Hayabusa 2 (artist's conception)

Hayabusa 2 (artist's conception)

Akihiro Ikeshita/JAXA

Japan aims for the heart of an asteroid

Japan today successfully launched Hayabusa 2, a spacecraft that if all goes well will return to Earth in 2020 carrying samples, including, for the first time, material from beneath the weathered surface of an asteroid.

Less than 2 hours after a Japan Aerospace Exploration Agency H-IIA rocket lifted off from the Tanegashima Space Center at 1:22 p.m. local time, Hayabusa 2, developed by the agency's Institute of Space and Astronautical Science, separated from the rocket's second stage and embarked on its planned 6-year round trip to asteroid 1999 JU3. The probe will collect data while circling the asteroid, deploy several small landers, and briefly touch down to collect surface samples. Then, in the most audacious gambit of the mission, Hayabusa 2 will release an impactor that will blast a crater into the asteroid. The spacecraft will then touch down a second time and capture ejecta. Comparing samples from the surface and from underground will give scientists a better idea of the original material of this asteroid type and how space weathers it.

The Hayabusa 2 team hopes their probe will have a far less eventful voyage than its predecessor. Before and after touching down on the asteroid Itokawa in 2005, the first Hayabusa had to overcome fuel leaks, multiple equipment failures, and a weeks-long loss of communications that had mission managers worried the craft was lost. But in 2010, after a 7-year, 6-billion-kilometer space odyssey, Hayabusa set an historic first: It brought samples from the surface of an asteroid back to Earth. Combining the findings of the Hayabusa missions, which target different asteroid types, and those of a European spacecraft's recent visit to a comet promises to sharpen our understanding of the early solar system and which of its varied bodies might have seeded our planet with water and organic compounds.