A lunar soil simulant (LSS-ISAC-1) for the lunar exploration programme of the Indian Space Research Organisation

Abstract

Lunar Regolith Simulants are imperative materials required for In-Situ Resource Utilization (ISRU), simulating physical and chemical properties of the lunar terrain, testing landers and mobility of rovers, and calibration of payloads and sensors. The available simulants do not represent all the lunar terrain environments and are insufficient to conduct the above experiments. The Indian Space Research Organization (ISRO) took up necessary steps to launch the Chandrayaan-2 mission after successfully completing the Chandrayaan-1 mission. The Chandrayaan-2 mission included an orbiter, a lander and a rover. ISRO's UR Rao Satellite Centre (URSC) has decided to have a dedicated Lunar Terrain Testing Facility (LTTF) at Bengaluru. URSC has planned for a bulk quantity of lunar soil simulant similar to Lunar highland composition. The task was assigned to the Centre for Geoinformatics and Planetary Studies, Department of Geology at Periyar University in southern India. The bulk quantity of Lunar soil stimulant was produced from the anorthosite rocks collected from the Sittampundi Anorthosite Complex (SAC) exposed in the southern part of India. We report the merit of the source area, geological setting, chemistry, mineral phase, soil characteristics, and grain size distribution of simulant material. The anorthosite rocks collected from SAC have a higher abundance of calcic plagioclase, and the proportion of major oxides is mostly equivalent to lunar highland anorthosite. ISRO's lunar soil simulant LSS-ISAC-1 has similarity with the Lunar highland regolith in the majority and has fidelity to represent the highland terrain. The testing facility, LTTF, was used for testing the soft landing of the lander and mobility of the rover of the Chandrayaan-2 mission.