On the 19th, the Space Debris Center of the China National Space Administration reported an "extremely dangerous rendezvous incident" between Russian satellite debris and the mainland's Tsinghua science satellite on its official micro-platform. The space debris, numbered 49863, was disintegrated from Russia's anti-satellite tests, the circular said. On the 18th Beijing time, it "passed by" with the Tsinghua Science Satellite (No. 46026), and the closest distance was only 14.5 meters. Space debris experts said in an exclusive interview with the Global Times reporter that the data released this time shows that the probability of collision between Russia's space 1408 fragments (no. 49863) and the mainland's Tsinghua science satellite is very high, which can be said to be very thrilling, and the two have maintained a safe distance at present, but it cannot be ruled out that the two will be close again in the future.
Tsinghua Science Satellite and Space 1408 Debris Rendezvous Relationship Image Source: Space Debris Center
The Space Debris Center of the China National Space Administration reported on the 19th that the early warning calculations of the Space Debris Monitoring and Application Center of the China National Space Administration found that in the "extremely dangerous rendezvous event" that occurred at about 10:49:29 on January 18, 2022, the collision probability between the mainland's Tsinghua Science Satellite (No. 46026) and Russia's Space 1408 fragment (No. 49863) was 3.71×10-4, the nearest distance was 14.5 meters, the relative speed was 5.27 km/s, and the intersection angle was 40.52 °.
Space debris expert Liu Jing told the Global Times reporter that in general, when space debris and spacecraft intersect, there are many situations between the two sides of the spacecraft, but it is indeed rare to see the two being separated by only ten meters this time, "On January 18, the Space Debris Center of the China National Space Administration found that Russia's Space 1408 debris and Tsinghua Science Satellite are very close, and researchers at the Space Debris Center viewed the previous observation data. Discover that the distance between the two ranges from 10 km to 8 km to 5 km ... Each time they orbit a little closer, the distance is gradually narrowing, and by the evening of January 18, the distance is the closest. It can be said that it is very thrilling, and the probability of the collision of the two is very high. ”
Liu Jing said that at present, when the world predicts the intersection of space objects, there will be some errors, comprehensive consideration of errors and other factors, generally the international will take evasive actions for space debris with a collision probability of 10-3, for some of the more important satellites, the collision probability of 10-4 will also take evasive actions, if you do not avoid it, you will take risks. This time, the probability of Russia's space 1408 fragments colliding with the mainland's Tsinghua science satellite is 371×10-4, and evasion action is theoretically needed. But the latest data shows that the distance between the two has become farther, more than five kilometers apart, and the probability of collision between the two has decreased, "but it cannot be ruled out that the two will be close again in the future." ”
Tsinghua Science Satellite Outline (Image from the Internet)
The notification also reveals that the space debris, numbered 49863, is the disintegration debris from Russia's anti-satellite test on November 15, 2021. According to previous public reports, on November 15 last year, Russia's anti-satellite test produced an estimated 1600 disintegration fragments larger than 10 centimeters in size, most of which were distributed in the orbital altitude range of 400 to 1100 kilometers.
Liu Jing told the Global Times that within this orbital altitude, the mainland has hundreds of satellites, and in theory, these space debris may pose a threat to the mainland's spacecraft. But since Russia's anti-satellite tests last November, the mainland has been closely monitoring the space debris generated by those tests. It is calculated based on the latest data every day, and then predict whether these debris and continental satellites are at risk of collision. "If there is, we need to quickly notify our country's satellites, do some evasion maneuvers in advance, and avoid these fragments, which is the most feasible method at present."
With the increasing frequency of human space activities, the problem of space debris and space debris has become a widespread concern of countries around the world. Some cutting-edge space technologies are also trying to be applied to space debris clearance missions.
"For example, the use of spacecraft to grab away space debris, or laser technology to remove these debris, but at present, these methods are still relatively difficult to use for debris removal, and no country has yet fully successfully realized this program, it should be said that these technologies are still in the research stage, and there is still a distance from practical application." Liu Jing said.
Space expert Huang Zhicheng said that in the case of the increasingly frequent impact of space debris on normal human space activities, the tasks of reducing and removing space debris should be put on the corresponding agenda. Among them, it is necessary not only to study experimental devices or spacecraft to remove space debris, but also to formulate corresponding international laws and regulations on the generation of space debris under the framework of the United Nations.