Learn Russian: Отклонись спутник от траектории, и мы провалим проект. - If the satellite deviates from the trajectory, we will fail the project.

This sentence uses an advanced conditional structure where an imperative verb replaces Если (If). It creates a slightly more dramatic or snappy tone than a standard "if" clause. It is similar to the English structure "Make one mistake, and you are fired."

Why does an imperative verb match with a third-person subject like спутник (satellite)? Aren't commands only for "you"?

Normally, yes. But in this specific conditional structure, the imperative form is "frozen." You use the singular ты (you) form of the imperative regardless of who or what the subject is—even if the subject is third-person (спутник) or plural.

Why do we use и (and) instead of то (then) to connect the two halves of the sentence?

Standard conditional sentences using Если often use то to introduce the result. However, when you use the imperative conditional structure, the clauses must be connected by a coordinating conjunction, usually и (and).

Is the word order important here? Could I say Спутник отклонись instead?

The word order is crucial. In this construction, the imperative verb must come first. Putting the subject before the verb would break the conditional pattern and sound like you are absurdly giving a direct command to the satellite.