Hayabusa-2: the rovers of Japan ready for landing on the asteroid

The Japanese space agency is preparing to deploy two robotic explorers to the surface of an asteroid.

On Friday, the Hayabusa-2 spacecraft will dispatch a pair of rovers on the rock of the 1km space called Ryugu.

Rover 1A and Rover 1B will move by hopping in the low gravity of Ryugu; they will capture images of the surface and measure temperatures.

Hayabusa-2 reached the Ryugu asteroid in June of this year after a trip of three and a half years.

If all goes well, Hayabusa-2 will be the first spaceship to successfully place robots on the surface of an asteroid.

The 1-km-wide space rock, officially known as 162173 Ryugu, belongs to a particularly primitive type of asteroid and is therefore a relic of the early days of our solar system. Studying it could shed light on the origin and evolution of our planet.

The rovers are stored in a drum-shaped container at the base of the Hayabusa-2 "tanker". Collectively, they form a 3.3-kg scientific ensemble called Minerva II-1.

Early Thursday morning (TSB), Hayabusa-2 began to descend to the Ryugu surface in preparation for the deployment.

Around 5:00 am (Paris time) on Friday (1:00 pm JST) – at a distance of about 60 meters from the asteroid – Hayabusa-2 will launch the launch of the two robots.

Japanese Space Agency officials said that when the front of the drum is dropped into space, the two rovers are then ejected from the container and fall independently onto the surface of the asteroid. .

Standalone rovers of 1kg move by hopping, using the low gravity of the asteroid. Each contains a motorized internal mass that rotates to generate force, propelling the robot onto the surface.

They are equipped with wide angle and stereo cameras to return images of Ryugu. The spine-shaped projections of the edges of the hoppers are sensors that measure surface temperatures on the asteroid.

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They will return their data to the tanker, who will then transmit the information to the Earth.

One of the main concerns for deployment is Ryugu's rougher surface than expected, which is carpeted with rocks with very few smooth plates.

The name Minerva comes from a detachable mini-lander carried by the first Hayabusa spacecraft, which explored a different asteroid – 25,143 Itokawa – in the mid-2000s. However, a small problem during the deployment caused the small landing gear never reached his target.

Officials and scientists at the Japan Aerospace Exploration Agency (Jaxa), which operates Hayabusa-2, are hoping for a better chance this time around.

Hayabusa-2 was launched on December 3, 2014 from the Tanegashima launch center, in the far south of Japan.

On 3 October, the tanker will deploy a lander called Mascot, developed by the German Aerospace Center (DLR) in collaboration with the French Space Agency (CNES).

And at the end of October, Hayabusa-2 will come down to the surface of Ryugu to collect a sample of rock and soil.

Later in the mission, Jaxa plans to blow up an explosive charge that will strike a crater on Ryugu's surface.

Hayabusa-2 would then descend into the crater to collect fresh rocks that had not been altered by exposure to the space environment.

These samples will then be sent to Earth for laboratory studies.

The spacecraft will depart Ryugu in December 2019 with the intention of returning to Earth with asteroid samples in 2020.

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