Atomic clocks on indigenous navigation satellite IRNSS-1A develops snag

The atomic clocks on the first satellite IRNSS-1A of the NavIC (Navigation with Indian Constellation), the indigenously built satellite-based positioning system, has developed a technical snag.
One of the three crucial rubidium timekeepers (atomic clock) on IRNSS-1A satellites failed six months ago and the other two followed subsequently. ISRO will soon launch one of its back up navigation satellites as a replacement to IRNSS-1A satellite.

Key Facts

• Remaining satellites of NavIC constellation (having total 7 satellites) are performing their core function of providing accurate position, navigation and time.
• Each satellite has three clocks and a total of 27 clocks for the navigation satellite system. These clocks are supplied same foreign vendor. These clocks are important to provide precise data.
• The troubled IRNSS-1A spacecraft was put in space in July 2013 and has an expected life span of 10 years. The seventh navigation satellite, IRNSS-1G, was launched in April 2016.

Atomic clock: It is an extremely accurate type of clock regulated by the vibrations of an atomic or molecular system. Its principle of operation is not based on nuclear physics, but rather on atomic physics. It uses the microwave signal that electrons in atoms emit when they change energy levels. The accuracy of an atomic clock depends on two factors, temperature of the sample atoms and frequency and intrinsic width of the electronic transition (higher frequencies and narrow lines increase the precision).

About NavIC (Navigation with Indian Constellation)

• NavIC also known as the Indian Regional Navigation Satellite System (IRNSS) is similar to the GPS (Global Positioning System) of US, Glonass of Russia and Galileo of Europe as well as China’s Beidou.
• Starting in July 2013, ISRO had launched all the seven navigation satellites of the IRNSS by April 2016. Each satellite has a life span of 10 years.
• IRNSS is said to be the “Indian GPS” that will give accurate real-time positioning and timing services over India and the region around it extending to 1,500km. Thus, NAVIC’s reach is regional.
• Applications of IRNSS: terrestrial, aerial and marine navigation, terrestrial navigation for hikers and travellers, vehicle tracking and fleet management, disaster management, integration with mobile phones, mapping and geodetic data capture and visual and voice navigation for drivers. Apart from the civilian applications, it will be used for defence purposes as well.

For more Information: IRNSS

Month: Current Affairs - January, 2017