Nearly six months after a prescribed fire burned out of control and incinerated hundreds of homes in New Mexico, the National Park Service is ready to start setting them again.Park Service officials have approved plans for seven tightly controlled prescribed fires-blazes set to reduce the possibility of wildfires-to clear underbrush in the Sequoia and Kings Canyon National Park and Yosemite National Park in California, and the Lake Mead National Recreation Area along the Arizona-Nevada line.