PSLV-C19 puts India’s first radar imaging satellite into orbit

M. Ramesh Updated - November 16, 2017 at 01:29 PM.

PSLV-C19 carrying the RISAT-1 lifting off from the Satish Dhawan Space Centre in Sriharikota near Chennai on Thursday. Photo: K. Pichumani

India’s reliable workhorse, the PSLV rocket, today accomplished its mission of putting RISAT-1 — the country’s first microwave imaging satellite — into its designated orbit.

This was for the 21st consecutive time (and 20th successful) that a PSLV rocket has taken a satellite, but today’s launch was different than the rest for two reasons.

First, the 1,850 kg RISAT-1 was the heaviest satellite to be carried by a Polar Satellite Launch Vehicle. Second, today’s event distinguishes itself in terms of the sophistication of equipment on board the satellite.

New technology

Unlike the conventional optical camera, the microwave image sensing technology can take pictures of the earth surfaces day and night, at all weather conditions (even through the clouds).

Soon after the launch, scientists at the Sriharikota satellite launch centre here described the satellite as a happy culmination of years of effort and a giant leap in India’s science and technology prowess.

The satellite was today injected at a point 480 km above the earth. Over the next three days, it will be nudged into its orbit at 536 km above the earth, where it will circle the planet over the poles, cutting the equator at an angle of 97.5 degrees.

The satellite will circle the earth 14 times a day. Its primary use is said to be crop prediction, but it is basically a camera up there and as such can be used to take pictures for any purpose.

21st PSLV launch

The PSLV-C19 was the 21st PSLV launch — including the one that was used to carry GSAT-12 and the other that carried the Chandrayaan-1.

Like those two, the PSLV-C19 was also the ‘heavy version’ of the PSLV family, with six strap on rockets. At lift-off at 5.47 am today, the PSLV-C19 stood 44.5 metres tall and weighed 321 tonnes.

The satellite cost Rs 378 crore, and the rocket, Rs 110 crore, making the mission worth Rs 488 crore.

More launches

Later, addressing a press conference, the Chairman of Indian Space Research Organisation, Dr K. Radhakrishnan, said that ISRO planned at least three more satellite launches from Sriharikota.

The next would be another PSLV flight in August, when the rocket could carry six satellites. Later, around October, ISRO will attempt a launch of a Geosynchronous Satellite Launch Vehicle rocket with an India-made cryogenic engine.

GSLV rocket

A GSLV with an indigenous cryo engine has not been successful so far, but Dr Radhakrishnan said that a lot of learnings from the previous failed launches have been taken into account.

This GSLV rocket will carry the GSAT-14 satellite, with twelve transponders and a ka band beacon. If successful, these transponders will add to the existing 208 that India has. Later in the financial year 2012-13, there will be another launch of a PSLV.

>mramesh@thehindu.co.in

Published on April 26, 2012 04:00