Two daring spacecraft aim to bring asteroid dust back to Earth

by:KKR Stone     2020-07-07
Welcome the fear of the provincial orange asteroid Dragon Palace.
The University of Tokyo\'s space chemist spent 10 years helping to design a mission to the surface of the Dragon Valley.
For a safe landing, the ship Hayabusa2 needs to find a wide and flat fine-
Dust on asteroids.
But in June 27, threeand-a-half-year journey ()
The Orange is the first one: the rock covered by the Dragon Palace. Big ones.
\"We can\'t find a 100% safe place to land,\" Tachibana said . \".
\"It seems to be a very dangerous place.
If Hayabusa2 can handle boulders
And any other challenges that arise.
It will be the second spacecraft to bring an asteroid back to Earth.
The delegation will answer questions that could not be answered by its predecessor.
The original Hayabusa delegation visited a beachand rock-
The asteroid Itokawa, which was covered in 2005.
But Itokawa has the wrong chemistry to solve the big problem about the origin of the life of this carbon in longgu
Suitable for the rich.
Hayabusa suffered a series of disasters that caused it to return to Earth in a few years, with less than 2,000 precious asteroid dust.
Tachibana of Japan\'s Aerospace Research and Development Agency (JAXA) and his colleagues are counting on Haybusa2 to return the surface part of the Dragon Valley to Earth in 2020.
If a bold plan to send a crater into an asteroid succeeds, the spacecraft will also get some underground particles.
A sister program at NASA, OSIRIS-
REx mission, brought back samples on December, 2023 ().
The two ships face serious challenges.
The probe must study objects whose gravity is so small that the sun can knock them off the track.
If the probe is able to collect samples, the spacecraft must maintain the original state of dust as it returns to Earth.
To make the most of these tasks, teams in Japan and the United States are working to cross cultural and bureaucratic differences.
But this uncertainty and anxiety is worth it.
Asteroids like Dragon Valley and Benu are one of the oldest and most interesting celestial bodies in the solar system.
They can master the key to some of the most pressing planetary problems: what is the origin of life before the planets, and how much the asteroid poses a threat to life on Earth. Of course, planetary scientists already have thousands of asteroid debris to study.
These meteorites fall to Earth every year, providing researchers with a great deal of material to cut, grind and study the history of the solar system.
Dante Lawrence Tower at the University of Arizona in Tucson, chief researcher at OSIRIS
Rex, in the first part of his career, tried to convince the meteorite to tell him if he needed molecules in his life.
For example, nucleic acids, amino acids and phosphorus as structural components of DNA
Probably originated in carbon-
Rich asteroids like Dragon Valley or Benu. Carbon-
Rich asteroids have been considered largely unchanged since their formation.
6 billion years ago, it made them perfect time capsules.
Some particles of such an asteroid can reveal what the early solar system was made.
The remote study of asteroids also shows that the original composition of life, even the chemical process necessary for the beginning of life, may exist in carbon-
Even before the planets grow, there are abundant asteroids.
\"We think that an asteroid like this may have sent this material to the surface of the early Earth, providing a seed or an integral part of life,\" Lawrence Tower said . \".
\"If we can show [the predecessor]of life]
From before Earth, I think the possibility of life in other parts of the solar system has increased significantly.
However, it is not enough to study meteorites to explore the concept in two ways: it is difficult to judge where they come from and they are contaminated.
Once the space rock hits the Earth\'s atmosphere, it begins to accumulate signs of life on Earth.
Therefore, any interesting organic compound in the meteorite may come from Earth, not from the asteroid itself.
There is no way to tell you.
\"We need samples of carbon.
\"The rich asteroids really answered my question,\" said Lawrence Tower . \".
Understanding the origin of the solar system, perhaps the beginning of life, makes it essential to bring clean, carefully selected samples to Earth Labs.
But the ship can\'t dig in with a shovel.
Didn\'t grab stones with claws like in arcade games.
The asteroid is so small.
From pole position to pole position, longgu is about 880 and Benu is about 510-
Their gravitational pull is so weak that reaching out and grabbing something might get the spacecraft off track with the asteroid.
So the spacecraft will reach out with proboscis instead of scooping or grabbing
Like a tube, either briefly touch down or hover over the surface.
This tricky effort has only been tried once before.
This is almost a disaster.
When the first Hayabusa spacecraft circled near the surface of Itokawa, it should use its three reaction wheels to stabilize itself and reach out to the surface of the collection tube, and a small bullet was fired inside the tube to stir the dust particles.
These dust particles will float on the tube and enter the sterile chamber for storage on the journey back to Earth.
Almost everything went wrong.
