Japanese spacecraft Hayabusa2 has rendezvoused with diamond-shaped asteroid Ryugu after launching from the Tanegashima spaceport in 2014 and making a 3.5-year journey.

The spacecraft commenced an 18-month stay at the asteroid to do an experiment which is the first of its kind — poke and blast a crater in the rocky surface of the target asteroid and collect samples to be brought back to Earth. The samples will arrive on the planet near the end of 2020.

‘Firefly Stone’ Asteroid

The spacecraft fired its thrusters in the morning of June 27 at 9:35 a.m. Japan time or 8:45 p.m. June 26 EDT, bringing the probe within a constant distance of about 20 kilometers or 12 miles from the asteroid.

“The status of Hayabusa2 is normal,” reported JAXA in a statement. “From this point, we are planning to conduct exploratory activities in the vicinity of the asteroid, including scientific observation of asteroid Ryugu and surveying the asteroid for sample collection.”

The Ryugu asteroid was discovered back in 1999, with its name derived from an undersea dragon palace, a popular element in the Japanese folktale.

July 24 photos revealed the asteroid’s actual shape — a square-like body with similarities to the shape of the firefly gemstone, another popular feature of the Japanese culture. Even its spin is longer than similar asteroids, it rotates around 7.5 hours versus other Type C asteroids, which usually spin about three hours.

Prospects For The Japanese Probe

The Hayabusa2 team now has to select the best location for the probe’s small lander and three rovers based on the asteroid’s shape and location, Space.com noted.

In a previous statement, Hayabasu2 project manager Yuichi Tsuda dubbed Ryugu’s form as “scientifically surprising” as well as posing a number of engineering challenges. Craters and rocks are now visible while the geographical features appear to vary from one place to another, he said.

Samples from the probe are expected to offer scientists a closer insight into the actual conditions when the solar system was formed billions of years ago. Hayabusa2 will go deeper than the earlier Hayabusa mission, which brought back dust from the asteroid Itokawa’s surface in 2010.

By about September or October, the probe is estimated to achieve its first “touchdown operation” on the space rock, and around this time it seeks to deploy a few small rovers. It will then sleep from November to December as the sun will largely block communications from the area to Earth and vice-versa.

By 2019, Hayabusa2 is hoped to start making its way back to the planet and then eject a capsule that contains the samples.