During the fourth orbit raising operations on Monday, the 440 Newton liquid engine stopped, while both primary and redundant coils were energised together, however the thrust level augmentation logic, as expected, came in and the operation continued using the attitude control thrusters and the spacecraft was “normal” and “100 per cent safe,” according to ISRO.
Following the glitch, the apogee was raised only to 78,276 km against the target of about one lakh km.
During the first three orbit-raising operations, the prime and redundant chains of gyros, accelerometers, 22 Newton attitude control thrusters, attitude and orbit control electronics as well as the associated logics for their fault detection isolation and reconfiguration were exercised successfully.
After successfully completing these operations, the mission is expected to take on the “crucial event” of the trans-Mars injection around 12:42 am on December 1.
ISRO's PSLV C 25 successfully injected the 1,350-kg Mangalyaan Orbiter (Mars craft) into orbit around Earth some 44 minutes after a textbook launch at 2:38 pm from Satish Dhawan Space Centre at Sriharikota on Tuesday last, marking the successful completion of the first stage of the Rs 450-crore mission.
