IRS-1D blast-off establishes India's capability to enter global commercial launch market

Challenge Ahead: To validate the new capability, scientists must quickly detect the snag and ensure that the PSLV launches in the next few years are successfulThere was nothing in the lift-off to indicate that things had gone more than just a trifle wrong with the launch. At precisely 10.17 a.m. on September 29, the cluster of rockets at the base of the five-storeyed Polar Satellite Launch Vehicle (PSLV) roared to life, bathing the launch pad at Sriharikota in a brilliant orange glare.The spacecraft, weighing as much as 294 tonnes - equivalent to 300 Fiat cars - rose ponderously at first. It then accelerated rapidly across the firmament, reaching a speed of 3,600 kmph, or three times the speed of sound, before disappearing in a blaze of flame and smoke.Twenty minutes later, space scientists tracking the PSLV on radar at the control centre reported that the rocket had successfully lobbed the highly sophisticated Indian Remote Sensing Satellite (IRS 1-D) into orbit at a height of 800 km over Antartica. They immediately hugged and congratulated each other. Prime Minister I.K. Gujral, who made it a point to witness the launch, talked of it being the "biggest moment" for India's space efforts. And K. Kasturirangan, chairman of the Indian Space Research Organisation (ISRO), described it a "perfect textbook launch". Not quite. For even before the back-slapping was over, scientists began to notice a worrying anomaly in the satellite's path. Instead of travelling in a circular orbit of 817 km over the polar regions of the earth, the satellite was following an elliptical trajectory. As a result, as the IRS 1-D spun around the earth once every 101 minutes, its perigee, or the point in its orbit closest to earth, dropped to 300 km. At such an orbit its powerful stereoscopic cameras, that can even photograph details of your house if directed, became almost myopic.The action then shifted to the Indian Satellite Tracking Centre (ISTRAC) at Bangalore. Scientists sat huddled for hours over computer consoles working out how the satellite could be nudged back to a circular orbit without significantly affecting its operational life of three years. IRS-1D carries 84 kg of fuel meant largely to keep its on-board systems ticking as well as to provide for nominal corrections in its course and speed. Scientists do fill it with some additional fuel for exigencies but certainly not enough to correct IRS-1D's significant loss of altitude.Click here to EnlargeTo minimise the loss in operational life, scientists were working towards pushing the satellite only up to 600 km instead of 800 km. That orbital height is considered sufficient for the satellite's sensors to function adequately and send back high-quality images.Such a manoeuvre is expected to consume 60 kg of fuel and will take close to a month to complete. ISRO scientists maintain that the satellite's operational life will be reduced by around six months, or by 16 per cent of the total of three years. Says IRS-1D Project Director R.K. Rajangam: "A s of now, we don't expect a major cutback on its life.'' Some experts, however, say the anomaly could lead to a reduction of almost a year of the satellite's life. Even as they were grappling with IRS-1D, reports came in of a serious malfunction in INSAT-2D, India's indigenously built communications satellite that had been launched only three months ago.Scientists have also begun investigating as to why the flaw developed in the PSLV flight. The spacecraft is configured into four stages, each having rocket motors for different purposes. The first three stages are meant to give the spacecraft the velocity to break free of gravity's pull and also an altitude close to the satellite's final orbit. These seemed to have gone according to the copybook. The flaw seems to have developed in the fourth and final stage.If all went according to plan, in the fourth stage motors would have powered the spacecraft from a height of 635 km to around 800 km and accelerated it to the desired speed of 7.45 km per second. All this within eight minutes. What happened, however, was because of a possibly minor malfunction in the fuel-injection chambers of the motor, it shut down in seven minutes. As a result, the spacecraft did not achieve the speed required; it also plunged into an elliptical orbit. It will take a couple of months before scientists come up with what really went wrong. Says Kasturirangan, who is confident the problem is a minor one: "There is no need to press the panic button. What is important is that the launch has established that India has the capability to put a satellite of IRS-1D'S class into orbit."Despite the imperfect ending, there is no doubt that the PSLV launch - the fourth in its series - is a major milestone in the Indian space programme. It demonstrates the country's ability not only to build satellites but also to launch them. India has now shaken off its dependence on Russian vehicles for launching its remote-sensing satellites. While the three previous IRS satellites were put into orbit by the Russian rockets for a hefty fee, this time's launch helped the country save up to Rs 70 crore in foreign exchange. Besides, India can now place into orbit smaller, low-earth orbit satellites for mobile phone services. Next year, it would be asserting itself as the first Third World country to commercialise its launch-vehicle operations. The 1998 PSLV flight will carry a 110 kg South Korean satellite piggy-back on the IRS-P4. This will mark the first commercial launch agreement with another country using an Indian launch vehicle. "No need to press the panic button. We've established our capability in space." K. Kasturirangan Chairman, ISRO"We are hoping that this will be the beginning of a series of commercial agreements," says N. Sampath, ISRO'S director of technology (transfer and international coordination). Though there is no final word on the price tag of the satellite launch, it is expected to fetch India at least Rs 54 crore at today's market rates. To become a major commercial launching power, however, India must show at least four to five successful flights of the PSLV. Of the four flown so far, the first failed when a software error in the on-board guidance system led to the spacecraft tumbling into the Bay of Bengal. The second and third were successful, but the weight of the satellites it carried was scaled down by 200 kg to 300 kg. The latest PSLV was a modified version, with far more powerful boosters that allowed it to lift the 1.2 tonne IRS-1D. Scientists must now quickly detect what actually went wrong and ensure that future launches are truly textbook ones.Published By: AtMigration Published On: Oct 13, 1997 00:00 IST--- ENDS ---

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IRS-1D blast-off establishes India's capability to enter global commercial launch market

Though IRS-1D strayed from its intended orbit, the blast-off established that India has the capability to enter the global commercial launch services market.

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