New Delhi: Days after India successfully tested an Anti-satellite Missile under Mission Shakti, Indian Space Research Organization (ISRO) is all set to launch country’s EMISAT satellite along with 28 nano satellites of global customers from Sriharikota on Monday. The 28 international customer satellites are from Lithuania, Spain, Switzerland and USA. EMISAT will measure the electromagnetic spectrum and intercept radio signals originating from communication systems and radars. This will be the first time ISRO is trying to launch satellites in three different orbits.

The Indian space agency said that the countdown for the launch of a new variant of the Indian rocket Polar Satellite Launch Vehicle (PSLV) carrying electronic intelligence satellite, EMISAT for the Defence Research Development Organisation (DRDO) began on Sunday at 6:27 AM. Apprising further, ISRO officials said that the  four-stage PSLV-C45 will blast off from the second launch pad at the spaceport of Sriharikota, about 125 kms from Chennai, at 9.27 AM Monday.

Several Firsts For ISRO

Today’s mission will mark several firsts to the credit of the space agency as it would manoeuvre satellites in various orbits and orbital experiments including on maritime satellite applications. According to ISRO, a new variant of the rocket PSLV-QL equipped with four Strap-On motors in the first stage is used for the launch. PSLV is a reliable and versatile launch vehicle for ISRO with 39 consecutive successful flights till June, 2017 and five-in-a row from January 2018.

In Monday’s mission, ISRO scientists would place the satellites and payloads in three different orbits, a first for the agency. After injecting the 436 kg primary satellite EMISAT, intended for electromagnetic spectrum measurement, at around 17 minutes from lift off in a 749 km orbit, they would restart the fourth stage again.

During this initiative, all the other 28 customer satellites, totally weighing about 220 kgs, would be released by lowering the fourth state to around 504 kms orbit. Again, the fourth stage would be reignited and further lowered to 485 kms orbit to serve as an orbital platform for carrying out space borne experimentations for the first time in ISRO’s history.

According to ISRO, this is the first time it has been envisaged to provide a micro-gravity environment for research organisations and academic institutes to perform experiments. The PS4-fourth stage hosts three payloads in this mission.

They are automatic identification system from ISRO for Maritime satellite applications capturing messages transmitted from ships. Automatic Packet Repeating System from AMSAT (Radio Amateur Satellite Corporation), India to assist amateur radio operators in tracking and monitoring position data.

Advanced Retarding Potential Analyzer for lonospheric Studies (ARIS) from Indian Institute of Space Science and Technology (IIST) for the structural and composition studies of ionosphere. The other 28 international satellites — 25 3U type, two 6U type and one 2U type nano satellites — are from Lithuania (two), Spain (1), Switzerland (1) and the United States (24). All these satellites are being launched under commercial arrangements, ISRO said.

According to the officials, the whole flight sequence will take about 180 minutes from the rocket’s lift off slated at 9:27 AM. Earlier its launch was set for March 21 but the launch was postponed to next month to ensure system readiness.

The PSLV is a four-stage engine expendable rocket with alternating solid and liquid fuel. In its normal configuration, the rocket will have six strap-on motors hugging it’s first stage. On January 24, the ISRO flew a PSLV with two strap-on motors while in March, it had four strap-on motors. The space agency also has two more PSLV variants — Core Alone (without any strap-on motors) and the larger PSLV-XL.

The ISRO selects the kind of rocket to be used based on the weight of satellites it carries. It will also be launching two more defence satellites sometime in July or August with its new rocket Small Satellite Launch Vehicle (SSLV).

(With agency inputs)