What is China’s secret Space Mission? What we know about the Shenlong Space Plane’s fourth flight and what it may be testing

China’s reusable Shenlong space plane has returned to orbit for its fourth mission, reigniting global curiosity about the objectives of what many analysts describe as China's secret space plane programme.

The robotic spacecraft, whose name means “Divine Dragon”, lifted off from the Jiuquan Satellite Launch Center in the Gobi Desert on February 6. While Chinese authorities confirmed the launch, they offered few specifics about its payload or mission goals, maintaining a pattern of limited disclosure that has marked all previous flights.

The latest mission places the Shenlong space plane back into low Earth orbit (LEO), where it is expected to operate autonomously for an undisclosed duration.

A History of Secrecy

The Shenlong space plane first flew in September 2020, followed by missions in May 2023 and September 2024. Those earlier flights lasted two days, 276 days and 266 days respectively, indicating that the vehicle is capable of extended orbital operations.

Official statements have consistently described the spacecraft as a test platform designed to develop “more convenient and affordable round-trip methods for the peaceful use of space.” Beyond that, little information has been released about its onboard experiments or manoeuvres.

The lack of transparency has prompted speculation among space analysts, particularly because Shenlong is widely believed to resemble the United States’ X-37B orbital test vehicle in both size and function.

Comparisons With the X-37B

Much like its American counterpart, China’s secret space plane is thought to be an autonomous, reusable craft capable of launching atop a rocket and landing horizontally on a runway.

The U.S. military has long described the X-37B as a technology demonstrator, testing advanced systems in orbit. Though the majority of its payloads remain classified, experts note that the vehicle has not engaged in aggressive behaviour in space and typically operates at relatively low altitudes, as per a report by Space.

Security analysts argue that similar physical limitations would apply to the Shenlong space plane. Its relatively small payload bay and limited power capacity make it an unlikely candidate for space-to-ground weaponry.

However, there is one key difference.

Rendezvous and Proximity Operations

Unlike the X-37B, the Shenlong space plane has reportedly conducted rendezvous and proximity operations (RPOs) during earlier missions.

Tracking data from the U.S. military, private space situational awareness firms and independent astronomers indicate that Shenlong released objects into orbit during its first three flights. Some of these objects demonstrated broadcasting or propulsion capabilities.

More notably, analysts observed that the spacecraft performed close manoeuvres and docking exercises with deployed satellites, a capability that has strategic implications.

RPO technology enables a spacecraft to approach, inspect, dock with, refuel or potentially disable another satellite. While such abilities can support peaceful activities like satellite servicing and debris removal, they may also carry military applications.

Why RPO Skills Matter

Mastering rendezvous and proximity operations is increasingly seen as essential in modern space strategy.

With thousands of satellites operating in low Earth orbit and geostationary orbit, the ability to repair, refuel or reposition assets offers significant commercial and strategic advantages. Countries including the United States and Russia have also developed similar technologies.

However, experts caution that such capabilities can be dual-use. The same manoeuvres that allow a spacecraft to service its own satellite could, in theory, be used to interfere with another nation’s assets.

This dual-use nature is one reason the Shenlong programme continues to draw scrutiny.

What Might Shenlong Be Testing?

While definitive answers remain elusive, analysts suggest that the fourth mission may focus on:

• Reusable spacecraft technologies
  
  
  
• Extended-duration orbital endurance
  
  
  
• Autonomous navigation systems
  
  
  
• Satellite deployment and retrieval experiments
  
  
  
• Further RPO demonstrations
  

The fact that previous missions lasted more than eight months suggests that long-term performance testing is a core objective.

At the same time, observers emphasise that the secrecy surrounding China’s secret space plane fuels suspicion. Greater transparency, they argue, could ease concerns about its purpose.

A Growing Era of Space Competition

The return of the Shenlong space plane underscores the intensifying technological competition in orbit. Reusable space vehicles are increasingly viewed as cost-effective tools for testing next-generation systems and maintaining strategic flexibility.

As more nations invest in orbital capabilities, calls for clearer norms and confidence-building measures in space are growing louder. Analysts say transparency and communication could help prevent misunderstandings in an increasingly crowded orbital environment.

For now, the Shenlong space plane continues its silent journey around Earth, its exact mission objectives known only to Chinese authorities.

FAQs

What is the Shenlong space plane?

The Shenlong space plane is a reusable, autonomous Chinese spacecraft designed to operate in low Earth orbit for technology testing and experimental missions.

Why is it called China’s secret space plane?

The programme is often described as China’s secret space plane because the government releases limited information about its payloads and activities.