LFB KR-1x2 "Twin-Boar" Liquid Fuel Engine
|LFB KR-1x2 "Twin-Boar" Liquid Fuel Engine|
| Liquid fuel engine by |
|Radial size||Large, Radial mounted|
|Max. Temp.||2000 K|
|Impact Tolerance||20 m/s|
|Unlock cost||65 000|
|Part configuration|| part.cfg|
|Liquid fuel engine|
|Maximum thrust||(1 atm)||1 866.67 kN|
|(vacuum)||2 000.00 kN|
|Isp||(1 atm)||280 s|
|Fuel consumption|| 135.96 /s
|Thrust vectoring||1.5 °|
|Liquid fuel tank|
|Liquid fuel||2 880|
|Oxidizer|| 3 520
|On the surface||Yes|
|In the ocean||Yes|
|On the launchpad||Yes|
|In the atmosphere||Yes|
|In an orbit||Yes|
|On an escape||Yes|
|Test by staging||Yes|
Like all liquid fuel engines, the Twin-Boar is throttleable, both by the main throttle and a thrust limiter tweakable. The minimum thrust level required for this booster to lift its own laden weight is 17.5%. In addition, the liquid fuel booster can be run longer by adding additional rocket fuel tanks, which the Twin-Boar will draw from.
This booster contains two engines at the bottom which are added radially, so the base of the booster is wider than a usual large tank. It also does not allow any parts to be attached below it. It contains the same amount of fuel as the Rockomax Jumbo-64 Fuel Tank (2880). The thrust is higher than the Rockomax "Mainsail" Liquid Engine and is thus the most powerful large-sized engine. However, its Isp is slightly (5-10 s) lower than that of the Mainsail at all altitudes.
The Twin-Boar is the only part that is simultaneously a liquid fuel tank and engine.
|“|| This liquid fuel booster system is a very purposeful piece of engineering. Instead of relying on single engines or solid rocket boosters, the KR-1x2 employs two modified KR-1 engines, fed by a built-in fuel system, as the source of its immense lifting power. All that self-contained goodness comes at the cost of not having a mounting point for its underside, and not being quite as efficient as dedicated engines. It also comes at quite a literal cost as well.
The Twin-Boar is an unusually good engine. Once the weight and cost of the fuel + tankage is subtracted out, it weighs almost the same as a Mainsail, but has 33% more thrust while actually being 13% cheaper. It's similar to a pair of lower-efficiency Vectors. The Twin-Boar also has highest thrust to weight ratio of any liquid fuel engine in the game and the second highest thrust to cost ratio, second only to the LV-T30 "Reliant" Liquid Fuel Engine. This makes it an excellent and cost-effective mid-game launcher for larger payloads.
It is also the best engine in the game for first stage recovery. It has a high impact tolerance of 20m/s, and being very tall makes it extremely buoyant in case of a splashdown. Even in the case of a bad landing which results in partial disintegration of the rest of the stage, the integrated fuel tank is always recovered, so the recovery percentage in case of a crash landing is higher than for other engines.
- The name LFB KR-1x2 might be a reference to the Advanced Boosters, a future Space Launch System Block 2 component.
- The names "KR-1x2", "Twin-Boar", and the part description all imply the existence of an LFB KR-1 "Boar" Liquid Fuel Engine. However, no such part exists.
- Changed cost (5900 -> 16400), reduced Isp from 320-360 s to 290-340 s, changed description.
- Initial release