This weekend I plan on running the Into the Maw introductory scenario with my group. It will be our first time playing RT. What I'm wondering about is the amount of time I should allot for the scenario. It seems like it would be a longer one, best split into two sessions, but I'm not sure. Any advice from anyone who has already run this scenario?

It depends on the group, and the GM. It can be over in a few hours if the players just go from plot point to plot point, and the GM doesn't do a lot of atmosphere and extra encounters. If the PC spend a lot time figuring out how to get to the ship, and deal with the challenges there you could add a session. If you add a little meat to the various running from place to place. A little role play and supense. You could take another session. Also some PCs will want to salvage the ship as a whole which could lead to all manner of things.