Why in news?
The recent launch of IRNSS-1H satellite as part of the NavIC (Navigation in Indian Constellation) project was a failure.
What went wrong in the launch?
- ISRO declared the “IRNSS-1H launch” a failure after a heat shield failed to separate.
- The heat shield is a protective cover provided around the satellite to help it withstand the adverse temperatures felt when a rocket is launched into space.
- Separation of the heat shield occurs mid-flight when the rocket leaves Earth’s atmosphere.
- The performance of PSLV-C39 went as per plan up to the point where the satellite had to be inserted in orbit but the heat shield prevented it from being deployed in space.
What is IRNSS & NavIC?
- IRNSS (Indian Regional Navigation Satellite Systems) is a group of satellites launched for providing satellite-based navigation services in the Indian subcontinent under the NavIC project on the lines of GPS – created by USA.
- It was designed mainly to provide an “Restricted Encrypted Service” for authorised users like the defence forces.
- But it also provides for accurate “position information services” to general users in India as well as the region, up to 1,500 km from the boundary.
- ISRO will also sell its capabilities to service providers like mobile phone manufacturers, vehicle manufacturers etc.
- The main reason for the development of IRNSS is the reliability that it offers when used for defence purposes.
- ISRO started work on the IRNSS programme in 1999 after the Kargil War, where Indian defence forces could not use American GPS in the conflict zone to locate its soldiers.
What was IRNSS-1H supposed to do?
- NavIC project with an indented cost of Rs.1,420 crores essentially comprises only seven satellites.
- IRNSS-1H, was the eighth satellite, launched to replace IRNSS-1A, which developed problems last year.
- It was supposed to sit in a “Sub-Geosynchronous Transfer Orbit”.
What made replacing of IRNSS-1A necessary?
- IRNSS-1A was the first satellite of the NavIC, launched in 2013.
- Recently, all the three RAFS-Atomic Clocks (Rubidium Atomic Frequency Standard clocks) on IRNSS-1A had failed, due to probable short circuiting.
- This rendered it ineffective for navigation services, which called for a replacement.
- While the clocks had failed, the rest of satellite components were found to be functioning perfectly.
- IRNSS-1A is currently being used for messaging activity.
Why are these clocks important?
- Atomic clocks are a key component in a navigation system for accurate timekeeping.
- This is crutial, as the determination of a person’s position on earth is subject to the accurate calculation of delays in signal transmission from the satellite to earth.
- Recognizing this importance, ISRO satellites are equipped with three clocks each — one being the primary timekeeper and two acting as backup.
- Due to the IRNSS-1A failure, modified versions of the original atomic clocks are being used by new satellites to overcome the technical issues.
Source: IndianExpress
