On January 1, the China National Space Administration released a set of exquisite images transmitted from distant Mars by the Tianwen-1 probe, showing the orbiter posing with Mars. Image source: China National Space Administration photo
China News Online Hai, January 4 Title: From Birthday Wishes to New Year's Greetings Unveiling the "Space Selfie Secret" of the Tianwen-1 Mars Probe
Author Zheng Yingying Ma Shuaisha
At the beginning of the new year in 2022, Chinese on Earth received a "New Year's greeting photo" from Mars, a set of exquisite images sent back from distant Mars by the Tianwen-1 probe, China's first Mars exploration mission. In fact, this is not the first time that the "space photographer" of "Tianwen-1" has appeared in the film. As early as 2020, during China's National Day, "Tianwen-1" sent photos to report safety to the motherland and express birthday wishes, which was the first deep-space "selfie" of the Tianwen-1 probe.
There is a secret to wanting a "space selfie" is not so simple
At the beginning of China's first independent Mars exploration project, the research and development team was thinking about how to do a good job of visual monitoring of the orbital working status of Mars probes. Mars, nearly 400 million kilometers from Earth, has no other "tourists" to help take pictures, and if you want to take ordinary selfies, it is not so simple. Because the "Tianwen-1" surrounder itself is too large, it needs a selfie stick up to 15 meters long to achieve its full-body photo selfie, which not only consumes large resources, but also has certain safety risks.
To this end, the Mars Orbiter Engineering Measurement Subsystem Team of the Eighth Academy of China Aerospace Science and Technology Group proposed a "separation monitoring scheme", designed a monitoring system composed of multiple separated measurement sensors, and completed the deep space "selfie" of the Tianwen-1 probe by throwing these "little guys" (separated measurement sensors) away.
According to reports, this "New Year's Day blessing" and the previous "birthday wishes" similar, by the Eighth Academy 803 developed by the separation measurement sensor in the ground control again to implement the separation monitoring task, in the process of slowly moving away, using its own two wide-angle lenses installed on both sides, take an image per second, through the WiFi transmission method, the image is transmitted back to the Tianwen-1 probe, and finally the orbiter and Mars group photo, orbiter local close-up, Mars North Pole ice sheet and other pictures are presented.
The picture shows the "Zhu Rong" rover photographing the fire surface landform. Image source: China National Space Administration photo
Ken hones on the self-cultivation of "space photographers"
On October 1, 2020, on the occasion of China's national celebration of the National Day and the Mid-Autumn Festival, the China National Space Administration released the flight image of China's first Mars exploration mission, the Tianwen-1 probe, and the five-star red flag on the map was dazzling and presented a bright Chinese red. This is the first deep-space "selfie" of China's Tianwen-1 probe. At that time, it was still on the way to "running the fire".
After more than a year, the "Tianwen-1" orbiter has been running in orbit for more than 500 days, and the photos sent back are more detailed. The exquisite set of images sent back from distant Mars by the Tianwen-1 probe released by the China National Space Administration on January 1, 2022, includes a group photo of the orbiter and Mars, a local close-up of the orbiter, the Arctic ice sheet of Mars, and the fire surface landform photographed by the Zhurong rover, showing the orbiter, the working status of the Zhurong rover and the surface form of Mars obtained.
Zheng Xunjiang, chief expert of the 803 Institute of the Eighth Academy, introduced that the separation measurement sensor is a product designed in accordance with the concept of "small satellite" of the surveillance camera, which needs to be within the total mass of 1kg (kg), under the environmental and reliability requirements of long-term flight of Mars exploration, to achieve lock unlocking, separation release / separation after self-power supply, automatic photography, WiFi communication and other functions, the development process has experienced no small challenges.
Wu Di, the product director of the 803 Institute of the Eighth Academy, said that the most important responsibility of the "space photographer" is of course to "shoot well", "in the orbit of Mars, the target characteristics, lighting conditions and lighting angles have undergone great changes, we simulated the lighting conditions of the Mars orbit on the ground, carried out hundreds of tests and verifications of different shooting angles, different light intensities, and different shooting positions, and finally formulated a segmented automatic exposure strategy in the background of Mars." (End)