[WIP] Real Scale Boosters

[NecroBones]

15 minutes ago, NathanKell said:

Yep, that's why I mentioned dual-plane separation and two decouples, in that post I made a ways back. Your saying it made sense and your were going with it made me think that you were indeed aware of the S-II interstage's dual-plane (vs. S-IVB's single-plane) methodology...

From the pics, looks like you've got it all sorted though.

Right, the part that I didn't realize was that single-plane separation in the other stage. I included the rest for completeness (and so people can follow my train of thought). I was more surprised by the difference between the two, and the hidden retro SRMs in the S-IC.

 

My next head scratcher is figuring out where the attitude control thrusters are on the Delta IV upper stages:

 

 

Edited January 9, 2016 by NecroBones

[jonrd463]

Necrobones, that's the biggest issue I have when I build real world launchers in RO with procedural parts. The nozzles are so well hidden in all the reference pictures I find, and I usually just give up and use the standard 4-way thrusters and pick locations based on CoM. It irritates the crap out of my OCD because I'm otherwise trying to maintain general fidelity with the real things.

[Phineas Freak]

The DCSS has the attitude control thrusters along the circumference of the bottom truss where the RL10 is mounted (along with the avionics, see the platform with the red Helium tanks).

Some really useful links:

Delta IV User's Guide

Spaceflight101 Delta IV 5.4 page

Delta IV vehicle design

Edit: a problem with the Delta IV is that in the heavy configuration, all CBCs are almost custom made because the attachment nodes, the propellant loading/detanking ports, the fuel lines and the avionics pods must be mirrored in order to be on the correct side. I would suggest to make just one CBC and not to worry about the positioning.

Edit, edit: heck, even going from the Delta IV M to the Delta IV M 4.2 requires a custom CBC. I have no idea what Boeing was doing when they designed it.

Edited January 9, 2016 by Phineas Freak

[NecroBones]

5 hours ago, Phineas Freak said:

The DCSS has the attitude control thrusters along the circumference of the bottom truss where the RL10 is mounted (along with the avionics, see the platform with the red Helium tanks).

Some really useful links:

Delta IV User's Guide

Spaceflight101 Delta IV 5.4 page

Delta IV vehicle design

Edit: a problem with the Delta IV is that in the heavy configuration, all CBCs are almost custom made because the attachment nodes, the propellant loading/detanking ports, the fuel lines and the avionics pods must be mirrored in order to be on the correct side. I would suggest to make just one CBC and not to worry about the positioning.

Edit, edit: heck, even going from the Delta IV M to the Delta IV M 4.2 requires a custom CBC. I have no idea what Boeing was doing when they designed it.

 

Thanks, yeah. Yesterday I was looking through the user's guide and spaceflight 101, and saw a nice close-up of the thrusters but no info about their positions. I figured it had to be on the equipment platform somewhere, but when studying the pictures, I just couldn't see them. I even saw one of the diagrams label the red spheres as hydrazine tanks, and the elongated ones as helium... so I figured the hydrazine tanks were probably close to where the ACS was.

 

That's an interesting irony actually. The CBC has to be custom finished almost every time, right after they explain in detail in the documentation about how the CBC's costs were reduced by making them all "common" until very late in the production cycle. I don't understand why they're not designed from the start to be almost 100% "common". Strange.

 

EDIT: Another thing to think about is that engine skirt extension. It looks like it starts in that collapsed position and then extends after stage separation? I could add a small animated toggle, but it wouldn't restrict when the engine can fire, I don't think.

Edited January 9, 2016 by NecroBones

[Phineas Freak]

And i made a mistake with the tanks...the small ones are for the Hydrazine...doh, I'm stupid!

You mean the RL10, right? If so then yes, the engine has a retractable nozzle extension ("cones" B and C). Or you can cheat a bit and increase the length of the interstage adapters by ~1 meter so that an alredy extended engine will fit inside them.

Edit: Bahamuto had made a plugin for this kind of engines (if you don't care about external plugins): linky

Edited January 9, 2016 by Phineas Freak

[NecroBones]

2 hours ago, Phineas Freak said:

And i made a mistake with the tanks...the small ones are for the Hydrazine...doh, I'm stupid!

You mean the RL10, right? If so then yes, the engine has a retractable nozzle extension ("cones" B and C). Or you can cheat a bit and increase the length of the interstage adapters by ~1 meter so that an alredy extended engine will fit inside them.

Yeah, it's easy to get all of this stuff mixed up. I could also cheat by making the nozzle extension non-colliding, and let it overlap the inside of the CBC a little.

