Engine Failure Mod Discussion

[mpink]

Hi there

I was watching the

and they mentioned the problems of trying to launch a rocket with 30 engines and how the chance of problems drastically increases with more engines.

This got me thinking about an engine failure mod and how much it would change the early stages of career mode.

So the theory gos a bit like this.

When you light up an engine a random number is produced to see if something gos wrong.

If a problem is detected a second number is generated to determine what the problem is from an engine specific error table.

For the moment im just thinking about engine problems and not trying to make a mock-up of the error tables.

A single Engine Error may trigger multiple engine problems that may change in severity over time so at this point im just trying to think of the simple problems that may happen and would love your help with suggestions.

All Engines

Explode - The engine just explodes (Part.explode())

Liquid Engines

Overheat - The engine generates more heat so it will explode if you dont reduce the thrust (ModuleEngines.heatProduction).

Thrust Limit - The engine is limited to a maximum % thrust so you must re-balance the craft in flight (ModuleEngines.thrustPercentage.maxValue).

Efficiency Problem - Lowering the ISP by a small amount would result in a fuel balance problem that cant be fixed by simple thrust adjustment on other engines (ModuleEngines.atmosphereCurve[]).

Hydraulic Leak - The engines gimbal slows down until it locks into place (ModuleGimbal.gimbalResponseSpeed (Could be overridden by using lock gimbal button and forcing downward thrust again)).

Stuck Valve - The engines throttle gets stuck at its current setting and so dosnt change with the throttle control (ModuleEngines.engineAccelerationSpeed ModuleEngines.engineDecelerationSpeed).

Damaged Ignitor - Prevents the engine from restarting if it is shutoff (ModuleEngines.allowRestart).

Solid Engines

Cracked Seal - The engine has a random crack causing thrust to escape. To do this i would randomly place a hacked sepratron and reduce the fuel and thrust values of the original engine.

Broken Nozzle - This is just a combination of Efficiency Problem and Thrust Limit but combined in a way as to maintain the same burn time with reduced thrust.

I have thrown together a basic test mod implementing the Explode result as it is the easiest to program and tested this with the LV30 and LV45 in the early stage career mode.

I have found it changed my design style and launch method a bit as I now have my launch towers on a separate stage so i can test my engines on low power before launching.

I also try harder to not layer my rocket with extra engines in separate stages as i know there is a chance they will pop when i light them up.

The final change its forced on me is to maintain a low level of thrust for the full orbital insertion as apposed to reaching a targeted speed and shutting the engines off until AP is reached.

Just for fun hears the chance table for 30 engines each having a 5% chance of error

Engines	| Chance Change	| Chance Of Error
----------------------------------------------
1	| 5.00%		| 5.00%
2	| 4.75%		| 9.75%
3	| 4.51%		| 14.26%
4	| 4.29%		| 18.55%
5	| 4.07%		| 22.62%
6	| 3.87%		| 26.49%
7	| 3.68%		| 30.17%
8	| 3.49%		| 33.66%
9	| 3.32%		| 36.98%
10	| 3.15%		| 40.13%
11	| 2.99%		| 43.12%
12	| 2.84%		| 45.96%
13	| 2.70%		| 48.67%
14	| 2.57%		| 51.23%
15	| 2.44%		| 53.67%
16	| 2.32%		| 55.99%
17	| 2.20%		| 58.19%
18	| 2.09%		| 60.28%
19	| 1.99%		| 62.26%
20	| 1.89%		| 64.15%
21	| 1.79%		| 65.94%
22	| 1.70%		| 67.65%
23	| 1.62%		| 69.26%
24	| 1.54%		| 70.80%
25	| 1.46%		| 72.26%
26	| 1.39%		| 73.65%
27	| 1.32%		| 74.97%
28	| 1.25%		| 76.22%
29	| 1.19%		| 77.41%
30	| 1.13%		| 78.54%

I am testing with a 5% error chance and trying to do Mun flybys using a 19 engine design. The 1st stage of 12 booster engines has had problems a few times and i can just shut off the opposite engine and still reach orbit with no problems. If the 2nd or 3rd stage engine breaks on ignition it is a fail and we have to shutdown and recover. Iv not had the 3rd stage engine break whilst attempting reentry yet but 5% is a bit steep so it will happen one day.

[Justin Kerbice]

You may be interested by this mod from Ippo.

Don't forget engines may failed, but also everything between the switches and buttons and the engines themselves (kind of loose of throttle control, a tiny electric wire melt and engine get an odd behaviour, leak, ...)

[mpink]

You may be interested by this mod from Ippo.

Don't forget engines may failed, but also everything between the switches and buttons and the engines themselves (kind of loose of throttle control, a tiny electric wire melt and engine get an odd behaviour, leak, ...)

I most certainly am interested thanks

Im not sure at this point that its going to be at the same level as what i was thinking as we seam to have a very different idea as to when errors could happen and what they should be but then i have only just read about it and not played it so i should go investigate..............