NASA announces its 10 latest trainee astronauts, who include a firefighter turned Harvard professor, a former member of the national cycle team, and a pilot who led the first-ever all-woman F-22 formation in combat. The 2021 class was whittled down from a field of more than 12,000 applicants and will now report for duty in January at the Johnson Space Center in Texas, where they will undergo two years of training. IMAGES AND SOUNDBITES