NASA is publicly addressing the subject of UFOs a year after launching a study into unexplained sightings. And it insists it's not hiding anything. The space agency televised Wednesday's four-hour meeting featuring an independent panel of experts. The team includes 16 scientists and other experts selected by NASA including retired astronaut Scott Kelly, the first American to spend nearly a year in space. NASA says several committee members have been subjected to online harassment for serving on the team. They say that detracts from the scientific process. A final report is expected by the end of July.