CHENNAI: Realising the country’s long cherished dream of owning an indigenous Navigation Satellite System is close at hand. At 12:50 pm on Thursday, it is expected to come to fruition if the nation’s space ‘work horse’, Polar Satellite Launch Vehicle (PSLV-C33), maintains its winning streak and successfully launches IRNSS-1G, seventh and the last satellite of the IRNSS constellation into the targeted Sub-Geosynchronous Transfer Orbit (Sub-GTO).
On Tuesday, the 51:30 hour countdown for the launch has begun at 9:20 am in Mission Control Centre (MCC) at Sriharikota. The launch will take place from the first launch pad of the Satish Dhawan Space Centre (SDSC), said senior officials at Indian Space Research Organisation (ISRO).
It would be a culmination of 17 years of hard work by Indian space scientists. India took a firm decision on IRNSS in 1999 after US government refused to share GPS data that would provide vital information on Pakistani troop positions during Kargil war. Speaking to Express over phone from Sriharikota, P Kunhikrishnan, director, SDSC, said the 44.4 metre tall IRNSS-1G has a lift-off mass of 1,431 kg. “The countdown is progressing smoothly and we are updating the details on the website,” he added.
As in the previous six launches of IRNSS satellites, PSLV-C33 will use ‘XL’ version of PSLV equipped with six strap-ons, each carrying 12 tons of propellant, an Isro official said. Three in the IRNSS constellation will be located in suitable orbital slots in the geostationary orbit and the remaining four in geosynchronous orbits with the required inclination and equatorial crossings in two different planes. All the satellites of the constellation are configured identically. The satellites are configured with I-1K Bus to be compatible for launch on-board PSLV. Though the full system comprises nine satellites - 7 in orbit and 2 on the ground as stand -by, ISRO is yet to take a decision on stand-by options.
Cost-effective
India proved to the world how robust and cost-effective the indigenous technologies are with the success of Mangalyaan or Mars Mission. Likewise, IRNSS will be operational with just 7 satellites while China’s regional system ‘Beidou’ is a constellation of 35 satellites!
Area of Operation
IRNSS will provide two types of services, viz., Standard Positioning Service (SPS) to all the users and Restricted Service (RS), an encrypted service provided only to authorised users. IRNSS System is expected to provide a position accuracy of better than 20 m in the primary service area.
Key applications
Terrestrial, Aerial and Marine Navigation
Disaster Management
Vehicle tracking and fleet management
Integration with mobile phones
Precise Timing
Mapping and Geodetic data capture
Terrestrial navigation aid for hikers and travellers
Visual and voice navigation for drivers
Rush hour
With launch time announced, scientists were busy giving final touches to the mission. Mono Methyl Hydrazine propellant filling operation of fourth stage (PS-4) of PSLV-C33 was completed on Tuesday and last minute operations were underway.