A Japanese spacecraft is nearing the end of an epic mission in which it made the first-ever collection of subsurface material from an asteroid in deep space.
As it approaches Earth this weekend, the Hayabusa2 spacecraft will eject a small capsule containing the gathered sample. The capsule will then travel a distance of about 135,000 miles before coming down in the Australian Outback, where it’ll be retrieved by a team of scientists.
It’s hoped that the collected samples, which unlike previously collected samples has been protected from space radiation and other environmental conditions due to its subsurface location, will give scientists new insight into the origins and evolution of the solar system, among other potential discoveries.
The ambitious mission, undertaken by JAXA — Japan’s equivalent of NASA — launched from the Tanegashima Space Center in the southwest of the country in December 2014.
Hayabusa2 reached the Ryugu asteroid in June 2018 after a three-and-a-half-year journey that covered about 180 million miles.
In February 2019, the spacecraft made the first of two landings on the 900-meter-wide asteroid, collecting a sample of rocks from the surface for return to Earth via a capsule.
Preparations for the more challenging procedure to collect a sample from beneath the surface of Ryugu began in April when Hayabusa2 fired a two-kilogram “bullet” into the asteroid to loosen rock particles. Several months later, the spacecraft made its second landing to gather up the material before transferring it to the capsule.
The mission also saw JAXA deploy two small rovers onto the surface of Ryugu to capture close-up images of the space rock, and perform tasks such as studying its composition and measuring its surface temperature.
With the mission now in its final stages, all eyes are on Sunday, December 6 (Saturday in the U.S.), when the capsule, which has a diameter of just 40 centimeters, is expected to come down in the Australian outback. A beacon signal emitted by the container will enable scientists to locate it soon after it returns.
Few doubt JAXA’s ability to nail this final part of the process as it performed a similar feat in 2010 when Hayabusa2’s predecessor returned with samples taken from the surface (not the subsurface, as with Hayabusa2) of another distant asteroid.
And Hayabusa2’s work isn’t yet done, either: Once the spacecraft has ejected the capsule, it’ll fly off into space again, making its way toward another faraway asteroid on a journey that’s expected to take 10 around years.
NASA is currently engaged in a similar type of mission after it recently retrieved rock samples from an asteroid more than 200 million miles from Earth. NASA’s OSIRIS-REx spacecraft will begin its trip home in March 2021, with the capsule and its contents expected to arrive on Earth in September 2023.
