Last Updated on July 30, 2026 by Vinod Saini
EMISAT: country’s first satellite for gathering electronic intelligence (ELINT) to locate hostile radars for military, and 28 foreign customer satellites were successfully launched by India’s Polar Satellite Launch Vehicle – PSLV-C45, in its 47th mission and the 1st mission of PSLV-QL: a new variant of PSLV with four strap-on motors, from Satish Dhawan Space Centre (SDSC) SHAR in Sriharikota on Monday 01 April 2019. This was also the longest flight for the Indian polar launch vehicle.
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 foreign customer satellites from four countries, which include 1BlueWalker-1 and 1 M6P from Lithuania, 1 Aistechsat-3 from Spain, 1 Astrocast-2 from Switzerland, and 20 Flock-4A and 4 LEMUR from USA, were launched under commercial arrangements. The satellites together weigh 220 kg.
- PSLV-C45 lifted off at 9:27 Hrs (IST) from the Second Launch Pad and injected India’s EMISAT into a 748 km sun-synchronous polar orbit, 17 minutes and 12 seconds after lift-off.
- Two solar arrays of EMISAT were deployed automatically after separation, and
- ISRO Telemetry Tracking and Command Network at Bengaluru assumed control of the satellite.
- EMISAT will be brought to its final operational configuration in the coming days.
- PSLV’s fourth stage engines were restarted twice, following separation of EMISAT, 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.
- PS4, 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 about 3 hours after lift-off.
- PS4 has carried following payloads:
- Automatic Identification System from ISRO,
- Automatic Packet Repeating System from AMSAT, India and
- Advanced Retarding Potential Analyser for ionospheres’ studies from Indian Institute of Space Science and Technology
ISRO Chairman Dr K Sivan congratulating the launch vehicle and satellite teams involved in the mission said, “Today’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,” and added that a new PSLV team executed today’s mission.
PSLV has launched 46 national satellites till now, which inlude10 satellites built by students from Indian Universities and 297 international customer satellites.
PSLV-C46 launch RISAT-2B in May 2019 will be its next mission.
