*8th Feb, 2025* *News of the Day* *Story of NavIC: crucial indigenous Satellite Navigation system, a few hurdles in development path* *Indian Regional Navigation Satellite System* The Indian Regional Navigation Satellite System (IRNSS), operationally referred to as the Navigation with India Constellation (NavIC) system, was conceived in 1999 following the war in Kargil. During this war, India’s military could not use the American Global Positioning System (GPS) in the conflict zone. (India and the US now cooperate in many fields, and Washington has approved the system.) The construction of seven-satellite constellation serving both defence and civilian needs started with the launch of first satellite in 2013. Eleven years later, however, only five of the 11 satellites launched in the NavIC program – including replacements for failed satellites – are fully operational. *What went wrong recently?* India’s space agency reported the partial failure of its NVS-02 navigation satellite due to the non-firing of its engines in space. As a result, the satellite was left in a sub-optimal orbit around Earth. Sub-optimal orbit means that the satellite could not be placed in the intended orbit. This satellite was launched on 29th January, 2025. *What happened to other failed satellites?* Mid-2016 onward, there were reports of failures of the rubidium atomic clocks used in several navigation satellites. There are three atomic clocks on each IRNSS satellite. Satellites rely on highly accurate atomic clocks like rubidium clocks to precisely time the signals they send, which is essential for calculating distances and thus, locations on Earth. If the rubidium clocks on a satellite fail, the satellite's ability to accurately pinpoint location data is significantly compromised, leading to inaccurate GPS readings and potentially major disruptions in navigation systems reliant on that satellite. Few other satellites launched were lost in the accidents during their journey itself. *Why is the IRNSS/ NavIC system important for India?* The NavIC satellites provide two types of services – Standard Positioning Service which is for general and commercial use, and Restricted Service which is meant for the defence forces – over the Indian landmass and neighbouring regions. A primary reason to develop an indigenous satellite navigation system like the IRNSS despite the existence of global systems such as the GPS (US), GLONASS (Russia), Galileo (Europe), Beidou (China), and QZSS (Japan), is the reliability that it offers in defence use. Relevance: GS Prelims & Mains Paper III; Science & Technology Source: Indian Express *Download the Complete Daily Current Affairs Pdf* https://www.prepmate.in/wp-content/uploads/2025/02/News-Juice-8th-February-2025.pdf