Bussard Ramjet

[SasquatchM]

Spaceport release

Here is a the WIP, still needs a bit of balancing as well as sounds, real textures and normal maps.

Edited June 5, 2013 by SasquatchM

[Scotius]

Wow. And let me repeat myself: Wow. Another fine piece of engineering from you May i ask which mod you used to get life support options and those plants?

[SasquatchM]

Actually I made the Hydroponics tank when I was considering doing a life support mod. They don't actually do anything useful atm. i am considering making them compatible with the Ioncross Crew Support Plugin.

[Scotius]

Aw, too bad. I'd love to have hydroponics to use in my space stations and planetary bases. Anyways, what makes new engine tick? I understand Bussard Ramjet uses interstellar hydrogene as a source of fuel. It should gave it very high ISP at the cost of thrust and huge weight.

[SasquatchM]

Here is the part.cfg. Keep in mind that this is NOT balanced yet. The hydrogen isn't reaction mass, it is actually being used as fuel in a fusion reactor.

PART  
{  

// --- general parameters ---
name = SM-Bussard-Ramjet
module = Part
author = SasquatchMarmalade

// --- asset parameters ---
mesh = model.mu
scale = 1
rescaleFactor = 1.25


// --- node definitions ---
node_stack_top = 0.0, 2.22417, 0.0, 0.0, 1.0, 0.0
node_stack_bottom = 0.0, -1.98312, 0.0, 0.0, 1.0, 0.0


// --- FX definitions ---

fx_exhaustFlame_blue = 0.0, -10.3, 0.0, 0.0, 1.0, 0.0, running
fx_gasJet_white = 0.0, -10.3, 0.0, 0.0, 1.0, 0.0, running

// --- Sound FX definition ---

sound_vent_medium = engage

sound_vent_soft = disengage
sound_explosion_low = flameout

// --- editor parameters ---
cost = 5000
category = Propulsion
subcategory = 0
title = SM-Bussard-Ramjet
manufacturer = SM Aeronautics
description = The Bussard Ramjet uses enormous electromagnetic fields as a ram scoop to collect hydrogen from the interstellar medium. This hydrogen is used to power a fusion reactor that vents from the rear of the ship propelling the ship.
// attachment rules: stack, srfAttach, allowStack, allowSrfAttach, allowCollision
attachRules = 1,0,1,1,0

// --- standard part parameters ---
mass = 4.5
dragModelType = default
maximum_drag = 0.2
minimum_drag = 0.2
angularDrag = 2
crashTolerance = 7
maxTemp = 2500
//stagingIcon = SOLID_BOOSTER

MODULE
{
	name = ModuleEngines
	thrustVectorTransformName = thrustTransform
	exhaustDamage = True
	ignitionThreshold = 0.1
	minThrust = 0
	maxThrust = 450
	heatProduction = 300
	fxOffset = 0, 0, 0.5
	useVelocityCurve = True
	PROPELLANT
	{
		name = CompressedHydrogen
       	        ratio = 1
		DrawGauge = True
	}
	PROPELLANT
	{
		name = ElectricCharge
		ratio = 10
		DrawGauge = True
	}
	atmosphereCurve
 	{
   	 key = 0 450
	 key = .001 100
  	 key = 1 0
 	}
	velocityCurve
	{
		key = 0 .1 0 0
		key = 2500 1 0 0
		key = 17500 1 0 0
		key = 32500 1 0 0
		key = 35000 .1 0 0
	}

[Mekan1k]

I tried to make one of these once... It did not turn out looking THAT AMAZING! +Rep

[Bluegobln]

That's the exact technique I was considering trying for this once I finished all my other endeavors, fantastic work. I was thinking of trying to use emissives on the scoop for even more cool effect but I don't know if the shaders will allow it with transparency.

At a certain velocity it should provide its own fuel completely. But the energy requirement would probably be immense for the magnetic field.

The weirdest part is your throttle should affect the scoop, but not the engine. The scoop can be adjusted, the engine runs based on how much hydrogen is being picked up (which is determined by the size of the scoop and your velocity). At least that's how I think its should work... *shrug*

[SasquatchM]

Emissives work like crap with any sort of transparency. To simulate the more fuel = going faster I tried to make a velocity curve that would sort of emulate that. If there were a way to make intakes work in vacuum and make them scalable based on throttle that would be perfect. The way it is now there isn't a way to make it have 0 thrust if the scoop is facing the wrong direction. I also, due to the lack of intakes, had to make a hydrogen generator to fake an intake, for whatever reason a hydrogen alternator keeps ending up with 0 fuel.

