mission profile: soft landing is one of main objectives of luna-25 DISD-LR ДИСД-ЛР The soft landing of the station should be provided by a Doppler speed and range meter (DISD-LR) developed by the Vega Concern (part of the Rostec State Corporation's Roselectronics holding). The DISD-LR device is being created in the conditions of import substitution, the developers note. According to the original plan, Luna 25 was supposed to be launched in 2014. However, various reasons provoked delays one after another. The last big postponement (from 2021 to 2023) was caused by the malfunction detected (80% accuracy in readings) in the Doppler speed and range meter (DISD-LR) during the tests. Being an important part of the soft landing system, this device couldn’t be ignored, and its insufficient accuracy may cost a mission. The repeated tests of DISD-LR and subsequent changes of the lander’s software caused a delay for almost two years 22 x 13x 2 Slotted waveguide antenna a...