Sriharikota: It was a bright sunny evening with clear sky. The roof top speakers at Indian Space Research Organisation's (ISRO) Satish Dhawan Space Centre, Sriharikota, Andhra Pradesh, crackled into life announcing the countdown for the launch of the Polar Satellite Launch Vehicle (PSLV C8).
Blasting off at the second launch pad, PSLV C8 rose upwards exactly at 3.30 pm on 23 April, 2007, with a deep throated growl.
With its 3.2-metre bulbous head (payload fairing) shining under the evening sun and with an orange flame at its tail followed by an anaconda-like white fume, the fat pen-shaped PSLV C8, India's first dedicated commercial rocket, gathered momentum towards the heavens.
Its 535kg luggage consisted of Agile, the Italian satellite weighing 352kg and ISRO's own 185kg advance avionics module (AAM). The Agile is an X-ray and Gamma ray astronomical satellite. The AAM is like a second equipment bay installed inside the PSLV to test launch vehicle avionics systems like mission computer, navigation and telemetry systems.
Twenty-two minutes into the flight, the 44-metre high rocket performed flawlessly. It slung the Agile, mounted on the dual launch adaptor, into a 550 km circular orbit inclined at an angle of 2.5 deg to the equator, or simply, into an equatorial orbit.
"It is a historic moment as the European satellite was put into precise orbit," said G Madhavan Nair, chairman ISRO. According to him the successful launch has once again proven the reliability of PSLV. "This is an important event in the commercial satellite launch field."
He has reasons to be proud since, the Antrix Corporation, ISRO's commercial arm, had bagged the Italian launch order amidst stiff global competition.
Mission director N Narayana Moorthy added, "The launch faced no technical hitch."
Compared to the earlier versions, this time PSLV C8 had a slimmer bottomline-resembling India's first generation of launch vehicle SLV-3, and the growl of its core motor was comparatively lower. This was because the rocket went up without its customary six strap-on motors as the payload was lighter.
The core-alone PSLV C8 weighed 230 tonnes as against the usual 295 tonnes. Further the propellant in the fourth stage is lower by about 400 kg as compared to previous PSLV editions.
According to Dr B N Suresh, director, Vikram Sarabhai Space Centre, the organisation has been working on core-alone rocket configurations for several years.
The change in configuration also reduced the rocket's overall costs to around Rs68 crore as against the usual PSLV's build up cost of about Rs85 crore. The success in building modular stages based on the requirement will enable ISRO to look at more dedicated commercial launches.
For ISRO, the Agile launch contract has been a long journey. It was in 2003 that the managing director of Carlogavazzi Space Dr Lanfranco Zucconi was at the same launch centre to witness the successful launch of PSLV C5. (See: From spinning wheel to spacecraft) Carlogavazzi Space is involved in design, development and fabrication of satellites. At that time the Italians had not signed the launch contract with ISRO. It was scouting for a reliable launcher.
Subsequently the launch service was arranged by Cosmos International, Germany through Antrix Corporation.
The successful launch of Agile using a dedicated rocket has signalled to the world that India is a serious player in the global satellite launch sector. Compared to many space launch centres of the world, Sriharikota's proximity to Equator is advantageous for launching payloads eastwards.Since its first successful launch in 1994, PSLV has launched eight Indian remote sensing satellites, an amateur radio satellite- Hamsat, a space recoverable capsule SRE-1 and six small satellites for foreign customers into 550-800 km high polar sun synchronous orbits (SSO). (See: The foreign payloads)
Besides, PSLV has launched India's exclusive meteorological satellite, Kalpana-1, into geosynchronous transfer orbit (GTO). PSLV will also be used to launch India's first spacecraft mission to moon, Chandrayaan-1, during 2008.