All the preparatory activities connected with the launch of advanced communication satellite GSAT-8 on board an Ariane-V rocket May 21 are progressing satisfactorily at Kourou in French Guiana, India's space agency said Tuesday.

The Indian Space Research Organisation (ISRO) said the launch of GSAT-8 is scheduled May 21 at 0208 a.m.(IST) from the spaceport in South America.

"All the pre-launch activities are progressing satisfactorily," said ISRO.

Originally the Ariane V rocket was scheduled to blast off May 20 but was postponed by a day to May 21.

According to ISRO, the launch postponement was necessitated by certain additional inspections by Arianespace.

The indigenously built 3.1-tonne (3,100kg) GSAT-8 has 24 Ku-band transponders -- automatic receivers and transmitters for communication and broadcast of signals -- for direct-to-home (DTH) services by state-run and private broadcasters.

Within 30 minutes after the launch, Ariane will deploy the heavy satellite in a elliptical geo-synchronous transfer orbit (GTO) and the space agency's master control facility (MCF) at Hasan in Karnataka, about 180 km from Bangalore, will take over its command and control.

The satellite will be gradually put in the 36,000 km geosynchronous orbit over the subsequent days and its antenna and solar panels will be deployed. The MCF will also test and monitor the health parameters of the payloads by June 1. It will be available for DTH services from next month.

Along with GSAT-8, the space agency is sending the global position system ( GPS . aided geo-augmented navigation (Gagan) to improve the accuracy of the United States' GPS.