The Hayabusa, the first Japanese asteroid probe, is now flying toward the asteroid Itokawa. The Hayabusa was launched by the M-V Launch Vehicle from Uchinoura, Kagoshima, on May 9, 2003. The probe was originally called the "MUSES-C," and was designed to verify new space engineering technology and serve as a pioneering tool in planetary science by bringing back surface materials from an asteroid for the first time in the history of mankind. The goal is to elucidate the origin of the asteroid and the mystery of the birth of the solar system.
The Hayabusa is scheduled to arrive at the asteroid Itokawa in late summer 2005 staying around there for three months to observe the surface and take materials (Diagram 3). The name "Hayabusa" means "falcon" in English, and the probe was named after this bird because the way it takes materials is similar to the bird catching pray. Hayabusa will leave the asteroid Itokawa at the end of 2005 and return to Earth in June 2007. (*3)
During its four-year mission, the Hayabusa will have had to overcome several challenges. The first one is a newly developed ion engine. The engine is currently running smoothly and has sped up the Hayabusa's anticipated arrive at the asteroid. The second challenge has been an Earth swing-by operation, which was successfully completed. On May 19, 2004, about a year after its liftoff, the Hayabusa came back near the Earth and was injected into our planet's orbit to use the Earth's gravity to slingshot it toward the asteroid. The Hayabusa swing-by is shown in Diagram 4. The next challenge is to arrive at the asteroid.
The asteroid Itokawa was named after Dr. Hideo Itokawa, the father of the Japanese launch vehicle. In 1955, the test launch of the first pencil rocket made by Dr. Itokawa was conducted (*4). Exactly 50 years later, the asteroid probe Hayabusa, which was launched by a M-V launch vehicle, is expected to arrive at the asteroid Itokawa. The late Dr. Itokawa would certainly be moved by the technological progress made over the last half a century.
The asteroid Itokawa is estimated to be about 500m in diameter and 300m in width according to observations by optical telescopes and radars from Earth. Some American probes have approached large asteroids, some 20 to 60 km in size. However, the asteroid Itokawa is much smaller. It is just like the asteroid B-612, the home of the Little Prince, in size. Diagram 5 shows the shape of the asteroid Itokawa. It looks like a sweet potato, and shape wise, it differs from the B-612. It is exciting to imagine what kind of images Hayabusa will send us when it arrives on the asteroid.
