On December 14, 1972, a capsule carrying the Apollo 17 astronauts Eugene Cernan and Harrison Schmitt rose from the lunar surface.
It was the day humans left the moon.
For a long time, they did not return, but that is changing. China, India and even smaller nations such as Israel and South Korea are performing robotic missions to the moon. Their lunar ambitions are being driven both by the desire to flex their technological muscles and by the rise of global nationalism.
"All countries are going to say:" Look at the things we can do in space, "says Emily Lakdawalla, with the Planetary Society, which promotes space exploration.
The Apollo missions were the cornerstone of a decade dedicated to running towards the moon. The United States had spent enormous sums to defeat the Soviet Union, whose lunar program with crew never managed to take off. But once the Americans had won, both sides lost interest.
"There was a dry patch," says Lakdawalla. America focused on missions in the deepest space, including the Viking landing modules on Mars and the Voyager probes to the outer solar system. Meanwhile, the Soviet Union concluded its Luna series of robotic missions to the moon and then plotted a course towards Venus. Human space flight remained close to home, with the USA UU Following its program of space shuttles and the Russians building a series of space stations that orbit the Earth.
Back to the moon
In the early 2000s, however, the moon was receiving a new flock of visitors. In 2003, the European Space Agency launched a small spacecraft known as SMART-1. He was followed by missions from Japan, China and India. NASA also launched missions, including the Lunar Reconnaissance Orbiter, which mapped the moon in great detail.
And then, in 2013, the China National Space Administration launched Chang & e-3. It was the first probe that really landed on the Moon in almost 40 years.
From the beginning, the Chinese have tried to explore space differently than did EE. UU During Apollo, according to Joan Johnson-Freese, professor of national security affairs at the Naval War College who has studied China's space program.
"They saw that we had an attitude of landing on the moon and, sadly, looking around and saying:" I was there, I did that, I got the belt buckle ", says Johnson-Freese. "So they decided that they were going to develop their lunar program in a very different way."
The long march of China
The Chinese have a step-by-step approach. Each step is ambitious, but not too expensive and not too difficult.
"The funding and labor investment of China's space exploration has been rational, restrained and scientific," Wu Weiren, the chief designer of China's lunar exploration program, said earlier this year on state television. The occasion was the landing of the last probe of China: Chang & # 39; e-4. It touched the other side of the moon on January 3, the first time a nation has landed there.
Bob Wimmer, a scientist at the University of Kiel in Germany, built a radiation detector for Chang & e-4. He says that the speed at which the Chinese work is amazing.
"European missions are extremely slow, Americans are twice as fast and Chinese are two to five times faster than Americans," he says. "It's incredibly intense."
From the moment he obtained funding until the moment his experiment was launched, barely a year had passed, which is nothing for a space mission. Wimmer describes him as "absolutely crazy," but adds that he would work with the Chinese again.
It remains to be seen if Chinese astronauts will follow in the footsteps of Apollo. Wimmer believes that the radiation detector he has installed at Chang & e-4 can serve only one purpose: "to prepare a human's landing on the moon, so they know what the radiation environment is."
Johnson-Freese says that the Chinese space program must still commit to sending a human team to the moon. Officially, he says, space missions are organized in two ways: one that sends humans on missions to low Earth orbit, while the other sends robots to probe the moon.
She also believes that the two parts of the Chinese program could join in the future. "His persistence leads me to believe that the next voice transmission we get from the moon may well be in Mandarin," says Johnson-Freese.
India is going to land
China is not the only country that watches the moon. Early next week, India plans to launch Chandrayaan-2, its second mission to the moon and the first to attempt a soft landing. That would come a little more than a decade later. His first mission, an orbiter known as Chandrayaan-1, in 2008.
Chandrayaan-1 helped boost India's space program, according to Sriram Bhiravarasu, a researcher at the Lunar and Planetary Institute in Houston. "The enthusiasm was very high, it just lit a spark in the researchers in India," he says. "I started my PhD just after Chandrayaan-1 was launched."
As the Indian research community gets going, he says, the nation also wants to go to other destinations.
"India plans missions for the exploration of Venus and also for Mars in the coming years," he says.
Johnson-Freese says that, much like during the Cold War, much of this new enthusiasm for space is very much based on earthly politics. India and China are competing for geopolitical points in Asia. They expect their space programs to make them look strong.
"Space has always meant a technological advance," she says. "So, both India and China are very anxious to show others in the region that they are the country, which are the ones who should want to work."
Lakdawalla of the Planetary Society welcomes the competition if that means that more lunar science will be realized. It has been decades since someone has visited the lunar surface. And there is still much to discover by humans, she says. "It's definitely time for scientists to return to the moon."