ISRO successfully launched EMISAT, a military satellite and 28 foreign satellites on Monday (April 1, 2019) using PSLV C 45 from Satish Dhawan Space Centre SHAR, Sriharikota. The 28 international customer satellites includes 24 from the US, two from Lithuania and one each from Spain and Switzerland
What is so special about the Mission?
- The specialty of this mission is that for the first time PSLV will launch satellites in three different orbits.
- Mission starts with the Launching of the satellite EMISAT into orbit at 780 km. After putting the Emisat into orbit, the rocket will be brought down to put the 28 foreign satellites in orbit at an altitude of 504 km. This will be followed by bringing the rocket down further to 485 km when the fourth stage/engine will turn into a platform to carry out scientific experiments.
- With the success of the mission, India have successfully lifted and put into orbit 297 foreign satellites till date.
What is so special about this PSLV Launch?
- It was the 47th mission of Polar Satellite Launch Vehicle, the workhorse of ISRO.
- It is the longest ever flight for the PSLV.
- The space agency used its third generation of PSLV for this launch. The new PSLV variant called QL with four strap-on boosters is used in this mission.
- It is for the first time, PSLV with four strap-on motors has been used. Till now, PSLV has used either two or six strap-on motors or without any strap-ons.
- This is the third consecutive PSLV mission in which ISRO will re-use its fourth stage (PS4) as a space testbed. Earlier, the stages wasted away as floating debris once they released the satellites.
- ISRO had equipped the PS4 stage with power-generating solar panels for the first time.
- The PS4 orbital platform is envisaged to provide a microgravity environment for research organisations and academic institutes to perform experiments.
- PS4 will carry three minor payloads or experiments:
- Automatic Identification System (AIS) from ISRO: for Maritime satellite applications capturing messages transmitted from ships.
- Automatic Packet Repeating System (APRS) from AMSAT (Radio Amateur Satellite Corporation): to assist 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 composition studies of ionosphere.
What is EMISAT?
- EMISAT is the country’s first satellite for gathering electronic intelligence (ELINT) and surveillance.
- These satellites can locate where hostile radars are; figure out what signals they send out in order to enable right actions; eavesdrop on radar communication; and much more.
- EMISAT was developed by Defence Research and Development Organization (DRDO).
- Weighing about 436 kg, EMISAT based on ISRO’s Indian Mini Satellite -2 (IMS-2) bus platform.
- The main capability of EMISAT is in signal intelligence — intercepting signals broadcasted by communication systems, radars, and other electronic systems.
- It can scan through ice, rain, coastal zones, land masses, forests and wave heights.
- ISRO will likely place EMISAT in a highly elliptical orbit. This gives satellites the maximum amount of time to record high-resolution signals from a specific area.
- EMISAT also has a special altimeter (a radar altitude measuring device) called ‘AltiKa’ that works in the Ka-band microwave region of the spectrum.
- The electronic surveillance payload of EMISAT was developed under a DRDO’s project called KAUTILYA.
- EMISAT is modelled after a satellite called SARAL (Satellite with ARgos and ALtika) developed cooperatively by ISRO and CNES (Space Agency of France).
- There are over 150 military satellites orbiting the earth. Most of the countries having such satellite does not publicise them.
- The U.S.is said to be having fifth-generation ELINT satellites; Russia is not far behind. China is believed to have two special constellations of military satellites for spying.
(Courtesy: Hindustan Times, FirstPost, The Hindu)