Chandrayaan-2: Second orbit raising manoeuvre performed

Rasheed Kappan, DHNS, Bengaluru,

Jul 26 2019, 13:57 ist
updated: Jul 26 2019, 16:48 ist

The Chandrayaan-2 moon mission took another step closer to the moon early Friday morning. At 1.08 am, the Indian Space Research Organisation (Isro) successfully performed the Mission's second orbit-raising manoeuvre within the influence of Earth's gravity.

Five such manoeuvres are planned within the Earth-bound phase. Since its launch from Sriharikota on July 22, Chandrayaan-2 has been going around the planet on an elliptical orbit. On Wednesday, the first orbit-raising had placed the Mission at a distance of 230 x 45,163 km.

When it reached the farthest point on this orbit from Earth (called apogee), the Mission's onboard propulsion system was fired to increase the apogee. The new orbit is at 251 x 54,829 km. On launch day, Chandrayaan-2 had been pushed to an orbit 6,000 km than planned by the GSLV Mk III.

This worked to Isro's advantage. The space agency's chairman, K Sivan had noted that the powerful rocket launcher, also dubbed 'Baahubali' for its massive size, had performed beyond expectations, thus saving fuel and time.

To achieve Friday's second orbit-raising, the onboard propulsion system was fired for a duration of 883 seconds. “All spacecraft parameters are normal. The third orbit raising manoeuvre is scheduled on July 29, 2019, between 2.30 pm and 3.30 pm,” an Isro statement said.

Despite a 'technical snag' that aborted the first planned launch in the last-hour, Isro had quickly corrected the faults and launched the Mission at 2.43 pm on July 22. The launch window was a narrow one-minute, but the rocket launcher had taken off with the 3,850 kg spacecraft seamlessly.

Once the Mission completes its Earth-bound phase, a Trans Lunar Insertion has been scheduled for August 14. Following a week-long trajectory, Chandrayaan-2 is expected to enter the Moon's orbit on August 20. A Lunar Bound Phase will follow before a soft-landing on September 7.

Unlike GSLV Mk III that was beyond Isro's control after launch, the spacecraft itself is monitored and controlled 24/7 by an Isro team. Every orbit height is simulated and recalculated on an hourly basis, according to Isro officials.