The Future of Low Earth Orbit: Could China's Tiangong Become the Sole Crewed Outpost?
Context
China's Tiangong space station, operational since 2021, may become the only permanently crewed outpost in Earth orbit if the International Space Station (ISS) retires around 2030 without a commercial successor ready. This scenario stems from two concurrent timelines: the planned retirement of the ISS and the still-unfinished development of commercial low Earth orbit stations.
Background
China was never an ISS partner. The Wolf Amendment, passed in 2011 as part of Public Law 112-10, Section 1340, prohibits NASA and the White House Office of Science and Technology Policy from using funds for bilateral programs with China or Chinese-owned companies without specific later authorization. It also restricts hosting official Chinese visitors at NASA facilities. While not an absolute ban on all contact, it made normal agency-to-agency cooperation legally and politically difficult.
Tiangong Station
Tiangong's core module, Tianhe, launched in 2021, followed by laboratory modules Wentian and Mengtian in 2022. Since the crew handover between Shenzhou 14 and Shenzhou 15, China has maintained continuous occupancy. The station has a regular crew rotation model with Shenzhou crew vehicles and Tianzhou cargo spacecraft. In 2025-2026, Tiangong continued operations despite a return spacecraft issue that forced adjustments to rotation and rescue planning.
Tiangong is smaller, nationally controlled, and mediates foreign access through Chinese institutions, unlike the ISS's intergovernmental structure.
ISS Retirement Plan
NASA plans to operate the ISS through 2030, with a controlled deorbit. In June 2024, NASA selected SpaceX to develop the US Deorbit Vehicle. The United States, Japan, Canada, and participating ESA countries have committed through 2030; Russia committed through at least 2028. Discussions about extending operations have occurred if more transition time is needed.
Commercial Station Development
NASA is supporting development of commercially owned and operated stations (Axiom Space, Starlab, Orbital Reef, Vast). As of mid-2026, no commercial replacement is operating as a crewed free-flying station. Certification, hardware development, and safety culture take time.
Implications of an Orbital Gap
If no commercial station is ready before ISS retirement:
- Symbolically, the center of gravity in low Earth orbit shifts to China.
- Practically, access to crewed laboratory facilities would be limited to Tiangong, affecting research schedules, astronaut training, diplomatic partnerships, and commercial microgravity work.
- Structurally, Tiangong is smaller, nationally controlled, and mediates foreign access through Chinese institutions, unlike the ISS's intergovernmental framework.
The future depends on the ISS deorbit vehicle, potential extension, commercial station progress, and China's continued operations.
Conclusion
The outcome will be determined by which system remains inhabited when the ISS era ends.