Japan aims for deep impact

The Japanese space agency has launched a mission to return samples collected from deep within an asteroid. The Japanese space agency (JAXA) launched Hayabusa 2 on 3 December from the Tanegashima Centre and it will now spend two years travelling to asteroid 1999 JU3. The asteroid is roughly spherical, 920m in diameter, rich in carbon and is thought to contain organic matter and hydrated minerals. Costing around $250m, the craft weighs almost 600kg and will attempt to investigate the origin of JU3's organic matter and water, and their relation to life and ocean water on Earth. Before landing the Hayabusa 2 will release a 2kg impactor which will aim to hit the asteroid's surface and make a small crater several metres in diameter. The craft will then land in the crater to collect samples from within the asteroid. Hitoshi Kuninaka, JAXA’s Hayabusa 2 program manager, said: “Scientists want to get materials from inside of the asteroid, so we developed the impactor. Once we release the impactor from the asteroid, it will be ignited about 40 minutes later. We cannot stop that ignition, so before the ignition the spacecraft will do an escape maneuver to the other side of the asteroid, and the time is very limited. We have to do the escape maneuver so the spacecraft will avoid serious damage from the impactor. I think that is one of the most difficult operations we have ever done.” The new craft, based on the original Hayabusa craft, was launched when the asteroid's path was at its closest to Earth. Hayabusa 2, formally approved by the Space Activities Commission in January 2012, will reach the body by the middle of 2018 and remain there for around 18 months to retrieve samples, before beginning its journey back to Earth in 2020. “This is a difficult mission, but in order for humans to expand from Earth into space, it will be necessary to meet challenges. We need a lot of technology and information about the solar system, and Hayabusa 2 will make a big step in these areas to help us be ready to plan and collaborate in the next step of space exploration,” said Kuninaka.