An image taken by the main Hayabusa2 spacecraft of the MINERVA-II2 rover during separation on 2 October 2019. Image credit: JAXA/Chiba Institute of Technology & collaborators
Japan’s asteroid mission has deployed its last rover to explore Ryugu’s rocky surface.
The Hayabusa2 spacecraft has been exploring the asteroid since June 2018, and it deployed three other landers to the asteroid’s surface last fall. Then, the mission switched its focus to sample collection. But now, Hayabusa2 is executing its last remaining task before turning for Earth: deploying its final rover, dubbed MINERVA-II2.
That process began on 2 October 2019 when the main spacecraft lowered itself to 1 kilometre (0.6 miles) above the asteroid’s surface to release MINERVA-II2. That’s much higher above the surface than its twins, MINERVA-II1A and MINERVA-II1B, were deployed, at about 50 metres (165 feet) above Ryugu’s surface.
The different approach is necessary because this rover is tackling different questions than its predecessors. The Hayabusa2 scientists want to be able to study the rover’s long, slow path down to Ryugu’s surface, with the main spacecraft watching its journey from an altitude of about 8-10 kilometres (5 miles). The lengthy descent will also let scientists more accurately study the gravitational field ...