Perseverance "takes a loneliness", why is it difficult to sample Mars?
According to media reports, NASA announced on August 7 that the Perseverance rover tried to collect rock samples on Mars and sealed them in a sample tube for the first time, but the data sent to the earth later showed that the sampling activities did not collect them. Rock samples.
Some netizens described it with regret: Perseverance "takes a loneliness" this time.
However, space experts still give it high praise.
Yang Yuguang, a researcher at the Second Academy of China Aerospace Science and Industry Corporation, said that although the Perseverance has not achieved results in this soil sample collection, this is the first attempt by humans to complete soil sample collection on Mars and bring it back to Earth for analysis. It is directly on Mars in the past. Compared with the related research and analysis work carried out with the stone-seeking cart, it has taken an important step forward.
Jiao Weixin, a professor at the School of Earth and Space Sciences at Peking University, believes that sampling return is the only way for manned exploration of Mars in the future.
Sampling and conducting research on extraterrestrial objects is one of the important means for mankind to explore the universe.
In the history of world spaceflight, humans have collected samples from the moon many times, providing direct evidence for scientists to study the moon.
According to Pang Zhihao, chief science communication expert of national space exploration technology, sampling of extraterrestrial objects is mainly divided into two methods: unmanned sampling and human sampling.
On September 12, 1970, the Soviet Union launched the Lunar 16 probe, which successfully reached the moon and retrieved 101 grams of lunar samples.
However, because the Soviet Union did not master the unmanned rendezvous and docking technology in lunar orbit at the time, the country only brought back 326 grams of samples during the three successful lunar sampling missions in the 1970s.
In the US Apollo program, astronauts personally "moved bricks" and collected about 380 kilograms of lunar samples.
Pang Zhihao said that comparing the two sampling methods has advantages and disadvantages.
Someone sampling can give full play to human subjective initiative, and astronauts can deal with and repair some technical problems on the spot, but the technology is undoubtedly more complicated to send people to other planets.
The cost and technical threshold of unmanned sampling is relatively low, but various unexpected problems may be encountered during the sampling process.
To compare samples from the Moon and Mars, the latter is undoubtedly more difficult.
Pang Zhihao said that the average distance between the earth and the moon is about 380,000 kilometers, while the distance between the earth and the fire is between 50 million and 400 million kilometers, which requires higher thrust for the launch vehicle.
At the same time, the gravitational force of Mars is about twice that of the moon's gravitational force, which brings greater challenges to the spacecraft's take-off and ascent.
In fact, the above-mentioned difficulties are mainly reflected in the round-trip process of the spacecraft, but the Perseverance did not even collect samples this time.
It is understood that Perseverance’s sampling and storage system uses hollow core bits and percussion bits at the end of an approximately 2-meter-long robotic arm to extract samples.
It carries 43 titanium sample tubes, and plans to collect samples of rocks and weathered stones at Jezero Crater, and bring them back to Earth for analysis in the future.
The telemetry data showed that the two drill bits were working as planned, but in the end there was no soil in the sample tube.
Some project personnel speculated that the reason for the sampling failure may be that the core target did not respond as expected, rather than the hardware problem of the sampling and caching system.
The project team is currently carrying out diagnostic analysis in order to arrange the next attempt.
Yang Yuguang said that this sampling work will provide a feasible idea for future related exploration and sampling work on Mars, and lay the foundation for mankind to go to Mars in the future for Mars exploration and exploration work.
Jiao Weixin believes that there are still shortcomings in the detection location of this exploration work. In the future, we should continue to go west based on the landing site detection to conduct deeper exploration of the alluvial fans and deltas around the crater. It helps to collect more scientifically valuable soil samples and helps people better understand biological information on Mars.
He said that the implementation of manned exploration of Mars in the future is inevitable for Mars exploration.
People need to conduct field surveys on Mars and select suitable locations for detection and sampling in order to efficiently carry out Mars exploration work and better understand Mars.
According to my country's announced Mars exploration plan, my country may implement a Mars sampling and return mission around 2030.
(Intern Xie Yukun reporter Fu Yifei)