How precious are asteroid samples? Scientists are anxious because they can't retrieve them after collecting them

Collecting samples from distant asteroids is an extremely difficult aerospace project, and few countries can currently do it. To achieve the return of asteroid samples, in addition to manufacturing highly reliable and adaptable unmanned probes that can travel through deep space, it is also necessary to have precise navigation capabilities, high-resolution imaging capabilities, and highly intelligent self-controlled drilling and collection technologies. Only by traveling billions of kilometers through deep space and going through life and death can a little bit of sample be brought back to Earth.

Currently, the only missions that have brought back asteroid samples from deep space are Japan's Hayabusa and Hayabusa 2, and NASA's OSIRIS-REx.

Hayabusa was launched in 2003 and returned with samples from the asteroid system Ryugu in 2010. It took seven years and traveled about 6 billion kilometers, but only retrieved 1,500 particles smaller than 10 microns, with a mass that can only be measured in milligrams. Hayabusa2 was launched in 2014 and returned to Earth in 2020 with samples from the asteroid Ryugu, collecting only 5.4 grams of gravel samples.

Scientists have used this small amount of asteroid samples to fill in many gaps in our understanding of the solar system. The most important discovery is that the samples contain at least 20,000 chemical components, including 20 types of amino acids. Liquid water was also found, which is the first time that humans have discovered the source of life outside the Earth.

Therefore, many scientists are convinced that life on Earth is most likely an alien, and that the seeds of life were brought to Earth by meteorites and then nurtured and evolved. Research is still ongoing, and as discoveries continue to deepen, more and more discoveries will be made about the formation of the solar system and the mysteries of the birth of life.

Therefore, exploring asteroids is an important activity in the world's aerospace industry, and has become a hot topic of competition among major space powers in recent years. The Osiris-REx probe launched by the United States in 2016 also took 7 years and traveled 6.4 billion kilometers to collect samples from the asteroid Bennu. It returned to Earth on September 24, 2023, and the released sample capsule successfully landed in Utah.

This is the first asteroid sampling probe launched by NASA, and the amount of samples collected is relatively large, so the scientific community has high expectations for this sample. However, after going through numerous difficulties and dangers, the samples were collected because the sealed can was stuck and the lid could not be opened, so the samples stayed inside, and the scientists were helpless and could only stare blankly.

Some friends may say that the samples have returned to Earth, and the containers are made by humans, so how can they not be opened? They can be pried open with an iron rod. Those great thieves in movies and TV shows can enter the most secure and solid vaults or bases as if they were in an empty space. Are these scientists not even as good as thieves?

In fact, this idea is too simplistic about the samples collected from outer space. These samples are much more valuable than any treasure on Earth. Even the samples collected from the moon are worth at least one million yuan per gram. For example, the Chang'e 5 mission cost 3 billion yuan to manufacture and launch, and brought back 1,731 grams of lunar samples. If we only count the value of the retrieved lunar samples, each gram is worth more than 1.7 million yuan, not including the research expenses of many scientists.

Sampling from asteroids requires much greater distance and is much more difficult than sampling from the moon. For example, Japan's Hayabusa 2 mission invested approximately $150 million and brought back 5.4 grams of samples from the asteroid Ryugu, at a cost of nearly $28 million per gram. NASA's OSIRIS-REx probe had a total investment of $1 billion and brought back 121.6 grams of samples from the asteroid Bennu, at a cost of $8.22 million per gram.

Therefore, the samples retrieved from asteroids are the most precious treasures on Earth. In order to ensure the purity of these treasures after they arrive on Earth, the most stringent sealing measures must be taken. They cannot be exposed to any dust, and not a trace of gas from the Earth's environment can come into contact with these treasures from outer space. This requires the probe to perform a series of complex sealing measures after taking samples in distant space, and it also needs to be opened in special closed facilities after returning to Earth.

