How do I get my dog to respond to me and come back when I call her, especially outdoors?

One of the dogs that I have, a German Shepherd/Husky breed named Tera (approx 2 yrs old), is always looking for an opportunity to get loose and take off. I have taken her to obedience school. She does respond, inside and when on a leash, to the command "come." However, when she is off of the leash she takes off. Eventually she does come home. I thought, at first, that it was because she knew there where cats that lived at a neighbor's house, which is true. When she does take off that is usually where I can find her. However, at the park the other day, I tested that theory. She took off and I had to go running after her. Luckily I finally caught up to her. My question is, how do I get her to respond to me and come back when I call her, especially when outdoors? I have another dog, a Pit Bull/Australian Shepherd breed named Molly (approx 4 yrs old), that does respond to my voice and listens when I call her to "come" commands indoors, on a leash, and outdoors. She has been a joy to train and have around. I know that each dog is different and I assume that some require different techniques in training.

Is there something I can do?

Sincerely,
Korey