Performance Analysis of Silicon Micromachined Inclinometers on Chandrayaan-3 Lander and Rover

The Chandrayaan-3 mission aimed to achieve a precise and soft landing on the lunar surface, followed by the deployment of the rover to explore lunar terrain and perform scientific experiments. The inclinometer played a critical role by measuring the tilt of both the Vikram lander and Pragyaan rover post-landing, ensuring the stability of both for further operations. The inclinometer also supported safe navigation on the uneven lunar terrain, contributing to the mission’s overall success. This paper discusses the successful operation of the first-ever silicon micromachined inclinometer on the Moon, as part of the Chandrayaan-3 mission. It provides detailed analysis of inclinometer data collected from the lander and the rover during the mission. The inclinometer, apart from measuring the tilt after the lander touchdown, also captured data while in lunar orbit and during quiet periods post-landing to assess the instrument’s intrinsic noise levels. The data from the inclinometer confirmed the stable orientation of the lander and the magnitude of the tilt with respect to the local gravity vector. This was vital information to plan the proper functioning of on-board instruments and initiating the rolling out of the rover. Furthermore, the inclinometer helped to verify the lander’s stability after the "Hop-On" maneuvers, where the lander was relocated by short term firings of its thrusters, highlighting its importance in stability assessment. This work demonstrates, for the first time, the use of inclinometer data in conjunction with stereo camera data for rover navigation and terrain modeling on the Moon. The results of the inclinometer readings, combined with the DEM generated, contributed to a better understanding of the lunar surface characteristics, which could be helpful in future missions to the Moon.