Popular Mechanics: This week the Japanese space agency’s asteroid-exploring spacecraft, Hayabusa2, will deploy a pair of rovers to explore the surface of an asteroid. It’s a mission of redemption as much as it is science, because the last time JAXA tried this, the mission ended in failure.
The Hayabusa2 probe left for asteroid Ryugu in December 2014 and is already well into its 1.5-year mission exploring the surface. It will return to Earth in 2020. The spacecraft is armed with a slew of sensors and probes, including a high-power ejector that will shoot a 0.5-gram tantalum bullet into the surface so it can study the ejected material.
Now JAXA is activating MINERVA-II1, a container holding a pair of octagonal, 2.5-pound rovers. (The acronym means “MIcro Nano Experimental Robot Vehicle for Asteroid.”) A few days ago, the JAXA Hayabusa team tweeted: “This week we will deploy the MINERVA-II1 rovers! Tomorrow (Sept 19) is the preparatory operation prior to the descent and on the 20th, the spacecraft will start descending towards Ryugu, The separation of MINERVA-II1 is scheduled for the 21st.” more here