nasa, teacher-in-space, designee, barbara, radding, morgan, chatted, with, stevenson, middle, school, students, yesterday, before, giving, talk, last, year, s, space, shuttle, mission, aboard, which, she, served, as, specialist, one, four, schools, in, hawai, visiting, part, ellison, onizuka, science, day, was, backup, candidate, to, late, christa, mcauliffe, challenger, spaceflight, that, exploded, during, launch, astronaut, talks, about, her, journey, international, station, endeavor, peppered, questions, visit, sixth-grader, daniel, ho, asked, adventures, student, davida, chong-hoffman, right, other, after, presentation, seventh-grader, cerina, cottrell, question, signed, photograph, herself