These complex operations include: how the detector collects samples, how to transport them in a sealed manner, how to open the sample cabin, how to remove the sample sealing device, how to open the sealed sample can, and how to remove the sample. Each step must be very precise to ensure the original state of the sample. These were carefully considered when the detector was designed, and the entire step method was actually practiced several months before the return of the detector.

The sampling and recovery process of the OSIRIS-REx detector is roughly as follows:

The OSIRIS-REx probe was launched in September 2016. After arriving at Bennu in 2018, it observed the asteroid for two years and only quickly approached the surface of Bennu in 2020. The sampling method was that at the moment of approaching the surface of Bennu, the probe sprayed nitrogen to stir the rocks and dust on the surface of Bennu, and swept the flying samples into the collector.

In fact, the Bennu asteroid, with a diameter of about 490 meters, is not a whole piece of interstellar rock, but a group of loose stones adsorbed together. This composition allows the probe to blow up more rock dust and collect a large number of samples, so that the extra samples are stuck on the outside of the collector.

After completing the sampling, the OSIRIS-REx probe will put the collector on its head into the sample chamber at the bottom of the probe. After confirming by shaking that the sample chamber is sealed and securely locked, it will begin its return journey in July 2021 and return to Earth in September 2023. It will release the return capsule in Utah, USA, and achieve a soft landing. Then, the probe, which has completed its mission, will fly past the Earth and enter a solar orbit to live its retirement life.

After receiving the return capsule, NASA staff carefully transported it to a nearby portable clean room, removed the heat shield and outer shell of the sample capsule, took out the collector, and sent it to a dedicated clean room at the Johnson Space Center in Houston within 24 hours to transfer the collector to the glove box.

The accident happened at this time. The research team found that the mouth of the sealed jar was stuck and could not open the large number of samples. Although it seems that this kind of jam can be opened with the right tools, in the extremely clean glove box, putting any tools in may destroy the purity of the samples. Therefore, scientists can only stare blankly and have not found a solution yet!

In other words, it is not that there is no way to open the stuck sample collector, but that the scientists are helpless because no disassembly tools can be put into the extremely clean glove box. If it is just an ordinary tank, any normal person can open it with conventional tools, but this is a sample of the Bennu asteroid that costs $4.26 million per gram, and no molecule of earth material is allowed to be mixed in.

So, are the samples collected from billions of kilometers useless? In fact, it is not that serious. On the contrary, there are more surprises: scientists have already obtained 70.5 grams of samples from the outside of the sample sealed tank. The original plan for this mission was to bring back a total of 60 grams of samples. Now, before opening the sealed collector tank, the mission has been completed by 17.5% more than the target.

About 30% of the samples from Bennu will be distributed to relevant laboratories around the world for research by 200 scientists, of which 4% will be given to Canada and 0.5% to Japan. NASA will keep at least 70% of the samples at the Johnson Space Center and temporarily seal them for further research by more scientists in a few years. As for the remaining samples stuck in the sample cans, scientists will soon find the "wrench" to open them.

Scientists have spent a huge amount of money to retrieve this little dust from a distant asteroid. Many people do not understand why they spend so much money and high technology to study the earth and help the poor. Of course, there are many scientists doing this kind of work, but what makes scientists different from ordinary people is that they have a longer-term vision and want to find out the truth of the universe.

Exploring and studying asteroids is to find out the truth about the solar system, how the earth was formed, and the past, present, and future of life and human beings. Understanding these will play a key role in the continuation and development of human beings in the future, avoiding cosmic disasters, and allowing human beings to go further on the road of reproduction.

Therefore, the expeditionary exploration of asteroids will continue. China's asteroid exploration program has also been launched, and it is expected to launch its first asteroid probe in 2024 to explore two celestial bodies at a time, namely an asteroid and a comet. There will be more exciting stories about asteroid exploration in the future, so let's wait and see.

This is an original article from Space-Time Communication. Please respect the author’s copyright. Thank you for your understanding and support.

Reference link: https://link.zhihu.com/?target=https%3A//www.iflscience.com/nasa-brings-back-actual-sample-of-asteroid-but-cant-open-the-lid-71285