Space and Physics

Japanese Spacecraft Successfully Touches Down On Asteroid Ryugu


Dr. Alfredo Carpineti

Senior Staff Writer & Space Correspondent

clockFeb 22 2019, 13:03 UTC

Artist's impression of Hayabusa 2. Courtesy of ISAS/JAXA

The Japanese Spacecraft Hayabusa 2 has successfully touched down on asteroid Ryugu and was able to collect a small sample of material to bring back to Earth for analysis. At 6.42pm EST (11.42pm GMT) on February 21, the craft landed on the asteroid and proceeded to shoot bullets into Ryugu. This unorthodox strategy was conceived to produce small clouds of asteroid dust to be collected by Hayabusa.


The craft doesn’t rest on the surface. It approaches the ground with a sampling horn from which 5-gram tantalum bullets are shot at 300 meters (984 feet) per second. The particles released by the impact are collected by the horn. So far, the probe has collected two samples. In total, it will collect three. 

Less than two hours after the collection took place, Hayabusa was given the “go” signal to move back to its surveying orbit around the asteroid. As it flew off, it snapped a picture showing the marks on the alien ground where it rested. The gravel-covered terrain is not at all what researchers had expected. They thought the ground of Ryugu would be covered in a fine powder. The more complex surface is the reason why the touchdown was postponed. Researchers at JAXA, the Japanese Space Agency, had to take more time to find the best location for collecting the sample.

Image taken by Hayabusa after touchdown from an altitude of  30m or less. JAXA, Tokyo University, Kochi Univ., Rikkyo University, Nagoya University, Chiba Institute of Technology, Meiji University, Aizu Univ., AIST

The third sample collection is scheduled to take place in April. This will be a sub-surface sample so its collection is extremely exciting. The spacecraft will release a free-flying gun that will shoot a 2.5-kilogram (5.5-pound) copper projectile using an explosive propellant charge from a distance of 500 meters (1,640 feet). It is expected to create a 2-meter-wide (6-foot) crater and release a lot of material. Hayabusa will wait a few weeks before descending and collecting its final sample.

Once the third sample is collected, the spacecraft will continue its scientific observations. Hayabusa 2 already successfully landed three rovers on the surface of Ryugu in 2018. A fourth one is going to be released in July 2019. At the end of the year, Hayabusa 2 will fire up its ion engines and begin its return to Earth. It is scheduled to arrive in December 2020. It will drop off its precious sample cargo, which is expected to land in Australia. At that point, the craft will have traveled over 5 billion kilometers (3 billion miles).


But that might not be the end of Hayabusa 2. It will still have enough fuel to extend its mission, so it might be sent to visit another asteroid near Earth.

Space and Physics