 

I detailed out the bottom of the CBC a bit. Of course they're normally a bit asymmetrical, but I made them more symmetrical so they can rotate any which way and still look good together.

 

 

[VenomousRequiem]

I can't wait to see your interpretation of the ICPS/DCSS.

[NecroBones]

2 hours ago, VenomousRequiem said:

I can't wait to see your interpretation of the ICPS/DCSS.

Me too. Heh.

 

[Phineas Freak]

Speaking of which, are you planning to do both 4 and 5 meter versions of the DCSS?

[NecroBones]

5 hours ago, Phineas Freak said:

Speaking of which, are you planning to do both 4 and 5 meter versions of the DCSS?

That's my plan. I want to be able to represent most of the Delta IV lineup.

 

Obviously right now these just have fairings thrown on (no DCSS yet), but I added some SRMs for the M+ variants. I took a guess at the exhaust angle and have them set to 10 degrees. But it might not be useful since KSP doesn't have random failures, so they don't need to point at the CoM.

 

[NecroBones]

Heh, I just discovered that I'll probably have to delete a lot of the dev screenshots from the imgur album sooner or later. People on reddit are trying to correct me on my ascent profile, without understanding that these were test launches to test decouplers and the like, and I don't bother steering when that's the case.

 

 

[VenomousRequiem]

How bad is the... you know... performance impact of these parts? I don't really understand why, but some parts kill performance, but you parts always seem to do fine. Are these the same way? I already have issues with that in RSS.

I guess my computer isn't the best in the world...

[NecroBones]

9 minutes ago, VenomousRequiem said:

How bad is the... you know... performance impact of these parts? I don't really understand why, but some parts kill performance, but you parts always seem to do fine. Are these the same way? I already have issues with that in RSS.

I guess my computer isn't the best in the world...

 

So far they've been fine. They're really no different than the SpaceY parts. In a way it performs better though, since the part count is pretty low.

[VenomousRequiem]

6 minutes ago, NecroBones said:

 

So far they've been fine. They're really no different than the SpaceY parts. In a way it performs better though, since the part count is pretty low.

Sick...  I worry about performance a lot.

Right now all I have is my laptop. It's got something like an AMD ATI-4500M quad-core 1.9GHz with an integrated Radeon HD 7640G, all running with 6Gb RAM. It's not too terribly great most of the time.

Edit- I just noticed... are the screenshots on that dev album even in RSS? :0

It looks like stock KSP, and I think a full Saturn V stack with Apollo had something like 17,000M/s DeltaV... imagine where you could go in stock KSP with 17,000M/s!

Edited January 10, 2016 by VenomousRequiem

[ensou04]

Been inloved with the your Suite of Part Mods, and THIS! THIS will seriously finish the cake! Going to watch this dev.
these would be perfect too with 64k Kerbin.

[Kartoffelkuchen]

Seems pretty awesome everything so far! Also good job on the bottom part of the Common (hehe) Core Booster, that was and is always my biggest pain when I work on the rocket! 

Looking forward to a release

[NecroBones]

9 hours ago, NecroBones said:

Heh, I just discovered that I'll probably have to delete a lot of the dev screenshots from the imgur album sooner or later. People on reddit are trying to correct me on my ascent profile, without understanding that these were test launches to test decouplers and the like, and I don't bother steering when that's the case.

So I re-read the thread on reddit, and it kinda looked like I was asking their opinion, so I think I opened the door. They were trying to be helpful rather than critiquing the launches. LOL. Oh well. I'll try to remember to disclaimer some of it in the future though.

 

8 hours ago, VenomousRequiem said:

Edit- I just noticed... are the screenshots on that dev album even in RSS? :0

It looks like stock KSP, and I think a full Saturn V stack with Apollo had something like 17,000M/s DeltaV... imagine where you could go in stock KSP with 17,000M/s!

Yeah, I'm just testing the parts in stock right now. As long as the dV, size, shape, thrust, etc are all OK, it should be fine for RSS/RO later. But yes, total overkill for stock! lol

 

6 hours ago, ensou04 said:

Been inloved with the your Suite of Part Mods, and THIS! THIS will seriously finish the cake! Going to watch this dev.
these would be perfect too with 64k Kerbin.

 

5 hours ago, Kartoffelkuchen said:

Seems pretty awesome everything so far! Also good job on the bottom part of the Common (hehe) Core Booster, that was and is always my biggest pain when I work on the rocket! 

Looking forward to a release

Thanks guys, glad you're liking it so far! There's more to come for sure.

