Atlanta-based TNT has a hit on its hands with "The Last Ship," which gets a second season of 13 episodes.

Its popular "Major Crimes" series gets another 15 episodes for a fourth season in 2015.

And its sci-fi series "Falling Skies' will close shop next year with ten more episodes in its fifth and final season.

"The Last Ship has become this summer's top drama among key adult demos with its epic scale and visceral storytelling. Major Crimes continues to be one of the most enduring and popular crime-drama franchises on television. And Falling Skies has begun an ambitious and thrilling story arc this summer as it sets the stage for next year's climactic final season," Michael Wright said in a press release.

TNT in the press release provides the numbers to justify why these shows are getting renewals:

Major Crimes is showing an uptick over last year, with 7 million viewers in Live + 7 delivery for its third season so far. It ranks second behind Rizzoli & Isles among the summer's top scripted series on basic cable. Major Crimes has also drawn key demo deliveries of 2.1 million adults 25-54 and 1.5 million adults 18-49.

Falling Skies has averaged more than 5.5 million viewers in Live + 7 delivery for its fourth season, including 2.5 million adults 25-54 and 2.1 million adults 18-49. It ranks behind The Last Ship and Rizzoli & Isles among basic cable's Top 3 scripted series this summer with adults 25-54.

TNT has not yet renewed "Rizzoli & Isles" but it's the network's most popular show (8.5 million DVR + 7 average this season) so it's a given that will be back.

I am not sure if the demographics guarantee the returns of "Murder in the First" (average 5 million DVR+& viewers)  or "Perception"(4.6 million) but their overall viewership numbers aren't bad.