On March 28, 2015, Indian Space Research Organization (ISRO) conducted successful launch of PSLV-XL launch vehicle with IRNSS-1D navigation satellite into a sub-geosynchronous transfer orbit from Satish Dhawan Space Center, Sriharikota, India
This was the 8th flight of PSLV in XL configuration and 29th launch overall for the Indian family of 'Polar Satellite Launch Vehicles'. Also, IRNSS-1D was the 4th out of 7 satellites, comprising the Indian Regional Navigational Satellite System (IRNSS), launched after IRNSS-1A, IRNSS-1B and IRNSS-1C.
IRNSS is an autonomous satellite navigation system, developed by ISRO and completely controlled by the Indian government. Having such navigation system would allow India to be independent from foreign global satellite systems such as GPS, Glonass, Galileo, or BeiDou. IRNSS would provide two services, the Standard Positioning Service open for civilian use and the Restricted Service, an encrypted one, for military users. Total IRNSS program development cost is estimated at $250 million.As it was told, IRNSS consists of seven satellites. Three of them are to be positioned in geostationary orbit (GEO), while the other four are to be in an inclined geosynchronous orbit (GSO). The satellites are based on I-1K (I-1000) satellite bus and both GEO and GSO spacecraft have the same configuration. Each satellite weighs around 1425 kg and has two payloads: navigation one and CDMA ranging payload in addition with a laser retro-reflector. The design of IRNSS system makes it inter-operable and compatible with US GPS and European Galileo satellite navigation systems.
PSLV family of Indian launchers currently has 3 configurations. PSLV, standard version of the rocket that has four stages and six strap-on boosters, PSLV-CA ('core alone') without strap-on boosters, and PSLV-XL, updated version of rocket's standard configuration boosted by more powerful, stretched strap-on boosters. Payload capacity of the most powerful PSLV-XL, that has orbited all IRNSS satellites, is 1800 kg to a 620 km altitude sun-synchronous orbit.IRNSS-1D mission was the first Indian launch of 2015 out of 4 planned. Also, this was the third launch of navigation satellites this week, after GPS IIF-9 mission conducted on March 25 by ULA from Cape Canaveral, and Galileo FOC 7 & 8 mission performed on March 27 by Arianespace from Guiana Space Center.