LV-T91 "Cheetah" Liquid Fuel Engine

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LV-T91 "Cheetah" Liquid Fuel Engine
Part image
Liquid fuel engine by
Jebediah Kerman's Junkyard and Spacecraft Parts Co

Radial size Medium
Cost (total) 850.00 Funds
Mass (total) 1.00 t
Drag 0.2-0.3
Max. Temp. 2000 K
Volume  ?
Impact Tolerance 7 m/s
Research Heavier rocketry.png Heavier Rocketry
Unlock cost 3 400 Funds
Since version 1.4.1
Part configuration LiquidEngineLV-T91.cfg
Maximum thrust (1 atm) 52.82 kN
(vacuum) 125.00 kN
Isp (1 atm) 150 s
(vacuum) 355 s
Fuel consumption 7.18 Units of fuel/s

Thrust vectoring 4 °

The LV-T91 "Cheetah" Liquid Fuel Engine is a liquid fuel engine with high efficiency in vacuum.


The Cheetah fits neatly between the Terrier and Poodle in terms of cost, mass, thrust, and thrust-to-weight ratio, and it has a slightly higher vacuum specific impulse than either.

(Its notably higher atmospheric Isp, while still too low to work well at Kerbin sea level, is an additional advantage in thin air e.g. Duna's.)

Overall, it performs well, though the range of delta-V, TWR, and payload mass for which it is the optimal engine may be narrow.

Product description

This engine will get you moving fast. Eventually.… Great for those long distance trips in space despite its namesake. Marketing, you know?

Jebediah Kerman's Junkyard and Spacecraft Parts Co


As of version 1.4.1 this engine has two models that can be switched in the editor. The Cap 1.875 variant is radial size medium, while the Bare variant is size small.

Cap1875 variant
Bare variant
The different variants of the engine


Real-world comparison

The LV-T91 was inspired by the American LR91, used as an upper stage engine in the Titan rocket family.


  • Increased unlock cost from 3000 to 3400
  • Decreased cost from 1000 to 850
  • Increased crash tolerance from 6 to 7
  • Increased EC generation from 3 to 5
  • Increased vectoring from 3 to 4
  • Improved Isp
  • Added ModuleTestSubject
  • Initial Release