KSP 1.11.x Cryogenic Engines [1.2.1]  Last Updated January 13, 2020 This modest part pack is designed to provide some new rocket engines that run on Liquid Hydrogen and Oxidizer. There are nine models provided, two in each of the 1.25, 1.875, 2.5 and 3.75m sizes and one in the 0.625,. These engines have better fuel efficiency than the KSP stock engines, up to 460s of Isp, but beware! They're more expensive and produce less thrust per unit weight. In addition,