[clort]

Yes. Generally, if you know where it is, it is not lost. If you don't then it is.

But, it also depends if you want to know where it is. If you don't know where something is and don't want to, its not lost its discarded.

[ultratalk]

Another usage of the word "lost" is to indicate when the spacecraft has become dysfunctional. Although, that one is the verb form, not the adjective.