The Indian Space Research Organisation (ISRO) has launched PSLV-C31 rocket successfully. Launched from Sriharikota space centre, near Chennai, the rocket is carrying the fifth satellite of India Regional Navigation Satellite System (IRNSS), the IRNSS-1E. As scheduled, the rocket blasted off from the second launch pad at 9.31 am (January 20, 2016). This was the first rocket launch of 2016. The fifth navigation satellite in the IRNSS space system, a constellation of seven satellites, would be at par with US-based GPS once the full complement of spacecraft is launched. The satellite’s life span is 12 years.

Though the full system comprises of nine satellites — seven in orbit and two on the ground as stand-by — the navigation services could be made operational with four satellites. The entire IRNSS constellation is planned to be completed this year itself.

 Payloads 

According to ISRO, the IRNSS-1E is carrying two types of payloads — navigation and ranging payloads.

The navigation payload will transmit navigation service signals to the users. A highly accurate Rubidium atomic clock is part of the navigation payload of the satellite, ISRO said. This payload will be operating in L5-band and S-band.

The ranging payload of IRNSS-1E consists of a C-band transponder (automatic receivers and transmitters of radio signals), which facilitates accurate determination of the range of the satellite. It is also carrying corner cube retro reflectors for laser ranging.

 Did You Know??? 

• Till date, India has launched four regional navigational satellites (IRNSS-1A, 1B, 1C and ID) to provide accurate position information service to users across the country and the region, extending up to an area of 1,500 kms.
• The first satellite IRNSS-1A was launched in July 2013, the second IRNSS-1B in April 2014, the third on October 2014 and the fourth on March 2015.
• Each satellite costs around Rs 150 crore and the PSLV-XL version rocket costs around Rs 130 crore.
• The seven rockets would involve an outlay of around Rs 910 crore. Once the regional navigation system is in place, India will no longer be dependent on other platforms

• Constellation means a group of associated or similar people or things.
• Transmitters are a set of equipment used to generate and transmit electromagnetic waves carrying messages or signals, especially those of radio or television.
• Transponder is a device for receiving a radio signal and automatically transmitting a different signal.
• Payload is the part of a vehicle’s load.