What will Chandrayaan-2 do on Moon for the next one year?

Sriharikota: Overcoming the initial setback to the launch scheduled for July 15, India’s heavy-lift rocket-Geosynchronous Satellite Launch Vehicle-Mark III (GSLV-Mk III) has successfully launched the Chandrayaan-2 spacecraft to the designated orbit from India’s Space Port at Sriharikota in SPSR Nellore District, Andhra Pradesh, India on Monday afternoon.

As scheduled, the rocket took off with textbook precision exactly at 2.43 pm from the second launch pad at Satish Dhawan Space Centre, Shar, Sriharikota. The Rs.375 crore GSLV-Mk III rocket began ascending towards the breaking free from the second launch pad here at Shar.

The 43.4-metre tall rocket weighing about 640 ton lifted off towards the blue skies with thick orange flame at its rear.

The rocket is nicknamed as 'Bahubali’ as like the hero in the all-time hit movie lifts a heavy Lingam, the rocket carried the 3.8-tonne Chandrayaan-2 spacecraft.

Just over 16 minutes into its flight, the rocket had injected Rs. 603 crore Chandrayaan-2 into an Earth parking 170x40,400 km orbit.

From this slot, it is going to be a 48-day long voyage for Chandrayaan-2 as the distance between the earth and the moon is 3.844 lakh km.

The ISRO engineers will raise the spacecraft by a series of manoeuvres to move it into Lunar Transfer Trajectory.

The Chandrayaan-2 consists of three segments - the Orbiter (weighing 2,379 kg, eight payloads), the lander-Vikram (1,471 kg, four payloads) and rover Pragyan (27 kg, two payloads).

The Indian space agency has named Lander Vikram in memory of country's space pioneer Vikram Sarabhai and rover Pragyan means wisdom in Sanskrit.

According to ISRO, on the day of landing, the Lander Vikram will detach from the Orbiter and then perform a series of complex manoeuvres comprising rough braking and fine braking.

Imaging of the landing site region prior to landing will be carried out for finding safe and hazard-free zones.

The Vikram is expected to finally land near the South Pole of the Moon on September 7, 2019, and carry out three scientific experiments.

ISRO scientists said that the lander will get separated from the Orbiter four days after the former enters the lunar orbit.

Vikram will soft-land from a height of 100 km from the Moon's surface. Subsequently, the six-wheeled rover Pragyan will roll out and carry out two experiments on the lunar surface for a period of one lunar day which is equal to 14 Earth days.

The Orbiter with eight scientific experiments will continue its mission for a duration of one year. It will be orbiting in 100x100 km lunar orbit.

The mission also has one passive experiment from the US space agency NASA.

ISRO officials said that the mission will also try to unravel the origins of the Moon.

To showcase India’s advancement in Space Research, the Lander, as well as the rover, have the Indian national flag painted on them. Ashoka Chakra is imprinted on the rover's wheels.

Incidentally, the success of the Chandrayaan-2 mission will make India the fourth country in the world to land and ride on the Moon surface after the US, Russia and China.

India launched its first Moon mission Chandrayaan-1 in October 2008 using its light rocket Polar Satellite Launch Vehicle (PSLV).

The GSLV-Mk III, with a capacity to carry a four-ton satellite, is a three-stage/engine rocket with two strap-on motors powered by solid fuel. The second stage is a core liquid fuel booster and the third is the cryogenic engine.

 It mentioned here that leakage of helium gas in cryogenic stage one hour before the launch had forced ISRO to abandon the launch scheduled for July 15. 

Till date, ISRO has sent up three GSLV-Mk III rockets. The first one was on December 18, 2014, carrying Crew Module Atmospheric Reentry Experiment (3.7 ton). The mission was also to test the rocket’s inflight structural stability.

The second and third GSLV-Mk III’s went up on June 5, 2017, and November 14, 2018, carrying communication satellites GSAT-19 (3.1 ton) and GSAT-29 (3.4 ton) respectively.

Interestingly, GSLV-Mk III will be used for India’s manned space mission slated in 2022.

India presently has two fully operational rockets -- the Polar Satellite Launch Vehicle (PSLV) and GSLV-Mk II -- with a lift-off mass of 415 ton and a carrying capacity of 2.5 tonnes.

Here is how the mission will unfold:

Mission sequence:

Earthbound phase                  Liftoff 22 July. Day 1 to Day 23 (23 days)

Trans Lunar Injection              Day 23

Lunar Transfer Trajectory       Day 23 to Day 30

Lunar Orbit Insertion              Day 30

Lunar Bound Phase               Day 30 to Day 42 (13 days)

Lander Orbiter Separation     Day 43

Deboosting                             Day 44

Powered Descent Starts        Day 48

Vikram Landing                      Day 48

Vikram Landing Site: High plain between two craters, Manzinus C and Simpetius N, at a latitude of about 70.9 degrees south, 22.7 degrees east. Alternate site: 67.7 degrees South 18.4 degree west