 

[NecroBones]

So here's another point of confusion I'm wondering about, while looking up numbers for things. This page on SpaceLaunchReport.com has stats for the Alliant SRMs for the Delta IV rockets. As usual I find minor discrepancies between different source of info. But in this case, I confused by the thrust numbers. It shows the thrust as considerably higher at sea level than in vacuum, which would imply that the ISP is better in the atmosphere. That seems totally upside-down to me. For now I've plugged the numbers in accordingly, since I haven't found anything better to give me both ISPs.

Edited January 10, 2016 by NecroBones

[VenomousRequiem]

Does it make anyone else nervous when the sides of the Detla IV heavy get singed from the flames of the engines starting? That seems dangerous.

[NecroBones]

28 minutes ago, NecroBones said:

So here's another point of confusion I'm wondering about, while looking up numbers for things. This page on SpaceLaunchReport.com has stats for the Alliant SRMs for the Delta IV rockets. As usual I find minor discrepancies between different source of info. But in this case, I confused by the thrust numbers. It shows the thrust as considerably higher at sea level than in vacuum, which would imply that the ISP is better in the atmosphere. That seems totally upside-down to me. For now I've plugged the numbers in accordingly, since I haven't found anything better to give me both ISPs.

So I have an idea about why they might have written it that way, and it still doesn't give a Vac ISP. It might be that the way the solid propellant is bored, that the combusting surface area reduces over time (from star-shaped to circular), and so the thrust diminishes. This would be an effect completely internal to the SRM, and not a function of altitude or air pressure, but it might be that under a normal ascent profile, that by the time it effectively reaches vacuum the thrust has gone down? It's just an idea. I could be way off.

 

 

11 minutes ago, VenomousRequiem said:

Does it make anyone else nervous when the sides of the Detla IV heavy get singed from the flames of the engines starting? That seems dangerous.

Yeah, it's surprisingly Kerbal of them to design it that way. I'm sure they took some burn-off into account in deciding how much insulation they need. The Falcon 9R singes itself up like crazy when landing too. It's probably even more "normal" than we realize. Heh.

 

[Glaran K'erman]

34 minutes ago, NecroBones said:

So here's another point of confusion I'm wondering about, while looking up numbers for things. This page on SpaceLaunchReport.com has stats for the Alliant SRMs for the Delta IV rockets. As usual I find minor discrepancies between different source of info. But in this case, I confused by the thrust numbers. It shows the thrust as considerably higher at sea level than in vacuum, which would imply that the ISP is better in the atmosphere. That seems totally upside-down to me. For now I've plugged the numbers in accordingly, since I haven't found anything better to give me both ISPs.

Seeing as they only burn for 90s they never make it to a vacuum in the standard Delta configs. I know the US military procures them for their own uses in which case they (GEM-60's) may go to space, but I doubt they release the numbers you want readily. http://www.acq.osd.mil/mibp/docs/srm_ind_cap_report-redacted_6-12-09.pdf a bit outdated but may prove useful.

Edited January 10, 2016 by Glaran K'erman

[Phineas Freak]

@NecroBonesto be on the safe side, check the Orbital ATK Motor Catalog. At page 43 it has the data for the GEM-60.

@VenomousRequiemanother thing that Boeing finds normal at their designs....but that's the way it works. It protects the CBC from getting hit by the RS-68 exhaust.

[NecroBones]

2 hours ago, Phineas Freak said:

@NecroBonesto be on the safe side, check the Orbital ATK Motor Catalog. At page 43 it has the data for the GEM-60.

At a glance the numbers look pretty close to what I already have. I'll compare more closely though. Thanks!

 

EDIT: Actually, this is helping me a lot. It shows that the thrust number on most other websites is just the maximum thrust, not the average. Also, it confirms the 10 degree cant (this is the second time I've guessed angles correctly on this project. I also guessed at the 35 degree canting on the Saturn S-IVB ullage SRMs, based on pictures). Now that I've said that, I'll probably guess everything else incorrectly from now on.

 

Edited January 10, 2016 by NecroBones

[Guest]

I found a good diagram of all of the parts of the Atlas V:

If you did an Atlas V 551, you'd likely have to add attachment points for the 5 SRBs.  There are a lot of variants, but they use several of the same parts, just in different configurations.

Atlas V 551:

I hope this comes in handy if you do decide to do an Atlas V.

[NecroBones]

4 hours ago, CliftonM said:

If you did an Atlas V 551, you'd likely have to add attachment points for the 5 SRBs.  There are a lot of variants, but they use several of the same parts, just in different configurations.

I hope this comes in handy if you do decide to do an Atlas V.

 

Yes, that'll come in handy. Thanks!