Young and promising astronaut born in the 1990s, Cai Minggui: Let the code he wrote "fly into space" signal | Beidou | Cai Minggui

For ordinary people, the presence of the Beidou is only perceived when the navigation service is turned on, but for astronauts like Cai Minggui, at the moment the Beidou is launched into space, various in orbit tests and signal analysis have already begun, and the test has already begun.

Cai Minggui, born in the 1990s, is a software designer for the Beidou-3 development team at the Xi'an Branch of the Fifth Academy of Aerospace Science and Technology. In the summer of 2015, after graduating from graduate school, she joined the Navigation Room of the Xi'an Branch of the Fifth Academy of Aerospace Science and Technology Group. Just one year later, the payload development work for the Beidou-3 networking star began, and she took over a signal generation software development task for the navigation task processor. She described herself as "a disciple who followed her master's footsteps and became a comrade in arms who fought together.".

During his participation in the development of Beidou, Cai Minggui was mainly responsible for developing software for generating and broadcasting downlink signals in the navigation processor. "The team adopts a 'digital+analog' approach, generating multi frequency digital signals modulated with ephemeris and other positioning information, pseudo-random ranging codes through software code running on digital devices. Then, through digital to analog conversion and upconversion processing, the RF analog signal is finally distributed to users." Cai Minggui explained to reporters.

"According to the signal interface files released by the system, terminals located on the ground, such as mobile navigation, car navigation, etc., can demodulate and analyze the information received from satellite signals to calculate the location and time of user terminals." Cai Minggui introduced that based on this, Beidou's positioning function has been applied to rich scenarios such as transportation, agricultural machinery and agriculture, meteorological monitoring, sharing economy, and ocean engineering.

Cai Minggui still remembers the situation before the delivery of the single machine. Before the 2018 Spring Festival, in order to eliminate the nanosecond jitter error caused by the navigation processor's on/off clock, she and her colleagues conducted thousands of indicator tests. "In order not to affect the progress, indicator testing can only be carried out synchronously during environmental testing on a single machine. There are many vacuum tanks and temperature chambers in the environmental testing hall, which generate particularly loud noise during operation. We need to repeatedly conduct on/off tests during temperature cycling at -25 to 70 degrees Celsius."

Cai Minggui told reporters that it takes half an hour to receive and calculate the pseudorange values of all three frequency points of navigation signals from the power on and off to the testing equipment. So, they stayed in the hall for several hours. "Not caring about going out to drink water or use the toilet, repeatedly testing, analyzing, discussing, and debugging the program on site." For several months, Cai Minggui described himself as often feeling "hollowed out" in his brain and body throughout the day.

In the process of participating in the development of the Beidou navigation processor, Cai Minggui remembered more of the joy and warmth of working with the team than the laborious battles with high loads. "The seniors just wish they could teach you everything they know, hoping you'll get better and better," she said with a smile. Experienced colleagues generously impart their experience to young people, "Fighting alongside them is the greatest confidence in my heart.".

"Not long after joining the company, I experienced many kind-hearted 'stuttering'. When I thought it was enough, the master and supervisor would repeatedly emphasize the reliability of the single machine and how to make the product better." At first, Cai Minggui didn't understand. But now, it has become a habit engraved in her bones to repeatedly try various possibilities and eliminate problems one by one with colleagues in a 360 degree blind spot.

In aerospace engineering, any type of product is composed of multiple components, and behind each success lies countless human efforts and efforts.

"As a software designer, it is a rare honor to have my code 'fly into space'." Cai Minggui also deeply felt that there are many unknown heroes in the aerospace industry, who may be assembly workers on production lines or security personnel transporting products. Although he had the privilege of participating in the development of some major models, Cai Minggui said, "It is an honor to witness the software 'Heavenly' that he participated in the design. It is normal for me not to be in front of others when I succeed. If I can help others achieve their dreams, it is also a shining moment."

The report of the 20th National Congress of the Communist Party of China made a strategic deployment to accelerate the construction of a strong aerospace country, which pointed out the direction for aerospace personnel. To accelerate the construction of a strong aerospace country, it is necessary to continuously and rapidly enhance China's ability to independently design, manufacture, launch, and apply space vehicles. Independence and high technological level are indispensable. "China's aerospace industry has achieved technological leaps in many fields. At present, achieving high level technology and self-reliance will enable us to remain invincible in the complex and changing situation, and make our own contributions to Chinese path to modernization and the great rejuvenation of the Chinese nation. Our journey is a sea of stars! Young people are promising and love light!" Cai Minggui said.

Director in Chief: Zhang Yayun

Editing: Shen Bofeng

Organizational structure of the "Youthful" series of micro videos

Guidance unit: Network Communication Bureau of the Central Cyberspace Administration

Production unit: China Youth Network

Supported by: China Internet Development Foundation