SABRE hybrid rocket engine (UPDATED 5/22/2013)

[1096bimu]

The SABRE concept air breathing hybrid rocket engine designed for SSTO vehicles. all model/texture/cfg file credits to me, but screw licensing, do whatever you want with them.

initial release features:

• nice low poly model with good detail
  
• compact size so it doesn't overflow your memory allocation
  
• heat emission animation
  
• allow collision so no more wtf why can't I attach BS
  

issues:

• no real air breathing mode, it's rocket all the way
  
• no atmosphere dependent thrust
  
• no intake close animation
  
• I know the intake cone is supposed to be black but it looks better in white
  

UPDATE 05/22/2013

*Mini version only, since the full size version is unreasonably large, and the curved design is impractical for modular construction and the aerodynamic models in this game.

*Added velocity curve

*Fixed ISP curve. Now switched to rocket ISP at around 28,000 meters.

Mini version

download:

https://docs.google.com/file/d/0B9Rbd1PQiNycM3FSNXRPbGxtSlU/edit?usp=sharing

Edited May 22, 2013 by 1096bimu

[Greys]

I just gotta say, a sabre engine is bent like that so the air intake will point downward from the nosecone and therefore be pointing more into the air stream; not to either side; but that's about the thing you made out of it; they look awesome.

I appreciate your openness, but given the recent forum crash we're starting to run into situations where mods and addon packs exist but their original listing does not and the authors are MIA; And because it did not seem to be important they did not include any form of licensing with the mod/addon. In a situation where we don't have the license anymore, it defaults to All Rights Reserved, and nobody can do anything with them regardless of what it was. so I would encourage you to include a copy of some license you like in the .7z folder to permanently clarify the issue. I would suggest you look at the CC-BY license or the Do What the **** You Want to Public License. The GNU licenses are also pretty good, but they're not very friendly unless you love legal language.

As far as making it properly a multimode engine, I've never tried to include two ModuleEngines definitions on a single part but I know you can have multiples of most other things; though they would both be activated by staging so that might not work to well, you should be able to control them separately from the rightclick or from actiongroups. Anything more than that you will need a mod to manage.

[1096bimu]

I have tried two engine modules in one, it does work and can solve the thrust issue by having an air breathing engine fire backwards. But I don't have a way to make it entirely air breathing because you can always activate both engine modules at the same time and get even more thrust out of it.

As for the pointing down, it was originally made that way but has lot of issues like when you use the mirror in SPA the other one will be bent upwards. also the slight upwards bend makes space flight very difficult. So I have decided to put the attach node on the top of the curve so if one really wants it to curve down he/she can just rotate it 90 degrees.

[little square dot]

I got super excited when I saw "hybrid" in the description, but alas... I'm definitely going to give it a go regardless, but I was wondering if you could provide any specs re: efficiency. (I would take a peek at the .cfg myself, but I'm at work atm, and not only do these computrons lack the software to decompress files, but they also restrict non-IT personnel from installing software=)

[1096bimu]

I got super excited when I saw "hybrid" in the description, but alas... I'm definitely going to give it a go regardless, but I was wondering if you could provide any specs re: efficiency. (I would take a peek at the .cfg myself, but I'm at work atm, and not only do these computrons lack the software to decompress files, but they also restrict non-IT personnel from installing software=)

full size version:

16 tonnes ~3000kN

ISP: 3600~460

these are realistic numbers, at least as close to as what I was able to find.

mini version:

9 tonnes ~2000kN

same ISP

Edited May 16, 2013 by 1096bimu

[lyndonguitar]

can you make a white version? so It will compliment b9 aerospace

[SasquatchM]

Just set your intake to

MODULE
{
  name = ModuleResourceIntake
  resourceName = Oxidizer
  checkForOxygen = True
  area = 0.04
  intakeSpeed = 0
  intakeTransformName = Intake  
}

RESOURCE
{
 name = Oxidizer
 amount = 10
 maxAmount = 10
}

and it will provide oxidizer as long as there is oxygen in the atmosphere and start using your tanks automatically when there is either not enough oxygen or none at all. You'll probably have to tweak those numbers a bit

[1096bimu]

intakes also tend to give it a gigantic drag when used with FAR..... but I'll try that

i just tried it, same with my previous experiments. flame out when there is no atmosphere, and lots of drag.

can you make a white version? so It will compliment b9 aerospace

you can just edit the full black texture into any color you want.

Edited May 17, 2013 by 1096bimu

[SasquatchM]

It shouldn't flame out if you have oxidizer tanks feeding it and I was unaware that you were using FAR

[lyndonguitar]

Is it possible to make it real hybrid? that would be awesome, also I've made it white now, thanks for the tip

[1096bimu]

It shouldn't flame out if you have oxidizer tanks feeding it and I was unaware that you were using FAR

it does flame out, even if I connect it to a fuel tank with the fuel pipe. You have to disable the oxidizer reserve on the engine to make it use your fuel tanks, which is really inconvenient.

[rosenkranz]

this is why the other SABER mod had the intake as a separate part.

[lyndonguitar]

this is why the other SABER mod had the intake as a separate part.

are you talking about this one? http://kerbalspaceprogram.com/skylon-pack/

I think that one had a similar problem on the hybrid feature

[rosenkranz]

yeah, it didn't do a true hybrid. It just had a separate intake that generated oxidizer rather than intakeair. I think the only real problem with that mod was that the vacuum isp was set to that of an NTR when it really shouldn't be any higher than a high efficiency rocket (380-410 isp).

[SasquatchM]

Try this perhaps:

MODULE
{
  name = ModuleResourceIntake
  resourceName = IntakeAir
  checkForOxygen = true
  area = 0.04
  intakeSpeed = 0
  intakeTransformName = Intake  
}

RESOURCE
{
 name = IntakeAir
 amount = 5
 maxAmount = 5
}

MODULE
{
	name = ModuleGenerator
	isAlwaysActive = true
	INPUT_RESOURCE
	{
	   name = IntakeAir
	   rate = 1
	}	
	OUTPUT_RESOURCE
	{
	   name = Oxidizer
	   rate = 1
	}	
}

attached to your part, the the intake uses a generator to make oxidizer which, perhaps using fuel lines, you ca use to pipe back and forth to the fuel tanks. Obviously you'll have to play with the numbers a bit to balance it. Add

atmosphereCurve
 	{
   	 key = 0 350
         key = .01 350  //this is where it adjust to be a non-airbreather
         key = .015 1500
	 key = 1 1500
 	}

you may have to add a couple more keys in to set up atmospheric values, but you get the idea.