The intercontinental ballistic missile (ICBM) would be test-fired by December 2010 said, Mr. M Natarajan DRDO Director General (R&D) and Scientific Advisor to the Defence Minister. Third motor was being added to the present range of AGNI missile. The test firing of the new ballistic missile, which would have a plus 5,000 km range follows the testing of AGNI III which has more than 3,000 km range by India twice already. Experts said that by adding a solid fuel propellant motor into the AGNI III a third stage motor will be attached to it to enhance its range to the 5,000-plus km category. Mr. Natarajan said that the new step would not be easy. ''We are adding a third motor to a system and this is not an easy task. But still we are confident that by December 2010 we would be successful in doing it.'' India had test fired the 'AGNI III' -- for the second time in April last year -- to test its efficacy.