Japan Launches Imaginative Mission To A Carbon-rich Asteroid

Japan’s Hayabusa 2 asteroid mission rockets into space Tuesday. Credit: JAXA

On Tuesday at 10:22 p.m. (CST) the Hayabusa 2 mission launched from Tanegashima Space Center in southern Japan. Destination: 1999 JU3, a C-type carbon-rich asteroid nearly 3,000 feet (900 meters) across.

C-type space rocks are the most common and may have delivered some of the essential chemical building blocks important to the origin of life on Earth during the formation of the planets 4.5 billion years ago. Scientists hope to detect water and organic molecules on this never-before-explored world-let.

Anybody want a peanut? This close up photo of 25143 Itokawa was taken by Hayabusa 1 in 2005. The Mars-crossing asteroid spans just 1,755 feet (535-meters). Credit: JAXA

This is Japan’s second mission to an asteroid. The first – Hayabusa 1 – made a round trip journey to 25143 Itokawa, a rocky asteroid just a third of a mile across some 123 million miles from the Sun, from 2003 to 2010. Even though that mission encountered numerous technical problems including a pointing system failure, a fuel leak and a malfunction of the device used to collect rock samples, engineers babied it back to Earth.

At the time, no one was knew for certain whether any samples had been gathered at all, but upon re-entry, scientists discovered a tiny fraction of material inside the craft landing vehicle. Success!

Artist depiction of Hayabusa 2 in orbit around the dark, carbon-rich asteroid 1999 JU3. Credit: JAXA

“We changed a lot of parts on Hayabusa 2,” said Hitoshi Kuninaka, JAXA’s Hayabusa 2 program manager. “We installed four reaction wheels, and Hayabusa 1 had only three. The sampling system also has some improvements. Our operations software was upgraded for better proximity operations around the asteroid.”

Like the first probe, Hayabusa 2 will propel itself with an ion engine, where ionized (electrified) xenon gas is accelerated through a strong electric field and expelled at high speed to produce a steady thrust. This time around, the engines were upgraded to produce more thrust. A new antenna system will beam back data at four times the previous rate.

One of the four MINERVA II robotic landers that will hop around the asteroid taking pictures and measurements. Credit: JAXA

The spacecraft will arrive at 1999 JU3, which orbits between Earth and Mars, in June 2018. Before dispatching four landing robots, the main spacecraft will study and map the surface from a distance of about 12 miles (20 km).The landers are mobile and able to hop across the asteroid to study its environment from several locations.

Warning – don’t hop too hard! 1999 JU3 is even smaller than Rosetta’s Comet with a gravitational pull 60,000 times weaker than Earth. It wouldn’t be difficult to bounce off the asteroid and not return to the surface for a long time much as what happened to the Philae lander.

Hayabusa 2 will remain at the asteroid for a year and a half, long enough to move in close and use its collection tube to gather rocks from three different locations. In an audacious move, the spacecraft will fire a 2-kilogram (4.4-pound) copper disk into the asteroid to blast out an artificial crater about 10 feet (several meters) across and 3 feet deep. Why? To sample more pristine rocks not exposed to direct solar radiation.

Hayabusa 2 samples the crater floor after the blast, gathering fresh rocks shielded from the damaging effects of cosmic and solar radiation. Credit: Akihiro Ikeshita / JAXA

After the explosion, the spacecraft will swing by and use its sampler arm to fire tiny “bullets” made of the element tantalum into the crater and funnel debris that ricochets up from the surface into its collection tube. Mission planners hope to harvest at least 1/10 of a gram of asteroid dust.

As the spacecraft returns to Earth’s vicinity, it will eject a container with the dust that will drop through the atmosphere and land by parachute in the Australian outback in December 2020.

This is a big week for rocket launches. NASA’s new Orion space capsule is scheduled to launch into orbit on an unmanned test flight at 6:05 a.m. (CST) tomorrow. If all goes well, this could be our first step toward a manned mission to Mars. You can watch the launch live on NASA TV.

3 Responses

  1. Good luck to Hayabusa2 and JAXA…
    “Hayabusa to Itokawa” flight was an historic flight, even though, the samples returned were very limited…

  2. Norman Sanker

    Hey Bob, it doesn’t seem likely that the Japanese would’ve had time to make any adjustments to their landers post-Philae, so how does their system differ from the ESA’s harpoon-and-screw-foot approach? It would be a shame to see the same thing happen again after such a long wait. Norman Sanker

    1. astrobob

      Hi Norman,
      Not sure how they’re different or could the same problem Philae experienced, but I’ll look into it.

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