Xi’an Satellite Measurement and Control Center Command Hall
CCTV News(Reporter, Wang Jiazhu) On June 19, more than a month ago, our country’s "Zhongxing 9A" radio and television live broadcast satellite failed to enter the predetermined orbit due to an abnormality in the launch process. However, after 16 days of full rescue, the satellite was successfully located in the predetermined orbit. The biggest credit behind this 16-day full rescue is the establishment of the earliest, largest and most functional spacecraft measurement and control center in China – Xi’an Satellite Measurement and Control Center.
From the "Dongfanghong No. 1" satellite flying into space, to the return of the first return satellite to survey the sky; from the "Shenzhou" spacecraft manned to ask the sky, to the "Chang’e" "Jade Rabbit" ten thousand miles to explore the moon; and then to rendezvous and docking to establish a space laboratory… In the past 50 years since its establishment, Xi’an Satellite Measurement and Control Center has successfully completed more than 300 major scientific research and test missions and successfully rescued more than 10 major malfunctioning satellites.
The center not only undertakes the real-time measurement and control of satellite launches, but also undertakes the long-term management of all spacecraft in orbit in our country. It is a veritable "big housekeeper" of Chinese satellites.
Fine management makes "China Star" live longer
On September 9, 2009, a special birthday party was held in a computer room of the Xi’an Satellite Measurement and Control Center: dozens of staff sat around a creative cake of "Satellite Guard the Motherland" and were celebrating the fifth birthday of the "Practice No. 6 A/B Double Star". The two "birthday stars" were soaring freely in the sky at that time.
The twin satellites were originally designed to have a lifespan of only two years, but under the careful management and care of scientific and technical personnel, they have been operating safely and stably. By 2009, they had been in service for five years.
Engineer Li Fangzheng was the B-star model supervisor. One day in 2005, after the satellite entered the country, he suddenly found that the satellite’s attitude was seriously out of order. If it was not solved in time, the satellite would lose its function forever. The satellite transit only lasted for ten minutes. In this short ten minutes, Li Fangzheng quickly performed power-saving maintenance on the satellite, organized "expert consultation", and formulated a treatment plan. After days and nights of hard work, the satellite’s condition finally returned to normal.
By 2017, the twin satellites had been working for 13 years and overdue for 11 years, making them a veritable "birthday star". Overdue service of a satellite was equivalent to a satellite doing the work of multiple satellites. Due to the high cost of satellite manufacturing and launch, the precise measurement and control of the monitoring and control personnel was equivalent to saving the country hundreds of millions of yuan.
According to reports, under the careful management of the Xi’an Satellite Measurement and Control Center, half of the satellites are currently in overdue service.
Remote diagnosis allows "China Star" to fly safely
Satellite in-orbit diagnosis and maintenance technology is the key and foundation of satellite health management, and has always been a key area of research for aerospace powers. It is very difficult for "people on the ground" to diagnose "stars in the sky". Without the support of big data, satellite diagnosis and maintenance can only be a castle in the air and passive water.
Therefore, the Xi’an Satellite Measurement and Control Center has focused on key research and made every effort to obtain the "medical qualification certificate" for satellite diagnosis and maintenance.
"In 2009, we managed more than 80 satellites, and the satellite failure rate was 2.7 times per day; in 2017, the number of satellites increased significantly, but the failure rate doubled. The improvement of fault diagnosis and maintenance level has eliminated many faults in the bud…" In February 2017, at the National Science and Technology Progress Award in Beijing, Fan Henghai, the chief engineer of the long-term management department of the center’s spacecraft, won the approval of the judges with a set of numbers.
In early April this year, the center organized a full-satellite health inspection of the Beidou second-generation navigation satellite. Relying on the independently developed service system, scientists and technicians completed the inspection process that originally took 10 hours in just 5 minutes. The data access speed was increased by 2 orders of magnitude, and the efficiency of satellite data analytics was significantly improved.
