Commissioning of Mars surface composition detector ground optical calibration Photo courtesy of Shanghai Institute of Technology, Chinese Academy of Sciences
Calibration and debugging of Mars mineral spectrum analyzer Shanghai Technology of Chinese Academy of Sciences Image courtesy of the property
On June 11, the National Space Administration announced the first batch of scientific images taken by the “Zhurong” Mars rover, marking the complete success of my country’s first Mars exploration mission. On this rover, it is equipped with a scientific payload-the Mars surface composition detector, which is developed by the Shanghai Institute of Technical Physics of the Chinese Academy of Sciences (hereinafter referred to as Shanghai Institute of Technology).
In addition to the Mars surface composition detector, Shanghai Institute of Technology is also responsible for the development of the Mars mineral spectrometer on the Mars orbiter, making the institute the only one to undertake two Scientific research institutions for the development of payloads.
Shu Rong, deputy director of the Shanghai Institute of Physics, and the load commander of the lunar and deep space exploration series, introduced that the Mars surface composition detector will test the elements and minerals on the surface of Mars in the landing zone. Heshishi carried out high-precision scientific exploration and “started on June 4th, and successfully downloaded the first set of data on the 5th.” The Mars mineral spectrometer was turned on on February 28, and it conducted multiple surveys of pre-selected landing areas.
According to a reporter from China Science Daily, Shanghai Institute of Technology has created a series of “firsts” in order to better complete this Mars exploration mission.
The anticipation and tension at the moment of “real gun combat”
Before the Mars surface composition detector was turned on, the Shu Rong team was worried. It followed “Zhu Rong After the “long journey”, whether the rover was in good condition and could it be “obedient”… Before successfully downloading the data, they were worried about whether the process of data returnSmooth…
Actually, the Shu Rong team has conducted countless simulation experiments in the early stage, but when it comes to “real gun combat”, it is difficult to conceal the inner tension and expectations.
In fact, the moment when the “Zhurong” rover landed was their most tense period. According to statistics, the success rate of the rover successfully landing on the surface of Mars is only 50%. Even if the rover successfully landed, what is the state of the Martian surface composition detector after the thermal shock during the fall of the fire? Can the detector attached to the outer side of the rover and weighing more than 1/2 of the rover’s load withstand the test of the large temperature difference between day and night on Mars?
The answer will be announced on June 4. On the same day, the Mars surface composition detector was turned on normally and the first set of data was successfully downloaded the next day. The Shu Rong team members were extremely excited and excited.
“After powering on, the probe calibrated the titanium sample plate and probed the Martian rocks near the’Zhurong’ rover.” Shu Rong said, At present, the telemetry data of the detector is normal and the working condition is stable.
The 2.5 to 3.4 micron hyperspectrum has the ability to detect water molecules.
Analysis requires the help of loads such as a Martian mineral spectrum analyzer. “Before landing, the scientific data obtained by the Mars mineral spectrum analyzer can help determine the mineral composition and distribution in the landing zone.” He Zhiping, a researcher at the Shanghai Institute of Technology and the chief designer of the Mars mineral spectrum analyzer, introduced that day. After Q1 entered the ring fire orbit, the analyzer was turned on for the first time on February 28.
Subsequently, the Mars mineral spectrometer was turned on several times and successfully obtained scientific data, which contributed to leaving a “Chinese mark” on Mars.
A reporter from China Science Daily learned that this payload has internationally advanced spectral detection capabilities, with a spectral detection range of 0.378 micrometers to 3.425 micrometers. There are as many as 576 segments. “Especially the 2.5-3.4 micron hyperspectral detection is my country’s first space verification application.” In He Zhiping’s view, this spectrum is of great value and has the ability to detect water molecules.
He further explained that in the past space-to-ground exploration missions, because the above-mentioned spectrum was absorbed by the earth’s atmosphere, this spectrum was never used for remote sensing of the ground. .
The mercury cadmium telluride detector needs to withstand the test of 200℃ temperature difference in the detection of the 1 micron to 3.4 micron spectrum. “It’s like throwing the instrument into the stove, then throwing it into the ice cubes, and it goes back and forth.” Said Zhou Songmin, an associate researcher at the Shanghai Institute of Technology and the chief designer of the infrared array detector of the Mars Mineral Spectrum Analyzer.
According to the design requirements, researchers need to carry out 500 cycle life tests, but in order to better adapt to the Martian environment of “ice and fire”, As many as 2000 trials have been carried out.
But the Martian mineral spectrum analyzer has not officially launched a scientific exploration mission. “Subsequently, the analyzer did not officially work until Q1 entered the scientific exploration orbit that day.” He Zhiping said that they also expected more discoveries from the analyzer.
Foreign research institutions specialize in analyzing their technical solutions
The workflow of the Mars surface composition detector is to first use an ultra-high-definition camera to “navigate” and study After the personnel find the target of interest, they comprehensively consider factors such as the sun’s altitude and temperature to give instructions to the detector, and it can work within the specified time.
But unlike lunar exploration, the research team combined active laser-induced breakdown spectroscopy detection technology and passive short-wave infrared spectroscopy detection technology this time. The former is our country’s first use in space.
Shu Rong introduced that active laser-induced breakdown spectroscopy detection is to shoot a beam of laser light from the payload, and use the instantaneous temperature up to thousands of degrees Celsius to excite the surface material on Mars. Plasma can analyze the element composition on the surface of Mars with high precision by detecting the spectral composition and gas composition of the spark, and “can analyze most of the elements in the periodic table.”
“Among the 12 calibration boards, a French calibration board is used. Our data can be mutually verified with existing international data.” In Shurong It seems that this is also the first substantial international cooperation.
In addition to the first application of active laser-induced breakdown spectroscopy detection technology, the research team realized for the first time self-developed indium in the range of 0.9 micron to 2.4 micron on the Martian surface composition detector. Space applications of gallium arsenide detectors.
Shao Xiumei, a researcher at the Shanghai Institute of Technology and a member of the InGaAs detector project team, introduced that the detector can convert optical signals into electrical signals, while the detection band of InGaAs detectors in previous missions is only 0.9 microns to 1.7 microns, but Mars The detection needs to be 2.4 microns. “Detectors in this band usually need to work under low temperature conditions, and the indium gallium arsenide detectors developed by us can meet the sensitivity requirements at room temperature.”
Shao Xiumei Said that the United States, Turkey and other research institutions have cited many papers of their project team to study and analyze their technical solutions.
It is reported that the two payloads of Shanghai Institute of Technology have inherited the experience and foundation of related payload development missions of the Chang’e lunar exploration project, and are useful for detecting elements and mineral compositions on the surface of Mars. It is of great significance and will provide important scientific basis for the study of the formation and geological evolution of Mars.
(Original title: China’s first Mars exploration mission was successful! Behind the development of two Shanghai “intelligent” Mars payloads)