Hayabusa 2: Japan’s Asteroid-Explorer Satellite

The Japanese space agency’s second asteroid-exploring satellite, Hayabusa 2, carries on board a camera that was paid for through private donations.

This is an indication of the popularity of the Japan Aerospace Exploration Agency (JAXA) space program, and particularly the Hayabusa missions.

The name “Haybusa” means “Peregrine Falcon”. The first Hayabusa mission returned to earth in 2010, carrying samples from asteroid Itokawa. Its adventures were the subject of three films, and it earned a place of honor at the space expo held in Tokyo last year. This was the first time that material from the asteroids was returned to earth for analysis.

The JAXA asteroid missions differ from NASA’s asteroid-exploring satellites in several ways. Instead of analyzing samples on board, the probes head back to earth, to safely deliver the capsules containing the off-earth materials. The probes themselves do not land on the asteroid’s surface, but carry smaller landing craft. Samples are scooped up from the surface by the probe using a “sampling horn.”

Hayabusa 2 was launched in December last year, and has settled for its long flight to Asteroid 1999 JU3. It will arrive at its destination in 2018, and spend a year there to study the surface and collect samples. It will then head back to earth, arriving in 2020. It is building on the first mission’s successes and learning from its mistakes.

Hayabusa 1 carried a small lander, which was unable to attach itself to the surface of the asteroid and floated away into space. Hayabusa 2 carries four small landers. The satellite carries a tiny camera attached to the sampling horn, which will confirm the positioning of the sampling arm. This camera has been funded by donations from the public.

Hayabusa 2 also carries a device known as an impactor, which will create a small explosion on the surface. Samples will be taken from the crater created by the impactor.

Both satellites use ion propulsion engines, which provide steady acceptation and maneuverability. Hayabusa 1 was incinerated and destroyed when it re-entered the earth’s atmosphere. Hayabusa 2 will not re-enter the earth’s atmosphere, however. Pausing only to deliver the capsule containing the samples collected on the asteroid, it will head off again into deep space, most likely to continue its asteroid-exploring mission.