Learn Russian: Чтобы спасти проект, мы должны доделать этот спутник. - To save the project, we must finish this satellite.

This lesson covers imperative conditionals. Since this sentence uses a standard 'чтобы' clause instead, how could we rewrite its meaning using an imperative conditional?

You could frame it as a hypothetical warning using the imperative: Не доделай мы этот спутник, проект бы закрыли (If we hadn't finished this satellite, the project would have been closed). Notice how the singular imperative доделай works with the plural subject мы to create that strong 'if' condition!

Why use доделать here instead of a more basic verb for 'to finish' like закончить?

The prefix до- adds the specific nuance of taking a task that is already in progress and pushing it to completion. While закончить is a fine general word for 'to finish,' доделать specifically means 'to finish doing or building something,' which perfectly fits an ongoing construction project like a satellite.

The first clause expresses purpose. Why is спасти in the infinitive here rather than the past tense?

Because the subject doing the saving is the same as the subject in the main clause (мы). If the subjects were different—for example, 'We must finish this satellite so that THEY can save the project'—you would be required to use the past tense in the чтобы clause: чтобы они спасли проект.

Instead of чтобы, could we translate this literally as an 'if' condition: Если мы хотим спасти...?