On Jan. 28, 1986 — hours after the space shuttle Challenger exploded shortly after its launch — President Ronald Reagan addressed the nation. “We will never forget them, nor the last time we saw them, this morning, as they prepared for their journey and waved goodbye and ‘slipped the surly bonds of earth’ to ‘touch the face of God,'” Reagan said about the seven crew members who died. | PBS NewsHour

The Challenger space shuttle tragedy shocked the entire world and reminded everyone of the gravity and intense dangers space exploration really is. Decades later, visiting space as a tourist is now closer than ever, but we must never forget those brave astronauts who risked everything to adventure into the great unknown. Today's epic new video revisits that tragic day and analyzes what caused the Challenger to experience a catastrophic failure. | The Infographics Show