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The Moon landings brought back samples of an extraterrestrial body.
But it would be 36 years before we could land on anything else
and bring bits of it home.
The goal was to bring home a new kind of sample, one that might date back
to the birth of our solar system and teach us a thing or two about early days on Earth.
For this mission, the Japanese team set their sights on the asteroid Itokawa.
And the spacecraft given this task was named Hayabusa.
It had a pretty rocky time, but ultimately, it was a huge success despite the setbacks.
Normally, for the chance to study asteroids, we have to let them come to us.
But in 2003, the Institute of Space and Astronautical Science,
the predecessor to the Japanese space agency JAXA, said “why wait?”
and planned the complicated trip for a probe to intercept Itokawa.
The asteroid was named after one of the fathers of Japanese rocket development,
Dr. Hideo Itokawa.
And Hayabusa, whose name means "falcon" in Japanese, was designed to
fly up to that asteroid, touch down, collect samples, and bring them back home.
But it didn’t have to make the journey alone.
Hayabusa traveled with a mini-lander on board: MINERVA,
which had its own goals to image Itokawa and take readings of its temperature.
While MINERVA’s work would happen only once it reached Itokawa,
Hayabusa would pioneer new technology to get there in the first place
and land safely, like autonomous navigation and electrical propulsion.
And, being the first mission to bring back asteroid samples,
not all of those new technologies worked perfectly.
In its first year of travel, Hayabusa encountered a solar flare that degraded its solar panels.
That meant Hayabusa’s ion engines didn’t have the power they were anticipated to have.
All in all, it was a bump in the road but nothing that Hayabusa couldn’t handle,
because two years after its launch,
Hayabusa made it to the Itokawa asteroid only a few months delayed.
Then came the landing… or multiple landings.
On November 4th, 2005, Hayabusa initiated its landing protocol and was nearing touchdown,
until its sensors detected some kind of interference above the asteroid surface.
It’s not clear what it was, so rather than risking a crash into an unexpected object,
Hayabusa aborted its first attempted landing.
One week after the first try, Hayabusa made it
far enough along the landing protocol to launch MINERVA.
But MINERVA never made it.
Hayabusa launched MINERVA a little too far from Itokawa’s surface.
And right after the deployment, Hayabusa automatically ascended
away from the asteroid, so neither of the robots touched Itokawa on that attempt.
Hayabusa still hadn’t landed on Itokawa
until the lucky third try one week after saying goodbye to MINERVA.
In what was becoming true Hayabusa fashion,
the landing was technically a success because it landed on the asteroid,
but it still didn’t go as planned.
Hayabusa lost contact with the team on Earth during touchdown,
and when the spacecraft came back online,
they realized that it had bounced twice and ended up 30 meters off target.
Don’t get me wrong, this was a huge success
as the first ever controlled landing on an asteroid.
But it didn’t hit the target it needed to, so the landing was promptly followed
by the first ever ascent from an asteroid 28 minutes after landing.
Now some explorers would have had to make do with the previous attempt,
but Hayabusa was prepared to try again.
This spacecraft had several fuel options to pull from,
so the solar panel issue didn't completely drain the onboard fuel reserves
required for another landing on Itokawa.
Finally, six days later, on November 25, attempt number four,
Hayabusa landed and fired two sampling bullets into the asteroid.
Those bullets collected samples totalling less than 1 gram
and held them in the re-entry capsule.
After all that trial and error, Hayabusa finally had what it came for.
But that tiny capsule of precious dust still had to make it back to Earth.
By 2010, Hayabusa had returned
and ejected the re-entry capsule to parachute down to Australia.
When it did, scientists analyzed it
to find that Itokawa was less dense than they thought, with porous insides.
They even found evidence of water in the minerals
that made up the returned samples.
That’s a far cry from liquid water, but it supports the idea that impacts
from similar objects could have been the source of up to half of Earth’s water.
But Hayabusa itself would only get so close to those sweet shores of home.
See, Hayabusa was never intended to return in one piece.
It had a bigger, brighter, destiny.
It was an opportunity to create an artificial meteor.
When meteors reach our atmosphere,
we don’t have any way of knowing what they’re made of.
We just see something burning up before our eyes.
So researchers took the opportunity to observe the light given off
from an object with a known composition.
They knew Hayabusa’s size, weight, and what it was made of.
So they watched it burn for science.
They observed Hayabusa as it hit the atmosphere and broke up into fragments.
Each fragment was accompanied by a large burst of light.
But the fragments didn’t each lead to one burst of light alone.
Instead, they each produced an additional ghost light that’s smaller, dimmer,
and farther away from the pieces of Hayabusa themselves.
And that will help scientists understand what it looks like
when other objects break up, too.
So Hayabusa got to go out in a blaze of glory,
and even its final moments had something to tell us.
But even though Hayabusa’s gone, it’s not forgotten,
and you can help memorialize it with this month’s SciShow Space Pin of the Month.
All year we’re celebrating missions that have explored the solar system,
and this month’s entry is the little falcon that could.
Like every pin of the month, this is a pre-order,
which means we’ll take orders all month,
then we’ll manufacture and ship all the orders we get.
And you’ll never be able to get this pin again…
but we’ll bring you another one next month, so stay tuned.
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