Very different.
"On" means that you're actually working on the terminal. As in building it, maintaining it, etc. It's clear from the context that in the example cited, it is referring to the initial construction of the terminal.
"In" or "at" doesn't mean you're working on the terminal. It means you're doing some work where you happen to be inside of it. In the case of "at", you could also just be nearby it.
So I disagree with mdchachi. You can't use "in" or "at" instead of "on" because that would change the meaning too much.