Japan Readies Hayabusa2 Asteroid Sample Return Mission for Launch – RESCHEDULED

UPDATE: The launch has been postponed a second time because of weather.  The new launch date is December 3, 1:22:04 pm JST (December 2, 11:22:04 pm EST).  This article is updated accordingly.

The Japan Aerospace Exploration Agency (JAXA) is getting ready to launch its second asteroid sample return mission, Hayabusa2, on December 2, 2014 Eastern Standard Time (EST), following a second weather delay.   Launch time is 11:22 pm EST, which is 1:22 pm December 3 Japan Standard Time (JST).  JAXA plans to provide live coverage of the launch on its website.

The original launch date was November 30 JST (November 29 EST).  That slipped to December 1 JST (November 30 EST) due to weather, and now has been rescheduled again due to weather.  JAXA currently plans to launch it on December 3 JST (December 2 EST).

Hayabusa2 is the successor to Hayabusa (also called MUSES-C), which successfully returned a small amount of material from the asteroid Itokawa in 2010.  Hayabusa overcame a number of technical challenges, including the loss of all four of its ion engines.  Japanese engineers were able to interconnect working components of different engines to create one that worked.   The landing of its sample return canister in Australia on June 14, 2010 Eastern Daylight Time generated considerable excitement around the world.   At that time it was unclear as to whether the sample mechanism had actually captured any material from Itokawa, but after they opened the canister, scientists determined it contained about 1,500 grains, which have been the subject of scientific analysis since that time.

Japan quickly decided to mount a second mission, Hayabusa2, with a number of improvements, including to the ion engines and the sample collection mechanism.   If launch takes place as scheduled, it will reach its target, asteroid 1999JU3, in mid-2018, remain there for 18 months orbiting the asteroid at a distance of about 20 kilometers (12.5 miles), and return to Earth at the end of 2020.

Artist’s concept of Hayabusa2 spacecraft above an asteroid.  Image credit:  JAXA website.

Among the science instruments on the 600 kilogram (1,322 pound) spacecraft is a small impactor made of pure copper (to distinguish it from other materials on the asteroid).  Called Liner, it will be dropped to the surface at a velocity of 2 kilometers (1.25 miles) per second to create an artificial crater by colliding with the asteroid.  That will expose fresh material below the asteroid’s surface to be collected by the sample return mechanism.   Hayabusa2 will also study the asteroid using a near infrared spectrometer (NIRS3) and a thermal infrared imager (TIR), deploy three small rovers (MINERVA) that can move several times by hopping, and a small lander (MASCOT) that can move once by hopping.   MASCOT was built by the German space agency, DLR, and the French space agency, CNES, who also teamed on the Philae lander that just landed on Comet 67P on November 12.  MASCOT has four observation devices (MicrOmega, MAG, CAM and MARA). 

Asteroids are categorized into several different types.  Two of the most prevalent are C (carbonaceous) and S (stony).  Asteroid 1999JU3 is a C-type, while Hayabusa’s target, Itokawa, was an S-type.  Thus, Hayabusa2 is not only bringing back additional asteroid samples, but from a different type of asteroid, broadening scientific knowledge about these objects left over from the formation of the solar system.

Launch will be on a Mithsibishi Heavy Industries (MHI) H-IIA rocket from Japan’s Tanagashima Space Center.  JAXA indicated it would provide live coverage of the launch and of spacecraft separation, but the times for that coverage are not posted on JAXA’s website yet.

(For those who are curious, we have published an article providing  a brief explanation of the difference between a comet and an asteroid and a list of other robotic comet and asteroid missions flown in the past or planned for the future.)