The Momma Clan

After cruising in space for nearly fifteen days, Chandrayaan-3 has finally left the earth’s trajectory and moved ahead on its way toward the moon on 1 st of August 1 a.m. The scientists at ISRO fired up the engines between 12:30 a.m. and 1:00 a.m. Tuesday night to put the spacecraft on the road to the moon. The spacecraft went through this critical translunar Injection in a move that lasted for about 30 minutes firing the engines of the propulsion module of the spacecraft to life, to increase its velocity further and setting it on the trajectory that will intercept the moon marking the beginning of its Lunar journey. In between the launch and the start of its lunar journey, five earth-bound maneuvers were done out of which four were performed to increase the altitude at the farthest point from the earth(apogee) and one was carried to increase the altitude from the nearest point(perigee) of the Earth.

A brief recap of the journey of Chandrayaan-3 so far:
Just after four years of Chandrayaan-2, Chandrayaan-3 was launched perched on the GSLV-MK III heavy-lift rocket, from the Satish Dhawan Space Centre, Sriharikota on the 14th of July, placing it in an elliptical orbit of 36500km by 170 km.

The spacecraft consisting of Lander Vikram and Rover Pragyan, designed to land on the lunar surface, collect important technical data, and conduct a series of scientific experiments will detach from Vikram and Pragyan at about 100 km from the moon from where the lander is expected to land near the south polar region of the moon on August 23 rd.

After its successful launch, Chandrayaan crossed several crucial milestones including earth-bound maneuvers before paving its way towards the moon. The first orbit-raising maneuver to increase its apogee from the Earth was successfully performed on the 15th of July at ISTRAC/ISRO, Bengaluru putting the spacecraft in the 41762 km by 173 km orbit.

Then on the 17th of July, the second orbit-raising maneuver was performed. An apogee firing or apogee maneuver was performed to place the spacecraft in a raised orbit at the apogee of the previous orbit. The spacecraft had then achieved the 41603 km by 226 km orbit followed by the third orbit raising maneuver (Earthbound perigee firing) i.e. when the spacecraft was at its closest point in the elliptical orbit around the earth on the 18th of July.

Then the fourth orbit-raising maneuver (Earthbound perigee firing) was completed on 20th July putting the spacecraft in the 71351 km by 233 km orbit and then the last orbit-raising maneuver (perigee firing) was performed on 25th July to put the spacecraft in the 127609 km by 236 km orbit. And then came the milestone that has been achieved on Tuesday night at 1:00 a.m. when the spacecraft was flying at perigee, as ISRO completed the translunar Injection successfully to slingshot Chandrayaan-3 towards the moon and with it begins its five-day journey towards the lunar orbit.

After the successful perigee firing, the 2145 kg. propulsion module carrying Vikram and Pragyan has bid goodbye to Earth forever and will travel in a straight path to reach the lunar orbit on 5 th of August after which a set of four-orbit maneuvers to bring down Chandrayaan to desired 100 km. orbit from the moon’s surface will be performed. And if everything goes well the propulsion module will separate from the
lander module on August 17 th and then deboost maneuvers will take place before the power descent phase for soft landing. And finally, India will create history by landing on the south pole when the lander touches down the lunar surface on August 23 rd 5:47 p.m.
Till then let’s keep our fingers crossed and keep praying for the success of Mission Chandrayaan.

Jai Hind

Amen