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The Japanese space agency is nearing the end of a voyage of discovery that aims to shed light on the early eons of the solar system and possibly provide clues to the origins of life on Earth.
But first, you will have to go on a scavenger hunt in the Australian outback.
This weekend, pieces of an asteroid will land in an arid region near Woomera, South Australia. These are being transported to Earth by Hayabusa2, a robotic space probe launched by JAXA, the Japanese space agency, in 2014 to explore an asteroid called Ryugu, a dark, carbon-rich rock just over half a mile wide.
The success of the mission and the science it produces will elevate Japan’s status as a central player in deep space exploration, along with NASA, the European Space Agency and Russia. JAXA currently has a spacecraft in orbit around Venus studying the planet’s hellish weather and is collaborating with the Europeans on a mission to Mercury.
In the next few years, Japan plans to bring back rocks from Phobos, a Mars moon, and contribute to NASA’s Artemis program to send astronauts to Earth’s moon.
But the immediate challenge will be searching in the dark for a 16-inch-wide capsule containing the asteroid samples somewhere in the middle of hundreds of square miles in a region 280 miles north of Adelaide, the nearest large city.
“It’s really in the middle of nowhere,” said Shogo Tachibana, the principal investigator in charge of analyzing the Hayabusa2 samples. He is part of a team of more than 70 people from Japan who have come to Woomera for the recovery of the capsule. The area, used by the Australian military for testing purposes, provides a wide open space that is ideal for the return of an interplanetary probe.
The small return capsule separated from the main spacecraft about 12 hours before the scheduled landing, when it was about 125,000 miles from Earth. JAXA will broadcast live coverage of the capsule landing beginning at 11:30 am ET on Saturday. (It will be hours before sunrise on Sunday in Australia).
The capsule is expected to hit the ground a few minutes before noon.
In an interview, Makoto Yoshikawa, the mission director, said there is an uncertainty of about 10 kilometers, or about six miles, in determining where the capsule will re-enter the atmosphere. At an altitude of six miles, the capsule will launch a parachute and where it will drift as it descends will increase uncertainty.
“The landing site depends on the wind that day,” Dr. Yoshikawa said. The area that searchers might have to cover could extend to about 60 miles, he said.
The superheated air fireball trail created by the re-entering pod will help guide the recovery team, as will the pod’s radio beacon. The task will be much more difficult if the beacon fails or if the parachute does not deploy.
There is also a bit of a rush. The team hopes to recover the capsule, conduct an initial analysis, and quickly return it to Japan within 100 hours. Despite the capsule being sealed, the concern is that Earth’s air is slowly seeping through. “There is no perfect seal,” said Dr. Tachibana.
Once the capsule is found, a helicopter will take it to a laboratory that has been installed at the Australian Air Force base in Woomera. There, an instrument will extract the gases inside the capsule that may have been released by the asteroid’s rocks as they were shaken and broken during re-entry. Dr. Yoshikawa said that scientists would also like to see if they can detect helium particles from the solar wind that slammed into the asteroid and became embedded in the rocks.
The gases would also reassure scientists that Hayabusa2 did indeed collect samples from Ryugu successfully. It takes a minimum of 0.1 grams, or less than 1/280 of an ounce, to declare success. The hope is that the spacecraft has recovered several grams.
In Japan, the Hayabusa2 team will begin the analysis of Ryugu’s samples. In about a year, some of the samples will be shared with other scientists for further study.
To collect these samples, Hayabusa2 landed on the asteroid in June 2018. It ran a series of investigations, each of increasing technical complexity. He launched probes to Ryugu’s surface, opened a hole in the asteroid to look at what’s below, and descended twice to the surface to grab small chunks of the asteroid, an operation that proved much more challenging than expected due to the many rocks in the surface.
Small worlds like Ryugu used to be of little interest to planetary scientists who focused on studying planets, said Masaki Fujimoto, deputy director general of the Institute for Space Science and Astronautics, part of JAXA. “Minor bodies, who cares?” he said. “But if you are serious about planetary system formation, small bodies really do matter.”
Ryugu’s study of mineral-trapped water could provide clues as to whether the water in Earth’s oceans comes from asteroids and whether carbon molecules could have seeded the building blocks of life.
Part of Ryugu’s samples will go to NASA, which is bringing back some rocks and dirt from another asteroid with its OSIRIS-REX mission. The OSIRIS-REX space probe has been studying a smaller, carbon-rich asteroid called Bennu and will start back to Earth next spring, leaving its rock samples in September 2023.
Ryugu and Bennu turned out to be surprisingly similar in some ways, both looking like tops and rocky surfaces, but different in other ways. Ryugu rocks seem to hold much less water, for example. The importance of similarities and differences will not become clear until scientists study the rocks in more detail.
“When the OSIRIS-REX sample returns, we will learn lessons from the Hayabusa2 mission,” said Harold C. Connolly Jr., a geology professor at Rowan University in New Jersey and a mission sample scientist for OSIRIS-REX. “The similarities and differences are absolutely fascinating.”
Dr. Connolly hopes to go to Japan next summer to participate in the analysis of Ryugu’s samples.
Hayabusa2 is not Japan’s first planetary mission. In fact, its name points to the existence of Hayabusa, a previous mission that brought back samples from another asteroid, Itokawa. But that mission, which launched in 2003 and returned in 2010, faced significant technical problems. So did JAXA’s Akatsuki spacecraft, currently in orbit around Venus, which the Japanese agency managed to restore to a science mission after years of hardship. A Japanese mission to Mars also failed in 2003.
By contrast, Hayabusa2’s operations have gone almost smoothly, although it retains the same overall design as its predecessor. “Actually, there are no big problems,” said Dr. Yoshikawa, the mission director. “Of course, little ones.”
He said the team studied the Hayabusa faults in detail and made the necessary changes, and also conducted numerous trials to try to anticipate any contingencies it might encounter.
Japanese missions generally operate on smaller budgets than NASA’s, and therefore typically carry fewer instruments. The cost of Hayabusa2 is less than $ 300 million, while the price of OSIRIS-REX will be around $ 1 billion.
Leaving Ryugu’s samples is not the end of the Hayabusa2 mission. After releasing the return capsule, the main spacecraft changed course to avoid a collision with Earth, losing 125 miles. It will now travel to another asteroid, a tiny one designated 1998 KY26 that is only 100 feet in diameter but spins rapidly, completing one rotation in less than 11 minutes.
Hayabusa2 will use two flybys of Earth to launch towards KY26, finally arriving in 2031. It will conduct some astronomical experiments during its extensive journey into deep space, and the spacecraft still carries one last projectile that it can use to test the surface of that rock. space.
