Safety of satellites assured

Technically known as Leonid Meteoroids8217;, meteor shower is associated with Comet 55P/ Temple-Tuttle whose orbital period is 33.3 years. The meteors are named Leonids as they appear to emanate from the Leo constellation.

quot;The comet emits low density debris on and around its track due to sublimation of ice and dust when it is in close proximity with the Sun,quot; Gopalan explained. quot;When Earth comes close to meteor shower some of its particles get attracted to it Earth, which is the reason behind their hyper-velocity speed of 71 kms per second.quot; This celestial explosion which, according to scientists, the people all over the world would be able to see with naked eyes, however, has posed a threat to at least 500 satellites launched by different countries, which would fall in its tracks.

The Indian satellites which may be affected include the Remote Sensing Satellites 8212; IRS-IB, IRS-IC, IRS-ID, IRS-P3, SROSS-C2 and the Communication satellites 8212; INSAT-ID, INSAT-2A, INSAT-2B and INSAT-2C. Many of these satellites with miniaturized, processor-based electronic and sensitive electro-optical devices on board are vulnerable to physical assault and plasma-oriented apacecraft-charging.

The damage could be catastrophic rapture, secondary fracture, leakage, vapourific flaxh, deflagration, deformation, reduced residual strength, fluid contamination etc. quot;The analysis of the Leonid storm effect using the available data shows that all Indian satellites serving scientific, communication and remote sensing missions are certain to undergo this ordeal with Leonid storm for the near full duration and Earth will not protect the satellites as the orbital planes will be exposed to the storm,quot; says an ISRO paper. The Indian space scientists, however, seem to be undeterred. quot;We are taking enough care to see that the possibility of the meteor shower hitting the satellites are minimised,quot; a confident Gopalan said. And preparations are being made on war-footing. quot;We have started assembling all our designs and operation staff at the IRS Satellites Tracking Centre in Bangalore as also at Hasan Karnataka based centre of INSAT Master Control System.quot; The ISRO scientists would start pre-exercises which willinclude switching off main power systems of all the satellites. Scientists will also ensure that the faces of the camera systems facing the skies are turned towards the ground. Satellites will be oriented in such a way which would leave little scope for the meteor shower to damage them.

According to Gopalan, the whole satellite operation will be suspended for 10 to 12 hours from evening of November 17 to the morning of November 18. As a result functioning of stock exchange, banking and telecommunication will be affected. He, however, said there was nothing to panic about. Besides, the world-wide station which are tracking ISRO satellites and support it would also be alerted.

ISRO could have shifted satellites to the other side of the Earth. Gopalan said it was not exercised for three reasons. quot;It was not cost-effective, also the risk involved now is still minimum and lastly had we exercised the option, communication services would have been affected for a long period.quot;