CHENNAI: The 50-hour countdown for the lift-off of the Polar Satellite Launch Vehicle (PSLV-C9) from Sriharikota, Andhra Pradesh, on Monday morning is under way. The vehicle will put as many as 10 satellites in orbit.
If the countdown, which began at 7.23 a.m. on Saturday proceeds without any “hold,” the PSLV-C9 will surge into space from the world-class second launch pad at 9.23 a.m. on Monday.
The challenge of this mission is that the fourth stage of the rocket should fire the 10 satellites into the orbit, one after another, in a timed sequence without any collision, said Indian Space Research Organisation (ISRO) officials. Two satellites belong to ISRO and other eight, called nano satellites, are from different countries. These are very small satellites and all of them together weigh only 50 kg.
Although the PSLV has successfully launched multiple satellites three times earlier (three satellites each on May 26, 1999 and October 22, 2001 and four satellites on January 10, 2007), this is the first time that ISRO is attempting to put in orbit as many as 10 satellites using a single rocket.
“It is a good experience to launch so many satellites” because it was quite an involved and complex task, said B.N. Suresh, former Director, Vikram Sarabhai Space Centre (VSSC), Thiruvananthapuram. The VSSC has built the PSLV-C9 which is a four-stage vehicle.
It is the “core-alone” version of the PSLV that will put the satellites in orbit. This version does not carry six strap-on booster motors that surround the first stage of the “standard version.” The core-alone, therefore, is a lighter vehicle weighing 230 tonnes instead of the standard configuration which weighs 295 tonnes.
The two Indian satellites being carried are Cartosat-2A and Indian Mini Satellite (IMS-1). Cartosat-2A, which weighs 690 kg, is a remote-sensing satellite and its images will have a resolution of one metre.
The images will be used in making maps which will provide valuable information in planning urban infrastructure, rural roads, ring roads, and settlements. They will also be used in defence applications.
The IMS-1, which weighs 83 kg, is also a remote-sensing satellite. The images sent down by its two cameras can be used to monitor features on the earth such as its vegetation and water bodies. The ISRO Satellite Centre, Bangalore, has built the two satellites.
Six of the eight nano satellites are clustered together and are named NLS-4. The University of Toronto, Canada, has developed the NLS-4. It comprises Cute 1.7 and SEEDS, both built in Japan while the remaining four – CAN-X2, AAUSAT-II, COMPASS-1 and Delphi-C3 —were built in Canada, Denmark, Germany and the Netherlands respectively.
The two other nano satellites, NLS-5 and Rubin-8, belong to the University of Toronto and Germany. Building these nano satellites amounted to “a good experimentation for several universities,” said Dr. Suresh.
ISRO officials said it would be a demanding mission because the fourth stage of the PSLV-C9 would have to be re-oriented each time it ejected a satellite into orbit.
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