Why is it so hard to land on the moon?

The space is difficult. It was the takeaway of September 7, when the Indian Space Research Organization (ISRO) lost contact with his Vikram Lunar Lander during an attempt to land at the south pole of the moon.

India was on the verge of becoming the fourth nation to successfully touch the lunar regolith, in a place that no other country had yet reached before. Although the space agency is still struggling to restore communication with Vikram – who has been seen lunar orbit – The unfortunate landing sequence seemed to be a painful echo of the situation earlier this year, when a private Israeli robotic lander, Beresheet, it's crushed in our natural satellite.

This is a reminder that despite the fact that humans have landed on the moon several times during the Apollo missions half a century ago, this remains a daunting task. Space journalist, more than a third of the 30 soft landing attempts made by agencies and space companies around the world have failed Lisa Grossman tweeted.

But why is it so hard to land on the moon?

Related: 5 strange and cool things we recently learned about the moon

Alicia Dwyer Cianciolo, an aerospace engineer at NASA's Langley Research Center in Cosby, Missouri, told Live Science that no single event was responsible for the many unsuccessful attempts. To land on the moon, "so much must happen in exactly the right order," she said. "If one of them does not do it, it's at that point that the problem starts."

First, you have to go to lunar orbit, which is not an easy task. The Saturn V Apollo vehicle contains enough propellant to propel astronauts to the moon in just three days. But in order to save on fuel costs, ISRO's recent Chandrayaan-2 mission, who wore Vikram, took a much more circuitous path and took more than a month to reach the moon.

Once in orbit, the spacecraft remains in contact with the Earth with the help of NASA Deep space network, which consists of three installations distributed in different parts of the globe and filled with parables that are always tuned, which keep in touch with remote robotic probes in space. Vikram's problems may be due to a communications failure, as the agency lost contact with the LG while it was just 2 km above the lunar surface.

There is little room for error when a probe screams towards its landing point at a speed similar to that of a missile. A faulty data transmission instrument that led to a complete shutdown of the engine seems to be what was done in the Israeli Beresheet lander on April 11th according to the Times of Israel.

On Earth, engineers can rely on GPS to guide autonomous vehicles, but there is no matching system on other celestial bodies, said Dwyer Cianciolo. "When you travel fast and you have to slow down in the void where you have very little information, it is difficult, no matter who you are and what you are trying to do," she said. added.

NASA is currently working with commercial enterprises this plan to deliver robots to the moon in the coming years. Future lunar navigators will have to trust their sensors, said Dwyer Cianciolo.

That's why the agency designs instruments that can sit on a vehicle chassis to scan for terrain, craters and other hazards, and make course corrections, which could be used on private spacecraft and for future NASA missions, "she added. This technology will be tested during the NASA descent sequence rover March 2020 to come, which will be launched next year and is expected to land on the red planet in February 2021.

Almost all failed lunar missions have been discovered, perhaps suggesting that it is helpful to have someone at the helm if there is a problem. At the time of Apollo, human eyes and reflexes contributed to successful landings. After spotting a rocky terrain at its intended landing point, Neil Armstrong took control of the Apollo 11 downhill vehicle and flew in search of a safer point of contact.

But with their experience as experimental test pilots, astronauts of this era should be able to exercise some control, said Dwyer Cianciolo. "We are accepting more autonomy nowadays," she added, noting that engineers would like future human explorers to rely on such systems to help them travel safely to and from the surface of the moon.

From China Chang probe & # 39; e-4, who landed on the moonlit face and deployed the Yutu-2 rover during the summer, reassures those who are worried about the difficulty of reaching the moon. Indian engineers can be reassured by the fact that their Chandrayaan-2 orbiter is still running and doing science, and that their next attempt may be more successful.

"My heart was dedicated to them because you know how much work and time was needed," said Dwyer Cianciolo. "But we are in a business where perseverance is paying off, so I hope."

Originally published on Science live.