Luna-25 crash: It's still tough to land on the moon

The Americans landed people on the moon in 1969 with less computing power than we have in our contemporary phones. So, why can't we land on the moon today? It's one of those irritating cliches that contain an element of truth. It's also a question that deserves an answer, with the United States, India, China, Japan and Israel all racing to get to the moon again. And then Russia, whose Luna-25, launched on a Soyuz rocket, crashed into the moon. 

Our engineering and technology — "rocket science" if you will — has developed in the 50+ years since the Cold War space race, when Neil Armstrong and Buzz Aldrin became the first people to walk on the moon. But we've not seen the same level of improvement across the board.

"Compared to the Apollo era, navigation technology is much more advanced today. Our on-board sensors allow more for precise and autonomous calculation of position and velocity, on-board computers are much faster, and advanced interfaces increase the situational awareness of ground and on-board crews alike," said Markus Landgraf, Senior System Architect and Moon Future Studies Team Lead at ESA's European Space Research and Technology Center in the Netherlands.

Spaceflight is not only about computing power, however. "Rocket engine technology has advanced since the 1960s, mainly in terms of performance due to better materials and understanding of the hydrodynamics and combustion processes. But while computers are many times faster than 50 years ago, the efficiency of rocket engines has increased only by 10 to 20%," said Landgraf.

Moon rockets: We understand the risks better

Our technology has improved as has our understanding of the risks — particularly the risks in the actual rocket science.

"In the 60s and 70s, we simply didn't understand the risks we were taking. Today, we have a better handle on those, but to overcome them, we add complexity to the solution. But complexity makes it easier to miss a mistake and for 'anomalies' to occur," said Malcolm Macdonald, a professor of spacecraft engineering at Strathclyde University, Scotland.

That's why we test rockets before we put people in them. We have learned from disasters such as the fire that broke out in the cabin of NASA's Apollo 1 moon mission in 1967. 

"Modern spacecraft are far more complex [now], which both drives up cost of development and testing, but also the risk of overlooking something," said Macdonald.

Moon landings are still risky: Craters and boulders

But the moon remains a perilous place to land — alone because of all the craters and boulders that make its surface uneven and unpredictable.

A 2020 study put the number of known craters at close to 140,000 ranging from between 1 (0.62 miles) and 8 kilometers in diameter, and others hundreds of kilometers in diameter, often incredibly steep. Then there are the boulders.

"Landing on the moon is still difficult. It requires deep experience in the lunar environment," said Landgraf.

There are better maps available now, but nothing beats being there. Craters and boulders pose in-situ threats that need to be assessed as you attempt a soft landing — that is, surviving, not crashing, like Russia's Luna-25.

Luna-25 aimed to be the first to land at the moon's south pole

The goal of Russia's Luna-25 mission was to land at the Boguslawsky Crater, which is about 95 kilometers (59 miles) in diameter and at the south pole.

The moon's south pole is thought to have deposits of ice water and possibly other resources that would be necessary for any humans to live and work on the moon and return to Earth. So, it's a region worth investigation.

In 2014, researchers conducted a safety study of landing sites at the Boguslawsky Crater. They found slopes of 5-10 degrees and other, more dangerous, slopes of about 45 degrees, and in an area of 4 square kilometers "more than 16,000 boulders between ~0.5 meters up to 13 meters in size."

So, there was fairly detailed information almost 10 years ahead of the mission. And yet the first thing that Yuri Borisov, the head the Russian space agency Roscosmos, said after Luna-25's August 11 launch was that they would have to look for an ideal place to land. Read: there is a lot we do not know about the moon.

Luna-25 joins a Soviet-era legacy of hit and miss

As it came into land, Roscosmos says its Luna-25 spacecraft "moved into an unpredictable orbit and ceased to exist as a result of a collision with the surface of the moon." Which means Luna-25 may have suffered a loss of communication with its Earth control or a mechanical error, combined with a crash.

Of Russia's (including Soviet Russia's) 14 Luna landing missions, seven have landed and seven have failed.

Other Luna and Zond missions were designed to merely orbit or circumnavigate the moon, not land on it.

India's Chandrayaan-3: Another south pole landing attempt

After 50+ years of seeming inaction, we are seeing a series of new moon missions, but also a string of failures.

In 2019, Israel attempted its first moon landing — Beresheet — and failed.

The same year, India's Chandrayaan-2 attempted to reach the moon and land a probe called Vikram at the south pole but failed.

And in April 2023, Japan's Hakuto-R also failed to land, apparently because it ran out of fuel.

"The Hakuto-R and Chandrayaan-2 [failures] both originated — roughly speaking — from improper or incomprehensive testing campaigns, potentially caused by cost reduction measures," Landgraf said.

But no one is giving up: India still wants to be the first to land at the south pole with Chandrayaan-3 which is set to touch down on the Moon's surface later this week.

Closely behind are NASA and its European partners, who have gotten closer with their own Artemis program, recently attempting a test launch of SpaceX's Starship rocket — which failed.