It is visible to the naked eye for barely 40 seconds but a space launch is the greatest sound and light show that I have ever watched. On January 5, I was privileged to witness the blast-off of India’s Geosynchronous Satellite Launch Vehicle, GSLV-D5, from the space port at Sriharikota in coastal Andhra Pradesh. I consider myself lucky to have seen over a dozen Indian space launches and for each one of them I confess I become a little boy again and watch the celestial spectacle with wide-eyed wonder.

On land, too, Shriharikota, which is about 80 km from Chennai, offers a fascinating drive. The road to the Satish Dhawan Space Centre snakes through Pulicat Lake Bird Sanctuary where the expansive brackish water lagoon attracts hordes of migratory birds in winter. On this trip I see a flock of flamingos delicately picking their way through the shallow waters, adding a hue of pink to the sea-blue lake.

The historic launch of GSLV-D5 at Sriharikota on January 5.

As I approach the space port, I feel the excitement grow. Standing 11-storey tall, GSLV is the mightiest satellite launcher that Indian space scientists have built so far. It is capable of carrying satellites weighing between 2 to 4 tonnes, injecting them into an orbit 36,000 km into space. In contrast, the Polar Satellite Launch Vehicle (PSLV), which is currently ISRO’s workhorse, can carry satellites weighing less than 2 tonnes, putting them into a polar orbit of around 800 km.

The key to GSLV’s ability to carry heavier satellites is the third stage, which consists of a cryogenic engine that uses super-cooled liquid hydrogen and oxygen as propellants. These propellants have to be stored at temperatures varying from -180 degrees to -150 degrees Celsius. (The coldest recorded temperatures in Antarctica are below -100 degrees C). Yet when the engine fires temperatures can soar to as much as 800 degrees Celsius — the melting point of aluminium. Apart from the extreme temperature variations that the engine has to withstand, it has high-speed turbo-pumps that have to operate at an RPM of 40,000, four times faster than passenger aircraft engines.

Building such a complex rocket engine requires mastery in metallurgy and combustion technology. ISRO had entered into a technology transfer agreement with Russia for the cryogenic engine in 1991. But under US pressure, Russia cancelled the deal in 1992 and only agreed to sell India fully assembled cryogenic engines so that the GSLV programme wouldn’t suffer.

Since then Indian scientists have struggled to master the technology. Even GSLV launchers fitted with Russian-built cryogenic engines have had a 50 per cent success rate. The first launch of the indigenously built cryogenic engine aboard a GSLV had failed in 2010. Scientists then worked for three years to fix the problems.

Before we enter the Master Control Centre (MCC), ISRO Chairman K. Radhakrishnan tells me he is confident that the launch will be a success. The MCC’s exterior resembles a saucer-shaped spaceship made famous by the movie Close encounters of the Third Kind. Inside, the centre is out of a James Bond flick with scientists hunched over rows of computer consoles. Giant TV monitors display visuals of different sections of the spacecraft on the launch pad apart from graphs of its expected flight path. Bright red digital clocks above them show the time in IST and GMT, besides the countdown. At various intervals, scientists intone updates on the health of the launch vehicle over the loudspeaker.

As the countdown enters the final phase, the silence is audible and the tension palpable. Every launch vehicle costs close to Rs 300 crore to build and is carrying a satellite worth the same amount. So each pop costs Rs 600 crore and the scientists are aware of the enormity of the stakes. Four minutes before blast-off, like many others present I move out to watch the launch from the balcony.

As the final count reaches 0, our hearts beat faster. We see orange fumes billowing from the ground and the spacecraft lifts off almost in slow motion. As it begins to gather momentum, the tail of dazzling orange flames grows longer and brighter. Then we hear a roar so deep it would match the sound of a squadron of fighter jets. The entire building shakes. In less than a minute the spacecraft is travelling at five times the speed of sound as it disappears into the firmament.

We enter the MCC to watch its progress on the huge monitors. A tiny blip represents its flight on the expected path. As each stage fires successfully, scientists and visitors clap excitedly. Five minutes after blast-off, as the cryogenic stage ignites, the thrill mounts. We wait for 11 more agonising minutes before the announcement comes that the launch is successful and the satellite has been injected into its planned orbit.

At the MCC, the scene is similar to India winning a cricket world cup as scientists hug each other and cheer. It is a historic day for India as the country joins the select band of five countries (US, Russia, France, China and Japan) that can build cryogenic engines. Despite my years of training as a journalist to remain neutral, I feel proud to be an Indian — 2014 had begun with a bang heard across the world.

raj@tribuneindia.com