| Auto: | all |
| IRNSS-1A | |
| Mission Type: | Navigation |
| Operator: | ISRO |
| Cospar Id: | 2013-034A |
| Satcat: | 39199 |
| Mission Duration: | 10 years |
| Spacecraft Bus: | I-1K |
| Manufacturer: | ISRO Satellite Centre Space Applications Centre |
| Dry Mass: | 614kg (1,354lb) |
| Launch Mass: | 1425kg (3,142lb) |
| Power: | 1,660 watts |
| Launch Rocket: | PSLV-XL C22 |
| Launch Site: | Satish Dhawan FLP |
| Launch Contractor: | ISRO |
| Orbit Epoch: | 22 January 2015, 16:27:41 UTC[1] |
| Orbit Reference: | Geocentric |
| Orbit Regime: | Geosynchronous |
| Orbit Periapsis: | 35706.1km (22,186.7miles) |
| Orbit Apoapsis: | 35882.7km (22,296.5miles) |
| Orbit Inclination: | 29.3° |
| Orbit Period: | 1436.1 minutes |
| Orbit Longitude: | 55° E |
| Apsis: | gee |
| Programme: | NavIC |
| Next Mission: | IRNSS-1B |
IRNSS-1A is the first navigational satellite in the Indian Regional Navigation Satellite System (IRNSS) series of satellites been placed in geosynchronous orbit.[1] [2]
The satellite has been developed at a cost of,[3] [4] and was launched on 1 July 2013. It will provide IRNSS services to the Indian public, which would be a system similar to Global Positioning System (GPS) but only for India and the region around it.[5]
Each IRNSS satellite has two payloads: a navigation payload and CDMA ranging payload in addition with a laser retro-reflector. The payload generates navigation signals at L5 and S-band. The design of the payload makes the IRNSS system inter-operable and compatible with GPS and Galileo.[6] The satellite is powered by two solar arrays, which generate power up to 1,660 watts, and has a lifetime of ten years.[1]
The satellite was launched from the Satish Dhawan Space Centre (SDSC) on 1 July 2013 at 11:41 PM (IST).[7] The launch was postponed from its initial launch date of 26 June 2013 due to a technical snag in the 2nd stage of the PSLV-C22 launch rocket.[8] ISRO then replaced the faulty component in the rocket and rescheduled the launch to 1 July 2013 at 11:43 p.m.[9] [10]
Scientists from the German Aerospace Centre (DLR)'s Institute of Communications and Navigation in Oberpfaffenhofen, Germany, have received signals from IRNSS-1A. On 23 July 2013, the German Aerospace Center scientists pointed their 30-meter dish antenna at Weilheim towards the satellite and found that it was already transmitting a signal in the L5 frequency band.[11]
The three Rubidium atomic clocks on-board IRNSS-1A failed, with the first failure occurring in July 2016. ISRO planned to replace it with IRNSS-1H, in August 2017, but this failed to separate from the launch vehicle.[12] [13] On 12 April 2018, ISRO launched successfully IRNSS-1I as a replacement for IRNSS-1A.[14]
The cause of failure was traced to one of the feed through capacitor carrying the DC supply to the physics package of clock, malfunctioning due to excessive rise in temperature.[15] IRNSS-1A and IRNSS-1G are now being used only for NavIC's short message broadcast service.[16] [17]