As the Indian Space Research Organisation (Isro) readies the launch of its multi-purpose third generation satellite Insat-3A sometime in September or October, it is preparing to take a huge leap forward in the communications satellite arena. Seven satellites are planned under Isro's next generation of Insat-4 series. 

Insat-4A through Insat-4G with Insat-4D as a spare, is what is being envisaged. The transponder capacity has been worked out after a detailed evaluation of the projected requirements by various users, the Press Trust of India has reported. 

Isro currently has five satellites - Insat-2C, Insat-2DT, Insat-2E, Insat-3B and Insat-3C - in operation.