Hayabusa2: Returning a sample from asteroid Ryugu

Mission Lead
Launch Date
2 Dec 2014
Current Status
Returning to Earth

Facts worth sharing

  • Asteroids are leftover planet-building materials from the birth of our solar system. Unlike Earth rocks shaped by eons of weathering and geologic activity, asteroids have remained largely unchanged, making them time capsules that can teach us about the origin and evolution of our solar system.
  • Hayabusa2 is returning samples of asteroid Ryugu to Earth in December 2020. Scientists will study the samples with high-precision instruments that are currently too large and power-hungry to fly in space.
  • After dropping off its Ryugu samples, Hayabusa2 will embark on an extended mission to study more asteroids. The spacecraft will fly past asteroid 2001 CC21 in 2026 and rendezvous with asteroid 1998 KY26 in 2031.

Why do we need Hayabusa2? 

Hayabusa2 (はやぶさ2) is a mission to survey near-Earth asteroid Ryugu and collect a surface sample for return to Earth. Our solar system is filled with countless asteroids, comets, and other small worlds left over from the disk of dust and gas that formed the planets 4.5 billion years ago. On Earth, weather and geological processes constantly alter the surface, but asteroids like Ryugu have remained largely unchanged since their formation. Studying the ages and compositions of different types of asteroids gives scientists important clues about how our solar system evolved.

Although modern spacecraft instruments can teach us a lot about other worlds, there are certain kinds of experiments that can only be done on Earth. Hayabusa2's samples of Ryugu will allow scientists to pin a precise date on when the asteroid’s materials formed, and when Ryugu may have been heated due to collisions with other asteroids. 

Because Hayabusa2 is still healthy, Japan's space agency JAXA is sending it on an extended mission to visit two more asteroids. The spacecraft will fly by asteroid 2001 CC21 once in 2026 and Earth two times in 2027 and 2028 before arriving at asteroid 1998 KY26 in 2031.

To assist with navigation around Ryugu, Hayabusa2 carried 5 baseball-like target markers it dropped to the surface. The makers contained names collected by The Planetary Society and JAXA in 2013.

Hayabusa2 Target Marker E Drop Images
Hayabusa2 Drops a Target Marker on Ryugu This overlay of images taken 4 seconds apart shows Hayabusa2 dropping a target marker on asteroid Ryugu in 2019. The markers bear names collected by The Planetary Society and Japan's space agency JAXA in 2013, and were used as navigational aids to help Hayabusa2 collect samples from the surface. JAXA, Chiba Inst. Tech & collaborators

Find your Hayabusa2 Messages from Earth certificate

The Planetary Society and the Japan Aerospace Exploration Agency invited people worldwide to submit their names for a round-trip ride to asteroid Bennu. Search for your certificate here.

How Hayabusa2 works

Hayabusa2 is equipped with a variety of instruments that helped it study Ryugu, and will help it study asteroids during its extended mission. Key technologies include a laser altimeter to create 3D maps, a thermal imager to measure surface temperatures, and a spectrometer to determine the composition of surface minerals.

Hayabusa2 collected its samples from Ryugu using a meter-long sample horn extending from the bottom of the spacecraft. When the horn touched the surface, it fired a bullet-like projectile that kicked surface material up the horn into a collection bin. Later, Hayabusa2 transferred the bin into an Earth-return capsule that the spacecraft will drop into Earth's atmosphere for recovery in Australia.

Hayabusa2 Second Touchdown (short clip)
Hayabusa2 Second Touchdown (short clip) This short clip shows Hayabusa 2's second touchdown, which occurred on 11 July 2019 at 01:06 UTC, as seen from the spacecraft's small monitor camera (CAM-H). The sequence plays at roughly 10 times normal speed. See the full video here. JAXA

One of the samples Hayabusa2 collected came from an artificial crater the spacecraft created. SCI, the Small Carry-on Impactor experiment, fired a copper plate into the surface to expose fresh asteroid material for collection. 

Hayabusa2 SCI impact (DCAM3 digital camera)
Hayabusa2 SCI impact (DCAM3 digital camera) Hayabusa2's deployable DCAM3 digital camera caught this view of debris spreading from Ryugu approximately 3 seconds after the SCI experiment detonated on 5 April 2019. JAXA

Hayabusa2 also deployed a series of rovers to study Ryugu up close. MASCOT, the Mobile Asteroid Surface Scout, carried a camera system, magnetometer, infrared microscope, and a radiometer. Hayabusa2 also carried three drum-shaped rovers named MINERVA, two of which successfully hopped around the surface.

Ryugu's Surface from MASCOT, in Color
Ryugu's Surface from MASCOT, in Color This color view of Ryugu's surface at night was created from images captured by MASCOT using red, green, and blue LEDs for illumination. MASCOT/DLR/JAXA

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