[Wikipedia](https://en.wikipedia.org/wiki/Two-body_problem_in_general_relativity) says:

> 
> According to Einstein's theory of general relativity, particles of
>  **negligible mass** travel along geodesics in the space-time.
> 
> 
> 

Does that "negligible mass" only refer to particles or objects like a spacecraft, whose mass are literally negligible to that of a black hole, are also taken into account?

If the mass of a spacecraft is not negligible, how has one to modify the geodesics equation corresponding to that mass?