The Indian Space Research Organisation (ISRO) began a 67-hour countdown at 6:32 a.m. on Monday ahead of the launch of the third regional navigation satellite, the IRNSS-1C.

The 1400-kg-plus spacecraft is slated to be flown on October 16, Thursdsy, at 1.32 a.m. on the PSLV-C26 launch vehicle from the space port located in coastal Andhra Pradesh. It is part of a seven-satellite IRNSS constellation that is being put in orbit over the next two years.

The Indian Regional Navigation Satellite System (IRNSS) is designed to provide precise location- and time-based services to a variety of users on land, sea and air across the Indian region - akin to the global services of the U.S. GPS.

The earlier planned launched on October 10 >was postponed due to some technical reasons.

IRNSS 1C with a lift-off mass of 1,425.4 kg would be shot into a sub Geosynchronous Transfer Orbit (sub GTO).

As part of its aspirations to build a regional navigational system equivalent to Global Positioning System of the US, ISRO plans to send seven satellites to put in place the Indian Regional Navigational Satellite System.

IRNSS 1C spacecraft photographed during ElectroMagnetic Interference & ElectroMagnetic Compatibility (EMI-EMC) tests >pic.twitter.com/Usouuxp50c — ISRO (@isro) >October 11, 2014

The first two satellites in the series, >IRNSS 1A and >IRNSS 1B were launched from Sriharikota on July 1 2013 and April 4 this year respectively.

ISRO needs to launch at least four of the seven satellites to start operations of the IRNSS, ISRO officials said.

(With inputs from PTI)