Chandrayaan 2 enters Moon’s orbit — play-by-play of how it happened

• Chandrayaan 2 successfully inserted itself into the Moon’s orbit today morning.
  
• It reached the Moon’s sphere of influence yesterday but had to slow in order to captured by the Moon’s gravity.
  
• If Chandrayaan 2 had missed calculated its velocity then it wouldn’t be on track to land on the Moon’s South Pole.
  

Chandrayaan 2 hit a new milestone today when it successfully left Earth’s orbit to enter the Moon’s orbit.

The completion of the Lunar Orbit Insertion (LOI) — also dubbed ‘lunar capture’ — puts india a step closer to making India the first country to land on the Moon’s South Pole.

The entire maneuver took approximately 28 minutes to complete and the spacecraft is now starting its orbit around the Moon preparing to get in position to put Vikram, the lander, on the lunar surface on 7 September 2019.

Play by play of how today’s critical maneuver went down:

For Chandrayaan 2 to reach the Moon’s sphere of influence or gravitational field, the spacecraft had to complete six orbits around the Earth.

After orbiting the planet for 28 days, the spacecraft finally reached the point where the Moon’s orbit intersects its path on 19 August 2019 at 3:00pm.

“At that point, Chandrayaan 2 was in the sphere of influence of the moon,” said ISRO Chairman K Sivan during the press conference.

Since it was now affected by the Moon’s gravitational force — the spacecraft is gaining speed.

Left as is, Chandrayaan 2 would keep getting faster and then eventually escape the Earth. To ensure that the spacecraft makes it to the moon — ISRO had to slow it down.

“In order to reduce the velocity of Chandrayaan 2 from 2.4 kmps to 2.1 kmps, the LOI maneuver was carried out today,” explained Sivan.

Now, Chandrayaan 2 is at an obit of 114 kilometers by 18,000 kilometers around the Moon.

Everything that could have gone wrong

Had LOI not been successful, the orbit of Chandrayaan 2 would have been off target.

As a result, Chandrayaan 2 wouldn’t have made it to the Moon’s South Pole and possibly have been lost altogether.

“Out of 10.9 kmps, in case there is a dispersion of 10 cmps difference, that will end with the orbital inclination towards the moon will be off by seven degrees. It will not be able to meet the requirement of meeting the soft landing on the South Pole,” said Sivan.

What’s next?

The next major milestone from Chandrayaan 2 will take place on 2 September 2019 when the lander, Vikram, will separate from the main spacecraft after four more lunar burns.

“Till now, all the operations were carried by the propulsion systems. After that, all the operations will be from the lander,” explained Sivan.

ISRO will also be constantly checking on the operations of Vikram to make sure that everything is functioning properly before attempting the soft landing on 7 September 2019.

See also:
Here’s why it’s going to take 7 weeks for Chandrayaan 2 to reach the Moon

Chandrayaan 2 will give India bragging rights even if it doesn’t find water

India’s second mission to the moon will use these 14 high-tech instruments to look for water