The planned launch of a new communications satellite has ended in a shower of debris for India, as the rocket carrying it went into a tailspin just moments after launch.

The telecoms satellite, which at more than 2,000kg was set to be the heaviest India had ever put into orbit, had a textbook start. The launch went well until the first stage of separation, Indian space officials said, at which point the rocket veered off course and exploded.

Debris from the explosion fell into the Bay of Bengal.

The precise cause of the malfunction is still unclear, and Madhavan Nair, chairman of the Indian Space Research Organisation (ISRO), is reported as saying: "We will analyse the data to see the sequence of events."

Officials denied the loss was a setback, describing it instead as a "disappointment", and maintaining that the launch rocket was well proven, following three successful launches.

The "disappointment" in fact follows 12 successful launches. But it also comes just days after a test fire of the Agni-III, a nuclear-capable ballistic missile, ended in failure. The surface-to-surface missile has a maximum range of around 3,000km, which means if the teething problems are resolved, it puts targets in China well within range.

As well as being a demonstration of its commercial capabilities, the launch was supposed to be a proving ground for India's lunar ambitions. The ISRO is working with NASA to get ready for an unmanned visit to the moon in 2008. ®