Two Japanese rovers will be launched on Friday 21 September local time and begin exploring the Ryugu asteroid.

By Daniel Herborn

Posted on September 21, 2018

Japan Aerospace Exploration Agency (JAXA) is behind the mission, which has involved sending the rovers to their destination inside the Hayabusa2 spacecraft. Hayabusa2 reached the asteroid in June after leaving the Tanegashima spaceport back in 2014.

At time of writing, the spacecraft had successfully descended to an altitude of about 1.5 km above Ryugu and had captured a series of photos of the asteroid.


Above: Artist’s impression of Rover 1A and Rover 1B

The two rovers, Rover 1A and Rover 1B, will move around in the low gravity of Ryugu and capture images and record temperatures. They are 7cm tall, hexagonal in shape and weigh only 1.1 kilograms each.

“Gravity on the surface of Ryugu is very weak, so a rover propelled by normal wheels or crawlers would float upwards as soon as it started to move,” Hayabusa2 team members wrote. “Therefore, this hopping mechanism was adopted for moving across the surface of such small celestial bodies. The rover is expected to remain in the air for up to 15 minutes after a single hop before landing, and to move up to 15 m (50 feet) horizontally.”

Hayabusa2 and its a rovers are a first in space exploration

If the rovers are successfully deployed, it will mark the first time a spacecraft has placed robot rovers on an asteroid surface. Hayabusa2’s predecessor collected a tiny fragment of an asteroid and returned back to earth in 2010 but was unable to land on the space rock.

Ryugu is one kilometre wide and has existed since the earliest days of our Solar System which formed more than 4.5 billion years ago. Its age means it is of particular interest to scientists and could give valuable insights into the evolution of the galaxy. Scientists believe the asteroid may contain chemical compounds which were vital as the catalyst for life on earth.

Asteroids often contain water, precious metals and carbon-rich compounds which may make them suitable for mining.


Above: Artist’s impression of Hayabusa-2 spacecraft departing from Ryugu

The rovers will collect data and samples from the asteroid

The mission will cost JAXA around US$150 million. It is anticipated the rovers will collect data on the asteroid until December 2019 and finally return to earth in December 2020.

NASA is also sending rovers to an asteroid to gather data. The OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer) is headed towards the asteroid Bennu and is on track to reach the asteroid’s orbit in December after almost two years of travel. It is expected to return on earth with its collected samples in September 2023.