A structural crack wouldn’t necessarily be in the hull of the habitat modules. The ISS has a big frame (the Integrated Truss Structure) which supports the solar arrays, power distribution and heat radiators. If the frame is damaged, firing the engines to maintain orbit might be impossible.
Atmospheric drag reduces the altitude by about 2 km a month on average. Orbital boosting can be performed by the station’s two main engines on the Zvezda service module
And most supply missions give it a boost before leaving as well. Also, the ISS can “glide” by turning it’s narrow end forward, getting less drag from the atmosphere and reduce the decay rate at the cost of power generation
A structural crack wouldn’t necessarily be in the hull of the habitat modules. The ISS has a big frame (the Integrated Truss Structure) which supports the solar arrays, power distribution and heat radiators. If the frame is damaged, firing the engines to maintain orbit might be impossible.
And most supply missions give it a boost before leaving as well. Also, the ISS can “glide” by turning it’s narrow end forward, getting less drag from the atmosphere and reduce the decay rate at the cost of power generation
Yup, but boosting and turning would both be things you wouldn’t want to do with a weakened frame.