Hey Andy!

Code-named "Adeline," the system would allow. a booster's main engines to fly itself back to Earth after lunch. 

"itself" is an emphatic pronoun, which emphasizes the noun that came before it. In this sentence, "itself" seems to be used incorrectly. "itself" should refer to "a booster," but the problem is that "booster" is written in possessive form. Hence, the noun that "itself" refers to is actually "main engines" (which would be the wrong noun).The sentence should read "A booster can use its engines to fly itself back to Earth after lunch. Great job catching this error!

Keep Moving Forward!