ISRO to launch a 'back-up' navigation satellite by month end

Indian Space Research Organisation (ISRO) will launch its navigation satellite IRNSS-1H by the end of this month to augment the existing seven satellites of NavIC constellation, a senior ISRO official said. To be launched on board PSLV-C39, IRNSS-1H will be a "back up" navigation satellite for IRNSS-1A, one among the seven satellites in the constellation, as its three rubidium atomic clocks on board had stopped functioning. More

(Source: Economic Times - Aug 2)