IRNSS-1A, INDIA's first navigation satellite

IRNSS-1A, INDIA's first navigation satellite now out in desired orbit

India has launched Polar Satellite Launching Vehicle(PSLV) carrying its first Regional Navigation satellite IRNSS-1A weighing 1425 kg with a total expenditure of Rs 16 billion on July 1, 11.41pm (IST) into the geosynchronous orbit from SDSC(Satish Dhawan Space Centre) at Sriharikota, out of the seven satellites that are ought to form IRNSS constellation. It Aims to provide marine, aerial and terrestrial navigation services as well as help during disasters and few more protected services accessible only by the government forces thereby serving military, government as well as the civilians. The remaining 6 are to be launched in future. This is the first midnight launch ever by ISRO. The Indian Prime Minister Manmohan Singh described it to be a milestone in India's Space Programme.

But how do these satellites help us in knowing our location??

Satellite navigation system consists of a number of satellites that work together. To determine their location on earth the receiver installed in electronic equipment obtain the signal transmitted along the line of sight by the navigation satellite which contains precise information regarding global position of satellite and the time of broadcast. The satellites in order to maintain time synchronization make use of atomic clock which uses an electronic oscillator oscillating at microwave frequency tuned to the Caesium or Rubidium electron transition frequency for its time calculating element since they are the most accurate. So these signals from different satellites captured by the receiver along with the receiver's internal clock help in making a precise calculation of the location. The satellite system with global coverage is called as Global Navigation Satellite System(GNSS). Till date only United States NAVSTAR Global Positioning System(GPS) and Russian GLONASS (GNSSs) fall under GNSS category.

The IRNSS-1A complete launch into the geosynchronous orbit according to ISRO has taken 20 minutes and 25.4 seconds.. The configuration used for IRNSS employs just 7 satellites to be placed at a height of 36,000 km appearing to travel in shape of the number 8 when observed from ground and would consume whole day to circle the Earth helping cover all over India and extending by 1,500 km. Four of the satellites are to be placed in two pairs in the inclined geosynchronous orbit and the rest three will be in the geostationary orbit appearing stationary. They are to use the L5 and S microwave frequency band for communication and so the GPS receiver will not work here which certain needs a new receiver. The launch of this has certainly reduced the fear India had since the navigation system used by them was GPS and under the control of US. Soon we would see by 2015 the IRNSS operating successfully and that would be a boon to the India's achievements on which the whole of India would be proud on driving to a greater success ahead.