The moon has languished in the shadows of space exploration since the heyday of manned missions in the 1960s and 1970s, eclipsed by projects focused on Mars, Jupiter and Saturn, not to mention the U.S. space shuttle and the International Space Station.
But now the tide is turning as the major economies prepare to mount ambitious missions to explore Earth’s nearest neighbor.
On Friday, Japan is scheduled to launch its SELENE (Selenological and Engineering Explorer) lunar exploration orbiter, nicknamed Kaguya, after the princess who returns to the moon in “The Tale of the Bamboo Cutter,” a folktale of the early Heian Period (794-1185).
China is expected to send its Chang’e-1 satellite to the moon by the end of this year. In 2008, India’s Chandrayaan-1 satellite and the United States’ Lunar Reconnaissance Orbiter and LCROSS satellites are scheduled to leave for the moon. Russia plans to launch its LUNA-GLOB satellite in 2012.
For these countries, their unmanned lunar satellites constitute the first step in a process of moon exploration that will lead to collecting samples with unmanned devices, sending manned spacecraft and building a space station.
Why is the moon suddenly a prime target for space exploration?
Kaguya’s main goal is to solve some of the mysteries of the moon left untouched by earlier missions, said Seiichi Sakamoto, a professor at the Japan Aerospace Exploration Agency’s external affairs office for space science. JAXA designs and conducts Japan’s space programs.
From 1969 to 1972, the U.S. Apollo program put six teams of astronauts on the moon to conduct a variety of experiments. In all, these men brought back 387 kg of rock samples, providing valuable information. Among their discoveries was that the moon formed some 4.5 billion years ago and that its face and far side have different geographical features.
But the lunar missions conducted by the U.S. and former Soviet Union in the 1960s and 1970s were a proxy fight in the Cold War era, Sakamoto said.
“Apollo’s principal task was to send humans to the moon, and scientific experiments were the secondary aim,” he said.
“We need to research (the entire moon) in detail” as recent data gathered by satellites — the U.S. Clementine mission in 1994 and Lunar Prospector in 1998-1999, and Europe’s SMART-1 in 2004 to 2006 — revealed how limited in some respects the Apollo findings are, he said.
From an orbit 100 km above the moon’s surface, Kaguya’s 3-ton main orbiter and two 50-kg satellites will gather data on mineral distribution and magnetic fields, among other things. Over the course of a year, 14 instruments will be deployed in 15 missions covering the entire moon.
While other countries plan to conduct similar lunar projects, the ¥32 billion Kaguya project is the most ambitious since the Apollo program in terms of the scale, Sakamoto said.
“We are trying to draw a map (of the moon) . . . with valuable information about what kinds of minerals exist in which areas or possible distributions of ice,” he said. “Understanding the moon’s origin and evolution is linked to understanding the Earth.”
Searching for natural resources on the moon has emerged as a major goal.
China reportedly hopes to discover such natural resources as uranium, potassium and helium-3, a rare element useful for nuclear fusion. Other resources, including ice, may be used to build or operate space stations and moon hotels in the future, some experts say.
But none of this is realistic in the short run, argues Shinya Matsuura, a science journalist specializing in space issues.
Kaguya’s goals and instruments
Kaguya’s goals and instruments
• Gather data on distribution of elements on the lunar surface (X-ray and gamma-ray spectrometers).
• Probe mineral distribution (multiband imager, spectral profiler).
• Study surface and subsurface features to learn about the moon’s evolution and draw map (terrain camera, lunar radar sounder, laser altimeter).
• Study the lunar environment, including magnetic fields and particles (lunar magnetometer, charged-particle spectrometer, plasma energy angle composition experiment, radio science).
• Take images of the magnetosphere and the ionosphere around the Earth, including auroras (upper atmosphere and plasma imager).
• Measure gravity fields on the near and far sides of the moon (relay satellite transponder, VLBI radio source).
• Capture moving and still images of the Earth (high-definition cameras).
“The technology for nuclear fusion has not been established yet. Using helium-3 requires more advanced technology. (The idea) is absurd,” he said, noting that mining and exploiting minerals is not currently within our grasp given the technological and financial obstacles.
But there are other reasons for going to the moon. For China and India, successfully launching their own lunar satellites would demonstrate their competence in space science and boost their national prestige, Matsuura said.
China plans to launch a lunar lander around 2010 and a sampling spacecraft around 2012. Like India, it is considering manned missions to the moon.
Matsuura speculates that China’s aggressive move may have pushed the U.S. to go to the moon again.
According to NASA’s Web site, the U.S. plans to send a manned spacecraft to the moon in 2020 and build a space outpost on one of the poles.
“An international law to regulate excavation and utilization of resources on the moon has not been established. So it’s possible that the first country (that finds resources) can claim them,” Matsuura said.
The Moon Agreement, adopted in 1979 at the U.N. General Assembly, bans any government, private organization or individual from owning resources or property on the moon, but none of the countries sending the lunar satellites has ratified it, although India has signed it.
The 1967 Outer Space Treaty, which has been ratified by major countries, forbids any government from claiming sovereignty over the moon and permits governments to use space development for peaceful purposes only.
In addition, the United States needs moon exploration projects to support its aerospace industry after the International Space Station is completed and the space shuttle is retired in 2010, Matsuura said.
Russia, another leading country in the space development field, has been goaded by the U.S. move and accelerated its moon mission project, according to Kazuto Suzuki, an associate professor at the University of Tsukuba in Ibaraki Prefecture and a space development policy expert.
As the race to explore the moon heats up, the Kaguya project is an opportunity for Japan to publicize its space technology, Suzuki said.
“It would be difficult for Japan to launch a manned spaceship to the moon” due to budget limitations, Suzuki said. “But (a successful launch) could deliver a message (to the rest of the world) that Japan can be a competitor” in space development.