The GSLV-F04, the country’s third operational GSLV flight, was all set to take off at 4.21 pm, but barely 15 seconds before take-off the signals relating to readiness of the cryo-stage failed to reach the automatic launch sequence programme and the systems put a hold on the mission.

Finally, the launch which had already been delayed by a day due to inclement weather, finally took off.

Later, ISRO chief Madhavan Nair said: “This mission from all point of view has been highly dramatic. But within two hours all the corrections were carried out, and it was a very nice take off.” The ISRO team had been weighed down heavily by the previous failure of the GSLV F02 in July 2006. So the success of the Rs 310 crore GSLV-F04 mission had been all the more vital.

“We had really gone through the mill. On one side we had the anxiety coming from the previous failure. There were a series of tests, retests, validations and corrections. But, when the countdown began on Sunday everything went precisely until the last 15 seconds when the check out computer did not receive the readiness signal from the cryogenic stage. The computer promptly put a hold and the entire operation was stopped,” explained Nair.

Corrective action took two hours before the vehicle took off at 6.21pm.

The 49-metre-tall GSLV-F04 is the fifth flight of India’s GSLV and the third operational flight. It has a lift-off mass of 415 tonnes and is a three stage vehicle with solid, liquid and cryogenic stages.

The INSAT-4CR to be launched into Geosynchronous Transfer Orbit (GTO) carries 12 high-power Ku-band transponders designed to provide communication services such as Direct-To-Home (DTH) television services, Video Picture Transmission (VPT) and Digital Satellite News Gathering.

The satellite is designed for a mission life of 10 years. The INSAT-4CR, weighing 2.130kg is to replace an identical satellite, INSAT-4C that was lost following the failure of the GSLV-F02 in July 2006.