(dramatic electronic music)
It's an audacious plan, seemingly impossible,
launch a space craft to a nearby asteroid
180 million miles away, land safely on top,
take samples, and return unharmed to Earth
with a souvenir from space.
But yesterday the Hayabusa2 spacecraft came one step closer
to completing that plan,
as it successfully descended onto the asteroid Ryugu
before collecting the first of three samples
from this pristine object.
(scientists applaud)
This latest triumph from JAXA, Japan's space agency,
wasn't as easy as its daring success might make it seem.
Unforeseen hazards not only delayed the mission
but also endangered its success.
(speaking in foreign language)
After a 3 1/2 year journey through space,
on June 27th, 2018, Hayabusa2 arrived at its destination.
The carbon-rich half-mile wide asteroid
orbits the sun between Earth and Mars.
And this primordial near-Earth object
could one day unravel the clues of our early solar system.
(intense music)
That Ryugu is believed to contain the organic matter
and hydraulic minerals, very important ingredient of life.
Technologically, it's a sample return mission,
so not only going to that asteroid,
but get there and going back from the asteroid to the Earth.
So, it's a roundtrip mission.
The asteroids are leftover fragments
of the planet formation process
and have been sitting out in the solar system
for the past 4 1/2 billion years relatively undisturbed.
And so by studying these objects,
we're really able to peer back into the past
and understand what the conditions were like
as planets were forming, both chemically and physically,
and perhaps our best link to understanding how planets
in our solar system actually formed.
Missions to small asteroids like Ryugu
could help shed new light on the mystery
of our planet's formation.
Hayabusa2 will collect a total of three separate samples
from the asteroid before returning them back to Earth.
But it can't do it alone.
The spacecraft spent its first two months on Ryugu
mapping out potential landing sites for its four rovers,
who in turn will scour the asteroid's surface
for sampling sites.
An initial two rovers were deployed
on Ryugu to great success,
becoming the first ever to land on an asteroid.
Ryugu's low gravity makes driving on the surface impossible.
So instead, these rovers must hop from location to location,
floating for up to 15 minutes per bounce,
all the while snapping important photographs of the terrain.
These pint-sized robotic wonders,
measuring roughly seven inches by three inches
and weighing less than 2 1/2 pounds,
are only slightly larger than a cellphone.
But their diminutive size shouldn't take away
from their big accomplishments,
as they revealed the first detailed images
of the asteroid's surface.
(dramatic music)
Shortly thereafter, MASCOT,
Hayabusa2's larger tumbling rover,
landed on the asteroid's southern hemisphere,
safely protected from the sun's violent radiation.
Racing to take advantage of MASCOT's 17 hours
of operational battery life,
the German scientists and engineers
who designed the vehicle were able
to explore two areas of the asteroid,
compiling data on Ryugu's gravitational and magnetic fields
as well as images to help select the best sampling sites.
And what engineers saw changed everything.
Before arriving at its destination,
scientists thought that Ryugu's surface
would be flat and featureless,
perfect for landing the probe and sampling its material.
Instead, it soon became apparent that Ryugu is littered
with large, hazardous boulders,
disrupting years of meticulous planning
and putting the mission's fate into jeopardy.
Hayabusa2's sampling instrument was designed to pierce
what was thought to be a soft surface.
Instead, engineers back in Japan
now had to test whether or not the instrument would be able
to effectively pierce the rocky terrain.
While the instrument appeared to work in the lab,
Ryugu may not be so forgiving.
Finding a suitable landing site
brought a new set of headaches.
How do you find a safe spot
amid a minefield of dangerous rocks?
After scouring through the latest maps,
a new location, LO8-E1 was chosen.
The problem, the landing site is roughly six meters wide,
a far cry from the previously planned
100-meter wide location.
(tense music)
Yesterday, mission members held their breath
as the spacecraft descended 20 kilometers
toward the surface.
The procedure required extreme navigational precision.
One wrong step could lead to a mission-ending catastrophe.
A target marker resembling a small metallic sphere
was deployed at the landing site
to guide the spacecraft
as it auto-corrected to avoid disaster.
The moment of truth was finally at hand.
(scientists applaud)
And the smiles told the story as Hayabusa2 successfully dove
to the surface and collected its first sample.
The craft is now scheduled
to collect one more surface sample
before it attempts an unprecedented grand finale,
blowing up part of the asteroid
to collect an untouched subsurface sample.
The risky maneuver, currently scheduled for April 2019,
seems to have been pulled right
from a science fiction movie.
The spacecraft will release a single-shot free-flying gun
as well as a remote camera before positioning itself
a safe distance from the targeted explosion site.
Once the camera gives the all clear,
the gun fires a copper projectile toward the asteroid
from an altitude of 500 meters where it is expected
to produce a two-meter wide crater upon impact.
Hayabusa2 will then wait a few weeks for the dust to settle
before beginning its final descent
and collection of the subsurface material.
It will then fire up its iron propulsion thrusters
and begin its journey back to Earth.
At close proximity, Hayabusa2 will jettison the samples
through the atmosphere towards the Australian Outback,
arriving safely by 2020.
But JAXA is not the only space agency
in the asteroid collection business.
NASA providing a little bit of friendly competition as well.
The OSIRIS-REx spacecraft has reached its own target, Bennu,
after a similar two-year journey.
Currently in orbit around the asteroid,
it too will take samples and return them to Earth.
While the spacecraft's mission will take longer
than its Japanese counterpart,
the asteroid's sample hull
will be 20,000 times larger than Hayabusa2's.
But space exploration is all about collaboration.
The two space agencies have agreed
to share their asteroid samples with one another.
NASA will receive 10% of Hayabusa2's collected sample,
while JAXA will receive a half a percent
of OSIRIS-REx's much larger hull.
Only time will tell what secrets
of the cosmos will be revealed
when these asteroids arrive to Earth.
(calm music)