Why so many lunar failures? | The Press

Between 1966 and 1976, no less than 18 American and Soviet missions managed to land on the Moon, with a success rate of 42%. However, since 2019, only 3 of the 11 moon landing missions have been successful. Have we lost the recipe for the Moon?

The best known lunar program is Apollo. This is an American manned program which took astronauts to the Moon six times between 1969 and 1972. All the planned moon landings were successful, except that ofApollo 13which could not take place due to an explosion in an oxygen tank told in the 1995 film of the same name, which starred Tom Hanks.

In early February, the Canadian Space Agency organized a media day with Canadian astronauts who will participate in the American Artemis lunar program. Jeremy Hansen must take off in 2025 with Artemis II, which will circle the Moon. Jenni Gibbons will take Mr. Hansen’s place if the latter cannot participate in the mission.

This was a good opportunity to ask them the question. Why so many lunar failures in recent years? Did the lunar programs of the 1970s have a secret that has been forgotten?

“With Apollo, we didn’t want to take any risks, because it was a human mission. And even for uninhabited probes, we wanted to avoid failures. Today, we have a more commercial approach. We want to do more with less. We are willing to fail in order to learn. It goes faster. This is the approach of SpaceX, for example,” Jeremy Hansen said.

For her part, Jenni Gibbons, who is an engineer, spoke about technological progress. “The power of Apollo’s computers was equivalent to what we have in our pocket with our phone today. Different technologies are used today for lunar missions. So you have to tame them. The complexity is also greater, in particular because we want to land near the South Pole. »

Apollo was expensive. Very expensive. More than 25 billion US dollars, or 3.3% of the US gross national product (GNP) in 1965. In comparison, Artemis will cost a total of 100 billion US dollars, less than 0.5% of US GNP in 2020.

The uninhabited probes of yesteryear weren’t bargains either. Take the American Surveyor lunar program, just before Apollo, in the 1960s. The budget for Surveyor exceeded 4 billion US dollars in today’s dollars (470 million in 1966-1968) for seven probes, while the private lander Odysseuswhich partially succeeded in its moon landing in February, has a budget of 115 million US dollars.

The success rate of uninhabited probes

Surveyor had a respectable success rate, with five successful moon landings in seven attempts (three moon landings with the US Ranger unmanned program had previously failed). However, the Soviet unmanned Luna program experienced a success rate comparable to that of today: only 7 of the 27 moon landings attempted between 1963 and 1976 were successful. In 2023, the landing of Luna 25 also failed.

In total, during the 1960s and 1970s, the United States and the USSR succeeded in 18 of the 43 attempted moon landings.

China has also been exploring the Moon since 2007. It has only had one failure in eight missions, including three moon landings. One reason for its success is that the Chang’e landers draw on the experience of the Soviet Luna program. China has learned lessons from Luna to avoid certain mistakes. The Chinese space budget is five times smaller than that of NASA.

The lunar South Pole is less illuminated, which explains why it still contains icy water. This water makes the South Pole attractive, because we can get fuel and oxygen from it. But that makes landing on the moon more difficult.

The South Pole is rugged, since there are no large equatorial plains where six manned Apollo missions landed between 1969 and 1972. The lander Odysseuswhich landed 300 km from the South Pole, broke one or two legs because of this rugged terrain.

The unusual orbit of Lunar Gateway

Among the innovations that complicate current space missions, there is the unprecedented orbit proposed by the American lunar orbital station Lunar Gatewaywhose construction will begin in 2025. Canada builds for Lunar Gateway a third-generation robotic arm that was used on the Space Shuttle and the International Space Station.

Maintaining the elliptical orbit of Lunar Gateway, which takes advantage of “Lagrange points” where the gravities of the Earth and the Sun counterbalance each other, will require ten times less fuel than with a circular orbit around the Moon. It will also take less energy for a cargo ship or a manned capsule coming from Earth to reach Lunar Gateway. The stability of this orbit has been tested since 2022 by the private nanosatellite CAPSTONE.

Look at the planned orbit of the orbital station Lunar Gateway