United States, Soviet Union, China and India. Japan was able to join the list of international superpowers when the Slim lander (Smart Lander for Investigating Moon) finally settled on the gray grains of the moon's surface on Friday afternoon.
That moment marked the end of a 110-day journey from Earth, a long way that requires much less fuel than the faster options often chosen by other lunar missions.
Finished by the author
Georg van Hal is the scientific editor of the Volkskrant newspaper. He writes about astronomy, physics, and space travel. Van Hal published books on everything from the universe to the smallest, most basic elements of reality.
On Christmas Day, the spacecraft reached orbit around the moon for the first time, and last Sunday, Slim performed a successful maneuver to lower the lander to an altitude of 600 kilometers above the surface of the moon. Meanwhile, the lander has already sent images of its destination back to Earth.
On this side
After the longest portion of the mission was successfully completed, the biggest challenge followed: making a soft landing. This means: a landing in which it is possible to slow down enough to land softly and without interruption on the surface of the moon.
To this end, the lander first had to descend to an altitude of 15 kilometers during the day on Friday. In order to land softly, he also had to successfully apply the brakes from a speed of more than 6,000 kilometers per hour to an almost complete stop. Slim did it vertically, but ended up horizontally on the slope of Cheoli Crater on the far side of the Moon. Completely according to plan, by the way. Below the lander are five aluminum legs that can collapse to better absorb the impact of the tilt maneuver.
Slim moved independently during the landing and navigated using images captured by his cameras. Then compare it to images of the landing site taken during the first lunar missions. In all, the landing, which began around 4 p.m., took about twenty minutes. After those 20 minutes had passed, it was not clear for a long time whether Slim was still working or not.
Bad maneuvers
In recent history, one lunar dream after another has turned into a variety of technical flaws and failed maneuvers. For example, in the past five years, missions undertaken by Israel (Beresheet), India (Vikram), Japan itself (Hakuto-R), Russia (Lwina-25), and the United States (Peregrine) have failed. A new attempt by India broke that chain of failures last year, making India the fourth country to land on the moon.
The only country to have achieved a successful series of moon landings in modern history is China. In the years 2009, 2013, 2019, and 2020, the country succeeded in landing on our global neighbor four times in a row. A fifth Chinese attempt is scheduled for later this year.
If the Japanese Slim lander is still operational, it will use instruments to map the formation of Shiuli Crater. The research will include olivine, a mineral that may have been released from beneath the moon's crust during the impact that caused the crater.
In addition, the lander carries two small lunar rovers that move in unique ways: Lev-1, which moves by jumping, and Lev-2, which rolls and looks like a kind of elongated baseball. The latter was developed with the help of Japanese toy manufacturer Takara Tomy, who also released a variation of this design (“Sora-q”).
