Sustaining a station

Tiangong supplies the workplace. Shenzhou transports crews and provides their route home. Tianzhou carries supplies and propellant and can remove waste. Keeping their courses separate makes these goals visible while their learning paths show how the programs depend on one another.

Crews use consumables, equipment ages and experiments finish or require new materials. In a fictional expedition, a component has a long replacement lead time. Waiting until it fails may leave the laboratory without a useful function. Inventory, inspection and delivery planning are therefore part of daily science support.

The controlled end of Tiangong 2 in 2019 illustrates that an orbital facility also needs an end-of-mission plan. That historical event does not set the retirement date of the later station. Separate completed history, current operations and future proposals rather than treating every announcement as an accomplished flight.