NASA investigating UFO sightings, agency chief says | Space NASA is now on the perplexing UFO case. NASA chief Bill Nelson, who assumed his post just last month, has asked agency researchers to look into the spate of UFO sightings that U.S. Navy pilots have reported over the past two decades, CNN reported. Nelson told CNN's Rachel Crane in an interview that the network posted online Friday (June 4). "The bottom line is, we want to know," he added. "And that's what we're trying to do."