China rescues satellites with pioneering gravitational maneuver
Chinese engineers have successfully rescued two satellites that were stuck in the wrong orbit for 123 days using an innovative "gravitational slingshot" method. According to experts, these satellites will help enable the piloting of unmanned spacecraft and facilitate autonomous control.
On March 15 at 8:15 AM Eastern Time, China launched two satellites atop a Yuanzheng-1S rocket mounted on a Long March-2C rocket. Although the first and second stages went smoothly, a technical issue with the upper stage prevented the satellites from reaching their intended orbit. After several months of rescue attempts, Chinese engineers sought solutions, including the possibility of deorbiting the satellites so they would burn up in the atmosphere.
They used the gravity of Earth, the Moon, and the Sun
Engineers worked for 123 days on the rescue, which ultimately succeeded thanks to a gravitational maneuver. Essentially, they used gravity to direct the satellites onto the correct orbits. Their efforts not only saved the satellite mission but also demonstrated a maneuver that could revolutionize deep space navigation.
The gravitational maneuver involved harnessing the gravitational forces of Earth, the Moon, and the Sun to guide the satellites onto the correct orbits. As a result, the engineers managed to regain control of the satellites, which were too close to Earth and spinning uncontrollably.
In an interview with CGTN Digital, Zhang Hao, a researcher at CSU, recalled that during his first mission, he initially did not focus on the launch problems. He noted that if the satellites had been destroyed, it would have meant the loss of years of work and investment. Zhang Hao explained that the team was divided into two groups: one remotely controlled the satellite engines to slow their rotation, while his team calculated the best route to bring the satellites back on course.
What are the future plans for the Chinese satellites?
Satellites DRO-A and DRO-B have joined the previously launched satellite DRO-L, forming a constellation designed to provide navigation services for spacecraft. According to Mao Xinyuan, another researcher at CSU, these satellites will allow for the localisation of a spacecraft within three hours, marking significant progress compared to current methods. Mao stated that these satellites will allow for the piloting of unmanned spacecraft and enable autonomous control.
These satellites are part of China's broader plans to increase its presence around Earth and the Moon. The aforementioned autonomous piloting capabilities will be crucial for sending crewed missions to the Moon by 2030 and supporting the construction of the International Lunar Research Station (ILRS).
