:
As the country's eighth regional navigation satellite gets lined up for launch on Thursday evening, two things are significant about this rather routine, repeat mission.
IRNSS-1H is being sent to space to back-up — and mostly replace — the functions of India’s first navigation satellite. IRNSS-1A was launched four years back. The Indian Space Research Organisation (ISRO) had to quickly get two back-ups ready when all three rubidium atomic clocks on 1A failed around mid-2016. ISRO Chairman A.S.Kiran Kumar had earlier said 1H has atomic clocks that have been corrected and improved.
Between 2013 and 2016, ISRO put up seven IRNSS satellites to form the Indian Regional Navigation Satellite System, since called NavIC or Navigation with Indian Constellation.
NavIC is the Indian regional version similar to the US Global Positioning System GPS. It will drive all position-based activities on ground, sea and air by giving near-accurate location details of persons or objects. It will be put to military, commercial and common everyday uses.
Industry assists
The 1,425-kg IRNSS-1H is also the first spacecraft that ISRO has assembled by involving 70 young engineers deployed by six industries. This was their new role for the first time in what ISRO calls AIT or assembly, integration and testing. Last December, ISRO chose a consortium of six small to medium-sized industries to work with it on a turnkey basis, for IRNSS-1H and the one that comes after it.
The next satellite, IRNSS-1I, is planned as a ground spare, to be launched in an emergency, and is expected to be ready in the first quarter of 2018. M. Annadurai, Director of the ISAC, ISRO’s spacecraft centre, had earlier said the consortium would have a bigger hand in the second project. The role has been stepped up as ISRO has so far only sourced hardware or materials from 500-odd industries.
IRNSS-1H is expected to augment and sharpen the NavIC data related to accuracy and time. An ISRO spokesman said that although four navigation satellites are sufficient, with an error of up to 20 metres day and night, having seven in orbit would provide near-perfect position information.