Before Hayabusa arrived at the asteroid, the largest sunspots of all time damaged the spacecraft\'s solar panels and one of its engines, slowed down the speed of the spacecraft, and delayed the asteroid rendezvous by three
Once in Itokawa, the two reaction wheels of the process fail, making it difficult for the process to maintain a uniform keel.
Hayabusa released a companion detector designed to land on the surface of Itokawa and measure the composition of the asteroid, but it is not marked and floats in space. The dust-
The stirring bullet did not fire, so it was not initially clear if there were any samples of the aircraft.
On the way back, the four engines of the probe failed one by one, forcing Hayabusa to detour home.
\"It has a lot of serious problems,\" said JAXA\'s Makoto Yoshikawa . \" He is the task manager for Hayabusa and hayabusa2.
For all the disasters of Hayabusa, the story of the mission has a complete ending.
The spaceship is desperate ()
Seized 1,534 Itokawa.
The planners of the new mission learned from the accidents of the original mission.
Hayabusa2 has four reaction wheels.
The engine and the more powerful communication system will send back more data to help scientists plan sample collection.
Even if the bullet is not fired, the mouth of the collection tube has teeth to feed the pebbles into the tube.
On September, hayabusa2 collected data on the composition, temperature and magnetic properties of asteroids on the surface of Ryugu ().
A similar warning when OSIRIS-
Rex goes in and collects samples from Bennu, which will only touch the asteroid briefly.
\"It\'s like five seconds of contact,\" said Lawrence Tower . \".
\"Get the sample and leave there.
The touch of the spacecraftAnd-
Go sample collection mechanism TAGSAM has a nitrogen jet at the end of the robot\'s arm.
When the arm touches the surface of Bennu, it releases a burst of nitrogen that folds the surface enough to blow the particles into the sample collector.
As a reward, the head of the sample collector is covered with stainless steel Velcro-
Just like a pad that can pick up surface dust when in contact. The remote-
Reach strategy avoids the hassle of anchoring an asteroid, but also raises its own question: no one knows how good it is --
When blowing around under low gravity, the behavior of the particle dust.
The engineers are worried about this problem.
\"When you come into contact with the surface of an asteroid, what actually happens is an unknown physical field,\" Lawrence Tower said . \". “I think [the surface]
It\'s like a liquid.
This is a really strange landscape.
When Hayabusa returned, Michelle Thompson, a planetary scientist at the University of tepudu, West Lafayette, New York.
The Itokawa grain was studied.
Such a limited supply forces scientists to get the most out of the sample.
Chapter 1 of Dr. ThompsonD.
The paper is about an Itokawa particle measuring 50 microns.
\"We still get some amazing science from these particles,\" she said . \".
These particles prove that most of the meteorites on Earth come from stones, carbon.
Poor asteroid like Itokawa).
\"In the context [Hayabusa’s]
\"The problem is that the amount of data generated by this task is incredible,\" Thompson said . \".
When Hayabusa struggled in space in 2006, the team at Yoshikawa had suggested that JAXA fly one to follow. up mission.
By then, Ji Chuan has set his sights on the Dragon Valley, a more attractive asteroid.
JAXA sent a spaceship to Itokawa because it was easy to reach, not because it was scientifically special.
But as a carbon
Longgu, a rich asteroid, is considered the oldest and most primitive material in the solar system.
The name of the Dragon Valley even cites a time capsule in a Japanese folk story in which hero Urashima Taro retrieved a box from the Dragon
The guarded castle is located on the bottom of the Sea, called Dragon Valley.
When the hero returned to the surface, he found that 300 had passed.
When he opened the box, he became an old man because the box contained all the passing time.
Ji Chuan and his colleagues put forward the task every year and were rejected every time --
Until Hayabusa came home on 2010.
Yoshikawa said the return of the spacecraft was praised in Japan.
\"The Japanese people were very surprised to see that Hayabusa really came to Earth.
An editorial on the ship was considered a \"high achiever\" and called for more funding for JAXA and space research.
On May 2011, the government of Japan approved the Hayabusa2 mission.
Orange, Ji Chuan, and other cosmic groups were able to launch the window for the next time, on 2014.
Like Hayabusa2, OSIRIS-
Before NASA chose Rex to fly, Rex was repeatedly rejected, also in May 2011.
Due to the orbit of Bennu, the next launch opportunity to reach the asteroid was until September 2016. That two-
The annual gap between JAXA and NASA launch has sparked some friendly competition among the teams.
\"Of course, we are good friends and we want to have a good relationship,\" Tachibana said . \".
