Chandrayaan 3: Takeaways for ISRO from Luna-25 crash-landing on Moon

Chandrayaan-3 will attempt its first lunar landing in under 100 hours, aiming for the moon's south polar region. ISRO's ambitious mission plans to achieve a soft landing on August 23. The Indian spacecraft has approached the Moon and is on track for a soft landing on the lunar surface by August 23, Wednesday. ISRO reported a successful reduction in the orbit of Chandrayaan-3's Lander Module on Sunday. The lander module of Chandrayaan-3, launched on July 14th, effectively detached from the Propulsion Module 35 days after the mission began.

Chandrayaan-3's mission goals include showcasing a secure and gentle lunar landing, demonstrating rover movement on the moon, and carrying out scientific experiments on-site. 

On Monday, ISRO unveiled pictures of the Lunar far side region, which were captured by the Lander Hazard Detection and Avoidance Camera (LHDAC). Images taken on Saturday revealed craters like Hayn, Boss L, Mare Humboldtianum, and Bel'kovich. The far side of the Moon refers to the part that's always turned away from Earth because of the Moon's synchronous rotation in its orbit.

The Lander Hazard Detection and Avoidance Camera (LHDAC), created by the Ahmedabad-based Space Applications Centre (SAC), a key research and development facility of ISRO, aids in identifying a secure landing spot devoid of boulders or deep trenches during the descent phase.

Here the term "synchronous rotation" refers to a phenomenon where an object, like the Moon, rotates on its axis at a rate that matches its orbital period around another object, in this case, the Earth. This means that the Moon takes almost the same amount of time to complete one full rotation on its axis as it does to orbit around the Earth. As a result, the same side of the Moon always faces the Earth, while the other side, known as the far side, remains hidden from our view. This is why we only see one side of the Moon from Earth.

Real fruit post Chandrayaan-3's Secure Landing: Space Physics Lab Director

Awaiting the planned gentle landing of Chandrayaan-3 on the moon's south pole, K Rajeev, the Director of the Space Physics Laboratory and a participant in the Chandrayaan-3 mission, highlighted the significance of the upcoming stages. Emphasizing the importance of the remaining phase, he stated, "The upcoming period is extremely crucial, as we will be entering a phase of power descent, navigation, and gradual descent to the surface."

On Sunday, ISRO announced the successful orbital adjustment of the Chandrayaan-3 mission's lander module. This development suggests that the Indian spacecraft is now scheduled to make contact with the lunar surface at 6.04 pm on August 23rd.

The most significant hurdle in a lunar landing

Space strategist PK Ghosh mentioned that transitioning an Indian spacecraft from a horizontal orientation to a vertical one presents a significant hurdle during lunar surface landings.

ISRO has provided information that India's spacecraft is just one step away from successfully landing on the Moon.

In the early hours of Sunday, August 20, India's third lunar mission, Chandrayaan-3, carried out its second deboosting manoeuvre. The ISRO tweeted that this operation effectively lowered the spacecraft's orbit to 25 km x 134 km. 

Additionally, the Indian space agency provided information about the live stream of the moon landing and locations within the country where it can be observed.

Russia's Luna-25 probe, marking the country's initial Moon mission in nearly half a century, experienced an unspecified incident during pre-landing manoeuvres and subsequently crashed onto the lunar surface, as confirmed by the Russian space agency Roscosmos on Sunday.

Chandrayaan 3: Learning from Luna 25

Monitor weather conditions closely: ISRO should carefully monitor weather conditions at the landing site of Chandrayaan 3 and make adjustments to the landing plan as needed. This includes monitoring the wind speed, temperature, and dust levels.

Consider all aspects of the landing plan: ISRO should carefully consider all aspects of the Chandrayaan 3 landing plan to minimize the risk of failure. This includes the trajectory of the spacecraft, the timing of the landing, and the use of retrorockets.

Be prepared for unforeseen events: Even with the best planning, there is always the possibility of unforeseen events that can lead to a crash. ISRO should be prepared for any eventuality and have contingency plans in place.

Be patient and persistent: Landing on the moon is a challenging task, and there is always the possibility of failure. ISRO should be patient and persistent in its efforts to land Chandrayaan 3.

Timeline of India's third moon mission

July 6: The moon mission's launch date of July 14 from Sriharikota, Andhra Pradesh, was announced by ISRO.

July 7: Successful completion of all vehicle electrical tests.

July 11: A 24-hour 'launch rehearsal' was conducted with success.

July 14: Chandrayaan-3 was launched into the intended orbit by ISRO's LVM3 M4.

July 15: In Bengaluru, the moon mission's first orbit-raising manoeuvre was successful, placing the spacecraft in a 41762 km x 173 km orbit.

July 17: Chandrayaan-3 was elevated to a 41603 km x 226 km orbit through the second orbit-raising manoeuvre.

July 22: The fourth orbit-raising manoeuvre and Earth-bound perigee firing were carried out successfully, resulting in Chandrayaan-3 reaching a 71351 km x 233 km orbit.

July 25: Successful execution of another orbit-raising manoeuvre.

August 1: Chandrayaan-3 enters the translunar orbit with a 288 km x 369328 km orbit.

August 5: Transition to the lunar orbit is completed with measurements of 164 km x 18074 km.

August 6: The orbit around the lunar surface is adjusted to 170 km x 4,313 km.

August 9: Further manoeuvre brings the spacecraft's orbit down to 174 km x 1437 km.

August 14: The moon mission embarks on the orbit circularization phase, achieving an orbit of 151 km x 179 km.

August 16: Chandrayaan-3 successfully enters the 153.163 km orbit after firing.

August 17: Separation of the landing module, encompassing the Vikram Lander and Pragyan rover, from its propulsion system.

August 18: Completion of the 'deboosting' operation, resulting in the spacecraft's orbit being adjusted to 113 km x 157 km.

August 20: Execution of Chandrayaan-3's second and final deboosting manoeuvre, resulting in the lander module's orbit being reduced to 25 km x 134 km.

August 23: Assuming all proceeds as planned, the Vikram Lander is anticipated to make contact with the lunar surface between 5:30 pm and 6:30 pm