Very few countries have done it: ISRO chief
SRIHARIKOTA: India set a record here on Monday when its Polar Satellite Launch Vehicle (PSLV-C9) fired 10 satellites into orbit in a precisely timed sequence.
As each satellite winged out of the vehicle, it had to be re-oriented to prevent collision. The feat proved the versatility, reliability and flexibility of the PSLV. This was the 13th PSLV flight and 12th successful one in a row.
A jubilant G. Madhavan Nair, Chairman, Indian Space Research Organisation (ISRO), told a press conference: “This is a memorable occasion for ISRO and India. We have set a record for launching 10 satellites into orbit [using a single vehicle]. Very few countries have done it. Russia launched 13 satellites at a time. We do not know the result. We have shown the world that we can do multiple launches in a precise manner. We are thrilled at the performance.”
However, the launch was not without its tense moments. As the 50-hour countdown progressed, an unseasonal trough of low pressure formed off the Andaman archipelago in the Bay of Bengal, where the Sriharikota island lies.
Luckily for ISRO, it did not develop into a large system and headed off north-east. “At 11 p.m. [on Sunday, April 27], we decided that the launch can go today [Monday]... We took these two factors into consideration. Otherwise, we would have scrapped [postponed] the launch,” Mr. Nair said.
At 9.24 a.m., under overcast conditions, the core-alone version of the PSLV sizzled into life in the second launch pad of the Satish Dhawan Space Centre and soared into the sky.
The core-alone version does not have the six strap-on booster motors that form part of the standard version. Each of the four stages of the vehicle fired on time. As the explosive bolts strapped between the stages ignited, each stage fell into the sea.
The fourth stage first fired Cartosat-2A into orbit at an altitude of 637 km about 885 seconds after lift-off. About 45 seconds later, it propelled IMS-into orbit. Then the six nano satellites belonging to a cluster called NLS-4 were injected into orbit at intervals of 20 seconds each. NLS-5, a single satellite, flew out and finally the tenth satellite Rubin-8 went along with the fourth stage into orbit.
There was anxiety when commands went out for the separation of the nano satellites, but the telemetry signals did not reach the ground. Confirmation of the separation did come later. Nineteen minutes after lift-off, a voice boomed from the Mission Control Centre: “Mission completed.”
Two satellites belonged to India and the remaining were very small ones built by universities in different countries. The Indian satellites were Cartosat-2A, used for preparing maps, and the Indian Mini Satellite — IMS-1, for remote-sensing.