“Hayabusa” 2 Lifts Off, Seeking Clues to the Origins of LifeScience Technology
On December 3, the Japan Aerospace Exploration Agency (JAXA) successfully launched the Hayabusa 2 probe on a Japanese H-IIA rocket from the Tanegashima Space Center. Like its predecessor Hayabusa, the probe aims to land on an asteroid, take samples, and bring them back to Earth in search of clues to the origins of life.
An Unprecedented Experiment
Hayabusa 2 is targeting an asteroid with the designation (162173) 1999 JU3, which orbits between Venus and Mars. The nearly spherical asteroid is around 920 meters in diameter, making it larger than the 500-meter peanut-shaped asteroid 25143 Itokawa that the first Hayabusa mission visited. And while Itokawa was an S-type asteroid, made up of only stone and metal, 1999 JU3 is a C-type asteroid, meaning that it is carbon-rich and believed to consist of the same organic matter found in animals and plants as well as hydrated minerals and water, essential to life’s beginnings. It is also thought to be unchanged in composition from the time that the solar system formed over 4 billion years ago.
The probe is scheduled to reach 1999 JU3 around mid-2018. It will remain there for approximately 18 months, collecting dust and rock samples and conducting research. Then, around the end of 2019, it will begin its journey back from the asteroid, traveling the 5.2 billion kilometers to Earth to complete its six-year mission and return with samples around the end of 2020.
The original Hayabusa mission was launched in May 2003 and finally returned safely in June 2010, but was plagued by problems along the way, as its planned four-year voyage extended to seven years and the probe ended up traveling 6 billion kilometers instead of 3.5 billion. Although it successfully landed on Itokawa, equipment failure and other issues meant it was unable to collect the hoped-for amount of sample material.
This time around, Hayabusa 2 will be testing new technologies. Using a device called a “small carry-on impactor” it will create an artificial crater several meters wide on the surface of the asteroid, making it possible to collect exposed below-surface material that has not been subject to the heat of the sun or space erosion. This is an unprecedented experiment.
A Distillation of Japanese Technologies
More than 100 Japanese companies, from manufacturing giants to small local factories with just a few dozen employees, have been involved in the Hayabusa 2 project. The 600-kilogram probe represents a distillation of Japan’s space exploration technologies.
Interest centers particularly on the small carry-on impactor, which is integral to the success of the mission. It weighs around 10 kilograms and consists of a copper liner welded to a stainless steel cone packed with explosives. When the explosives are detonated the copper liner is discharged at a speed of 2 kilometers per second, melting and transforming into the shape of a softball before hitting the surface of the asteroid and forming a crater.
The cone and copper liner were produced by Tamatech, an 83-employee precision machining company based in Kagamiishi, Fukushima Prefecture. After much trial and error, it successfully reduced the thickness of the cone material from the previous 3 millimeters to a mere 1 millimeter in order to reduce weight. The explosives were also produced in Fukushima, in the village of Nishigō at the Shirakawa Plant of Nippon Kōki, a Tokyo-based company with 444 employees. In March 2011, the year after JAXA placed the order for the explosive element, the Great East Japan Earthquake forced a one-month delay in production. After the plant reopened and restarted its experiments, Nippon Kōki and Tamatech worked together to bring the impactor to completion in October 2013.
The device for collecting samples is a “sampler horn,” a meter-long tubular device extending from the bottom of the probe. When the end of this device comes into contact with the asteroid, it will fire small projectiles at the surface and collect dust and rock samples thrown up by the impact. The part connecting the springs in this device was produced by workers at Shimohira Seisakusho, an aerospace component manufacturer in Yokohama with just 30 employees.(Originally written in Japanese by Nagasawa Takaaki of the Nippon.com editorial department and published on December 3, 2014. Banner photo: A successful launch for Hayabusa 2. © Jiji.)