In the parliamentary reply mentioned earlier, the government noted that “around 12,000 trains are targeted for tracking in real-time using NavIC and other GNSS constellations” and “around 8,700 trains are already equipped with NavIC along with other GNSS constellations.” Apart from IRNSS-1F, IRNSS-1A launched on July 1, 2013, IRNSS-1C put in orbit on October 16, 2014, IRNSS-1D launched on March 28, 2015, IRNSS-1E on January 20, 2016, and IRNSS-1G on April 28, 2016, have suffered atomic clock failures.