By Kazuki Fujisawa / Yomiuri Shimbun Staff WriterIn 1969, mankind landed on the moon for the first time. The U.S. Apollo 11 lunar landing and manned exploration were broadcast across Earth and the world was moved by the “one small step” Neil Armstrong made on the moon’s surface. Since then, almost half a century has passed. In countries all over the globe, including Japan, the dream of unmanned and manned lunar exploration has been rekindled.
During the Cold War following World War II, the United States and the Soviet Union competed with each other in lunar exploration. The Soviet Union, which had succeeded in launching the world’s first artificial satellite in 1957, reached the moon with the Luna 2 in 1959 and landed the Luna 9 on the moon in 1966.
The U.S. made a comeback under the Apollo program (see below). The Apollo 11 mission sent astronauts to the moon for the first time in 1969, and during the Apollo 15 mission in 1971, astronauts conducted a geological survey using a lunar rover for the first time. However, due to manned lunar exploration being seen as too costly, the program ended with a final launch in 1972. Although the Soviet Union subsequently sent unmanned probes to the moon, they too abandoned full-scale lunar exploration by 1976.
Yasunori Matogawa, 74, an expert in space engineering at the Japan Aerospace Exploration Agency and a professor emeritus, said although lunar exploration carried out through the ’70s “stirred mankind’s frontier spirit and spurred the development of technologies required for space development, it was rooted in U.S.-Soviet political aspirations, and it was inadequate as a scientific investigation that aims to solve the moon’s mysteries or make use of the moon.”
Although the enthusiasm of the Apollo program faded and passed, an experiment by the Clementine spacecraft launched in 1994 — which was the first such launch by the U.S. in roughly 20 years — found evidence that suggested the presence of water on the moon, igniting renewed interest in exploration.
In the 21st century, the moon — being the closest celestial body from Earth — has become an exploration target for countries with emerging space programs. In 2007, Japan launched SELENE, nicknamed Kaguya (see below), which took detailed images of the moon during its roughly 18-month-long mission.
In 2008, India launched the Chandrayaan-1 lunar probe, and in 2013, China successfully landed the Chang’e 3 lunar explorer on the moon’s surface and used the Yutu lunar rover to analyze the moon’s geology and soil.
Dormant future energy
A result of this exploration was that the moon was found to contain water, helium-3 — which is believed to be a potential future source of energy — and mineral resources.
“Spacecraft and rover technologies have advanced, and enthusiasm and attitudes toward lunar exploration in various countries have improved,” said Junya Terazono, 49, an associate professor from the University of Aizu who is an expert in planetary science.
In 2013, 12 space agencies from around the world including those from Japan, the U.S., and India put together a space exploration timetable with the manned exploration of Mars as its final objective. Within the plan to expand space development from the International Space Station (ISS) to Mars was the goal of reviving manned missions around the moon by the 2020s.
SELENE discovered three vertical holes on the moon’s surface with diameters and depths of around 50 to 100 meters. Believed to have less drastic temperature fluctuations and less exposure to cosmic radiation and meteorite collisions, the bottoms of these lunar holes have emerged as promising candidates for the sites of lunar bases.
The absence of an atmosphere on the moon allows for more efficient solar power generation than on Earth and also makes it an ideal site for astronomical observations. Japan is planning to launch the SLIM (Smart Lander for Investigating Moon) lunar probe in 2020 to investigate the area near these holes.
Private-sector space development is thriving in Europe and the United States. In 2007, a U.S. foundation started a prize competition involving a race in which teams compete to become the world’s first private-sector lunar explorer. In Japan, the private-sector team Hakuto (white rabbit) was formed by companies that include a major telecommunications company and an airline company. They plan on launching a rover this year.
“I want to make Japan’s first lunar rover mission successful through private-sector power,” said team leader Takeshi Hakamada, 37.
Formed from planetary collision?
There are several theories on the moon’s origins. The most prominent of these is the giant impact theory, which posits that 4.6 billion years ago, a Mars-sized planet collided with a newly formed Earth, and the resulting debris gathered to form the moon. In addition to this, there are several other theories, such as the fission theory in which the primeval Earth broke apart, or the capture theory in which the moon was formed elsewhere and captured by the Earth’s gravity. The surface of the moon is covered with a sandy material known as regolith and countless craters.
■ SELENE (Kaguya)
The Selenological and Engineering Explorer was Japan’s first large lunar probe. It consisted of a primary satellite named Kaguya that orbited the moon at an altitude of roughly 100 kilometers and two sub-satellites (Okina and Ouna). Equipped with high-definition cameras, it captured the moon’s topography in vivid detail. Said to be the most comprehensive lunar mission since the Apollo program, its objective was to shed light on the moon’s origins and evolution. In June 2009, operations ended and it was sent crashing into the moon. Its name derives from Kaguyahime (Princess Kaguya), who appears in the Japanese folk tale “Taketori Monogatari” (The Tale of the Bamboo-Cutter) and comes from the moon.
■ Apollo program
A manned lunar exploration program started in 1961 and carried out by the National Aeronautics and Space Administration (NASA). The Apollo 8 mission was the first to bring astronauts into orbit around the moon. By the end of the final Apollo 17 mission in 1972, the program had used a total of six spacecraft to land 12 astronauts on the moon’s surface and bring a total of 382 kilograms of moon rocks back to Earth. Although Apollo 13 had to abandon its lunar landing when an oxygen tank exploded en route to the moon, the astronauts were miraculously able to make it back to Earth safely. The total cost of the program amounted to $25 billion (roughly ¥9 trillion at exchange rates of the time).Speech