India's newest communications satellite and the nation's largest rocket were both destroyed during a dramatic failure just moments after lifting off today. The vehicle crashed into the Bay of Bengal a few miles offshore of the launch site after disintegrating in mid-air.

The INSAT 4C satellite lifted off into cloudy skies shrouded atop a Geosynchronous Satellite Launch Vehicle at 1208 GMT (8:08 a.m. EDT), or in the late afternoon at the Satish Dhawan Space Center on the island of Sriharikota on India's east coast.

Problems with the flight began soon after the launch, according to Indian news reports. The rocket began straying from the planned trajectory and officials then declared an emergency. The remnants of the GSLV and its payload plummeted into the Bay of Bengal.

"Things have gone wrong in the stage of separation (of the booster from the launch vehicle)," said Indian Space Research Organization Chairman G. Madhavan Nair. "We have to analyze the data - why it went wrong."

Nair later said the initial focus of engineers probing the disaster was on one of four liquid-fueled strap-on boosters. Pressure in one of the engines dropped to zero, and it stopped producing the required amount of thrust, according to the Press Trust of India.

The situation created asymmetrical thrust around the vehicle, which then began to tilt up to 10 degrees. This led to a destruct command from ground controllers to disable and tear apart the rocket before it threatened inhabited areas.

The first stage of the GSLV consists of a solid-fueled core designed to burn for about one minute and 47 seconds. Four strap-on boosters each carry a single Vikas engine fed by a hydrazine-derived fuel and nitrogen tetroxide oxidizer. The boosters were supposed to fire for about two minutes and 29 seconds.

At that point, the entire first stage - the core motor and liquid-fueled boosters combined - was to be jettisoned from the GSLV's hypergolic second stage at an altitude of over 43 miles and a velocity of almost 6,300 miles per hour.

Officials with ISRO will immediately begin an investigation to determine the precise cause of the accident.

"Data received from the vehicle is being analyzed to pinpoint the exact reasons," ISRO said in a one-paragraph statement a few hours after the rocket was lost.

Had the flight continued on as planned, the 4,780-pound INSAT 4C satellite was to have been deployed into its targeted geostationary transfer orbit about 17 minutes after launch.

INSAT 4C was then supposed to unfurl its two solar panels and use an on-board propulsion system to guide itself into a circular geostationary orbit some 22,300 miles in altitude. The final operational location for the satellite was to have been above the Maldives at 74 degrees East longitude along the Equator.

The spacecraft carried 12 Ku-band transponders for direct-to-home broadcasting, video picture transmission, and digital satellite news gathering services. INSAT 4C was supposed to carry out a ten-year mission, and was the second member of the INSAT 4 series to be launched.

Today's launch was a turning point in India's space program because it marked the first time a heritage INSAT satellite was launched aboard a domestic Indian rocket. Other satellites in the INSAT fleet such as EDUSAT and KALPANA 1 have previously flown into space using the GSLV and the Polar Satellite Launch Vehicle. Earlier INSAT craft were delivered to their orbital perches commercially with European Ariane rockets, Delta launchers, and the space shuttle.

One additional Indian payload - INSAT 4B - is still awaiting launch aboard an Ariane 5 rocket late this year or in 2007. Otherwise, ISRO officials had planned to exclusively use locally produced launchers for all of their future space missions, including INSAT satellites.

This strategy may be in doubt after today's dramatic failure, depending on the length of the investigation and what is required to fix any problems discovered. The next flight of the GSLV was scheduled to be next year.

The INSAT constellation is the largest domestic communications satellite system in the Asia-Pacific region. The fleet consists of nine operational satellites serving customers in the fields of telecommunications, meteorology, and education.

The blastoff was also the first for a GSLV from the center's new launch pad, which was inaugurated last year by a launch of the smaller Polar Satellite Launch Vehicle. The complex uses a clean-pad concept that integrates the rocket in an assembly building before rolling it to the launch pad shortly before liftoff.

The mission was the fourth flight of the GSLV since debuting in 2001. In addition to the solid-fueled core and Vikas-powered strap-on boosters, the second stage uses another Vikas powerplant fed by hypergolic fuel. The third stage is largely provided by Russia, and its RD-56M engine burns liquid oxygen and liquid hydrogen.

Indian engineers have been hard at work developing an indigenous cryogenic upper stage to replace the Russian design flown in the first four launches of the GSLV. The upgrade will also increase payload capacity to geostationary transfer orbit by up to 25 percent to around 5,500 pounds. Engine testing for the new upper stage resulted in it receiving flight qualification, and full-up stage systems tests were planned in the next few months, ISRO said.

The inaugural launch of the new cryogenic third stage had been scheduled for the next GSLV mission in 2007.