[Scotius]

What about changing geometry or size of magnetic scoop? Wider field = more hydrogen = more thrust. It could look like a reversed umbrella

[SasquatchM]

Well, the scoop does grow and shrink with throttle, the problem with the engines is that they are all or nothing, as far as i know anyway. So if there is not enough fuel it won't just work at a reduced rate, it just won't work at all. Hence the velocity curves. I also read that they think that 35000m/s is the max velocity from on of these before the drag of the various interstellar particles makes further acceleration impossible. The real question is what should the minimum velocity be for ignition? I decided to set it low with a very cripple velocity curve just to make it useable a low speeds in orbit. That is easily changeable, but now additional rockets must be added for lower speed maneuvers thus increasing part count on the ships.

[SasquatchM]

Screen shots of 0 thrust and full power with updated textures and normals added

[Mekan1k]

OOOHHH!

I hope you release an early version soon!

Things kerbals say about this mod:

It looks perfect!

I want to use it....

WHOOO1!!!!!1!!

[SasquatchM]

Well, here ya go then: Download

Feedback on balancing would be nice. It is for all intents and purposes a self fueling engine, so I feel I may have to dial down the performance or increase the weight. Make sure to add some batteries and solar panels.

Edited June 4, 2013 by SasquatchM

[Mekan1k]

Ok- this engine seems ideal. It has near-infinite fuel, and the faster you go, the more thrust and efficiency there is.

Do you mind if I use this mod in my story?

EDIT: I should be more specific. The engine has potentially a higher amount of delta-v than other engines, due to it's massive potential thrust and near-infinite fuel, but you need to get the engines up to a rather high speed before there is enough thrust. So, well, it is more like... A massive booster for long-range engines. Either that, or a long-term engine for long-term missions.

Overall, well balanced.

Edited June 4, 2013 by Mekan1k

[SasquatchM]

Story away good sir.

This is definitely a long range design. There are many better engines for just getting to Mun or Minmus

Edited June 4, 2013 by SasquatchM

[Scotius]

Definitely good engine for big interplanetary vessels. Now i have to somehow design my heavy tug around it. Do you have any sounds for it, BTW? It's a bit eerie experience when a ship is acceletaring on huge, blue flame in dead silence.

[RoboRay]

Do you mind if I use this mod in my story?

It's a 50-year old idea, so there's no patent worries.

[Itsdavyjones]

Gah, now I am having trouble deciding in either using this or the Orion drive for my AAR. Great drive though.

[SasquatchM]

I'll probably just use the same sounds as the nerva

[SasquatchM]

Updated textures and a few model tweaks. Added sound (couldn't find a good base for a custom sound so uses the same sounds as the stock nuclear engines). replaced video on the main page with an update showing the new model and textures. Somewhat annoyed as the vid i uploaded seems to be a bit glitched.

[SasquatchM]

released on Spaceport

[magnemoe]

Gah, now I am having trouble deciding in either using this or the Orion drive for my AAR. Great drive though.

Use the orion to get up in speed and then activate the bussard, Jeb approve of this solution.

Only downside of this is the lack of other star systems

[magnemoe]

Played a bit with this. One issue is that the trust is very dependent on SOI, this can be very confusing, however even 40kN free trust is nothing to complain about,

[Itsdavyjones]

Use the orion to get up in speed and then activate the bussard, Jeb approve of this solution.

Only downside of this is the lack of other star systems

I was actually thinking of this, or using the ram jet to get going, and the Orion to break. Depending on how much delta v I get from Orion.

[Dompyongyang]

Posted this on the comments section of the download page at spaceport. Hoping for a quick response. Again, great mod and I hope to get it to work!

Ran out of Compressed Hydrogen in a matter of 30 seconds. I was in orbit at 100KM testing it out. Basic ship, MK1 pod, 4 500 Charge batteries, and Bussard ramjet engine on the bottom. Had a standard fuselage as well to attach two XXL solar arrays which were deployed when used.

I watched my resources during my test ad the Compressed-H depleted quickly.

I’m sure I’m doing something wrong…. any suggestions?