Learn Farsi: ممکن است بالن بدون اینکه تلاطم داشته باشد، اوج بگیرد. - It is possible that the hot air balloon gains altitude without having turbulence.

momken ast (it is possible) is an impersonal expression of probability that requires the present subjunctive. It directly controls the main action at the very end of the sentence, forcing gereftan into the subjunctive form begirad. Notice that the connecting word "that" (ke) is omitted here after ast, which is very common in Farsi.

Why is there a second subjunctive verb, dâšte bâšad, in the middle of the sentence?

It is triggered by the phrase bedun-e in-ke (without). In Farsi, you cannot say "without having" using an equivalent to an English "-ing" form. Instead, you use bedun-e in-ke (literally "without this that") followed by a conjugated verb in the present subjunctive.

Why doesn't the subjunctive verb dâšte bâšad start with the usual be- prefix?

The verb dâštan (to have) is a major exception to the subjunctive rules. It never takes the be- prefix. Instead, its present subjunctive is formed using its past participle dâšte followed by the subjunctive forms of "to be" (in this third-person singular case, bâšad).

How do the words owj begirad translate to "gains altitude"?

owj means the peak, zenith, or highest point. begirad is the subjunctive form of gereftan (to take or get). Together, the compound verb owj gereftan literally means "to take peak", which is the natural Farsi expression for an aircraft or balloon taking to the sky or gaining altitude.