Now that Japan’s Hayabusa 2 has passed its three-month checkout following a launch last December, the asteroid-exploring spacecraft has settled down for the long voyage to its destination: asteroid 1999 JU3, where it will arrive in June 2018 for more than a year of study and sample collection.
The spacecraft uses the same kind of slow-but-steady ion propulsion that its predecessor did more than a decade ago, on Japan’s first asteroid mission. Hayabusa 2’s ion engines will fire continuously to accelerate and adjust its orbit until an Earth swing-by scheduled for later this year gives it an additional boost.
The Japanese people were captivated by the original Hayabusa mission, which successfully returned samples from the asteroid Itokawa in 2010, despite a series of technical problems. Three movies about the mission were released in 2011 and 2012, all of which attracted great public attention, and more than 370,000 visitors saw a full-size replica of the Hayabusa spacecraft on display at a space expo in Tokyo last summer.
This time, the Japanese people aren’t mere spectators—they financed one of the instruments flying on board Hayabusa 2. In 2012, JAXA began accepting donations from the public in order to let enthusiasts across Japan participate in space exploration. Donors were allowed to choose the purpose of their contribution, and many selected Hayabusa 2, which received more than $200,000 in donations.
About half of that money was used to develop the CAM-C, a small camera attached to the end of the sampling horn that will collect material from the asteroid. This camera will play a vital role in confirming the extension of the sampling horn when it arrives at 1999 JU3.
After its asteroid studies are complete, Hayabusa 2 will leave for Earth in November 2019, and is expected to arrive home in November 2020. But unlike its predecessor, Hayabusa 2 will not re-enter the atmosphere. Only the capsule containing the asteroid samples will return to the ground; the main spacecraft will head back to deep space. Its next target is yet to be determined, but given the scientific instruments onboard, it will most likely be another asteroid. And if all goes well, the spacecraft will continue to explore long after 2020.
Here’s a (silent) animation showing the mission’s main milestones.