Wednesday, October 12, 2011

Indian rocket launch delayed by one minute to avoid collision

The PSLV-C18 rocket carrying an Indian-French satellite that will study monsoon patterns and global warming, launches from the space centre in Sriharikota - AFP

A lot can happen in a matter of one minute, officials said on Wednesday about the postponement of a rocket launch by 60 seconds to prevent the four satellites it put into orbit colliding with space debris.
The Indian Space Research Organisation (ISRO) delayed the launch of its Polar Satellite Launch Vehicle-C18 (PSLV-C18) ferrying four satellites, including the Rs.172 crore Indo-French collaborative weather satellite Megha-Tropiques.
"Originally the launch was scheduled for 11 a.m. after taking into account the time zone difference between India and France. However the launch was delayed by one minute to avoid any possibility of the satellites colliding with space debris," ISRO chairman K. Radhakrishnan told reporters here.
The assessment on space debris in low earth orbit is made continuously and based on that, the decision to postpone the launch by a minute was taken.

Radhakrishnan said a rocket's launch time is fixed based on the kind of satellite that is being flown out.
He said the 50-hour countdown for the launch went off well and the flight sequence was perfect.
The Megha Tropiques satellite makes India only the second nation in the world to launch such a space mission. As for the Indian Space Research Organisation (ISRO), its Polar Satellite Launch Vehicle (PSLV) rocket went past the half century mark of satellite launches since 1993.
The PSLV-C18 - standing 44 metres and weighing 230 tonnes - soared towards the heavens from the first launch pad of the Sriharikota spaceport, 80 kms from Tamil Nadu's capital Chennai, ferrying four satellites together weighing 1,042.6 kg.
"The PSLV-C18 has been a grand success. Very precisely, four satellites were injected in circular orbit," ISRO chairman K. Radhakrishnan said.
He termed the Megha Tropiques mission as the beginning of a new era of cooperation between India and France.
"It's a truly global mission," he added.
Hailing ISRO for the successful launch of Megha Tropioques, a scientist of the French space agency Centre National d'Études Spatiales (CNES) described it as a 'professional launch'.
"ISRO's launch is unique. It's very good," he added.
CNES has built three instruments of Megha Tropiques: SAPHIR, SCARAB and GPS-ROS. The fourth, MADRAS, is a joint effort of ISRO and CNES.
Megha Tropiques with its circular orbit inclined 20 degrees to the equator will enable climate research and also aid scientists seeking to refine prediction models.
The previous such effort, the Tropical Rainfall Measuring Mission (TRMM) - a joint mission of NASA and the Japan Aerospace Exploration Agency (JAXA) designed to monitor and study tropical rainfall - was launched on November 27, 1997.
The three small satellites that were ferried by the PSLV-C18 were the 10.9 kg SRMSAT built by the students of SRM University near Chennai, the three kg remote sensing satellite Jugnu from the Indian Institute of Technology-Kanpur (IIT-K) and the 28.7 kg VesselSat from LuxSpace of Luxembourg to locate ships on high seas.
With a rich orange flame at its tail, the rocket left behind a huge tail of white fumes as it ascended towards the blue sky amid resounding cheers of ISRO scientists and the media team assembled at the launch centre.
People perched atop the nearby buildings happily clapped as PSLV-C18 - the rocket's core alone variant - without its six strap-on booster motors went up.
Around 22 minutes into the flight the rocket first spat out Megha Tropiques and followed it up with SRMSAT, VesselSat and Jugnu.
The whole process got completed in 25 minutes from blast off. ISRO, with its network of ground stations, monitored its health.
The Rs.1.1 crore SRMSAT using a grating spectrometer will monitor greenhouse gases, carbon dioxide and water vapour in the atmosphere
The Jugnu satellite is intended to prove the indigenously developed camera system for imaging the earth in the near infrared region and test image processing algorithms, evaluate global positioning satellite (GPS) receiver for its use in satellite navigation.
VesselSat will be used to detect ships at sea automatically from the signals they emit in the regions covered by it. The satellite carries two signal receivers called Automatic Identification System for ships (AIS).
The PSLV rocket has now launched successfully 52 satellites out of 53 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 to reach orbit.
The PSLV is a four stage (engine) rocket powered by solid and liquid propellants alternatively. The first and third stages are fired by solid propellant and the second and fourth stages are fired by liquid propellant.
ISRO has developed three PSLV variants. The first is the standard variant weighing around 290 tonnes with six strap-on motors measuring 11.3 metres with a fuel capacity of nine tonnes.

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