A new variant of India's Polar Satellite Launch Vehicle (PSLV) rocket on Thursday night lifted off with the country's defence imaging satellite "Microsat R" and student satellite "Kalamsat".
About 14 minutes into the flight, the rocket would eject Microsat R at an altitude of about 277 km.
"There is an increased demand for satellites from strategic sectors. About six-seven satellites are planned to be built," a senior official told IANS earlier.
The GSAT-7 and GSAT-7A are the two dedicated military communication satellites, while all other earth observation and communication satellites launched earlier were of dual use -- civilian and defence.
At about 103rd minute after the lift-off, the rocket's fourth stage would turn into an orbital platform for Kalamsat at an altitude of 450 km.
The Kalamsat is a payload developed by students and Chennai-based Space Kidz India. It will be the first to use the rocket's fourth stage as an orbital platform. The fourth stage will be moved to higher circular orbit so as to establish an orbital platform for carrying out experiments, the ISRO had said.
Speaking to IANS earlier, Chairman of Indian Space Research Organisation (ISRO) K. Sivan said the rocket would launch DRDO satellite Microsat R weighing about 700 kg and Kalamsat.
"To reduce weight and increase the mass, an aluminium tank is being used for the first time in the fourth stage," Sivan said.
The PSLV is a four-stage engine expendable rocket with alternating solid and liquid fuel.
In its normal configuration, the rocket would have six strap-on motors hugging its first stage.
But the 44.4-metre tall rocket that lifted off on Thursday had two strap-on motors and its configuration is designated as PSLV-DL.