On June 16, the National Space Administration released 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, the Mars Surface Composition Explorer, a scientific payload developed by the Shanghai Institute of Technical Physics of the Chinese Academy of Sciences (hereinafter referred to as the Shanghai Institute of Technical Physics), is carried.

On the 11th, the National Space Administration released the first batch of scientific images of the Tianwen-1 probe landing on Mars, and announced the panorama of the landing site, the topography of Mars, the “China Imprint” and the “Patrol Group Photo” taken by the Zhurong Mars rover. The picture marks the complete success of my country’s first Mars exploration mission. The reporter learned from the Shanghai Institute of Technical Physics, Chinese Academy of Sciences that the fire detection “Shanghai Eye” developed by the institute, the Mars Mineral Spectrometer on the orbiter, and the Mars Surface Composition Detector on the Zhurong Mars rover have all started successfully. , and successfully download the detection data. While excited to obtain the first batch of scientific data, the Mars payload development team of the Shanghai Institute of Technology and Objects is already considering how to improve payload performance and scientific detection capabilities.

After Tianwen-1 entered the orbit around the fire, the Martian Mineral Spectrometer was turned on for the first time on February 28, and has since been turned on several times to obtain scientific data from the landing area. It is expected that after July, the Tianwen-1 orbiter will enter the scientific exploration orbit, and the Martian Mineral Spectrometer will officially enter the working state. It has internationally advanced spectral detection capabilities, the spectral detection range can extend from 0.378 microns to 3.425 microns, and the detection spectrum is as many as 576.

The Mars Surface Composition Detector, which followed Zhu Rong’s car on the surface of Mars, was not turned on until June 4, and the first batch of data was sent back to Earth on June 5. According to Shu Rong, deputy director of the Shanghai Institute of Technology and the commander of the lunar and deep space exploration series payloads, this payload combines two technologies of active laser-induced breakdown spectroscopy and passive short-infrared spectroscopy. “The sensitivity of the equipment is very high, and two calibration plates from China and France are used at the same time. Our data can be mutually verified with existing international data.” Shu Rong said, this will strongly prove the scientific research strength of my country’s planetary exploration.

The highest temperature on the surface of Mars is 20 to 30 degrees Celsius, while at night it is only tens of degrees below zero. The load is most afraid of “low temperature challenge”, and it is designed with the standard of -100 ℃ during development. Right now, Mars is entering summer, the weather is relatively stable, and the temperature is gradually rising, which is a good time for patrol detection.

Since the calibration rod and laser of the Mars Surface Composition Explorer are exposed outside the Zhurong rover, it is difficult to keep warm. The working period of the probe is selected around 2:00 p.m. on the Martian day, so that the instrument can naturally heat up and save energy for the rover.

The infrared focal plane detector in the Mars Mineral Spectrometer on the orbiter also experiences low temperature operation and normal temperature storage. For this reason, researchers have adopted various temperature control methods to ensure the performance and reliability of the payload.

In a test laboratory of the Shanghai Institute of Technology, the first batch of devices that came off the production line in 2017 has undergone 2,000 “ice and fire” temperature cycles. This has exceeded the requirements of the Mars mission by three times, explained Zhou Songmin, an associate researcher at the Materials and Devices Center of the Shanghai Institute of Technology.

In addition to the Mars Surface Composition Detector, the Shanghai Institute of Technology is also responsible for the development of the Martian Mineral Spectrometer on the Mars Orbiter, making the Institute the only scientific research institution that undertakes the development of two payloads.

Shu Rong, deputy director of the Shanghai Institute of Technology and load commander of the lunar and deep space exploration series, introduced that the Mars Surface Composition Explorer will carry out high-precision scientific exploration of the elements, minerals and rocks on the Martian surface in the landing zone. The machine was turned on, and the first set of data was successfully downloaded on the 5th.” The Martian Mineral Spectrometer was turned on on February 28 and conducted multiple detections of the pre-selected landing area.

In order to better complete this Mars exploration mission, the Shanghai Institute of Technology has created a series of “firsts”.

Expectation and tension at the moment of “real gun combat”

Before the Mars Surface Composition Detector was turned on, the Shu Rong team was worried whether it would be in good health and “obedient” after the “long journey” with the “Zhurong” rover… Before the data was successfully downloaded, they were worried again. Did the return process go smoothly…

In fact, Shu Rong’s team has carried out countless simulation experiments in the early stage, but when it comes to “real gun combat”, it is difficult to hide the inner tension and expectation.

