Asteroid Explorer Hayabusa2, launched by the Japan Space Exploration Agency from its Tanegashima Space Center in Kagoshima Prefecture on Dec. 5, is flying without a hitch so far. The spacecraft is a successor to Hayabusa, which was launched in 2003 and arrived back on Earth in 2010 after collecting surface samples from Asteroid Itokawa in 2005.
While Hayabusa’s achievement has been laudable and Hayabusa2 is an upgraded and improved version, Japan should not feel complacent. It must move to the next phase in space exploration, since the nation’s overall space exploration capabilities thus far leave much to be desired.
The target of Hayabusa2 is 1999 JU3, a tiny asteroid with a diameter of some 900 meters, circling the sun with its path between the orbits of Earth and Mars.
The explorer is scheduled to reach the asteroid in the summer of 2018, then return to Earth in 2020 after covering a total distance of 5.2 billion km. To approach the asteroid, the spacecraft will use the “swing-by” method in which the gravitational pull of Earth is used for acceleration — a factor that will accounts for its long voyage.
The asteroid is believed to contain organic matter and water — essential ingredients for the existence of life. It is hoped that samples taken from it will indicate how the solar system originated some 4.6 billion years ago. Hayabusa2 will try to create a crater on the asteroid’s surface by firing a copper missile at the surface, then take samples. It is scheduled to drop the samples taken from the asteroid in an Australian desert in December 2020, then continue to explore the solar system with the help of an energy-saving ion engine, which creates thrust through an ion acceleration process.
Even if the Hayabusa2 mission is successful, Japan should seek higher goals — acquiring the capabilities needed to expand the horizon of its space exploration.
To ensure accurate control of a spacecraft’s orbit, Japan will need to have a communication station in the Southern Hemisphere. Currently it only has one such facility at home and must rely on the communication network of NASA (National Aeronautics and Space Administration) of the United States.
Japan has established technologies to send a spacecraft to an asteroid, Mars and Venus. Japan also has acquired technologies to make a spacecraft circle the moon. But it has not yet sent up a spacecraft that can orbit a celestial body with greater gravitational pull than the moon — such as Mars and Venus. Developing spacecraft that can land on the moon and Mars should become near-term goals for Japan.
Before Japan establishes the technologies to achieve these goals, it should consider what kinds of samples it should collect from these heavenly bodies. Such samples could include moon rocks that are younger than those collected by U.S. spacecraft. The samples might prove whether life exists on Mars, or did so in the past.
One big problem is the direction of the Abe administration’s basic plan for space development. It is inclined too much toward the use of space technologies for security purposes and development of the space industry. But the budget picture for space exploration itself is limited. If more funds are diverted toward launching and maintaining spy satellites, the foundation for basic space science research will weaken, and it will be difficult to rebuild this foundation once it is neglected. Government officials, politicians, space scientists and other parties concerned should seriously discuss the direction of Japan’s space science.
Finally, the Abe administration should not treat space projects as a new category of public works aimed at fattening certain business sectors.