The Indian space agency has got the patent for its method of manufacturing highland lunar soil simulant or simply lunar/moon soil.
As a part of its Moon landing mission Chandrayaan-2, the Indian Space Research Organisation (ISRO) had to prepare an artificial moon surface so that the Vikram lander and Pragyaan rover could be tested.
On May 18, the Indian Patent Office granted patent to ISRO for an invention as to the method of manufacturing highland lunar soil simulant.
The patent is valid for 20 years from the date of filing the application, i.e., May 15, 2014. The inventors are: I. Venugopal, S.A. Kannan, Shamrao, V. Chandra Babu (all from ISRO), S. Anbazhagan, S. Arivazhagan, C.R. Paramasivam, M. Chinnamuthu (all from the Department of Geology, Periyar University, Salem, Tamil Nadu) and K. Muthukkumaran from the National Institute of Technology, Tiruchirappalli, Tamil Nadu.
“The surface of the earth and that of the moon are entirely different. So we had to create an artificial moon surface and test our rover and lander,” M. Annadurai, who retired as Director, U.R. Rao Satellite Centre (URSC), formerly ISRO Satellite Centre, had told IANS.
Importing lunar soil like substance from the US was a costly affair and ISRO looked for a local solution as its need was about 60/70 tonnes of soil.
Many geologists had told ISRO that near Salem in Tamil Nadu, there were “anorthosite” rocks that would be similar to the features of moon soil or regolith.
The ISRO finalised to take the “anorthosite” rocks from Sithampoondi and Kunnamalai villages in Tamil Nadu for moon soil.
Annadurai said the rocks were crushed to the required size and moved to Bengaluru where its Lunar Terrain Test Facility was located and the test bed was created.
As per the patent papers filed, the invention relates to a lunar simulant prepared from a terrestrial analogue and a method for producing and manufacturing it.
The simulant is almost equivalent to the regolith of the lunar highland region and comparable with Apollo 16 return samples.
The lunar soil simulant can be used for scientific studies of lunar terrain relating to mobility/trafficability of rover for scientific explorations or for the study of geo-technical/mechanical properties of lunar soil for understanding the engineering behaviour of lunar regolith or to carry out fundamental research work (theoretical and experimental) to postulate a broad design philosophy for realising civil engineering structures on the Moon surface, and to make a pathway to lunar locomotive engineering.
Lunar exploration requires a full understanding of the physical and chemical properties of lunar surface soil as most of the building materials have to be produced out of the regolith for human settlement on the Moon.
As per the papers filed by ISRO, compositionally, the lunar soils fall into two broad groups: The highland soils, which are developed on anorthositic bedrock, and mare soils, which are developed on basaltic bedrock. Mare soils can be further sub-classified as to high or low titanium content soils.
Highland soils are relatively enriched in aluminium and calcium, while mare soils are relatively enriched in iron, magnesium and titanium. The use of lunar simulants is focused on physical characteristics of the lunar regolith for undertaking landing and transportation activities.
“There are more than 30 lunar simulants that have been produced to date, some of which have been exhausted,” ISRO said.
Most of the countries produced simulants representing the lunar mare region.
The lunar highland crust occupies 83 per cent of the lunar surface. However, only limited number of simulants represent the regolith of the lunar highland region, ISRO said.
According to the Indian space agency, most of the future missions propose for soft landing on the lunar highland region. Hence, there is an urgent need for a bulk quantity of lunar soil simulant, which represents the highland lunar crust.
The lunar soil simulant of the present invention is exclusively manufactured to represent the lunar highland region. The regolith of the lunar highland region is mainly derived from anorthositic rock formation.
The present simulant produced and manufactured in bulk quantity exactly from similar rock samples identified and picked out from the Sittampundi Anorthosite Complex, India.
Moreover, the invention satisfied all aspects, including mineralogy, bulk chemistry, grain size distribution and geo-mechanical properties.
As the mission to land the Vikram moon lander safely failed earlier, India is planning a similar mission going forward.