A space capsule carrying dust and rocks from an asteroid is expected to land in the South Australian desert early Sunday morning.
- The Hayabusa2 probe was launched in 2014 and took four years to reach its destination
- His capsule is within hours of landing on earth
- Scientists hope to learn a lot about the early solar system
The Japanese capsule Hayabusa2, which is returning from its mission to the asteroid Ryugu, is expected to land on the Woomera Forbidden Area approximately 500 kilometers northwest of Adelaide at approximately 4:00 am (local time).
It will put on a spectacular show in the morning twilight as it makes its way to Earth.
Then the hunt will begin to find the landing spot.
Professor Fujimoto said the mission will help scientists answer some of the fundamental questions about how our solar system formed and where elements like water come from.
“By studying the Ryugu sample we will be able to understand the process that made our planet habitable,” he said.
“The reason we care about these primordial asteroids is that they are connected to the process that made our planet possible.”
Hayabusa2 will be the second asteroid champion mission to return to Woomera, a 122,000-square-kilometer defense area that encompasses the traditional lands of six Aboriginal groups.
In 2010, Hayabusa1 returned with specks of dust blown off the surface of an asteroid called Itokawa.
There are many similarities between the two missions and some fundamental differences.
The mission at a glance
Launched in 2014, Hayabusa2 took four years to reach the diamond-shaped space rock between Earth and Mars.
When he arrived, the scientists realized that Ryugu was covered by far more boulders than they expected, but they eventually grounded two “hopping” rovers. and blew up a crater to collect rock fragments.
While Hayabusa1 has collected dust from the surface, this is the first mission to collect rocks from below the surface.
“When we got to Ryugu we were so shocked to see the rock surface everywhere, so it was really hard to find a landing spot, but we made the touchdown twice,” said Professor Fujimoto.
The cameras on the spacecraft indicate that it has collected about 1 gram of space dirt.
In November last year, the spacecraft began its journey back to Earth.
After traveling more than 5.2 billion kilometers in six years, it is ready to send the capsule to Earth.
Unlike last time, the same Hayabusa2 spacecraft will not return to Earth.
Instead, after separating from the capsule a day before landing, it will fly away on a new mission to meet three other asteroids between 2026 and 2031.
So what’s the landing plan?
As the capsule descends towards Earth at supersonic speeds, its trajectory will be traced by teams of scientists scattered hundreds of kilometers on the ground and in the air.
As the only international observer, Australian scientist Trevor Ireland will be aboard the helicopter tasked with locating the capsule somewhere in an area tens of kilometers wide.
“We should pretty much know where it is as it goes down,” said Professor Ireland of the Australian National University, who was also on the science team for the Hayabusa1 mission.
As the capsule slows down in Earth’s atmosphere, the heat shield around it will glow like a fireball for about 40-50 seconds above Coober Pedy, 400 kilometers north of Woomera.
‘The last time was very spectacular because the spacecraft came with it,’ said Professor Ireland.
“This time we don’t want it to be that spectacular, we just want to see that beautiful red glow of the oncoming space capsule.”
Once the capsule slows down enough, it will deploy a drag parachute and then a second main parachute.
Scientists, including four teams from the Desert Fireball Network at Curtin University, will track the capsule’s trajectory as it crosses the sky.
“The Desert Fireball Network team will be installing cameras all along the Stuart Highway to take pictures of this brilliant shooting star,” said team leader Ellie Sansom, currently in Coober Pedy.
The Desert Fireball Network has also teamed up with a group of Japanese researchers who can’t be in Australia due to the COVID-19 pandemic, and is putting out tools from them that listen for the sonic boom and detect any ground shaking.
In Woomera, more than 70 Japanese scientists will track the descent using radar, Professor Ireland said.
“The radar guys will have a much longer view of it when it arrives because once the parachute is opened they will have a bigger object to look at,” he said.
A beacon on the capsule will help Japanese scientists refine the position.
‘The last time the radio signals were within a few hundred meters,’ said Professor Ireland.
Meanwhile, NASA scientists flying two airplanes will watch as the material blows off the capsule’s heat shield as it descends.
Could the weather affect the landing?
Clouds not really. Wind definitely.
Meteorites fall into Earth’s atmosphere all the time regardless of clouds, but strong winds could affect where the capsule lands.
‘When the capsule is under the parachute, it can travel a reasonable distance,’ said Professor Ireland.
“The last 10 kilometers are the big deal as it’s going down, once it gets into our weather systems.”
If the weather is not favorable, it will also make recovery a little more complicated.
“If it’s not a very nice day, they will try to contain it very quickly so it doesn’t get covered in dust or rain.”
What happens when it lands?
Once the capsule lands, a team including Professor Ireland will head out to find it.
“I would be very surprised if it was a long search,” he said.
Once the capsule is deemed safe, the team can get to work to make sure there are no cracks or contamination.
“The last one [from Hayabusa1] it was absolutely pristine, there wasn’t a mark on it, “he said.
“It was inside these heat shields as it’s coming down, and space … it’s not a dirty environment, so we don’t think there will be too much contamination.”
The team will then take the sample back to base, where it will check for gas leaking from the capsule – an initial indication that they have a sample inside.
It will then be packed and sent back to Japan for weighing and analysis.
“We should have a pretty good idea within a couple of weeks that there is a champion there,” said Professor Ireland.
What do scientists hope to learn?
Asteroids can tell us how our solar system was formed.
‘All this little information is important in understanding what happened 4.5 billion years ago,’ said Professor Ireland.
While Itokawa is an S-type or stony asteroid thought to come from the inner solar system, Ryugu is a C-type asteroid, believed to contain organic material and water from the outer solar system.
Although type C asteroids are the most common type (about 75% of asteroids are type C), meteorites from them rarely make it to Earth.
“If we can relate both of these two types of asteroids to meteorites arriving on Earth, then we have a much better solution as to what is really happening with our meteor collections.”
That said, there are a lot more meteorites and asteroids out there.
NASA’s OSIRIS-Rex mission, which is currently exploring another C-type asteroid called Bennu, will return to Earth, landing in Utah in 2023.
Professor Ireland will also be involved in the analysis of Bennu’s powders.
“Meteorites are beautiful, they give us those early solar system stamps, but there’s nothing like getting a sample.”