Inline Monoprop Engine

[Sanic]

  This is a small addition, but one that needs to be made nonetheless. I propose an inline monopropellant engine, to give small probes an injection of realism and a bit more DeltaV. Most interplanetary probes in history have used small, low thrust monopropellant engines for their maneuvers. Unfortunately, KSP only gives us inefficient radial engines, which are too fuel hungry and too powerful. I know this probably isn't as useful as some other engine ideas, but I feel there should be an inline monopropellant engine. 

I want to hear what you guys have to say about this idea.

And if there's a 1.0.5 mod for this, please tell me.

Edited December 9, 2015 by Sanic

[sebi.zzr]

You can try these,RLA Stockalike.

[Hysterrics]

YES! _{yesyesyesyesyesyesyesyesyesyesyes} We need more love for Monoprop in the stock game! Shuttle OMS engines are ridiculously hard to build because the only monoprop engine is radial. SQUAD PLS

 

[ShmikeTP]

I also think this would be a good addition to the game. We have a large selection of engines for LF/OX and SolidFuel, but only one monopropellant engine. Maybe a .625 and 1.25 engine could be added to the game?

[pandaman]

Yes, I could find a use for this.

[Racescort666]

1 hour ago, Sequinox said:

YES! _{yesyesyesyesyesyesyesyesyesyesyes} We need more love for Monoprop in the stock game! Shuttle OMS engines are ridiculously hard to build because the only monoprop engine is radial. SQUAD PLS

 

While I agree it would be nice for this type of engine, Space Shuttle OMS was bipropellant: https://en.wikipedia.org/wiki/Space_Shuttle_Orbital_Maneuvering_System

[ment18]

9 minutes ago, Racescort666 said:

While I agree it would be nice for this type of engine, Space Shuttle OMS was bipropellant: https://en.wikipedia.org/wiki/Space_Shuttle_Orbital_Maneuvering_System

An inline engine would be nice but I'm not sure how these 'monopropellant' engines work, their isp(250s) is way to high to be compressed gas(68s).  The only possible explanation is that monopropellant is really two different substances combined by the game.  Even the blocks have 240s.  The name is misleading.

 

http://cdn.intechopen.com/pdfs-wm/37528.pdf

http://wiki.kerbalspaceprogram.com/wiki/O-10_%22Puff%22_MonoPropellant_Fuel_Engine

 

Edited December 9, 2015 by ment18
citation

[rocketbuilder]

No monoprop engines do exist in RL -  they work by passing a fuel through a catalyst to start combustion.

But yeah, all sizes (except maybe not 3.75) inline engines would be great.

[steuben]

20 hours ago, rocketbuilder said:

No monoprop engines do exist in RL -  they work by passing a fuel through a catalyst to start combustion.

 

Some do, the H₂O₂ ones on... something, for example (though those are more decomposition than combustion). Others are just fuel and oxidizer in one molecule waiting for a spark, a shake, the phase of the moon, quantum fluctuations, or general orneriness to start combustion. "Ignition!" by John Clark explains them better. It sounded like a very kerbal experience.

But seconding stock size 0 and size 1 monoprop engines.

[Wahgineer]

23 hours ago, Racescort666 said:

While I agree it would be nice for this type of engine, Space Shuttle OMS was bipropellant: https://en.wikipedia.org/wiki/Space_Shuttle_Orbital_Maneuvering_System

But the problem with putting bipropellant OME's on our space shuttles is that the main engines may accidentally consume the shuttles on-board fuel supply, leaving us with no way to get to orbit. By using monopropellant, this issue is removed, plus we have the bonus of no-longer needing separate RCS tanks that take up payload space and increase overall mass.

[Matt77]

The last few suggestions regarding the actual topic were interesting ideas.  I hope they don't get drowned out by the offtopic discussion above, which is also interesting and worthy of it's own thread (nudge nudge wink wink!)

[mattinoz]

I was under the impression that peroxide H₂O₂ just kind of spontaneously exploded when released in to a low pressure environment.

[KerbonautInTraining]

I think inline engines similar to the "Ant" and "Spark" would be reasonable.

Why bother with big monoprop engines? In real life they would be favorable because of the storable, self igniting, pressurized propellant. KSP doesn't model any of the aforementioned advantages, and currently has a very limited selection of tanks, so there's really no point.

[Racescort666]

On 12/10/2015 at 1:21 PM, awsumindyman said:

But the problem with putting bipropellant OME's on our space shuttles is that the main engines may accidentally consume the shuttles on-board fuel supply, leaving us with no way to get to orbit. By using monopropellant, this issue is removed, plus we have the bonus of no-longer needing separate RCS tanks that take up payload space and increase overall mass.

Yeah, that's the problem. Just thinking out loud for those that might want to stick to LF/OX but it would be nice if you could toggle fuel tanks by action group. There's probably a mod for that but we're talking about the stock game. 

For the LF/OX Main engines and monoprop OMS, an inline monoprop would be useful.

[cantab]

Modular Rocket Systems has some monoprop engines too.

Balance is a bit tricky. I think the first thing that's wanted is to make the monopropellant tanks have a decent mass ratio, currently they're awful. Then assuming they are less efficient that bipropellant engines, what do we make the advantage? Higher TWR is currently used, but too high and it bumps against the lifter engines. Lower absolute mass is an option, but would need remaking the Ant and Spider as monoprop engines I think. Low cost is good for career but not for other game modes.