A regional navigation satellite system with just seven spacecraft and in civil domain is unique to India.
India's own Regional Navigation Satellite System, the IRNSS, is all set to be completed in space on Thursday when the seventh and last of its spacecraft gets placed in orbit.
The 1,425-kg satellite, IRNSS-1G, will be launched at 12.50 p.m. IST from the Satish Dhawan Space Centre on April 28, 2016. The
countdown for the launch of the satellite aboard the PSLV C33 began at 9.20 a.m. on Tuesday. The integration of the rocket on the launch pad and the propellant filling operations will be taken up at different stages during the 51.30-hours countdown.
A regional navigation satellite system with just seven spacecraft and in civil domain is unique to India. The three global versions of other countries offer worldwide commercial coverage and are operated by their respective militaries. IRNSS will be to the subcontinent what the GPS is to its users worldwide, but with far greater precision and in Indian control, according to the Indian Space Research Organisation. It is expected to provide position accuracy of better than 20 m over Indian region and also an area extending up to 1,500 sq. km around India.
The well-known GPS is owned by the U.S. Air Force; Russia has GLONASS and China is expanding its regional BeiDou into a global system, also operated by its military. Europe’s GALILEO is a civil global system. They each have between 28 and 35 satellites.
IRNSS will drive both everyday uses as a 24/7 standard service for air, sea, ship transport among others and will also be used for military and missile-related applications as an encrypted and restricted service.
IRNSS-1G is slated to be flown on the homegrown launcher, PSLV C33, from the Sriharikota launch port in coastal Andhra Pradesh. It will be the 35th PSLV flight in the last two decades.
Over the next three to six months, all the IRNSS satellites in the fleet would be stabilised as a constellation, their signals and performance verified and later put to use, an ISRO official had said.
The fleet has two spare satellites kept ready on ground to be flown in an emergency. A full-fledged ground control centre in Bengaluru and tracking stations across the country have been put in place.
The constellation has been in the making since July 2013 when the first spacecraft, IRNSS-1A, was launched. ISRO placed the previous two spacecraft,
IRNSS-1E and
IRNSS-1F, in January and March this year, each with a designed life of 12 years.
They are identical with each carrying a navigation payload and a ranging payload in different bands, according to ISRO.
