.    CobaltWolf has modeled the Gen2 UTC Thrust termination system into all our nosecones, even though Generation 3 and 4 SRMs did not have it

 

  On 7/12/2023 at 2:39 PM, CobaltWolf said:

I believe it has something to do with igniting the SRB - though I thought usually the ignitor was at the top. A lot of the STAR motors have them.

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Most of the STar Solid motors are Bottom up  Burning, which is actually closer to pre WWII rocket motors than modern rockets.

Typical SRM burn styles are:

"Bottom Up" or "Back To Front" where a SOLID fuel is burnt and burns from the exit nozzle all the way up the cylindrical body to the nose. This actually causes extreme stress on the rocket leading to extra mass.

"Holy Moses"   Named as it was first used on the 5" HVAR nicknamed Holy Moses in WWII, is a solid fuel back-to-front burn like above but cavities and holes are molded into the fuel to provide a more consistent burn.   Notoriously fragile and is the main reason the 11.75" Tiny Tim Rocket left service because the motors would blow up on ignition if one of the channels was blocked.

"Star Power Bottom Up"   Where a central cavity is in the fuel and provides a way to maintain a similar temperature throughout the burn time, requires a circular or semi-circular pressure vessel.  You know like most of the Star series of SRMs

"Inside Out" is the typical burn pattern most people today think of.  Utilized by all the long and comparatively thin SRMs like the UA-120x family, SRMU, 156/146" Shuttle SRB etc   Where a cylindrical or star-shaped central cavity is burned in a near-simultaneous burn from end to end of the rocket, and it burns from the center of the fuel to the outer edge where the fuel joins the "hull" of the rocket motor.    Even the 256" Aerojet monolithic SRMs utilized this burn pattern.

 

  On 7/12/2023 at 4:57 PM, CobaltWolf said:

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Purdey

[Pappystein]

I should mention the Talos (RIM-8)  booster is the transitional step between "Holy Moses" and "Inside Out".   It has a non-hollow pattern in it that is basically several "inside out" star patterns in parallel with each other (early SRMs) and, in its final form a single star pattern.

[Sudragon]

  On 7/13/2023 at 2:17 PM, RocketBoy1641 said:

On the matter of shutdown; some SRBs have a thrust termination system where they dump thrust either equally for and aft (net 0 thrust) or dump through side vents in a way that ends forward thrust.  The later seems more reasonable with PAMs/kickstanges and similar things that you can't burn toward the top of the stack.

 

I don't think they are all that common b/c it is cheaper to have less working pieces and push less mass (unspent fuel).  Restart options would take a lot of extra weight and complexity unless you use a solid/liquid hybrid.  Those are an interesting lot.  You have fuel or oxidizer as the solid and the liquid is the other.  Cut the liquid and the reaction dies.  Restart with hypergol or Tea-Teb.

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  Quote

I don't think they are all that common b/c it is cheaper to have less working pieces and push less mass (unspent fuel).  Restart options would take a lot of extra weight and complexity unless you use a solid/liquid hybrid.  Those are an interesting lot.  You have fuel or oxidizer as the solid and the liquid is the other.  Cut the liquid and the reaction dies.  Restart with hypergol or Tea-Teb.

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The Virgin Galactic ship uses a hybrid engine. Solid  hydroxyl-terminated polybutadiene (HTPB) and Nitrous Oxide. Orrrr Nylon and NoS. 

[Zorg]

So just to let you all know I'm not dead and that work has started on the next project

Below are 3 variations of the LR-105 Atlas sustainer engine. From left to right they represent NA3, NA5 and the last represents NA6, NA7 and RS56 OSA.

This is still early work in progress and theres some fixes and adjustments still due. Also the powerhead is largely based on photos of an Atlas E NA6 so all the small details around there wont be accurate to every version but its broadly representative. Anyway just wanted to share since it beginning to look like something.

[CobaltWolf]

Fun from Twitter

EDIT: OH! Also, Viking update - I made a really nice launch adapter for it.

Edited July 14, 2023 by CobaltWolf

[RocketBoy1641]

  On 7/14/2023 at 2:25 PM, CobaltWolf said:

Fun from Twitter

EDIT: OH! Also, Viking update - I made a really nice launch adapter for it.

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Love the Twitter pic!

Oh, and launch adapters matter.  They really make it believable and less explode ring is attached to the engine bell.

[kspbutitscursed]

  On 7/14/2023 at 2:25 PM, CobaltWolf said:

Fun from Twitter

EDIT: OH! Also, Viking update - I made a really nice launch adapter for it.

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WOW i love this mod sooo much i think that if you do 1.14 update for BDB this will be in it

[Starhelperdude]

  On 7/14/2023 at 2:02 PM, Zorg said:

So just to let you all know I'm not dead and that work has started on the next project

Below are 3 variations of the LR-105 Atlas sustainer engine. From left to right they represent NA3, NA5 and the last represents NA6, NA7 and RS56 OSA.

