The launch of India's second lunar mission has been halted less than an hour before the scheduled blast-off, due to a technical problem.

The countdown stopped 56 minutes before the launch after a "technical snag was observed in launch vehicle system," India's space agency said. The satellite had been scheduled for launch at 02:51 local time on Monday (21:21 GMT Sunday) from Sriharikota space station on India's eastern coast. A new launch date will follow soon.

What is this mission all about?

India hopes the $150m mission, Chandrayaan-2, will be the first to land on the Moon's south pole. It will focus on the lunar surface, searching for water and minerals and measuring moonquakes, among other things. If successful, India will become the fourth country to make a soft landing on the Moon's surface. Only the US, China and the former Soviet Union have been able to do so. India's Prime Minister, Narendra Modi has championed the country's space programmes, but critics would like to see poverty at home tackled first. The chief of the Indian Space Research Organisation (Isro), K Sivan, said this was "the most complex space mission ever to be undertaken by the agency". If the launch had gone to plan, the lander and rover would have been expected to touch down in early September. India's space agency is yet to give more details on why the launch was delayed and how it will affect the timeline. The country's first lunar mission in 2008 - Chandrayaan-1 - did not land on the lunar surface, but it carried out the first and most detailed search for water on the Moon using radars.

How will it get to the Moon?

Chandrayaan-2 (Moon vehicle 2) will attempt a soft landing near the little-explored south pole of the Moon. India is using its most powerful rocket, the Geosynchronous Satellite Launch Vehicle Mark III (GSLV Mk-III), in this mission. It weighs 640 tonnes (almost 1.5 times the weight of a fully-loaded 747 jumbo jet) and at 44 metres (144ft) is as high as a 14-storey building. The spacecraft weighs 2,379kg (5,244lb) and has three distinct parts: an orbiter, a lander and a rover. The orbiter, which has a mission life of a year, will take images of the lunar surface, and "sniff" the tenuous atmosphere. The lander (named Vikram, after the founder of Isro) weighs about half as much, and carries within its belly a 27kg Moon rover with instruments to analyse the lunar soil. In its 14-day life, the rover (called Pragyan - wisdom in Sanskrit) can travel up to a half a kilometre from the lander and will send data and images back to Earth for analysis. "India can hope to get the first selfies from the lunar surface once the rover gets on its job," Dr Sivan said. BBC