\"But we are also competitors. ” OSIRIS-
REx is larger than Hayabusa2 and plans to collect up to 20,000 times of asteroid dust
Up to two kilos, the best-
This is the case compared to hayabusa2\'s total dose of 100 mg.
For the sake of competition, says Tachibana, hayabusa2\'s team started doing everything first.
\"They are worried that we will cast a shadow over them,\" said Lawrence Tower . \".
He recalled that the initial meetings between the teams were tense.
But both groups think it\'s better to work together.
\"This is the first time since Apollo . . . . . .
\"Returning tasks will achieve the same goal,\" said Tachibana . \". “The U. S.
The Soviet Union could not talk to each other.
\"It was in the middle of the Cold War.
\"We can talk to each other this time.
On November 2014, NASA and JAXA signed a memorandum promising to share data, software and samples.
JAXA will provide NASA with 10% samples of Dragon Valley, and NASA will provide 0 samples.
5% of JAXA\'s larger Bennu sample.
Nevertheless, the two space agencies are inconsistent on all issues.
\"Hayabusa2 and OSIRIS-
Cosmic chemist nak Zi said: \"Rex has a completely different philosophy of sampling.
NASA Johnson Space Center Messenger in Houston
She oversees sample site selection for OSIRIS
Rex will be responsible for storing samples.
Schedule by task: OSIRIS-
REx will spend more than a year drawing the Bennu map in detail.
Its set of scientific instruments, including three cameras, a laser height meter and three optical meters, will figure out what the asteroid is on the entire surface before the team selects the unique sampling location of the task
On the other hand, Hayabusa2 scientists in August, less than two months after the spacecraft arrived at Willow Valley ().
Initially, the team planned to collect the first sample in October, but it turned out that boulders were very difficult, so the sampling was delayed until February 2019 at the earliest.
Hayabusa2 will sample the three sites to capture as many mineral diversity of asteroids as possible.
One of the samples will come from several-meter-
A wide crater that does not exist yet.
The ship will make the hole by firing two bullets.
The kilogram of copper is thrown on an asteroid and then hidden on the other side of the Dragon Valley to avoid debris when the projectile hits.
The purpose is to see if the interior of the asteroid is different from the surface.
It\'s hard to imagine NASA approving such a crazy move, Nak said.
A messenger who grew up in Japan. It’s too risky.
\"The way NASA does it is: the success rate must be very high,\" she said . \".
But she supported hayabusa2\'s bold move.
\"I am Japanese in my heart,\" she said . \"
\"So, I think, \'Go!
Still, the surprise of Dragon Valley at Boulder Stadium has made Lawrence Tower in laure village-
Messenger and other Osiris.
The Rex team is nervous about Bunu.
\"I \'ve been awake at night and looking forward to Benu,\" said Lawrence Tower . \".
\"It was a charming and terrible time.
\"In line with NASA\'s cautious approach, OSIRIS-
The REx team knows much more about Bennu than JAXA knows about Ryugu before the mission starts.
On 1999, Bennu was close enough to Earth, 2005 and 2011 M, and the radio telescope could map the shape of an asteroid (
Although not close enough to reveal a lot of details).
\"We compiled the most comprehensive database of astronomy for any asteroid in the solar system,\" Lawrence Tower said of the team\'s previous work with Benu.
These radio measurements allow researchers to see how sunlight pushes asteroids into orbit, a phenomenon known as the yakofsky effect.
When asteroids roll in space, they absorb the sun on one side and re-
When the sides are away from the sun, energy is emitted later as heat.
The power to radiate heat is enough to push the asteroid around, which makes it difficult to predict the orbit of the asteroid in the long run.
The yakofsky effect calculation gives a worrying prediction: the probability of Bennu hitting the Earth at the end of the 22nd century was 2,700, one of the highest probability of any known asteroid.
Only when Bennu is smooth enough for the spacecraft to get a sample. as OSIRIS-
REx\'s contact with Bennu did not calm the team\'s concerns in December 3.
Kevin Walsh, a planetary scientist at the Boulder Southwest Institute in Colorado, said that with a meat eye, Benu seems to have as many boulders as longgu, perhaps a little less.
\"Even if we convince ourselves to have a free boulder site, it\'s likely to change later.
\"So we have to look,\" Walsh said, who made an early comparison between Benu and Willow Valley in Washington, D. C. , on December 11. C.
Conference of the American Geophysical Union
\"We have a lot of tools to find the least dangerous places, even if we can\'t find a place where there is no danger at all.
It\'s a relief, nak-Messenger says.
But every mission so far surprised her.
\"I don\'t guess at random anymore,\" she said . \".
\"Nature is wild.
Science News.
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