In fact, the moment when the “Zhurong” rover landed was their most nervous 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 would the state of the Mars Surface Composition Explorer be after the thermal shock when it fell? Can a probe that is attached to the outside of the rover and weighs 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 revealed on June 4. On the same day, the Mars Surface Composition Explorer was powered on normally and successfully downloaded the first set of data the next day. The members of Shu Rong’s team were extremely excited and excited.

“After starting up, the detector calibrated the titanium sample plate and detected the Martian rocks near the ‘Zhurong’ rover.” Shu Rong said that the current telemetry data of the detector is normal and the working state is stable.

2.5 to 3.4 micron hyperspectral with the ability to detect water molecules

The analysis of the pre-selected landing area by Tianwen-1 requires the help of payloads such as the Martian Mineral Spectrometer. “Before landing, the scientific data obtained by the Mars Mineral Spectrometer Analyzer will help determine the mineral composition and distribution in the landing area,” said He Zhiping, a researcher at the Shanghai Institute of Technology and the chief designer of the Mars Mineral Spectrometer Analyzer. The analyzer turned on for the first time on February 28, after the Q-1 entered the Ring of Fire orbit.

Subsequently, the Martian Mineral Spectrometer has been turned on several times, successfully obtaining scientific data, and contributing to leaving the “Chinese mark” on Mars.

This payload has internationally advanced spectral detection capabilities, with a spectral detection range of 0.378 microns to 3.425 microns and as many as 576 detection spectral bands. “Especially in the hyperspectral detection of 2.5 microns to 3.4 microns, it is the first time that my country has verified applications in space.” 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-earth exploration missions, since the above-mentioned spectrum was absorbed by the earth’s atmosphere, the remote sensing observation of this spectrum was never used.

In the detection of the Martian Mineral Spectrometer in the 1 micron to 3.4 micron spectrum, the mercury cadmium telluride detector needs to withstand the test of a temperature difference of 200 °C. “It’s like throwing the instrument into the stove, then throwing it into the ice cubes, and the cycle goes back and forth.” Zhou Songmin, an associate researcher at the Shanghai Institute of Technology and the chief designer of the infrared area array detector of the Mars Mineral Spectrum Analyzer, likened to this.

According to the design requirements, the researchers need to carry out 500 cycle life tests, but they have carried out as many as 2,000 tests on the ground in order to better adapt it to the “ice and fire” Martian environment.

But the Martian Mineral Spectrometer has not officially launched a scientific exploration mission. “Follow-up, the analyzer will not officially work until Wen-1 enters the scientific exploration orbit that day.” He Zhiping said that they also expect more discoveries from the analyzer.

Foreign research institutions specialize in analyzing their technical solutions

The workflow of the Mars Surface Composition Explorer is to first “navigate” with an ultra-high-definition camera. After the researchers find the target of interest, they will issue instructions to the probe after comprehensively considering factors such as the sun’s altitude angle and temperature, and it can be within a specified time. Work.

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 the first time my country has used it in space.

According to Shu Rong, active laser-induced breakdown spectroscopic detection is to shoot a laser beam from the load, and use the instantaneous temperature as high as thousands of degrees Celsius to excite the material on the surface of Mars into plasma. The element composition on the surface of Mars can be accurately analyzed, and “most of the elements in the periodic table can be analyzed.”

“Among the 12 calibration boards, a French calibration board is used, and our data can be mutually verified with existing international data.” In Shu Rong’s view, this is also the first substantial international cooperation.

In addition to applying the active laser-induced breakdown spectroscopy detection technology for the first time, the research team first realized the aerospace application of the self-developed indium gallium arsenide detector in the wavelength range of 0.9 microns to 2.4 microns on the Mars surface composition detector.

Shao Xiumei, a researcher at the Shanghai Institute of Technology and a member of the indium gallium arsenide detector project team, introduced that the detector can convert optical signals into electrical signals, while the detection band of the indium gallium arsenide detectors of previous missions is only 0.9 microns to 1.7 microns, but Mars exploration Need to 2.4 microns. “Detectors in this band usually need to work at low temperature, and the indium gallium arsenide detector we developed can meet the sensitivity requirements at room temperature.”

Shao Xiumei said that research institutions such as the United States and Turkey have cited many papers of their project team to study and analyze their technical solutions.

It is reported that the two payloads of the Shanghai Institute of Technology and Materials have inherited the experience and foundation of the related payload development tasks of the Chang’e lunar exploration project. .