What Was the Iran-Contra Affair?

Seventy three seconds after take off the Space Shuttle Challenger encounters unexpected disaster. Find out more in this clip from Season 1, "Challenger Disaster."

On January 28, 1986, the tenth mission of the space shuttle Challenger ended in tragic disaster. We remember the seven astronauts who lost their lives that day, including Christa McAuliffe, who was chosen by NASA to pioneer its Teacher in Space program.

Each year, government estimates suggest roughly 200,000 Americans are involved in cults—often in secret and largely by choice. Who are they? And what can we learn from the tragic story of Heaven’s Gate?

With just 37 seconds to react, could Titanic have avoided disaster—or was the tragedy inevitable?