ISRO Launches EMISAT Satellite

• 02 Apr 2019

The Indian Space Research Organisation (ISRO) has launched the EMISAT satellite on onboard the PSLV-C45 from the Satish Dhawan Space Centre in Sriharikota, Andhra Pradesh.

• The Polar Satellite Launch Vehicle (PSLV) was also carrying 28 international nanosatellites — 24 from the US, two from Lithuania and one each from Spain and Switzerland.
• The flight of PSLV was also the longest mission of the PSLV, lasting around three hours.

EMISAT Satellite

• The EMISAT satellite is aimed at electromagnetic spectrum measurement.
• It is an electronic intelligence satellite for the Defence Research and Development Organisation (DRDO).
• About Satellite
  • Mass: 436 kg
  • Manufacturer: ISRO
  • Orbit Type: Sun-synchronous Polar orbit(SSPO)
  • Altitude: About 753 km.

Polar Orbit

• A polar orbit travels north-south over the poles and takes approximately 90 minutes for a full revolution.
• These orbits have an inclination near 90 degrees. This allows the satellite to see virtually every part of the Earth as the Earth rotates underneath it.
• An orbit is called sun-synchronous when the angle between the line joining the center of the Earth and the satellite and the Sun is constant throughout the orbit.]

Purpose of Satellite

• EMISAT is an all weather and all terrain condition satellite, which will allow it to work through clouds, rain, forest and coastal areas.
• EMISAT is an ELINT (Electronic Intelligence) satellite, which means it will have a radar to measure the electromagnetic spectrum - so as to intercept and analyze radar signals, find their location, identify the hostile radars based on their radio frequency (RF) signature.
• This will be a vital tool for India when EMISAT along with the Airborne Warning and Control System (AWACS) can effectively locate, tackle and silence enemy radars, and secure Indian airspace.

Significance of Launch

• This mission was significant as this was the first time a PSLV has placed objects in three different orbits.
• The fourth stage was restarted and stopped twice to bring PSLV to the altitude of 507 km after EMISAT launch.
• At the fourth stage three experimental payloads were deployed:
  • Automatic Identification System (AIS) for Maritime satellite applications capturing messages transmitted from ships
  • Automatic Packet Repeating System (APRS) from AMSAT (Radio Amateur Satellite Corporation), India - assists amateur radio operators in tracking and monitoring position data
  • Advanced Retarding Potential Analyzer for Ionospheric Studies (ARIS) from Indian Institute of Space Science and Technology (IIST) - for the structural and compositional studies of the ionosphere.
• This is the first time it has been envisaged to provide a microgravity environment for research organizations and academic institutes to perform experiments.