Four new ISRO Earth stations in Hassan soon

Well-placed sources at the MCF told Deccan Herald: “Along with the seven earth stations we have, which are used to monitor a constellation of satellites, we are readying for the IRNS programme, for which we will get four new stations.”

The stations will be in the configurations of 1:3 –– one big station and three small stations –– costing an estimated Rs 12 crore. The big station will consume most of the dedicated fund, Rs 10 crore, and all the other stations together will cost about Rs 2 crore.

According to sources from ISRO, the space agency is gearing up for the launch of the first IRNS satellite (IRNSS) by the end of this year using its Polar Satellite Launch Vehicle (PSLV) to place the satellites in the designated orbits.

IRNSS, they said will consist three satellites (called GEOs) on the geostationary arc above India and four (called GSOs) in two highly inclined quazi-zenith orbits.

The GEOs, they said: “...Will be located at 34 degree East, 83 degree East and 132 degree East, while the GSOs will be in orbits with a 24,000-km apogee and 250-km perigee inclined at 29 degrees. Two of the GSOs will cross the equator at 55 degree East and two at 111 degree East.”

The GEO satellites will have a 9.4 year lifespan and the GSOs will be designed to have a life of 11 years.  The entire constellation will be in place by 2012. The system will require a sophisticated ground segment. The spacecraft control centre (SCC) in Hassan will contain two telemetry uplink stations and a navigation centre, while a laser ranging centre, 20 ranging and integrity monitoring stations and a timing centre will be established.

“We will have a data communications network to connect the entire system,” sources added.

IRNSS signals will consist of a Special Positioning Service (SPS) and a Precision Service (PS) and the ground segment will consist of multi-constellation receivers capable of simultaneously receiving signals from all seven satellites while over Indian territory and also GPS signals augmented by the Gagan system, which is already in use.