Study on geomechanical properties of lunar soil simulant (LSS-ISAC-1) for chandrayaan mission q I. Venugopal a , Kasinathan Muthukkumaran b,⇑ , M. Annadurai c , T. Prabu d , S. Anbazhagan e a C&MG LEOS, U R Rao Satellite Centre, Indian Space Research Organization, Bangalore, India b Department of Civil Engineering, National Institute of Technology, Tiruchirappalli, Tamil Nadu, India c U R Rao Satellite Centre, Indian Space Research Organization, Bangalore, India d Department of Civil Engineering, National Institute of Technology, Tiruchirappalli, Tamil Nadu, India e Centre for Geoinformatics & Planetary Studies, Dept. of Geology, Periyar University, Salem, Tamil Nadu, India Received 13 January 2020; received in revised form 13 August 2020; accepted 16 August 2020 Abstract Under Chandrayaan - II mission, simulation studies on lunar terrain were required for evaluation of the performance of rover and lander. In order to carry out mobility tests of a rover, it was required to prepare a lunar terrain testbed, which required a large quantity of lunar soil to represent the terrain conditions of the Moon. Under such compelling circumstances, U R Rao Satellite Centre (URSC), Indian Space Research Organization (ISRO), Bangalore, India has decided to manufacture indigenously lunar highland soil simulant, which can represent bulk chemistry, mineralogy and geomechanical properties of actual lunar highland soils brought by Apollo-16 mis- sion of USA. This paper presents the process of manufacturing new lunar highland soil simulant (LSS-ISAC-1) and its various geome- chanical properties such as cohesive modulus of deformation, frictional modulus of deformation, sinkage exponent, cohesion stress, angle of internal friction, shear deformation modulus and bulk density. The same were compared with the properties of actual lunar highland soil brought to the Earth by the Apollo-16. This new lunar highland soil simulant is being used for all qualifying tests required to be performed for the indigenously developed rover and the lander of the Chandrayaan mission. Ó 2020 COSPAR. Published by Elsevier Ltd. All rights reserved. Keywords: Lunar simulant; Shear deformation modulus; Sinkage exponent; Lander & rover; Drawbar pull; Bearing pressure 1. Introduction Since the announcement in 2004 of a new vision for the United States Space Exploration program, lunar explo- ration has become one of the most pressing global scientific problems to be tackled, so that the Moon could act as a launchpad for further space exploration and interplanetary missions. As a part of this, Chandrayaan – II lander with the rover was scheduled to land in the South polar region, where the terrain composition is believed to be closer to lunar highland soil composition with anorthosite rocks (Mitchell et al., 1973; Carrier et al., 1991). It is understood that wheel-soil interaction properties will influence the movement performance of the rover on the lunar terrain. Hence, the characterization of lunar soil is essential for the optimal design of rovers (Liu et al., 2009; Ishigami et al., 2007; Tao et al., 2006). https://doi.org/10.1016/j.asr.2020.08.021 0273-1177/Ó 2020 COSPAR. Published by Elsevier Ltd. All rights reserved. q This project is supported and funded by the Indian Space Research Organization (ISRO), Department of Space, India, under the ISRO RESPOND Project No: 426. ⇑ Corresponding author. E-mail addresses: ivenu@leos.gov.in (I. Venugopal), kmk@nitt.edu (K. Muthukkumaran), mylswamy.annadurai@gmail.com (M. Annadurai), tp.civilnitt@gmail.com (T. Prabu), anbu02@periyaruniversity.ac.in (S. Anbazhagan). www.elsevier.com/locate/asr Available online at www.sciencedirect.com ScienceDirect Advances in Space Research xxx (2020) xxx–xxx Please cite this article as: I. Venugopal, K. Muthukkumaran, M. Annadurai et al., Study on geomechanical properties of lunar soil simulant (LSS- ISAC-1) for chandrayaan mission, Advances in Space Research, https://doi.org/10.1016/j.asr.2020.08.021