National Geographic Channel has renewed “Rocket City Rednecks” for a 16-episode second season, while HGTV has extended three of its series, including the long-running “Selling New York.”

“Rednecks,” which was NatGeo’s top-rated series premiere in 2011, will resume production in March for a premiere later this year. The show features a family of Huntsville, Ala., science experts who mix country ingenuity with their advanced knowledge to tackle real-world scenarios.

“Last season we bombproofed a truck with empty beer cans and nearly drowned in a self-made submarine, and this season promises to be just as exciting,” said NASA research scientist and series regular Travis Taylor. “Some of the projects we are developing for the new season include building a real-life Knight Rider, designing a one-man helicopter and developing a massive laser that can blow things up.”

Louis Tarantino, Douglas Cohen and Tim Evans produce the show for Flight 33.

HGTV ordered 13 new episodes each of “My Yard Goes Disney,” “Room Crashers” and “Selling New York.”

“My Yard,” a combined effort between HGTV and Disney Parks to give homeowners magical backyard makeovers, will begin airing new episodes in June. “Crashers,” hosted by HGTV “Design Star” finalist Todd Davis and returning for its third season this summer, goes around the country to look for weekend warriors who need design help.

“Selling” will head into its eighth season with new episodes featuring its three upscale real-estate firms in Manhattan.