José Hernández was born to Mexican parents. As poor migrant farm workers, the Hernández family followed a route that spanned California and Mexico, picking fruit in different locations at different times of the year. Although he was born in California, Hernández did not learn English until he was 12 years old. In the 1970s, when Hernández was still a child, speaking Spanish at home was more common among the Latino population. Today, 60 percent of U.S.-born Latinos five and older speak Spanish at home, and about 90 percent of U.S.-born Latino children learn to speak English fluently. Even at a young age, when other children were enjoying weekends and vacations, Hernández helped in the fields. He moved with his family and from school to school until he was in third grade. Then, a teacher convinced his parents that the constant change was hurting him and his siblings.

Despite his interrupted schooling, Hernández took a strong interest in math and science. It might have seemed unachievable considering his humble beginnings, but his dedication to studies and personal development led to a college degree and then a master's degree in engineering. After 11 rejection letters from NASA, his perseverance paid off and he was accepted to its astronaut training program. Of the estimated 7.4 billion people who live on Earth, a small fraction of 1 percent have gone to space like Hernández did in 2009 on the Space Shuttle Discovery.