गातुं वित्त्वा गातुमित।
First, know the way, find and pursue it
असफलताः एव सोपानशिलाः सन्ति
Failures are the stepping stones
From 2019 till 2023, 6 lunar missions were attempted of which only 2 remained successful- Chandrayaan 3 and China’s Chang’s 5.
Israel’s Beresheet, Emirates and Japan’s Hakuto-R, India’s Chandrayaan 2, Russias Luna-25 failed to land softly on moon and they crashed onto the lunar surface.
India successfully remained the first country to do a safe and soft landing on the south pole of the moon and 4th nation to land on the moon after US, China and the soviet union.
Chandrayaan 3 mission with a vision got ignited with Chandrayaan 1, a little disturbed with Chandrayaan 2 but persistence, perseverance brought triumph in Chandrayaan 3 . Launched on July 14 with a budget of Rs 615 crore LVM-3 ( LIGHT vehicle mark-3) had successfully put spacecraft containing propulsion module and lunar module weighing 3900 kgs approximately into the space from Satish Dhawan space centre at Sriharikota.
The spacecraft entered into Phase 1 in which multiple orbit-raising maneuvers were performed around the Earth from July 15 to July 31. On August 1 the spacecraft was introduced into translunar orbit ( 288 km x 369328 km) and this phase is called translunar injection phase which was completed by August 5. From August 6 to 16 phase 3 and 4 was completed in which the spacecraft was inserted into lunar orbit and moon-centric, moon-bound maneuvers were performed to decrease the orbit from 164km x 18074 km to 163 km x 153 km. On August 17, the landing module got separated from the propulsion module with a message from the landing module: ” Thanks for the ride mate”. From August 18-20, successful deboosting operations were performed and the orbit was reduced to 25 km x 134 km. With everything set on the final 4 phases of descent – rough braking, altitude holding, fine braking and terminal descent phase the velocity both horizontal and vertical were reduced gradually and oriented for soft landing successfully on August 2023 at 18:04 hours as scheduled.
Lessons learnt from the past:
1. Testing, Testing and Testing: This is the major preparation done before Chandrayaan 3. It is Failure based design
2. Stronger and height-adjustable legs to withstand greater velocities ( landing velocity enhanced from 2 mts/sec to 3 mts/sec) and discrepancy in surface
3 . More fuel added to Vikram’s lander to come back if necessary
4. Laser Doppler velocity metre a new sensor to look into the lunar terrain while landing. It is used by police as a Radar speed gun and similar technology is used to know the exact speed of the lander in Chandrayaan 3.
5. The Chandrayaan 2 lander has 5 engines but Chandrayaan 3 lander has 4 engines- the centre engine was removed and even landing was made possible with 2 engines. Chandrayaan 2 mission lander had crash landed during descent as it was unable to control the speed. This is been corrected in the Chandrayaan 3 lander by controlling the last 15 minutes of descent using computer logic which is already fed into the lander’s computers, guidance algorithms and navigation systems. By using artificial intelligence, autonomous hazard detection, avoidance system was developed which can prevent crash landing
6. Extended solar panels were used to lander to generate more power even if not oriented properly towards the sun
7. Special antennas for tracking, telemetry and command redundancy were used
8. The landing area in Chandrayaan 2 was 500×500 mts but now in Chandrayaan 3 area of landing was increased to 4 km x 2.5 km. Also, additional fuel is kept for an additional 150 mts change in location if any untoward difficulty in landing in the precise place
9. Orbitor of Chandrayaan 2 helped the lander of Chandrayaan 3 by sending high-resolution images of the landing area
10. Increased speed of telemetry data transmission from 1 kbps to 4 kbps helped in better communication during descent
Reaching successfully on lunar space half the job is done, but further assignments need to be done like:
1. Vikram lander has 3 payloads
a. RAMBHA-LP: helps to measure near-surface density and changes
b. ChaSTE: To measure thermal properties at poles
c. ILSA: To study about moonquakes
2. Pragyan rover has 2 payloads
a. APXS: Alpha Particle X-Ray Spectrometer: To study mineralogical composition and know about the origin of moon
b. LIBS: To determine the elemental composition of the moons soil
3. If more evidence of frozen water can be found on moon, it may be a source for renewable energy
4. May become a future place for the international space station
5. By fingerprinting on the lunar surface, there is a potential role needs to be played by India in global space policy
6. Having experience in conducting successful lunar missions will increase the confidence of our scientists in upcoming missions to Mars, sun and Gaganyaan
7. Maybe a possible location to protect the planet from asteroids
8. Future launching stations to distant bodies like Mars, Neptune, etc., require less fuel as the gravity of the moon is much lesser than that of Earth
With a prolonged journey of 40 days, covering a distance of 3.8 lakh kms, the journey to the south pole of moon, the hardship of our scientists didn’t go in vain and Prime minister Narendra Modi said “We are witness to the new flight of new India. New history has been written,” and “India’s successful moon mission is not India’s alone…Our approach of one earth, one family one future is resonating across the globe…Moon mission is based on the same human centric approach. So, this success belongs to all of humanity,”
Jai jawan, jai kisan, jai vignan, jai anusandhan….