China uses 'gravitational slingshots' to save 2 satellites that were stuck in the wrong orbit for 123 days

In the unforgiving realm of space, where one wrong calculation can doom a multimillion-dollar mission, China has pulled off a spectacular save that reads like something out of a science fiction novel. Using a series of carefully planned gravitational slingshots, Chinese scientists rescued two satellites that had been stuck in the wrong orbit for 123 days—marking a breakthrough in space recovery strategies and a testament to the country’s growing capabilities in space technology.

Launched in October 2023 aboard a Long March-2C rocket, the satellites—named DRO-A and DRO-B—were destined for distant retrograde orbit (DRO), a highly stable and fuel-efficient orbital path that hovers around 70,000 kilometers from the Moon. But things didn’t go as planned. A malfunction in the rocket’s upper stage left both satellites stranded in a far lower orbit, with their systems compromised and a major mission failure looming.

Rather than accept the loss, Chinese scientists mounted a daring and highly complex rescue operation. Over the next four months, they used the natural gravitational pulls of the Earth, Moon, and Sun to slowly and methodically nudge the satellites back on course—a maneuver known as a “gravitational slingshot” or gravity assist. The feat is not only a remarkable achievement in its own right but also signals China’s increasing ambition and technical prowess in deep space exploration.

The story began with high expectations. The satellites were part of China’s larger vision to establish navigational and communication infrastructure in cislunar space—the region between the Earth and the Moon. Their specific mission was to act as navigational beacons for future spacecraft traveling to the Moon, providing reference points much like lighthouses do for ships at sea.

But shortly after liftoff, it became clear that the mission was in trouble. A fault in the Yuanzheng-1S upper stage prevented the satellites from reaching their planned orbit. To make matters worse, both satellites ended up spinning uncontrollably and had suffered damage that impaired their solar panel deployment, threatening their power supply. In most cases, this would have spelled the end of the mission.

However, Chinese space engineers from the Technology and Engineering Center for Space Utilization (CSU), under the Chinese Academy of Sciences, weren’t ready to give up.

With direct propulsion unable to salvage the situation due to the satellites’ compromised state and limited fuel, engineers turned to an alternative solution rooted in orbital mechanics: gravitational slingshots. This maneuver involves using the gravity of celestial bodies to alter the path and speed of a spacecraft without using much fuel—something that has been used in planetary missions like Voyager and Cassini but rarely for Earth-orbiting satellite rescue.

A two-pronged team formed quickly. One group worked tirelessly to stabilize the spinning satellites using limited onboard thrusters. The second group began the intricate calculations needed to plan out a rescue trajectory—one that would bring the satellites close enough to the Moon and Earth multiple times in just the right configuration to “steal” a little bit of gravitational energy at each pass.

Over a span of 123 days, the team executed a carefully choreographed series of flybys, adjusting the trajectory with minimal fuel while taking advantage of the ever-shifting geometry of the Earth-Moon system. Each slingshot maneuver brought the satellites a bit closer to their intended path. By mid-February 2024, the satellites finally settled into their target orbits.

The success of this rescue operation is astonishing when considering the complexity and risks involved. Gravitational maneuvers require extreme precision and deep understanding of celestial mechanics. Even the smallest error in timing or position can result in a complete failure or cause the spacecraft to be flung into deep space or crash into the Moon or Earth.

Moreover, DRO—or distant retrograde orbit—is particularly challenging to reach. Unlike orbits close to Earth, DRO is influenced by both Earth’s and Moon’s gravity, making it a dynamically complex region. Yet it also offers stability and long-term fuel savings for satellites stationed there, which is why it’s a prime choice for future lunar missions, including NASA’s Artemis program.

In essence, China managed to carry out a mission previously considered near-impossible: rescuing two damaged satellites using nature’s own forces, without relying on brute mechanical corrections or excessive fuel.

DRO-A and DRO-B are not ordinary satellites. Their role is critical for the development of cislunar infrastructure. Positioned in DRO, they serve as reference beacons for autonomous navigation—a technology that will be vital for future lunar missions involving both crewed and uncrewed spacecraft.

Traditionally, space agencies rely on ground stations to track and guide missions. However, for long-duration operations near the Moon, reliance on Earth-based tracking is inefficient and time-consuming. With satellites stationed in DRO, spacecraft will be able to “triangulate” their positions much more quickly and with higher accuracy, cutting down navigation times from hours or days to mere minutes.

The success of these satellites will not only benefit China’s own lunar ambitions—such as its plans for a Moon base in the 2030s—but could also potentially be part of international collaborations in the future.

Beyond the technical success, this mission reflects China’s growing strategic capabilities in space. In recent years, China has rapidly expanded its space program, from operating its own space station (Tiangong), to landing rovers on the Moon and Mars, to planning future crewed missions beyond low Earth orbit.

This satellite rescue demonstrates that China is not only investing in new missions but is also capable of handling unexpected failures with innovation and skill. The ability to execute complex orbital maneuvers like gravitational slingshots in Earth-Moon space is a capability that only a handful of space agencies possess.

It also sends a message to the international community: China is not merely participating in the space race—it’s helping redefine its rules.

China’s rescue of the DRO-A and DRO-B satellites using gravitational slingshot maneuvers is a masterclass in space navigation, resourcefulness, and scientific ingenuity. The operation turned what seemed like a failed mission into a triumph, setting a precedent for future satellite recoveries and highlighting the value of understanding and harnessing natural celestial forces.

As space becomes increasingly crowded and competitive, such moments serve as powerful reminders of the human capacity to innovate under pressure. China’s 123-day satellite rescue may well become a landmark case study in the history of space exploration—proof that in the vast silence of space, brains can sometimes be more powerful than brawn.