This is still early work in progress and theres some fixes and adjustments still due. Also the powerhead is largely based on photos of an Atlas E NA6 so all the small details around there wont be accurate to every version but its broadly representative. Anyway just wanted to share since it beginning to look like something.

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Incredible!

question: how will the booster engines be like? (minus the atlas E/F ones that had completely seperate booster engines) will they be conjoined (shared pumps and everything and also shared GG for RS-56OBA) and then also standalone ones for kitbashing stuff or will they be just single?

[TheAnonymous]

I can't seem to fit the LEM inside the fairing without the model overlapping with the Service Module Engine. Also, the Service Module Doors aren't opening for me, any ideas why?

[Zorg]

  On 7/15/2023 at 4:01 AM, Starhelperdude said:

Incredible!

question: how will the booster engines be like? (minus the atlas E/F ones that had completely seperate booster engines) will they be conjoined (shared pumps and everything and also shared GG for RS-56OBA) and then also standalone ones for kitbashing stuff or will they be just single?

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I seriously thought about doing the combined version but after due consideration it just poses a lot of problems and complexity. The powerhead is very complicated to model and different in each version, presents problems with node attachment (not insurmountable but unnecessarily annoying), the mounting hardware would be quite difficult for generic use etc.

The plan then is just to model MA1, MA2, MA5 and MA5A as single engines with just the chamber and the relevant pipes just going up and off to the side. MA3 (Atlas E/F) will be fully modelled with its independent powerhead of course. There will also be mesh switches on the booster skirt for different pipes as well as a unique variant for E/F

You can see the overall plan here:

https://github.com/CobaltWolf/Bluedog-Design-Bureau/issues/974

 

  On 7/15/2023 at 4:17 AM, TheAnonymous said:

I can't seem to fit the LEM inside the fairing without the model overlapping with the Service Module Engine. Also, the Service Module Doors aren't opening for me, any ideas why?

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You can take a look at the craft file to see how its put together correctly. If you downloaded the mod from CKAN you can get the craft files from our spacedock download.

Edited July 15, 2023 by Zorg

[Starhelperdude]

I heard that there are like, 2 upgrades for the LR-101 verniers, with one destined for Atlas 2 having less thrust due to a study showing that it could be controlled with less thrust. if such variants are real, will we get them as part upgrade configs? (no model changes)

[Zorg]

  On 7/15/2023 at 8:47 AM, Starhelperdude said:

I heard that there are like, 2 upgrades for the LR-101 verniers, with one destined for Atlas 2 having less thrust due to a study showing that it could be controlled with less thrust. if such variants are real, will we get them as part upgrade configs? (no model changes)

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Sure thing if you can find a reliable source for those stats. I havent looked at LR-101 in any detail yet.

[Pappystein]

  On 7/14/2023 at 5:28 AM, Sudragon said:

The Virgin Galactic ship uses a hybrid engine. Solid  hydroxyl-terminated polybutadiene (HTPB) and Nitrous Oxide. Orrrr Nylon and NoS. 

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Except the NOS is an extra oxidizer... it is more like an Afterburner than a normal Fuel + Oxidizer mix.     

  On 7/15/2023 at 11:54 AM, Zorg said:

Sure thing if you can find a reliable source for those stats. I havent looked at LR-101 in any detail yet.

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Most of my info is on the fact that LR-101s were utilized in multiple launchers (Thor, Atlas, several upper stage proposals.)   So if any source on this alternate versions for the Atlas were available I would love to see them too!

[CobaltWolf]

  On 7/15/2023 at 4:17 AM, TheAnonymous said:

I can't seem to fit the LEM inside the fairing without the model overlapping with the Service Module Engine. Also, the Service Module Doors aren't opening for me, any ideas why?

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How are you attaching the LM? The bottom node on the descent stage is actually two identical nodes - one should have the engine attached to it, one should attach to the SLA. 
 

Do you mean the SIM bay on the Service Module? It should be something you decouple. I think. If I remember. 
 

  On 7/15/2023 at 8:47 AM, Starhelperdude said:

I heard that there are like, 2 upgrades for the LR-101 verniers, with one destined for Atlas 2 having less thrust due to a study showing that it could be controlled with less thrust. if such variants are real, will we get them as part upgrade configs? (no model changes)

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I thought the Atlas 2 omitted the LR-101s and that’s why it had the roll thruster module. 
 

 

[Starhelperdude]

  On 7/15/2023 at 3:02 PM, CobaltWolf said:

How are you attaching the LM? The bottom node on the descent stage is actually two identical nodes - one should have the engine attached to it, one should attach to the SLA. 
 

Do you mean the SIM bay on the Service Module? It should be something you decouple. I think. If I remember. 
 

I thought the Atlas 2 omitted the LR-101s and that’s why it had the roll thruster module. 
 

 

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my bad, I meant Atlas 1