After watching Avengers: Endgame, many fans were left with a burning question: How was Captain Marvel able to track down and save Tony Stark and Nebula amid the expanse of deep space? While the film does not directly disclose the process, comments from the filmmakers as well as evidence from earlier films serve to throw light on this riddle.
According to the director's remarks and earlier movie scene analyses, which may be pieced together, Carol Danvers met the Avengers upon her return to Earth after Nick Fury paged her. She was then informed of the catastrophic situation and learned of Tony and Nebula's situation in space. She was then able to locate and rescue the duo from their peril thanks to help from other heroes present.
Captain Marvel could rescueTony Stark and Nebula in Avengers: Endgame because of "some sort of homing beacon"
To understand how Captain Marvel rescued Tony Stark and Nebula, one must first go back to the mid-credits sequence in her standalone film, Captain Marvel. Carol returns to Earth in this scene after getting Nick Fury's sos pager signal shortly before he disintegrates due to Thanos' snap.
Her arrival on Earth soon after the snap lays the groundwork for her participation in the events of Avengers: Endgame.
Joe Russo, one of the directors, offered a clear explanation for Captain Marvel's rescue mission on the commentary track featured in the digital release of Avengers: Endgame. Danvers, he stated, did not have intrinsic knowledge of Tony and Nebula's locations.
Instead, her expedition began on Earth after receiving a distress signal from Nick Fury during the post-credits sequence of her own film. Russo explained,
"The missing narrative of course is that she came to Earth, met the Avengers, was brought up to speed on what was happening, and there's some sort of homing beacon on that ship that she tracks and brings the two of them back to Earth."
The crucial detail in this situation is that Tony and Nebula's ship, the Benatar, has a homing beacon on board. Tony used his Iron Man helmet to record messages in an effort to get in touch with Pepper Potts. He wasn't sure if Pepper would get these messages, but the helmet might have acted as a beacon, letting Carol know where they were and that they were still alive.
Captain Marvel started by knowing that the Benatar was the escape ship and that the ship's location might be intercepted. Because of her incredible speed and cosmic powers, Carol Danvers was able to reach Tony Stark and Nebula when their circumstances seemed to be in the worst possible state.
The rescue operation began on Earth when Captain Marvel first encountered the Avengers and learned of their dire predicament.
This revelation demonstrates the extensive storytelling present in the Marvel Cinematic Universe and provides a satisfactory resolution to one of the unresolved issues from Avengers: Endgame.