The Hayabusa2 encounters with the asteroid Ryugu were deliciously packaged. In February, the Japanese probe collected its first sample by moving closer to it and firing a bullet into the surface of the asteroid to stir the material, which it then grabbed with a horn-shaped collector. Then, in April, he projected a much larger impact on Ryugu, creating an artificial crater to examine the material rising below the surface. Thursday, Hayabusa2 returned to the crime scene and fired a second bullet, recovering items from his new crater.
Astronomers were not sure they could find a safe place to land in the new crater. They spent the last few months exploring the area and analyzing the images that Hayabusa2 sent back. The success of collecting this second sample means that the mission has achieved all its main objectives and can return to Earth later this year on a positive note.
A rocky trip
Hayabusa2 is only one of the spacecraft currently monitoring an asteroid in order to bring back pieces of its rocky partner. OSIRIS-REx, a NASA mission, is studying the asteroid Bennu in the same way. Astronomers often find asteroid fragments in the form of meteorites falling on Earth, but getting samples directly from space gives them a clearer picture of where and how these space rocks are formed. and how they have spent the history of the solar system over the last billion years. .
The mission team behind Hayabusa2 had to work hard to get the spacecraft to complete the work started when it was launched in 2014. Its asteroid, Ryugu, was more irregular and rocky than planned by mission planners. . The spacecraft must descend to the surface to collect its samples, and it is not designed to withstand rough or uneven terrain. The engineering team found that to ensure a safe touch, it had to significantly increase the accuracy of their touchdown targeting.
It took longer than expected, and the craft has a schedule to meet. According to the chronology of his mission, Ryugu is expected to leave Ryugu in December in order to bring his samples back to Earth for study. It's also a race against time, as Ryugu's surface is about to get too hot to be handled by Hayabusa2, which means she can not extend her stay indefinitely.
But the engineering team has persevered and Hayabusa2 has now successfully completed all of its mission objectives. He still has a few months of work to do in orbit around Ryugu, taking pictures and measurements remotely, before returning to Earth with his favorite samples.
If you want to relive the whole meeting, JAXA has put his livestream online.