Chandrayaan 2: Fourth orbit raising manoeuvre in Earth orbit complete, one more to go

The next ‘burn’ or firing of the propulsion system is scheduled on August 6 between 2:30 and 3:30 pm. During the manoevre, the orbit will be raised to 221 x 1,43,585 km.

The Indian Space Research Organisation (ISRO) successfully carried out the fourth of the five planned orbit-raising manoeuvre of Chandryaan-2 in the Earth’s orbit on Friday afternoon. The space agency will be performing one more orbit-raising manoeuvre in the Earth’s orbit before the spacecraft enters into a trans-lunar path and begins its journey towards the moon.

In the course of 23 days, the scientists have to carry out a total of five orbit raising manoeuvres - four to increase the apogee and one to increase the perigee or the point on the elliptical orbit closest to the Earth.(AP)

On Friday, the scientists fired the propulsion system on-board Chandrayaan 2 for 646 seconds at 3:27 pm and raised the orbit to 277 x 89,472 km. The manoeuvre was to increase the apogee or the farthest point from the Earth on the highly elliptical orbit.

“All spacecraft parameters are normal,” said ISRO in a statement.

In the course of 23 days, the scientists have to carry out a total of five orbit raising manoeuvres - four to increase the apogee and one to increase the perigee or the point on the elliptical orbit closest to the Earth.

The next ‘burn’ or firing of the propulsion system is scheduled on August 6 between 2:30 and 3:30 pm. During the manoevre, the orbit will be raised to 221 x 1,43,585 km.

Chandrayaan 2, India’s second mission to moon, was launched on July 22, a week after the first attempt was aborted due to technical snag. Although, ISRO officially did not reveal the cause for the delay - that led to the July 15 launch being cancelled less than an hour before the launch - former ISRO scientists, who knew about the developments, said that the launch had to be postponed due to a helium leak in the propulsion tank.

Once the problem was automatically detected by the launch vehicle system, the scientists detected and fixed the problem within 24 hours, ISRO chairperson K Sivan had said on the day of the launch.

After readjusting the course of the spacecraft to keep the date with the moon on September 7 02:58 am, India’s heaviest launch vehicle, Mark III (GSLV-Mk III), put Chandrayaan 2 into the Earth’s orbit.

The vehicle, however, ‘over-performed’ on the day of the launch giving a boost of 6,000 km to the spacecraft, which helped ISRO in reducing the number of manoeuvres from six to five in the earth orbit, saving fuel.

The spacecraft will stay in the trans-lunar orbit for seven days and then 13 days in the lunar orbit, where four burns will be performed to adjust the orbit for the landing of the lander-rover on the South Pole of the moon.