New Delhi, Apr 26 (IANS): Prime Minister Manmohan Singh Thursday congratulated scientists of India's space agency ISRO for the successful launch of the PSLV-C19 rocket that has put into orbit the Radar Imaging Satellite (Risat-1).

"I would like to warmly congratulate all scientists of the Indian Space Research Organisation for the successful launch today of the Polar Satellite Launch Vehicle (PSLV)-C19 carrying the Radar Imaging Satellite-1 (Risat-1), the heaviest satellite launched till date using PSLV," Manmohan Singh said in his message soon after the successful launch.

He said the 20th consecutive successful launch of the PSLV "is an important milestone" in India's space programme and "is testimony" to ISRO's mastery of the complex launch vehicle technology.

"I have no doubt that Risat-1's all weather, day-night imaging ability will significantly contribute to the nation's remote sensing capabilities. The country is proud of ISRO's achievements and I wish the organisation all success in its future endeavours," he added.

The Risat-1 was launched into orbit from the Sriharikota spaceport in Andhra Pradesh, some 80 km from Chennai.

With the launch of Risat-1, India has now joined a select group of nations having such a technology.