Hernandez grew up the son of Mexican migrant farm workers, meaning his education was often disrupted as his parents followed the crops - he didn't become fluent in English until he was 12.
However, Hernandez went on to earn a Master's degree in electrical and computer engineering from UC-Santa Barbara and went on to become an astronaut. He traveled in space, heading to the International Space Station as a mission specialist and now runs his own foundation, Reaching For The Stars.
His foundation aims to get youth in central California interested in STEM (science, technology, engineering and math) fields and provides first-generation high school seniors with scholarships.
His success story is a perfect example of what parents can do for their children, even in the most difficult of situations. You can read his full interview with CNN here; it's incredibly inspiring. My favourite anecdote from the interview is this:
"I began dreaming of going into space after watching the Apollo 17 moon landing when I was 10. That was the last mission to the moon. I'm so glad I saw it! I'd go outside and look at the moon and come back in to see them walking on the surface of it on TV.
That night I shared my dream with my dad. Instead of bursting my bubble, he gave me a recipe for success:
Decide what you want to do in life. Recognise how far you are from your goal. Draw a road map from where you are to where you want to go. Get your education and make an effort.
'Always do more than people expect, m'hijo,' he said."