[1.1.x] Space Shuttle Engines (2016-07-03)

[dtobi]

This linear aerospike sounds great. So far the only mod that adds one is RLA Stockalike, and it's an extremely small one. How large is the one you're planning on adding? Or do you plan on implementing a couple of different sizes, for example, 1.25 meter and 2.5 meter, etc?

I'm curious about the "large gimbal range" this motor is going to have. How does it it achieve this gimbal? To my knowledge, the two ways to get a linear aerospike motor to effectively gimbal involves either altering the thrust of one side or ejecting gas from the spike to adjust the flow pattern. If it's the first, does gimbaling the motor actually result in decreased thrust?

Sadly I can't properly simulate the aerospike to that degree. I have two options: only gimbal the trust vectors or gimbal the ramp and the trust vectors like in this video at minute 17:

https://www.google.de/url?sa=t&source=web&rct=j&ei=JaO4UpvSB8nItQbd94GwBQ&url=http://www.youtube.com/watch%3Fv%3D-0Y0FS8Z1Qk&cd=3&ved=0CD8QtwIwAg&usg=AFQjCNHbGk2QKewTYPe723XGF3PaDb393A&sig2=gvIRRNy1NSzK7ln8IxIfaA

Edit: at the moment I have implemented the second option.

2nd edit: it is a 2.5 m part right now. I've never seen any images of small linear aerospikes. These things seem to be quit big always.

Edited December 23, 2013 by dtobi

[Arran]

i just downloaded this mod, and dispite i cant get any of the stockships that came with it mod up in orbit, i really like it alot.

They fit perfectly into my vision of KSP how i like to play, and i really love the look of it.

Thanks for sharing this with us..

[Firov]

Sadly I can't properly simulate the aerospike to that degree. I have two options: only gimbal the trust vectors or gimbal the ramp and the trust vectors like in this video at minute 17:

https://www.google.de/url?sa=t&source=web&rct=j&ei=JaO4UpvSB8nItQbd94GwBQ&url=http://www.youtube.com/watch%3Fv%3D-0Y0FS8Z1Qk&cd=3&ved=0CD8QtwIwAg&usg=AFQjCNHbGk2QKewTYPe723XGF3PaDb393A&sig2=gvIRRNy1NSzK7ln8IxIfaA

Edit: at the moment I have implemented the second option.

Ah, alright. From what little I can find, one problem that was discovered with that approach is that at speed aerospike motors rely on the surrounding airflow to maintain combustion pressure. By increasing the angle of the aerospike you would increase pressure on one side and reduce it on the other which could cause complications.

Though I looked it up any apparently the X-33 and Venture Star were planning on using differential thrust, like I originally thought. It's tough to find details for a cancelled project like that, but it seems like the original plan was to increase the throttle on the opposite side to maintain overall thrust levels.

http://www.pwrengineering.com/dataresources/X-33AttitudeControlUsingTheXRS-2200LinearAerospikeEngine.pdf

[dtobi]

i just downloaded this mod, and dispite i cant get any of the stockships that came with it mod up in orbit, i really like it alot.

They fit perfectly into my vision of KSP how i like to play, and i really love the look of it.

Thanks for sharing this with us..

Try looking at some ascents of the real shuttle. If you mimic its behavior, you should get them up. What's your problem exactly?

The fun in it is, that shuttles fly different than the usual ksp rockets and that they require a different design approach. That's why I like them. You have to learn new things even if you mastered many of KSP's challenges.

Edited December 23, 2013 by dtobi

[dtobi]

A christmas present for you:

A new release is out. Feedback is appreciated!

V0.9 Tweakables, new gimbal logic and linear aerospike

* Added a completely new gimbal logic:

- Proper roll support (can be activated on demand)

- Proper part-based x and y limitations (even when the part is rotated)

- Tweakables: tweak gimballing speed and trim the 0 position (it does not change the gimbal range)

* Added tweakables to timer (now you can set the duration with a slider)

* Added linear aerospike with mechanic gimballing

* Added Atlantis C craft as demonstration for the aerospike

* Updated the other example craft

* Removed redundancy to exsurgent engineer .dll (it is not used any more)

This one was a really big thing for me. I wrote the whole gimballing module code from scratch. It is now more flexible and will allow a ton of tweaks and additions. Try the tweakables for the engines.

And here is the aerospike in action:

Edited December 24, 2013 by dtobi

[MechieMan21]

As a head's up, some of the example craft files included in this pack require both B9 Aerospace and Procedural Wings.