"We have collected and sorted out more than 1,800 fault cases at home and abroad, established more than 100,000 diagnostic knowledge, and independently developed this spacecraft fault diagnosis expert system." Li Weiping, a senior engineer, said that since the system was in operation, they have found and solved more than 800 satellite faults.
The technician said confidently: "With these new systems, we have the ability to’check the pulse number ‘, and we can better escort the satellite."
Heaven and earth rescue brings "China Star" back to life
Over the years, the Xi’an Satellite Measurement and Control Center has successfully completed more than 200 real-time satellite launch measurement and control missions and 11 Shenzhou spacecraft measurement and control missions. What makes the measurement and control people most proud is the "Heaven and Earth Rescue" that came back to life and turned the tide when the satellite malfunctioned.
In June 2002, the software system of the overdue China-Brazil Earth Resources Satellite malfunctioned suddenly, and the attitude was out of control. After 15 days and nights of fierce fighting and hundreds of laps of uninterrupted tracking, the center restored the satellite to its normal attitude. Experts from the Brazilian Space Research Institute marveled: This is a miracle! China’s space measurement and control technology is amazing!
In the center, as long as the famous "double-star rescue" is mentioned, everyone knows it. In the middle of the night on October 23, 2006, senior engineer Han Zhongmin’s phone suddenly rang: a satellite in orbit suddenly failed, the attitude was out of control, the satellite downlink signal was sometimes absent, the remote control command sent by the ground was basically not executed, and the satellite function was lost.
In the following two months, Han Zhongmin and colleagues repeatedly deliberated and carefully designed more than 20 emergency remote control operations, and sent 4,216 remote control commands successively. Many technicians lamented that more remote control commands were issued during the rescue period than others in their lifetime.
On December 30, 2006, according to the calculations of the satellite measurement and control center, the Yuanwang survey ship captured the satellite over the southern hemisphere and successfully injected remote control commands. After a 69-day battle, the satellite was finally brought back to life.
On February 3, 2007, a Beidou satellite that had just been launched lost contact with the ground and could not receive a downlink signal for 17 consecutive days. At that time, many people in the industry felt very pessimistic, believing that the star had completely lost control and the possibility of coming back to life was slim.
During the 60-day rescue period, more than 1,000 engineers and technicians from the central measurement and control system participated in the rescue work and sent more than 100,000 remote control instructions to the satellite, which finally brought the satellite back to life and made the rescue work a complete success.
In September 2010, the helium gas of the "Xinnuo VI" satellite leaked. If it was not disposed of in time, the satellite would be completely disabled. In the following seven days, the center went through a series of orbit changes and capture controls to successfully locate the satellite and return it to normal.
In August 2011, shortly after the "Ocean 2" satellite was launched into orbit, it mischievously tumbled and continued to tumble. The ground commands were sent again and again, but the satellite still did not listen to the commands, and as the rotation accelerated, it was in danger of disintegrating at any time.
"As long as the satellite still has a glimmer of hope for successful rescue, we can’t give up!" Fan Henghai, who was the leader of the flight control team at the time, was ordered in danger. Finally, after 45 consecutive days and nights of hard work, the satellite came back to life, recovered major losses for the country, and gave birth to a large number of important research results, which were highly praised by the State Oceanic Administration, aerospace science and technology group companies and other units.
So far, the Xi’an Satellite Measurement and Control Center has successfully rescued more than 10 major malfunctioning satellites, saving billions of dollars in economic losses for the country.
Shell Financial News (Reporter Bai Haotian) On June 13, the dark blue G318 was officially launched, with a total of six models, priced from 175,900 yuan to 318,000 yuan. Its two-wheel drive empty suspension version is equipped with air suspension + CDC + double fork arms, priced at less than 200,000 yuan. According to the official, the order channel opened for 60 minutes, and the G318 order has exceeded 3,000 units.
