After 20 years of research and trials, the Defence Research and Development Organisation has decided to scrap the Trishul missile project -- one of the most ambitious surface-to-air missile initiatives in the country.

Trishul, which underwent seven "successful test-firings" over the years at INS Dronacharya, the Indian Navy's offshore establishment at Kochi, has been found wanting in "technical and operational capabilities."

Senior DRDO scientists said the defence ministry decided to dump the short-range quick-reaction missile because "its command guidance never worked properly."

Trishul was part of the Integrated Guided Missile Development programme. Of the other four missiles -- Agni, Prithvi, Akash, Nag -- that were part of the IGMD programme, only two -- Agni and Prithvi -- have shown positive results.

Though each test flight of Trishul was described as successful, a DRDO scientist said there were scores of technical problems that the missile encountered.

As per the country's defence plans, these surface-to-air missiles were to have replaced the Russian-supplied OSA-AK and Kvadrat systems by early 1990s.

The Trishul project was launched in 1983 and officials say the DRDO has so far spent around Rs 3 billion on its development.

"The main reason why we are shelving Trishul is because the missile technology we have been using is obsolete. I do not know why the DRDO continued with the project all these years. It has been a waste of time and money," a senior official at the Southern Naval Command told rediff.com.

He said the Indian Navy had lost interest in Trishul long back and it had even written to the defence ministry four years back asking the government to abandon the project.