HOUSTON — China has increased its orbital rocket launches in recent years while abandoning spent upper stages in long-lived low-Earth orbits, contrary to widely accepted international space debris mitigation practices, according to space domain awareness expert Jim Shell.

In 2023, China launched a record 93 orbital rockets, making it the second-most active spacefaring nation globally. That figure follows 64 launches in 2022 and marks a sharp rise from a decade ago, when China had never launched more than 20 orbital rockets in a single year. Much of this growth supports the deployment of Chinese satellite megaconstellations such as Guowang and Spacesail, which operate at altitudes above 800 kilometers.

Shell wrote on LinkedIn early Monday that "China continues to abandon many rocket bodies in high low-Earth orbit." He added, "The total mass of orbital debris is a key variable influencing the long-term sustainment of space. There is broad agreement that abandoning rocket body upper stages in long-lived orbits is not a best practice. In fact, all the major spacefaring nations have acknowledged this."

According to Shell’s analysis, the mass of Chinese rocket bodies in long-lived orbits—between 600 km and 2,000 km altitude—has more than doubled in the past five years, rising from less than 100 metric tons to 252 metric tons. By comparison, the United States has about 57 metric tons of spent upper stages in similar orbits, while Russia has approximately 800 metric tons, though that amount is gradually declining as older stages reenter the atmosphere.

Rocket upper stages are the segments that separate from the first stage and deliver payloads into orbit. When left in orbit without disposal measures, these multi-ton objects become uncontrolled, long-term hazards. Most modern launch providers reserve propellant to perform a disposal burn after mission completion—either deorbiting the stage into a remote ocean area like Point Nemo or sending it into heliocentric orbit for high-altitude missions.

Although satellites outnumber spent rocket bodies by more than 10-to-1, rocket bodies are typically larger and cannot maneuver to avoid collisions. As a result, they constitute most of the objects rated as the "most concerning" pieces of space debris.