MUMBAI: India's manned space flight programme will move a step forward with the much-awaited launch of the advanced Geo-Synchronous Satellite Launch Vehicle (GSLV-MIII) on December 18 between 9am and 12pm from Sriharikota.The mission has evoked global interest because its only payload is the unmanned Crew Module Atmospheric Re-entry Experiment.After the Mars mission, the GSLV Mark-III flight is considered the next important step in India's nearly 50-year-old space programme.Speaking to TOI on Tuesday, GSLV Mark-III project director S Somanath said the primary aim of the first flight is to test the new rocket which has the capability to carry four-tonne class Insat-series communication satellites that are currently being flown by Arianespace.Somanath said that 325 seconds after the lift off, the crew module — made of aluminium alloy and with a lift-off mass of 3,735kg — will separate from the rocket at an altitude of 126km. Three different types of parachutes tested at facilities in Chandigarh and at Sriharikota by dropping them from a helicopter will be deployed during the descent. About 1,280 seconds after the launch the module will splashdown in the Bay of Bengal at a point 600km from Port Blair. It will be recovered by the Indian Coast Guard.Somanath said that the module has an ablative thermal protection system because during re-entry into the atmosphere, it will experience heat around 1,600 degrees C.