Three visitors from the earth in one month! "Hope" enters the orbit of the ring fire, this year the Mars exploration curtain officially opened
[Global Times Special Correspondent Chenyang Global Times Correspondent Deng Xiaoci] On the evening of the 9th, Beijing time, the UAE’s "Hope" probe successfully achieved a "space brake" and entered Mars orbit.
This not only marked a landmark breakthrough in the Arab world’s first Mars exploration mission, but also opened the curtain on Mars exploration this year.
After the "Hope", China's Tianwen-1 probe and the US probe "Perseverance" will also visit Mars within this month.
Photograph of Mars taken by China Tianwen-1.
Three visitors from the earth in one month
The US "Space" website stated on the 9th that the "Martian New Year" on February 7 has just passed, and the red planet will welcome three visitors from Earth.
At about 23 o'clock on the 9th, Beijing time, the UAE's "Hope" probe finally arrived near Mars and began a crucial step after a long journey of 7 months.
The UAE Space Agency stated on social media that the "Hope" will perform a 27-minute "space brake" without human intervention.
"The probe started six engines to work at full capacity, and at the cost of consuming half of the fuel it carried, it reduced its flight speed from 121,000 kilometers per hour to 18,000 kilometers per hour, and then entered Mars orbit." Vice President and Prime Minister of the UAE Le Maktoum said, “For the first time in history, the UAE has brought the Arab world into a new field of deep space. Our space mission has conveyed hope and confidence to Arab youth.”
After entering the orbit of Mars, the "Hope" will not land on the surface of Mars, but will conduct various surveys around Mars.
It will study the Martian atmosphere and Martian daily and seasonal cycles, and obtain the laws of Martian climate change.
At the same time, the "Hope" also made the UAE the fifth country and region to successfully explore Mars after the United States, the Soviet Union, the European Space Agency and India.
The "Scientific American" website stated on the 9th that because Mars missions need to consider the positional relationship between the Earth and Mars, the time window suitable for the launch of Mars probes is relatively short. Therefore, the Mars probes of various countries focused on launching in the summer of 2020 will be concentrated. Arrived on Mars in February.
China's Tianwen-1 probe will also try to orbit Mars within 24 hours after the "Hope" arrives on Mars.
"This is China's first independent interplanetary mission and represents a big step forward in China's aerospace ambitions and capabilities."
The US "Perseverance" probe will arrive on Mars on February 18.
Where is the difficulty in getting into Mars orbit
Chinese aerospace expert Pang Zhihao told the Global Times reporter on the 9th that in order to be captured by Mars gravity, the Mars rover must adjust its flight attitude when preparing to enter the Martian orbit. The nozzle of the engine should be pointed forward. When the time is right, the engine will ignite. To reduce the speed of the detector, there is only one chance.
Since Mars is farther from the earth than the moon is, and the communication delay is more than 10 minutes, the ground cannot monitor this braking process in real time, and can only rely on the autonomous execution of the detector.
For this reason, ground commanders need to inject the relevant control program data for attitude adjustment and braking "brake" into the detector in advance.
In addition, when the probe enters the orbit of Mars, the timing and size of the brake “brake” must be very precise. If the brake ignition time is too long or too strong, the probe speed drops too much, it will hit the Mars head-on; if the brake ignites If the time is too short or too light, the probe will fly too fast, and it will fly away from Mars along a parabolic trajectory, causing failure to enter the Martian orbit.
Only when the timing and duration of the "brake" are not bad, can an ideal capture track be formed.
The US "Space" website also stated that the "space brake" of the Mars rover is very difficult, and the US-Soviet Mars rover has "broke down the sand" in this critical link.
For example, in 1974, the Soviet Union's "Mars 4" probe failed to enter the Martian orbit due to the failure of the brake engine, and the "brake failure" caused too fast.
In 1999, the US "Mars Climate Orbiter" attempted to enter the orbit of Mars because the flight path was too close to Mars, which caused the probe to disintegrate and damage soon after entering the Martian atmosphere.
Subsequent investigation found that this was because its flight system software used imperial units, while ground personnel used metric units when inputting parameters. The confusion caused by this led to a deviation in the navigation of the detector.
The follow-up landing of the Sino-US probe still has challenges
According to the "Scientific American" website, the success rate of previous Mars exploration missions is less than half. After the critical link of "space brakes" entering Mars orbit, those probes that need to land on Mars will also pass the "7 Minutes of Terror". Test: The Mars rover has to overcome the high temperature in just 7 minutes and autonomously complete the slow-down landing process consisting of a large number of steps.
Considering that the Martian atmosphere is extremely thin, this deceleration process is more challenging than landing on Earth.
According to the report, although the US "Perseverance" probe arrived on Mars late, it will try to land directly after it enters the Martian orbit.
In contrast, China's understanding of the Martian environment is not sufficient. After Tianwen-1 enters the Martian orbit, it will first conduct environmental exploration and is scheduled to land on Mars in May.