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A Japanese Spacecraft is Closing in on a Mineable Asteroid

Wednesday, June 13, 2018

Is humanity on its way to mining asteroids?

Last week, we told you about Made in Space, the California company manufacturing ultra-high-quality fiber optics and more aboard the International Space Station. As deliriously ambitious as their mission of making humans “multiplanetary” sounds, they’re not the only ones chasing big dreams among the stars: JAXA, the Japanese Space Exploration Agency, seems to be laying the foundation for an equally sci-fi-sounding goal: asteroid mining.

The name of their latest spacecraft is Hayabusa 2, a blockish probe sporting solar panel wings, on course for an intercept with the nearby asteroid Ryugu. I mean “nearby” in the astronomical sense, of course; Hayabusa 2 has already traveled almost two billion miles to reach Ryugu since its launch in 2014, with less than a thousand left to go—and it’s getting closer by the day; on Monday, JAXA posted a pair of images of the asteroid as seen from the probe's onboard camera.

At left is a long exposure, with the camera's shutter open for roughly three minutes, while the right-hand image was captured in under a tenth of a second. This second image was taken with the goal of studying the asteroid's shape, but little detail is visible at this distance aside from the fact that the asteroid seems to be roughly spherical.
Image Credit: JAXA
Much like the ESA’s recent asteroid exploration mission Rosetta, Hayabusa 2 is equipped with a lander module—although the asteroid's gravity is weak enough that Hayabusa 2 itself will be able to touch down on the rock as well, to conduct some sampling. The detachable lander probe, dubbed MASCOT, was engineered by a collaboration between JAXA's German and French counterparts. MASCOT will also have enough thrust to to defy the weak surface gravity of the asteroid, letting it "hop" from place to place, making observations as it goes. In 2020, once its mission is complete, MASCOT will remain behind while Hayabusa 2 makes its way home—propelled by an ion drive, samples in hand—from one of the first extraterrestrial "prospecting" missions ever conducted.

A schematic overview of the Hayabusa 2 craft.
Image Credit: JAXA

Not to be outdone by the Rosetta and Philae’s “harpoons in space”, JAXA has armed Hayabusa 2 with a shaped charge of the high explosive octogen, which will let it blast a deep crater in the asteroid’s surface, enabling a much faster and more indepth analysis of the asteroid’s composition than would be possible with drills alone. Hayabusa 2 is also carrying a payload of several tiny rovers called MINERVAs, which will hop over the asteroid's surface as well, making observations of their own.

What will Hayabusa 2 and MASCOT find? Nobody's sure, but the prospects are exciting; based on its appearance, Ryugu is expected to yield iron, nickel, and cobalt, and is ranked #1 among the solar system's known asteroids in terms of cost-effective mining potential by the website Asterank. While their algorithm takes a lot of things into account, including the asteroids' expected composition, the feature that makes Ryugu the most appealing—both for scientific study and any potential future missions—is the similarity between its orbit and our own: it takes about a year to loop around the sun, and does so at a distance roughly equal to Earth's. That means that spacecraft trying to get to Ryugu don't have to carry the high-thrust propulsion systems that it takes to get moving the same speed as faster or slower-moving objects. Remember: anything that takes off from Earth is still going to be moving around the sun in the roughly same direction and at the same speed as Earth, so the difference between Earth's velocity and the target body's velocity has to be accounted and corrected for by a ship's engines, bringing it as close as possible to the target's speed.

Each glowing dot in this image from Asterank's animated display is an asteroid. The white dashed line is Ryugu's orbit, while the blue one is Earth's. The interactive display is really cool, but watching it too long can give you anxiety about the number of colossal rocks making close passes by Earth.
Image Credit: Asterank
Now, we might be getting ahead of ourselves—the mission is purely exploratory, and asteroid mining isn't likely to be a profitable endeavor anytime soon. But in addition to the scientific value of this mission, which should offer clues about the dynamics of planet formation and the early history of the solar system, it's possible that JAXA is thinking very long-term.* Out of all the countries with significant space programs, Japan is the ideal candidate to pave the way for asteroid mining. The island nation is comparatively tiny and poor in mineral resources, but with a robust economy and a world-leading focus on science and technology. If Ryugu turns out to have significant deposits of cobalt, which plays an increasingly important role in the global economy thanks to its use in heavy-duty magnets and lithium-ion batteries, it's not out of the question that the next few centuries could see a space-based robotic mining operation providing a better alternative to the ethically and environmentally dubious practices that currently surround the acquisition of this rare earth metal.

That doesn't seem likely to happen for a while, but in the meantime, Hayabusa 2 is sure to provide an exciting show at the frontier of space exploration—you can follow the craft and its lander on Twitter for frequent updates on the mission's status; the teams managing their accounts do a great job of narrating the probe's journey from a first-person perspective, and convey all all the excitement that this extraordinary journey brings. Stay tuned for updates on what Hayabusa and MASCOT find!

—Stephen Skolnick

*For more on this mission and its goals, check out this interview with Haya2 project manager Hitoshi Kuninaka
Posted by Positron