Japan’s Hayabusa 2 has made its closest approach to the Ryugu asteroid yet after arriving in mid-June. The approach brought the spacecraft within less than one kilometer of the surface of the asteroid.
The Hayabusa 2 spacecraft arrived at the near-Earth asteroid 162173 Ryugu on June 27, 2018. Since arriving, the spacecraft has proceeded through a number of decent operations taking it from an altitude of 20 kilometers to as little as 400 meters above the surface of the asteroid. The latest set of decent operations began in early August and are being used to measure the asteroid’s gravitational forces.
To accurately map the gravitational forces being exerted by the asteroid, JAXA ground controllers disable the spacecraft’s rocket control thrusters. This allows onboard sensors to calculate the effect of Ryugu’s gravitational field on the spacecraft. Following reaching a 400-meter minimum altitude on August 6, Hayabusa 2 fired jets to climb away from the asteroid.
Once gravitational measurements have been completed, navigators at JAXA’s control center in Sagamihara will be able to determine a suitable landing site for the first of three planned touchdowns. If all goes well, the agency plans to complete the first touchdown and rover deployment between September and October this year. Touchdowns two and three and the second rover deployment are planned for the first half of 2019.
In addition to the touchdown and rover operations, the Hayabusa 2 spacecraft will conduct a crater generation operation between March and April 2019. It will see operators release an impactor that will create an artificial crater on the surface of the asteroid. The spacecraft will then touchdown near the crater location in order to allow the rover to collect samples.
Following the completion of all scientific operations, Hayabusa 2 will depart the asteroid towards the end of 2019 to begin its journey home. It is expected to return to Earth by December 2020.