Spacecraft navigation without GPS. Comparison table: Examples: Astrix 90 fibre optic gyroscope FOG used on ExoMars Hazard avoidance in ALHAT in project Morpheus lander SPLICE NDL Navigational Doppler Lidar to be used on Intuitive Machines IM-1 , as early as Nov 15 2023, launched by Spacex falcon 9 Chandrayaan-3 landing: Laser Inertial Referencing and Accelerometer Package (LIRAP): LIRAP is like a special “balance and motion sensor” for the lander. It helps the lander understand its position, orientation, and any movements it makes during its descent and landing on the lunar surface. ( Laser gyroscope) Chandrayaan-2 had a front-facing camera(TMC-2). Still, the communication system could not transfer the images in real-time. But now the communication system has been beefed up to enable the front-facing camera of the CY3 lander to transmit the images in real-time to the ISRO control centre. The images are collected as part of the autonomous hazard ide...