ISRO set to launch 7 satellites in 1200 seconds

By siliconindia   |   Tuesday, 22 September 2009, 23:10 IST   |    18 Comments
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ISRO set to launch 7 satellites in 1200 seconds
Bangalore: The Indian Space Research Organization (ISRO) will launch seven satellites in 1,200 seconds, similar to the launch in April 2008 when it launched 10 satellites, on Wednesday from Sriharikota. ISRO will put six nano satellites and one major ocean satellite into orbit, as the final 51 hour countdown began on Monday morning. Out of the six nano satellites, four are from Germany; one is from Switzerland and one from Turkey. The seventh is a big one, India's Oceansat-2 weighing 960 kilograms. It will take 1200 seconds from the time of launch to ejection of satellites. As Oceansat-2 will be ejected after 1,055 seconds, the other four nano satellites will be ejected in the next 45 seconds. Two others will stay with the fourth stage of the rocket which will be on its own once the different stages of the rocket get separated. The order of ejection is similar to the April 2008 launch featuring one big satellite, Cartosat-2A and nine other nano satellites. Once the Polar Satellite Launch Vehicle (PSLV) takes off and reaches a certain height and velocity, it will first launch the Oceansat-2 and few seconds later, the first of four nano satellites will be launched. These satellites will be launched every 10-12 seconds one after the other. "The rocket re-orients itself every time a satellite is to be placed in orbit. The re-orientation ensures one satellite doesn't collide with another. The rocket effectively re-orients itself four to five times in the space of one flight," explained a scientist. The rocket's brain would make all calculations in advance, from ejection of first satellite to the fifth. The exact moment of ejection and then re-orientation for the next ejection is worked out in advance. All mathematical calculations on the ground, launch sequence and flight path have to work on zero error. "There is no room for error. The rocket has to be in flight till the last minute which means all systems on board have to function to perfection. Once the first and second stages separate and the fourth stage (the engines) stop, the ejection process begins until every satellite circulates in orbit," said an official. Oceansat-2 is India's second satellite to study oceans and their interaction with the atmosphere. It is the 16th remote sensing satellite of India. It is in a cuboid shape with two solar panels projecting from its sides. The satellite will map fishing zones around India, measure ocean surface, wind speeds, atmospheric temperature and humidity. This mission is PSLV's 16th, as from September 1993 to April 2009, PSLV has been launched 15 times. With fourteen successful launches, it failed only once. "It is known that PSLV has been a very successful launch vehicle. Countries realise it is a vehicle or rocket very well suited for launch of nano satellites. We were on to our 16th mission with PSLV and Germany and Swtizerland were looking for a mission. Our needs coincided and that's how we have the six nano satellites," said S Satish, Spokesperson, ISRO.