The Japan Aerospace Exploration Agency (JAXA) has succeeded in putting its Akatsuki probe into orbit around Venus. To space enthusiasts, the feat no doubt stirred up memories of the Hayabusa asteroid explorer's return to Earth in 2010.
JAXA had attempted to put the Akatsuki probe into orbit in Venus five years ago, but was unsuccessful due to failure of the probe's main engine. Scientists accordingly waited for another opportunity for the probe to approach the planet. The latest achievement marks the first time that a Japanese probe has been put into orbit around a planet other than Earth.
The Akatsuki project team deserves credit for its strenuous efforts, overcoming dangers to succeed in putting the probe into orbit on its second attempt. Its experiences will surely be a valuable asset for Japan's future space science exploration projects.
Earth and Venus are similar in size and mass, and they have been described as twin planets. But the environment on Venus is completely different from that on Earth. Venus' atmosphere consists of a thick layer of carbon dioxide, with sulfuric acid clouds. The surface temperature hovers around a searing 460 degrees Celsius. The atmosphere is in a state of super-rotation, with winds blowing at a fierce 100 meters per second. Akatsuki's main job is to unravel the reasons behind the weather phenomena.
A total of 25 billion yen went into development of Akatsuki, which was launched in May 2010 from Tanegashima Space Center in Kagoshima Prefecture. The probe spent seven months heading toward Venus, but failed to enter the planet's orbit, and instead went into a different orbit around the sun.
On a renewed attempt to insert the probe into orbit around Venus, JAXA scientists only had use of small attitude control engines. After tens of thousands of calculations, they settled on the method of waiting for the probe to pass Venus again, then putting the small engines' thrusters in reverse as it flew by.
Furthermore, because the probe flew closer to the sun than had originally been envisioned, scientists always had the most heat-resistant part facing the sun. The successful renewed attempt to enter Venus' orbit -- a result of original ideas and efforts -- attests to the high level of Japanese science and technology.
Akatsuki has survived beyond its planned lifespan, but the equipment on board is functioning properly, and test measurements have begun. The probe is the first with a focus on the weather of Venus to be successfully put in orbit around the planet. We hope it will be successful in delivering its results to the world.
Under Japan's basic plan for space projects, which was set in January, Japan will be involved in three projects similar the Akatsuki mission over the next decade. One of the projects under consideration is a mission to bring back a sample from a natural satellite of Mars.
Akatsuki has achieved results of which it can be proud from a global perspective, but Japan must concede that it doesn't have the same level of experience with probes of planets as the United States or Europe. It is possible that the probe could encounter all sorts of problems in the future.
Nevertheless, such scientific exploration does not only pursue the mysteries of space, but also facilitates technological development and personnel training. We hope that the government and JAXA will make an effort to convey the significance and appeal of this exploration.