[dtobi]

As a head's up, some of the example craft files included in this pack require both B9 Aerospace and Procedural Wings.

Darn, you're so right. Procedural wings became such a natural thing for me that I forgot to mention it on the image. Sorry.

[MechieMan21]

Other than that everything looks great so far.

[dtobi]

Hi everyone.

I would need your help for preparing the 1.0 release. With that release I would like to have all the engine specs fixed. To this end, I'd like to ask you to tell me if you think that a specific engine is overpowered, underpowered, too light or to heavy, too cheap or too expensive, tech tree positions are odd....

The goal is to be close to the stock parts to stay compatible with the stock style of gameplay and other mods like mission controller.

I would really appreciate your help and I will give credit to everyone who contributes in the readme and the first post.

Please discuss vividly.

[BananaDealer]

This has probably been stated before, but the attachment points for the small radial mounts aren't set up properly. The radial attachment point (the one that's supposed to attach to the main fuselage) is in the same place as the stackable point (where the engine is supposed to go.

Otherwise, this is a great mod and I foresee using it a ton in the future.

[dtobi]

This has probably been stated before, but the attachment points for the small radial mounts aren't set up properly. The radial attachment point (the one that's supposed to attach to the main fuselage) is in the same place as the stackable point (where the engine is supposed to go.

Otherwise, this is a great mod and I foresee using it a ton in the future.

I think what you mean is that they sink in?The radials (small and medium) are supposed to sink in. Look at the firefly example craft to see how they should be used.

Cheers!

[wasmic]

Hi everyone.

I would need your help for preparing the 1.0 release. With that release I would like to have all the engine specs fixed. To this end, I'd like to ask you to tell me if you think that a specific engine is overpowered, underpowered, too light or to heavy, too cheap or too expensive, tech tree positions are odd....

The goal is to be close to the stock parts to stay compatible with the stock style of gameplay and other mods like mission controller.

I would really appreciate your help and I will give credit to everyone who contributes in the readme and the first post.

Please discuss vividly.

Well, the engines do have a quite high Isp, but it is kinda needed, as the shuttle would otherwise not be able to lift itself due to too much fuel. And the real life SSMEs actually had a better Isp than the current engines. I believe the balance is quite good, although I have not used the Big Bang engines and I have not tried the newest versione yet.

[Firov]

Dtobi, overall the balance is pretty good on these engines I'd say. The only engines that might be "overpowered" are actually the OMS engines, which have incredibly high ISP and excellent thrust for their size. Pound for pound nothing can compare to their combined thrust/ISP/weight, either in stock KSP or most parts mods. In reality, the shuttle's OMS engines had less vacuum ISP than the SSMEs at 316 seconds vs 452.3 seconds for the SSME's.

So I'd say a slight reduction in thrust and possibly the ISP for both the single and the double OMS engines would be warranted. Perhaps 25-30 for the single engine and 45-55 for the double engine. For the ISP I'd say between 280 and 310 would probably be well balanced, based on the actual shuttle's OMS ISP.

But as for the shuttle main engines, they're pretty much perfect. Powerful and efficient, but not overly so, especially compared to the actual shuttle's SSME's.

EDIT - One improvement that would be nice to see for the shuttle engines, at least the X3, is a reduction in it's heat generation. Right now it's pretty much impossible to run the engine beyond 90% throttle without a very rapid overheat and explode, in almost any flight regime. At least it's possible to hard cap the throttle at 90% with tweakables now, but even so the actual shuttle's engines were regeneratively cooled and capable of safely operating at up to 109% of original design specifications, so it might be nice to see the X3 capable of operating at least at it's design specifications. Not necessary, obviously, but I figured I'd mention it.

Edited December 25, 2013 by Firov

[Thesonicgalaxy]

Am i the only one who feels the X3 should be in Heavier Rocketry? I feel that it being in very heavy rocketry is a little late in the tree. I honestly hope i'm not cheating by editing the config so it will be in Heavier Rocketry..

[Hyomoto]

I have some bugs that have come up. The shuttle engines don't seem to care much about tweakables, I tried to shut down their gimbals in the VAB but it doesn't persist over to the pad (and reverts back upon returning to the VAB so it just seems to not save). I also adjusted the gimbal position and though it appears correctly in the VAB, and it displays in the right click menu on the pad, it clearly isn't obeying that number. So it just seems to be tweakables aren't saving or being applied. The second problem is to counter the first but, I placed 'toggle gimbal' into my action group, but when I hit the button it doesn't toggle them on the pad. I can right click and do it manually, the action group just isn't being applied.

