Learn Russian: Стыковка будет успешной, словно мы делали это тысячу раз. - The docking will be successful, as if we had done this a thousand times.

Just like in English ('as if we had done this'), словно sets up a hypothetical or unreal comparison. In Russian, conjunctions of unreal comparison like словно, будто, or как будто are followed by a verb in the past tense to show that the action isn't actually happening, regardless of the tense in the main clause. Notice that you don't need to add the conditional particle бы here; the conjunction and the past tense do the job together.

Why is the adjective успешной in the instrumental case instead of the nominative успешная?

When describing what something will be using the future tense of the verb быть (here, будет), Russian strongly prefers the instrumental case for the adjective. You will sometimes hear the nominative in very casual speech, but the instrumental (будет успешной) is the standard way to express a future state or expected result.

Why is the word for a thousand in the accusative case (тысячу) here?

In Russian, when you state how many times an action occurs or how long it lasts, the entire expression of time or frequency takes the accusative case. Since тысяча grammatically acts like a feminine noun ending in -а, it changes to тысячу in the accusative. The word раз (times) is in the genitive plural, which happens to look identical to its nominative singular form.

Could we use the perfective verb сделали instead of the imperfective делали here?