HOME > 英会話 > 英語で話そう! イマドキの日本 > 「宇宙ビジネス」を切り開くイプシロン

執筆 春日聡子


Epsilon opens new doors to “Space Business”

宇宙航空研究開発機構(JAXA)は、2013年9月14日の午後2時に、次世代ロケット、「イプシロン」の初号機を、鹿児島県の内之浦宇宙空間観測所から打ち上げました。発射から1時間後、イプシロン初号機は惑星分光観測衛星、スプリントA、通称「ひさき」を無事切り離し、軌道に乗せました。日本のロケットが発射されるのは、7年ぶりのことです。先代のM-V(ミュー・ファイブ)は、打ち上げに莫大な費用がかかることを理由に引退となりました。イプシロン初号機の打ち上げ成功は、日本の宇宙計画において、新時代の幕開けとなるのでしょうか。10/25 Up



JAXA -- the Japan Aerospace Exploration Agency -- launched the first of its new-generation rocket, Epsilon at 2:00 pm on September 14, 2013 from the Uchinoura Space Center in Kagoshima prefecture. An hour after its launch, Epsilon-1 successfully released the planet observation satellite, SPRINT-A, now nicknamed “Hisaki,”*1 into planned orbit. It is the first Japanese rocket to be launched in seven years; Epsilon's predecessor M-V was retired due to high costs. Will Epsilon-1's successful launch mark the beginning of a new era in Japan's space program?


What kind of a rocket is Epsilon?

Epsilon is a solid-fuel rocket that is approximately 24 meters tall, 2.6 meters in diameter, and weighs about 90 tons. It is about half the size of the H-IIA, Japan's primary large-scale rocket. It is a three-stage rocket in which the existing solid rocket booster of the H-IIA is used as the first stage, and the upgraded version of the upper stage of the M-V is used as the second and third stage. By using existing technologies, JAXA was able to cap the development costs to 20 billion yen, which is 40 percent less than the M-V. Further, Epsilon can now be built in a very short time period. JAXA calls Epsilon “the culmination of decades of advancement in Japanese solid-rocket technology.”*2


What is the significance of Epsilon?

The most significant feature of Epsilon is that it is the world's first rocket to incorporate artificial intelligence. The Epsilon uses artificial intelligence to perform autonomous checks, so it only requires eight people at the launch site, and two desktop computers to control the launch. JAXA refers to this as “mobile launch control.” As a result, the launch cost has been reduced to 3.8 billion yen, approximately half of that of the M-V. The number of days it takes from setting up the rocket at the launch site to the actual launch date has also been reduced from the previous 42 days to just 7 days.


What is planned for Japan's space program in the future?

The main aim in creating the Epsilon had always been to make space missions more affordable. It has been reported that the government will now start negotiations with emerging countries to launch their satellites using the Epsilon.*3 JAXA will continue to work with the government and seek ways to reduce costs to make Epsilon more competitive against rockets made in Europe, Russia, India, and China. The successful launch of the Epsilon is opening new possibilities for Japan's space program.








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