dreamliners. a two-day hearing kicking off today as the national transportation safety board takes a closer look at one fire in particular just days after the faa approved boeing s plan to get its fleet back in the air. dan springer is live in seattle. dan? reporter: yeah, jon. the faa approved the battery fix even as the company answers tough questions about the fire back in january that led to the dreamliner fleet getting grounded. the plane s lithium ion battery sured a short which led to the failure of all eight cells. boeing s new plan includes a redesigned battery that has more insulation between the cells to prevent what s called thermal runaway. the battery charger has been redesigned to reduce the total amount of energy in the battery so it doesn t work as hard, and it s going to be in a better steel containment box that won t allow oxygen to fuel a fire. the ntsb put boeing on the defensive this morning about its assumptions that turned out to be wrong. what we can t do i
reporter: katie is fitted with a blood pressure collar, she ll wear it for 24 hours so researchers can get baseline measurements. in space she ll repeat the experiment. up there blood pressure is lower. these researchers believe gravity on earth may contribute to high blood pressure. high blood pressure is one of the most dangerous conditions presently. it kills about 8 million people a year, so we really want to know what is the cause for high blood pressure in so many people? reporter: and the heart muscle, it may actually shrink in weightlessness because it doesn t work as hard. does that happen all at once or is it something that happens gradually over time? reporter: what doctors and researchers learned from astronaut ultrasounds may help develop better exercise routines for people who are bedridden or wheelchair bound. all right. you ready? yep. ready and push. reporter: her ankles and legs, lower back, abdominal