By Blaine Curcio

July 26, 2019

Figure 1 Hayabusa2 Spacecraft, Source: Go Miyazaki

Lots of space missions have names and characters that would make great children’s stories. Take for example China’s Chang’e Lunar Missions, whereby the Moon Goddess (Chang’e in Chinese, the name of the landers) carries, in some instances, the Jade Rabbit (Yutu, the name of the rovers, with the Jade Rabbit derived from Chinese mythology) to another celestial body (the moon) to explore this new world. Certainly, a foundation for a fantastic children’s story. The Japan Aerospace Exploration Agency (JAXA) is achieving with its Hayabusa2 mission, however, perhaps the most impressive storyline of any space mission in recent years. In short, JAXA sent a Peregrine Falcon on a mission to the Dragon Palace in outer space, to swoop down from the sky, collect a bucket of stardust, and return to earth safely with the stardust. That is to say, JAXA’s Hayabusa2 spacecraft (Hayabusa translating to Peregrine Falcon) was sent to the 162173 Ryugu asteroid (Ryugu being the Japanese word for Dragon Palace) to collect some of the purest minerals in the solar system, via blowing a hole in the asteroid, before returning to earth with its precious cargo. Watching this mission unfold during mid-July on JAXA’s live webcast was one of the more surreal experiences in my recent memory, and indeed, the story of the Peregrine Falcon gathering stardust from the Dragon Palace deserves a more detailed telling.

Hayabusa2—Origins of the Peregrine Falcon

The Hayabusa2 mission was preceded by the Hayabusa mission, with the two missions having similar goals of flying a spacecraft with rovers to a near-earth asteroid, collecting a mineral sample and other information, and returning to earth. The first Hayabusa mission in the mid-2000s sent a spacecraft to the 25143 Itokawa asteroid. The mission was successful insofar as the Hayabusa spacecraft returned to earth, though it took far longer than expected due to a variety of technical challenges, and the mission saw the failure of the MINERVA rover to deploy. Following the first Hayabusa mission, JAXA received approval for Hayabusa2 in 2010, with the mission having been budgeted to cost just under US$200 million. Hayabusa2 aimed to travel to 162173 Ryugu, an asteroid named after the underwater Dragon Palace in Japanese folklore. The Ryugu asteroid is special because it is made of minerals from the beginning of the universe. As well, being relatively large at around 1 kilometer in diameter (think approx. 11 American Football fields), Ryugu has an inside that is well-protected, with the asteroid’s exterior being ravaged by the process of traveling through space at 100,000km per hour for billions of years. By having an interior that is well-protected, Ryugu has effectively maintained pristine minerals from near the beginning of the universe, a treasure that JAXA’s Peregrine Falcon was built to capture.

With Falcon-Like Speed and Precision

In addition to Hayabusa2’s surface mineral sampling, the mission planned for a sub-surface mineral sampling, which would require somehow getting beneath the asteroid’s surface, but would also yield minerals that were protected from outer space, i.e. pristine minerals from near the beginning of the universe.

 After the deployment of the MINERVA rovers, subsequent collection and relay of information from the surface of the asteroid to JAXA back on earth, and analysis of data by JAXA scientists, the spot for Hayabusa2’s scoop of minerals was selected, with the date finalized as 11 July, 2019.

The daring collection of minerals consisted of several parts. First, Hayabusa2 lowered itself to a few hundred meters above the surface of the asteroid. The spacecraft then deployed a small explosive device, which fell towards the surface of the asteroid. The spacecraft then moved to the other side of the asteroid to shield itself from the blast caused by the explosion, with the blast then creating a hole in the asteroid’s surface that was around ten meters wide. Hayabusa2 then descended to the asteroid’s surface and collected minerals from the crater in a flawless landing, with the Peregrine Falcon having acquired the priceless minerals from the Dragon Palace.

Figure 2 First Photo Taken from an Asteroid, by MINERVA-II on Ryugu. Source: JAXA

The Aftermath

Following the 11 July collection of minerals, the Hayabusa2 will continue to study the asteroid for the rest of 2019, before beginning its one-year return to earth culminating in an expected late-2020 return. Japan will allow for researchers and institutes in other countries to request samples of the minerals, and the spacecraft may have sufficient fuel remaining to conduct further studies of another asteroid after the return of the samples to earth. Moving forward, Japan’s space program can take pride in the success of the second iteration of their Peregrine Falcon in its mission to collect stardust from the Dragon Palace. And if ever there were to be a children’s book of space stories, most certainly the tale of Hayabusa2 would be chapter 1.