By Venkatachari Jagannathan
Sriharikota (Andhra Pradesh): On an early Thursday morning, an Indian rocket successfully launched into orbit a microwave Radar Imaging Satellite (Risat-1) from the spaceport here in Andhra Pradesh, some 80 km from Chennai. With the launch of Risat-1, India has now joined a select group of nations having such a technology.
The indigenously built Risat-1, with a life span of five years, will be used for disaster prediction and agriculture forestry. The high resolution pictures and microwave imaging from Risat-1 could also be used for defence purposes as it can look through the clouds and fog.
At 5.47 a.m., the rocket – Polar Satellite Launch Vehicle C19 (PSLV-C19) – standing 44.5 metres tall and weighing 321 tonnes and with a one-way ticket, hurtled towards the skies ferrying the 1,858 kg Risat-1 after unshackling itself from launch pad No.1.
With a rich orange flame at its tail and a plume of white smoke, the rocket ascended towards the blue sky amidst the resounding cheers of ISRO scientists and media team assembled at the launch centre.
People perched atop nearby buildings too happily clapped as PSLV-C19 went up.
Space scientists at the new rocket mission control room of the Indian Space Research Organisation (ISRO) were glued to their computer screens watching the rocket escaping the earth’s gravitational pull.
The ISRO-made Risat-1 is the heaviest luggage so far ferried by a PSLV since 1993.
At around 17 minutes into the flight, PSLV-C19 delivered Risat-1 into a polar circular orbit at an altitude of 480 km and an orbital inclination of 97.552 degrees.
ISRO, with its network of ground stations, monitored its health.
“PSLV-C19 mission is a grand success. This is the 20th successive successful flight of PSLV. India’s first radar imaging satellite was injected precisely into orbit,” ISRO chairman K. Radhakrishnan said after the launch.
With this launch India joins a select group of nations like the US, Canada, Europe and others to have such an advanced technology. It is a 30 year effort, he added.
“With Risat-1 we can now forecast Kharif season,” Radhakrishnan said.
According to satellite director N. Valarmathi, Risat-1 can take images in all weather conditions and during day and night.
“The satellite has high storage device and other several unique features,” she added.
For ISRO, this is the first launch this fiscal as well as in the calendar year.
According to Radhakrishnan, the Indian space agency is planning couple of more satellite launches – communication and remote sensing satellites – this year.
He said the space agency would launch a communication satellite weighing 3.5 tonne through the Ariane rocket from French Guiana and two PSLV mission later this year.
He said ISRO will send SARAL satellite – an Indo-French initiative – using its PSLV rocket from here. There will also be the launch of first Indian regional navigational satellite this fiscal.
Speaking about the status of the space agency’s heavy rocket – Geosynchronous Satellite Launch Vehicle (GSLV)- that can carry communication satellites, Radhakrishnan said the advanced rocket GSLV Mark III has crossed several milestones and an experimental flight will be made in an year from now.
He said the experimental flight will be to test the rocket systems in the atmospheric flight phase.
The Indian made cryogenic engine is also undergoing several tests.
Meanwhile, the solar panes of Risat-1 were deployed successfully soon after it was injected into the orbit.
According to Radhakrishan, in three days time the satellite will be taken up to its intended orbit at an altitude of 536 km by firing the on-board motors.
Remote sensing satellites send back pictures and other data for use. India has the largest constellation of remote sensing satellites in the world providing imagery in a variety of spatial resolutions, from more than a metre ranging up to 500 metres, and is a major player in vending such data in the global market.
With 11 remote sensing/earth observation satellites orbiting in the space, India is a world leader in the remote sensing data market. The 11 satellites are TES, Resourcesat-1, Cartosat-1, 2, 2A and 2B, IMS-1, Risat-2, Oceansat-2, Resourcesat-2 and Megha-Tropiques.
Risat-1’s synthetic aperture radar (SAR) can acquire data in C-band and would orbit the earth 14 times a day.
In 2009, ISRO had launched 300 kg Risat-2 with an Israeli built SAR enabling earth observation in all weather, day and night conditions.
With Thursday’s launch the PSLV rocket has launched successfully 53 satellites out of 54 it carried – majorly remote sensing/earth observation satellites both Indian and foreign – and has been a major revenue earner for ISRO.
The one failure happened in 1993 when the satellite was not able reach the orbit.
The rocket that delivered Risat-1 in the space is ISRO’s four stage PSLV’s upgraded variant called PSLV-XL.
The letters XL stand for extra large as the six strap-on motors hugging the rocket at the bottom can carry 12 tonnes of solid fuel as against the base version that has a fuel capacity of nine tonnes.
The PSLV’s four stages are fuelled with solid and liquid propellants. The first and third stages are fuelled by solid fuel, while the second and fourth stages are powered by liquid fuel.
ISRO had used the PSLV-XL variant for its Chandrayaan-1 moon mission in 2008 and for launching the GSAT-12 communications satellite in 2011.