Posted on 05/09/2025 8:06:39 AM PDT by Red Badger
China pulls off a stunning space rescue, using a gravity slingshot to save its stranded moon satellites from certain destruction.
A render of the navigation system. Image credit: CSU | The Daily Galaxy --Great Discoveries Channel In March 2024, China launched two satellites, DRO-A and DRO-B, as part of an ambitious mission aimed at positioning them in a distant retrograde orbit (DRO) around the moon. Their task was to provide critical navigation and tracking support for spacecraft within Earth-moon space. However, due to a malfunction with the Yuanzheng-1S upper stage of the launch vehicle, the satellites were stranded in an unintended orbit. According to China Global Television Network (CGTN), the problem left the satellites in a precarious position, potentially resulting in their destruction. But a determined team at China’s Technology and Engineering Center for Space Utilization (CSU) found a way to save them by utilizing an innovative technique – a gravity slingshot. The approach, involving the Earth, the Moon, and the Sun, allowed the team to maneuver the satellites into the correct orbit, achieving success after a remarkable 123-day operation.
The Technical Struggles and Initial Failure When China’s Long March-2C rocket successfully launched the satellites into space, everything seemed to be on track. The first two stages of the rocket performed as expected, but the third-stage malfunction occurred due to an issue with the Yuanzheng-1S upper stage, preventing the satellites from reaching their intended orbit around the moon. Initially, the satellites drifted into a much closer orbit around Earth, far from the planned distant retrograde orbit. The team at CSU quickly lost contact with DRO-A and DRO-B, creating an overwhelming challenge for the engineers. “If the satellites were destroyed, that would have been a waste of the years of effort that we put in and the money invested in the mission,” said Zhang Hao, a member of the CSU team. “It would also be a mental blow to the team.” The situation was dire, as the loss of these satellites would have meant not only a huge financial loss but also a significant setback for China’s ambitions in space.
A Gravity Slingshot Strategy: Engineering Ingenuity Rather than giving up, CSU embarked on an ambitious rescue mission. The team divided into two specialized units, each working in parallel to address the challenge. One group focused on controlling the satellites’ thrusters, attempting to slow their unwanted spin in space. The other group, led by Zhang Hao, concentrated on calculating the most efficient route to return the satellites to their intended orbit. This required a meticulous approach, considering the damage sustained during launch, which prevented the satellites from receiving enough sunlight to charge their power systems. Given these constraints, the team devised a strategy to use the gravity of Earth, the Moon, and the Sun as a substitute for energy, effectively performing a gravity slingshot that would accelerate the satellites back on track without relying on fuel. “We divided into two teams,” Hao explained, “One team remotely controls the satellites’ thrusters to slow down the spinning. The other team, my team, calculated the best route to move the satellites back on track.”
The 123-Day Mission and Successful Resumption of Operations The gravity slingshot method took a total of 123 days to complete, as engineers patiently used gravity assists from multiple celestial bodies to navigate the satellites into the correct orbit. Despite the time-consuming process, the team recognized that the benefits outweighed the costs of energy consumption. Mao Xinyuan, a CSU researcher, explained, “If you don’t want to consume much energy, you must replace it with something else. We chose to consume more time in order to save energy.” By mid-July 2024, the satellites successfully reached their destination, and the team began preparations to separate them. The satellites were finally able to begin working with a third satellite, DRO-L, which had previously been launched into low Earth orbit to assist in tracking and positioning. The successful operation marked an extraordinary achievement in space engineering, as the satellites now served their critical purpose of improving spacecraft navigation.
A Game-Changer in Space Navigation With the DRO-A and DRO-B satellites now in their proper orbits, they serve an essential role as part of a larger network designed to improve spacecraft tracking capabilities. These satellites will act as “lighthouses in space,” assisting in the accurate and rapid identification of spacecraft locations within the Earth-moon system. As Mao put it, “They will act as lighthouses in space.” Before the satellites were in place, locating a spacecraft could take more than two days using traditional land-based positioning systems. Now, thanks to the DRO network, spacecraft can be located in just three hours. This breakthrough represents a major step forward in the efficiency of space missions, particularly as space exploration continues to grow and as spacecraft move deeper into the solar system.
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Space Ping!.........................
Bkmk
Well if China says so it must be true.
Probably part of the secrets Clinton gave them via Loral.
Yes you are correct.
“DRO-A” and “DRO-B”?
How boring! What happened to the cool Chinese names like “Seven Happiness Lunar Mission” or “Five Stars Happiness Orbiter” or “Golden Joy Exploration”?
It’s bizarre how much can be done from such a great distance. My son worked with a solar observatory satellite at NASA. It had a scheduled mission life of two years. Sometime around year ten a gyro failed and they lost contact with it. The gyro failure pointed the solar panel away from the sun. Several years later the satellite had gained enough passive energy to reconnect with earth and they actually regained control of it. As far as I know, it’s still operational.
"...but the third-stage malfunction occurred due to an issue with the Yuanzheng-1S upper stage..."
That's like saying 'the car malfunctioned due to an issue with the car.'
The word 'slingshot' was used 6 times.
At another point, the writer talked about the slingshot, saying they "use[d] the gravity of Earth, the Moon, and the Sun as a substitute for energy" and later repeated that with the phrase "used gravity assists from multiple celestial bodies".
It's a nice story, but should have been written using half the words expended.
I wonder if the Chinese will have better luck.
No, he isn’t, gravity assist is Orbit Mechanics 101.
Textbook crap that was first thought up by the Ukrainian mathematical physicist Kondratyuk.
Been done a bunch of times by NASA and other operators.
https://en.wikipedia.org/wiki/Gravity_assist#Historical_origins
But don’t let facts get in your way, Genius.
PS: this technique was also depicted in the movie “The Martian” when the original mother ship needed to get back into Martian orbit when it was almost back to Earth and out of propellant.
Sometimes ya just gotta screw up to see what skills ya have.
ah...they been watchin too many star trek episodes
Slingshot Around The Sun For Saturn
https://whatculture.com/trekculture/10-star-trek-timelines-that-were-erased?page=9
On the internet as well so............
My great grandfather, Sir Isaac Biden invented gravity, no joke man.
Good save.
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