Also, using action-group manager it shows up as 'two objects' but the group is empty, and even after setting it up with AGM, it STILL ignores the command.

EDIT: I tried the action-group again during lift-off realizing I forgot to hit the gimbals and it worked, but it also reset the pitch angle. And once, disabled, doesn't re-enable them.

Edited December 25, 2013 by Hyomoto

[dtobi]

EDIT: I tried the action-group again during lift-off realizing I forgot to hit the gimbals and it worked, but it also reset the pitch angle. And once, disabled, doesn't re-enable them.

D'oh! I implemented the reset for the pitch as a real reset, not a toggle. That's why. I can change or to a toggle of you think that would be more useful or intuitive.

About the action group manager. I haven't used it before. I might try it next.

[wasmic]

I don't think you should nerf the Orbital Maneuvering Systems too much, at least not Isp-wise. I'd say don't put the isp below 350, but you could increase their weight, possibly even double it. This would make them useless on small probes, where they're currently overpowered, but still iseful on large shuttles.

[Arran]

Try looking at some ascents of the real shuttle. If you mimic its behavior, you should get them up. What's your problem exactly?

The fun in it is, that shuttles fly different than the usual ksp rockets and that they require a different design approach. That's why I like them. You have to learn new things even if you mastered many of KSP's challenges.

It seems my MJ as wrecking havoc on my reaction wheels, in combination with some other mods, making them alot less effective as they should be, like they never engaged.

Thus making flying asymetrical ships near impossible, they where so twitchy that at the moment they seemed impossible to fly..

Now that i removed MJ again, the reaction wheels started to apply they intented force again, and the shuttles became controllable..

The other mods i really need, MJ is just for the lazy moments, so i can do without..

Now i just need to "learn" how to fly and design them. But fortunate the unflyable state they where in, at the time i wrote my first comment, is solved.

I reinstalled MJ since 0.18, at the same time that i installed this mod.. So i didnt noticed at first the Reaction Wheels where not functioning.

So back to old-skool manual liftoffs

[dtobi]

I don't think you should nerf the Orbital Maneuvering Systems too much, at least not Isp-wise. I'd say don't put the isp below 350, but you could increase their weight, possibly even double it. This would make them useless on small probes, where they're currently overpowered, but still iseful on large shuttles.

Excellent point. Lowing the ISP too much might create problems for shuttles that need to drop their tank before stable orbit is achieved.

I also would like the size similar to what it is now. After all, they are mostly used with the shuttle shoulders, which hold the OMS engines in the real shuttle. Maybe I'll make them larger and sink the additional parts into the mother part (e.g., the shoulders).

[Hyomoto]

D'oh! I implemented the reset for the pitch as a real reset, not a toggle. That's why. I can change or to a toggle of you think that would be more useful or intuitive.

About the action group manager. I haven't used it before. I might try it next.

I would think the expected behavior is simply that the gimbals would be toggle on and off, and not reset the pitch trim. Just to clarify, the 'toggle gimbals' resets the pitch and disables the gimbals, and when assigned to an action-group, does not turn them back on. I don't think I tried just hitting the button again, maybe its a deeper problem. Anyways, I sort of figured that was the purpose of setting the pitch trim ahead of time was you could angle them just the way you want, zero them out if you will. Resetting that when you toggle the gimbals is more likely to cause a problem than be helpful (or at least it was in my case)!

As far as AGM goes, it just allows you to edit your action groups in-flight. I won't say it doesn't, but I will say I don't see why it would cause a problem or affect this part if that's what you are thinking.

[dtobi]

Has anybody tried the aerospike yet?

[jamberpilot]

is it possible that you could host the download for this mod for past version of the game?

[dtobi]

is it possible that you could host the download for this m!od for past version of the game?

Sure. I'll post a link to 0.8.x later when I am back on my PC.

[dtobi]

Here is the link to the last .22 Version:https://dl.dropboxusercontent.com/u/3061183/Space-shuttle-engines-2013-11-24-v0.8.1.zip

[dtobi]

A new update is out:

V0.9.1 New Smart Parts Version (Caution! Compatibility notice below!)

* Complete overhaul of the smart parts

* New remote controller part (control other vessel's action groups over radio)

* Altimeter action group trigger

* Updated example craft

* Trim can now be toggled

IMPORTANT: Please delete the old Klockheed Martian folder before updating. Please also delete the example craft files.

PLEASE NOTE: The update 0.9.1 may break existing ships with action group triggers. If you want to recover your ships, you can copy the parts from the Legacy folder into your Klockheed Martian folder. This will give you the outdated action groupdevices back.