Japan Boldly Goes
|Jun 25, 2010|
Suddenly, Japan's awareness of its space program has come alive after decades during which, for the most part, the Japanese paid little attention to their country's exploration plans or even realized they had one.
Japanese astronauts, usually piggybacking onto other nations' missions into space, are normally good for a day or so of newspaper stories and perhaps a goodwill visit to some schoolchildren. But that all came to a flaming end earlier this month when the space probe Hayabusa streaked across the sky over Western Australia, safely jettisoning its payload for scientists to examine after a seven-year space voyage to a tiny pinprick of an asteroid, Itokawa, 300 million kilometers from earth – and back.
The Japanese, not to mention the rest of the world, suddenly woke up to the fact that their country had become just the second country in world history, and the first since the Apollo missions to the moon in the 1970s, to send a space vehicle to another world and then return it to Earth. Japan is on the cutting edge of space exploration.
If that weren't enough, only a few days earlier the Japanese space agency, known as the Japan Aeronautical Exploration Agency (JAXA), launched the Akatsuki on a voyage to Venus, where it is expected to go into orbit around the planet and obtain information on climate patterns. It carries an array of cameras and other instruments to capture the movement of the atmosphere.
Japan is by no means the first country to send an exploratory probe to Venus, but it is the first one to focus primarily on climate. It will complement a soon-to-launch European probe meant to orbit both poles to study the chemical composition of Venus's atmosphere.
The same rocket carried aloft yet another space vehicle, the Ikaros, which is billed as the world's first space "yacht." By that the agency means it will deploy a "sail" made up of an extraordinarily thin polymer membrane designed to catch the solar wind and propel the probe onward.
The asteroid Itokawa is only about 500 meters long and 200 wide, or about the size of Hibiya Park in downtown Tokyo. It was only discovered in 1998, or about five years before the space probe was launched in May 2003. It was named, at Tokyo's request, after Hideo Itokawa, generally considered the father of Japanese rocket development.
The mission can be considered a success in that the probe landed on Itokawa and returned to earth with its payload, but it is as yet uncertain whether the probe brought back any "asteroid rocks" to examine. The device that was to shoot metal balls into the asteroid's surface to kick up debris to be collected malfunctioned.
The space agency hopes that just by settling on the surface of the planetoid may have stirred up enough collectable dust to learn something. The capsule was recovered in Australia and shipped directly to the JAXA's laboratory in Kanagawa prefecture. As of this writing, the technicians have not yet tried to open the capsule and examine what's inside. Preliminary X-rays of the insides were not optimistic that it had collected enough asteroid material for serious analysis, but that remains to be seen.
Scientists were hoping to learn from the dust something about the formation of the solar system, estimated to have been 4.6 billion years ago. Unlike other planets and the Earth, Itokawa is believed to have been unchanged since the beginning of the solar system.
Whether that part of the mission is a success is in many ways irrelevant. The mission has already profoundly changed the way Japanese, and the Japanese government, look at space exploration. Even Renho Murata, the new cabinet minister charged with identifying wasteful government spending, and a bloodhound on science projects, was impressed.
"It is a feat that all Japanese should be proud of," she said. "This is a major message to the world." Editorials in leading Japanese newspapers piled on the praise: "We believe Hayabusa has clearly shown us what Japan can – and should - aim for," said the Asahi Shimbun. One could speculate that the space agency budget, only about a tenth of the U.S. budget for space exploration, is pretty safe.
Among other things the Hayabusa mission demonstrated conclusively that Japan has the technology for long-distance missions (At 2,592 days it was the longest space voyage on record, eclipsing the 2,542 days of the American "Stardust" mission of 1999-2006), which collected cosmic dust but did not land on another world.
Additionally, the long voyage was accomplished despite overcoming numerous glitches along the way, using a small-sized high performance ion engine developed by the NEC Corp., which creates thrust by expelling xenon ions. Although the thrust is weak, the probe gradually gathers speed over time.
JAXA technicians had to overcome numerous setbacks during the seven-year voyage. Three of the four ion thrusters stopped working during the flight, a fuel leak rendered the chemical engine inoperable, two of the three attitude control antennas broke down and communication was lost for 50 days after the second landing on the minor planet.
Many of Japan's industrial giants contributed parts to the flight. They included besides NEC, such companies as Fujitsu, which provided systems for orbit control; IHI which helped design the payload capsule; Mitsubishi Electric for the ground antennas used to control the flight, and Mitsubishi Heavy Industries; the chemical engines. The companies could hardly ask for better advertisement for their cutting edge technologies than that they propelled the Hayabusa for seven years of space travel and brought it back to earth safely.