Robert Rodriguez burst on to the scene in 1992 with the very, very low-budget action film El Mariachi. (Apparently, he earned money to make the film as a test subject in scientific experiments.) He made hits like Once Upon a Time in Mexico and the Spy Kids series, but unlike other indie directors of his generation who joined the studio system, Rodriguez stayed in Austin and turned his home into Troublemaker Studios. He continued to make movies with remarkable thrift — mixing, editing, and even designing special effects himself. So his latest project feels like a big departure: Rodriguez is overseeing a new cable TV network.