BENGALURU: In what's likely to become India's biggest science programme in the next few years, Isro has started work on building igloos on the Moon. These 'lunar habitats', as scientists call them, will be built by sending robots and 3D printers to the Moon, and by using lunar soil and other material.The project has seen progress with a working model - created using a 3D printer - sitting in the space agency's lunar terrain test facility. Scientists have drawn up five designs of the lunar habitats, and hope their work could contribute to plans of creating outposts on the Moon. Although there's no mission plan yet, Isro wants to have the technology ready for building these structures.Isro Satellite Centre (Isac) director M Annadurai likened the igloos on the Moon to India's outpost in Antarctica. "We are planning to use the Moon as an outpost - like missions in Antarctica. In the long run, the space station is likely to be scrapped. Many countries, including the US, are considering building more permanent structures on the Moon and working out of there. When that happens, we want India to have contributed," he told TOI.According to him, astronauts going to the Earth's satellite in the future will spend more than just a few hours there. "To keep them safe and help them work from there, we need smart materials, which is what we are focusing on building," he said.Annadurai said the space agency has mastered the process of creating lunar simulant (material that approximate the properties of lunar soil), and it has about 60 tonnes of it. Its properties match 99.6% with the samples brought from Moon by Apollo missions.