Just minutes after the Aditya-L1 mission was declared a success, Isro on Saturday said: “…Pragyan 100! Meanwhile, over the Moon, Pragan rover has traversed over 100 metres and is continuing.”
Rover operations are not fully autonomous and require commands to be sent from Earth. Pragyan’s movement is riddled with multiple challenges, each of which need to be overcome every time the rover moves.
For every path planning, onboard navigation camera data must be downloaded to ground for generation of a digital elevation model (DEM), then the ground and mechanisms team will decide which path to take and uplink the command for the rover to follow.
The maximum DEM that can be generated is only for 5 metres each time the navigation camera sends images, which means every time the rover is commanded to move, it can at best cover 5 metres.
Even there, there are challenges of obstacles. For instance, Pragyan has so far safely negotiated a small crater whose depth was 10cm (100mm) and avoided a bigger crater whose diametre was 4 metres to choose a safer path. Isro has already done multiple rover movements as of Saturday
