Rocket Engines

Rocket Engines give you their max output in kN with this you can calculate what they can reasonably carry into orbit depending on the planet or moon you are on. Force = Mass * Acceleration. Acceleration is equal to the planet's gravity, Mass is given in kg per part of the rocket, and Force is kN. If your thrust force listed below is less than the weight of the rocket in kN then you will not even take off. It is better to have a thrust much higher than the weight of the rocket or else you risk running out of fuel on launch and on landing.

Liquid propellants bring greater efficiencies. Using Nitrous Oxide as oxidizer provides excessive thrust values. Keep in mind that N2O fuel mix is 1.9375 times heavier at same moles, or 2.15 times heavier at same volume, while thrust boost is around 1.5-1.7. Engine efficiency determines "bonus" thrust multiplier, meaning engine with higher efficiency will give more thrust consuming same amount of fuel. Thus using liquid engines is more favorable if one can cool fuel down, moreover Pressure Fed Engines consume fuel inversely proportional to its temperature. On the other hand if Volatiles and Oxygen are in excess (e.g. farm on Vulcan) is may be much easier to opt for Pressure Fed Gas Engine. It will provide ~40kN at 20°C.

Name	Base Power Usage	Rocket Mass Contribution	Max Thrust	Real Max Thrust		Efficiency	Exhaust Velocity
				Using O2	Using N2O
Pressure Fed Gas Engine	10W	500kg	40.3kN	59.9kN	41.9kN	96%	3.86km/s (Isp: 394s)
Pumped Gas Engine	200W	500kg	16.2kN	16.3kN	24.4kN	100%	4.02km/s (Isp: 411s)
Pumped Liquid Engine	200W	500kg	17.9kN	18.7kN	31.3kN	140%	5.56km/s (Isp: 568s)
Pressure Fed Liquid Engine	20W	500kg	29.3kN	38kN	58.7kN	160%	6.31km/s (Isp: 644s)
Update 0.2.6091.26702 - 01/17/2026 Rocket_Engines