In space travel there is a saying that the first 50 miles and the last 50 miles are the most dangerous. See how a single spark inside a spacecraft or a micrometeoroid less than an inch wide hitting a space station can turn a routine mission into a lethal nightmare. As the missions become longer, venturing to Mars and beyond, the potential disasters will only become bigger. What would happen if a spacecraft ventured too close to a black hole or was hit by a gamma ray burst?

• Neil deGrasse Tyson
• Erik Thompson
• Alex Filippenko

• David Brin
• David Ackroyd
• Michio Kaku