Cheni, April 11: The 32-hour countdown for Thursday’s early launch of the IRNSS-1L vigation satellite is progressing smoothly at the Sriharikota rocket port, around 105 km from here, Indian space agency officials said. The countdown began at 8.04 p.m. on Tuesday.
The 1,425-kg satellite — part of the Indian Regiol vigation Satellite System (IRNSS) — will be carried by Polar Satellite Launch Vehicle (PSLV) rocket XL variant that will blast off on Thursday at around 4.04 a.m., said an official of the Indian Space Research Organisation (ISRO). This will be the ninth of the IRNSS satellite series and will be a replacement for IRNSS-1A as its rubidium atomic clocks have failed. The atomic clocks are important to provide the accurate positiol data. Simply put, the IRNSS or vIC (vigation with Indian Constellation) is similar to the US-owned GPS. The Rs 1,420-crore Indian satellite vigation system vIC consists of nine satellites — seven in orbit and two as substitutes. The IRNSS-1L will be the second satellite that will be sent up as replacement for IRNSS-1A. The first replacement IRNSS-1H satellite launch mission ended in a failure. Each satellite has three Rubidium atomic clocks and a total of 27 clocks for the vigation satellite system (including the standby satellites) were supplied by the same vendor. Like its other IRNSS predecessors, IRNSS-1L also carries two types of payloads for vigation and ranging. Around 19 minutes 20 seconds after the lift-off, the rocket will sling IRNSS-1L at an altitude of around 507 km. (IANS)