Cosmos 398 was the final space test of the LK moon lander test using the T2K version. It followed the same program as Cosmos 398. The LK ("Lunniy korabl" - lunar craft) was the Soviet lunar lander - the Russian counterpart of the American LM Lunar Module. The LK was to have landed a Soviet citizen on the moon before the Americans, winning the moon race. This was not to be, for various reasons. Because the translunar payload of the Russian N1 rocket was only 70% that of the American Saturn V, the LK differed in many ways from the LM. It had a different landing profile; it was only 1/3 the weight of the LM; it was limited to a crew of one; it had no docking tunnel (the cosmonaut had to space walk from the LK to the LOK lunar orbiter). Unlike the LM, the LK did not use a separate descent stage to go from lunar orbit to landing on the surface. A braking stage, the Block D, took the LK out of lunar orbit and slowed it to 100 m/s at an altitude of 4 km above the lunar surface. From there the LK used the engines of its Block E stage to soft land on the moon. The Block E also served as the ascent stage to return the LK to lunar orbit. The LK consisted of four primary modules: The LPU landing gear, which allowed landing on the lunar surface. The LPU remained behind on the lunar surface, acting as a launch pad for the rest of the LK; The Block E rocket stage, which soft landed the LK on the moon and returned it to lunar orbit; The Lunar Cabin, the pressurised semi-spherical cabin where the cosmonaut was located; The Integrated Orientation System, a pod of small thrusters to orient the spacecraft. Atop the pod was the large hexagonal grid of the Kontakt docking system.