PSLV-C45 launches EMISAT, 28 foreign satellites

India’s Polar Satellite Launch Vehicle (PSLV-C45) on Monday successfully launched an electronic intelligence satellite EMISAT and 28 international customer satellites from the Satish Dhawan Space Centre (SDSC) SHAR in Sriharikota.

This flight marked the first mission of PSLV-QL, a new variant of PSLV with four strap-on motors. PSLV-C45 lifted off at 9.27 am from the Second Launch Pad and injected India’s EMISAT into a 748 km sun-synchronous polar orbit, 17 minutes and 12 seconds after liftoff.

After separation, the two solar arrays of EMISAT were deployed automatically and the Indian Space Research Organisation (ISRO) Telemetry Tracking and Command Network at Bengaluru assumed control of the satellite. In the coming days, the satellite will be brought to its final operational configuration.

Following the separation of EMISAT, the vehicle’s fourth stage engines were restarted twice to place the 28 international customer satellites precisely into a sun-synchronous orbit of 504 km height. The last customer satellite was placed into its designated orbit 1 hour and 55 minutes after lift-off.

About three hours after lift-off, the fourth stage (PS4) of the vehicle was moved to a lower circular orbit of 485 km after two restarts to establish it as an orbital platform for carrying out experiments with its three payloads.

EMISAT is a satellite built around ISRO’s Mini Satellite-2 bus weighing about 436 kg. The satellite is intended for electromagnetic spectrum measurement.

28 satellites

The 28 international customer satellites, together weighing about 220 kg, are from four countries. Among them, 24 are from the United States, two from Lithuania and one each from Spain and Switzerland. These foreign satellites were launched as part of commercial arrangements.

The payloads carried by PS4 are Automatic Identification System from ISRO, Automatic Packet Repeating System from AMSAT, India and Advanced Retarding Potential Analyzer for ionospheric studies from Indian Institute of Space Science and Technology.

ISRO Chairman, K Sivan said the Monday's PSLV mission was unique in several ways. “It was a four strap-on new variant. The vehicle achieved three different orbits and for the first, the PS4 stage is powered by solar panels,” he explained.

A new PSLV team executed the mission, he informed. So far, PSLV has launched 46 national satellites, 10 satellites built by students from Indian Universities and 297 international customer satellites, including the satellites launched on Monday. In its next mission, PSLV-C46 is scheduled to launch the RISAT-2B in May 2019.

ISRO has scheduled about 30 missions for this year, including launch vehicles and space crafts. The missions include Chandrayaan-2.