Patience required when India is one small step away from its first moon landing
by Wang Yanan
The moon lander of India's Chandrayaan-2 plan was just 2.1 kilometers away from the lunar surface when it lost communication. Compared with the 380,000 kilometers between the Earth and the moon, this distance was so close that it was virtually one step away.
Therefore, the failure of the Indian lunar exploration mission appears pitiful. With just one more step, India could have been the first country to make a soft touchdown on the south pole of the moon, and the fourth country to land on the moon after the US, Russia and China.
Chandrayaan-2 consisted of a lunar orbiter, a lander and a lunar rover. The orbiter was the communication relay connecting the lander with its ground control center in India.
In contrast, China's Chang'e-4, which successfully made a soft landing on the far side of the moon, adopted a more simplified 2-part structure consisting of a lander and a rover. Its communication relay satellite Queqiao was sent into space earlier by another rocket.
Chandrayaan-2 was designed to be a one-time mission. When entering space, it adjusted its orbit frequently before finally entering lunar orbit. Prior to landing on the moon, the lander should have separated from the orbiter and then begun its descent. The separating-descending process added complexity to the mission, which required a large amount of computing and prior trials.
Considering the Russian technologies utilized in both the lander and the rover, the implementation of that research became more challenging. After Chandrayaan-2 failed to land on the moon, the news came that it had deviated from its trajectory during the final stage of descent, with a 1-kilometer deviance from its intended landing site. This indicates a probable control problem derived from the mission's structure.
As a major developing country, India has been making enormous progress in space technology.
The last decade has seen the country make many accomplishments, particularly advances in rocket science, as well as with measurement and control technology. India became the fourth entity in the world to successfully conduct a Mars exploration when the Mars Orbiter Mission Mangalyaan entered Martian orbit.
However, in comparison with India's ambition, its space industry still has a long way to go in terms of rocket dynamic forces, automatic control, telecommunications, and materials technologies.
India's lunar mission appears to have been a little premature. The 2008 lunar probe Chandrayaan-1 didn't complete its task perfectly, which meant that there were certain technological deficiencies. After that launch, India didn't carry out similar projects. However, Chandrayaan-2 directly upgraded the task to "orbiting plus landing," obviously imposing a heavy burden on the research team and also increasing the mission's risks.
Chandrayaan-2 was not a complete failure and the orbiter can still perform parts of its probing task until its one-year service life ends.
Originally, India had planned to launch Chandrayaan-3 in 2024 and make another attempt at a lunar soft landing. With the clear implications of Chandrayaan-2, perhaps India will make corresponding adjustments.
If India can work at a steadier pace, it likely will be able to make more significant achievements in space technology.
The author is the editor-in-chief at Aerospace Knowledge magazine of the Chinese Society of Aeronautics and Astronautics.
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